{"pageNumber":"333","pageRowStart":"8300","pageSize":"25","recordCount":10450,"records":[{"id":70018060,"text":"70018060 - 1996 - Applications of inductively coupled plasma-mass spectrometry in environmental radiochemistry","interactions":[],"lastModifiedDate":"2012-03-12T17:19:56","indexId":"70018060","displayToPublicDate":"1996-01-01T00:00:00","publicationYear":"1996","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":3465,"text":"Spectroscopy","active":true,"publicationSubtype":{"id":10}},"title":"Applications of inductively coupled plasma-mass spectrometry in environmental radiochemistry","docAbstract":"The state of the art in ICP-MS is now such that there are few discernible differences between radiochemical and mass spectrometric determinations of longlived radionuclides. Indeed, ICP-MS may provide better (more sensitive) data for many radionuclides, depending upon how one wishes to define \"long-lived.\" In lowlevel determinations, sample preparation remains an important part of the analytical procedure, even with ICP-MS, but the speed and isotopic selectivity of the mass spectrometer appear to offer distinct procedural advantages over radiochemical techniques. Therefore, \"radioanalytical\" ICP-MS applications should continue to grow, especially in the area of radiation protection, but further research (on efficient sample introduction, for example) and method development may be required to get ICP-MS \"off the ground\" in the geochemical research areas that have traditionally been supported by radiochemistry.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Spectroscopy","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","issn":"08876703","usgsCitation":"Grain, J., 1996, Applications of inductively coupled plasma-mass spectrometry in environmental radiochemistry: Spectroscopy, v. 11, no. 2, p. 30-39.","startPage":"30","endPage":"39","numberOfPages":"10","costCenters":[],"links":[{"id":228969,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"11","issue":"2","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"5059ecc8e4b0c8380cd494a4","contributors":{"authors":[{"text":"Grain, J.S.","contributorId":57226,"corporation":false,"usgs":true,"family":"Grain","given":"J.S.","email":"","affiliations":[],"preferred":false,"id":378341,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}}
,{"id":70018056,"text":"70018056 - 1996 - Occurrence and significance of stalactites within the epithermal deposits at Creede, Colorado","interactions":[],"lastModifiedDate":"2012-03-12T17:19:56","indexId":"70018056","displayToPublicDate":"1996-01-01T00:00:00","publicationYear":"1996","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1177,"text":"Canadian Mineralogist","active":true,"publicationSubtype":{"id":10}},"title":"Occurrence and significance of stalactites within the epithermal deposits at Creede, Colorado","docAbstract":"In addition to the common and abundant features in karst terranes, stalactites involving a wide variety of minerals have also been found in other settings, including epigenetic mineral deposits, but these are almost always associated with supergene stages. Here we describe a different mode of occurrence from the Creede epithermal ore deposits, in Colorado, wherein stalactites of silica, sphalerite, galena, or pyrite formed in a vapor-dominated setting, below the paleo-water table, and except possibly for pyrite, as part of the hypogene mineralization. Axial cavities may, or may not, be present. No stalagmites have been recognized. The stalactites are small, from a few millimeters to a few centimeters long and a few millimeters in outer diameter. They represent only a small fraction of one percent of the total mineralization, and are covered by later crystals. Their growth orientation usually is unobservable; however, the parallel arrangement of all stalactites in a given specimen, consistency with indicators of gravitational settling, and the common presence of axial structures make the stalactitic interpretation almost unavoidable. In contrast with common carbonate stalactites, the growth mechanism for the sulfide and silica stalactites requires extensive evaporation. Stalactitic forms have also been reported from other deposits, mostly epithermal or Mississippi-Valley-type occurrences, but we caution that stalactite-like features can form by alternative processes.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Canadian Mineralogist","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","issn":"00084476","usgsCitation":"Campbell, W.R., and Barton, P.B., 1996, Occurrence and significance of stalactites within the epithermal deposits at Creede, Colorado: Canadian Mineralogist, v. 34, no. 5, p. 905-930.","startPage":"905","endPage":"930","numberOfPages":"26","costCenters":[],"links":[{"id":228918,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"34","issue":"5","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a6b7de4b0c8380cd7471b","contributors":{"authors":[{"text":"Campbell, W. R.","contributorId":20775,"corporation":false,"usgs":true,"family":"Campbell","given":"W.","email":"","middleInitial":"R.","affiliations":[],"preferred":false,"id":378332,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Barton, P. B. Jr.","contributorId":23683,"corporation":false,"usgs":true,"family":"Barton","given":"P.","suffix":"Jr.","email":"","middleInitial":"B.","affiliations":[],"preferred":false,"id":378333,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}}
,{"id":70017773,"text":"70017773 - 1996 - Late Quaternary transgressive large dunes on the sediment-starved Adriatic shelf","interactions":[],"lastModifiedDate":"2024-01-05T01:42:51.576231","indexId":"70017773","displayToPublicDate":"1996-01-01T00:00:00","publicationYear":"1996","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1785,"text":"Geological Society Special Publication","active":true,"publicationSubtype":{"id":10}},"title":"Late Quaternary transgressive large dunes on the sediment-starved Adriatic shelf","docAbstract":"The Adriatic epicontinental basin is a low-gradient shelf where the late-Quaternary transgressive systems tract (TST) is composed of thin parasequences of backbarrier, shoreface and offshore deposits. The facies and internal architecture of the late-Quaternary TST in the Adriatic epicontinental basin changed consistently from early transgression to late transgression reflecting: (1) fluctuations in the balance between sediment supply and accommodation increase, and (2) a progressive intensification of the oceanographic regime, driven by the transgressive widening of the basin to as much as seven times its lowstand extent. One of the consequences of this trend is that high-energy marine bedforms such as sand ridges and sand waves characterize only areas that were flooded close to the end of the late-Quaternary sea-level rise, when the wind fetch was maximum and bigger waves and stronger storm currents could form. We studied the morphology, sediment composition and sequence-stratigraphical setting of a field of asymmetric bedforms (typically 3 m high and 600 m in wavelength) in 20-24 m water depth offshore the Venice Lagoon in the sediment-starved North Adriatic shelf. The sand that forms these large dunes derived from a drowned transgressive coastal deposit reworked by marine processes. Early cementation took place over most of the dune crests limiting their activity and preventing their destruction. Both the formation and deactivation of this field of sand dunes occurred over a short time interval close to the turn-around point that separates the late-Quaternary sea-level rise and the following highstand and reflect rapid changes in the oceanographic regime of the basin.","language":"English","publisher":"Geological Society, London","doi":"10.1144/GSL.SP.1996.117.01.09","issn":"03058719","usgsCitation":"Correggiari, A., Field, M., and Trincardi, F., 1996, Late Quaternary transgressive large dunes on the sediment-starved Adriatic shelf: Geological Society Special Publication, v. 117, p. 155-169, https://doi.org/10.1144/GSL.SP.1996.117.01.09.","productDescription":"15 p.","startPage":"155","endPage":"169","numberOfPages":"15","costCenters":[],"links":[{"id":228724,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"117","noUsgsAuthors":false,"publicationDate":"1996-10-15","publicationStatus":"PW","scienceBaseUri":"505a453be4b0c8380cd67143","contributors":{"authors":[{"text":"Correggiari, A.","contributorId":88110,"corporation":false,"usgs":true,"family":"Correggiari","given":"A.","email":"","affiliations":[],"preferred":false,"id":377529,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Field, M.E.","contributorId":27052,"corporation":false,"usgs":true,"family":"Field","given":"M.E.","affiliations":[],"preferred":false,"id":377528,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Trincardi, F.","contributorId":94794,"corporation":false,"usgs":true,"family":"Trincardi","given":"F.","affiliations":[],"preferred":false,"id":377530,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}}
,{"id":70018055,"text":"70018055 - 1996 - Large-magnitude Middle Ordovician volcanic ash falls in North America and Europe: Dimensions, emplacement and post-emplacement characteristics","interactions":[],"lastModifiedDate":"2012-03-12T17:19:56","indexId":"70018055","displayToPublicDate":"1996-01-01T00:00:00","publicationYear":"1996","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2499,"text":"Journal of Volcanology and Geothermal Research","active":true,"publicationSubtype":{"id":10}},"title":"Large-magnitude Middle Ordovician volcanic ash falls in North America and Europe: Dimensions, emplacement and post-emplacement characteristics","docAbstract":"Middle Ordovician K-bentonites represent some of the largest known fallout ash deposits in the Phanerozoic Era. They cover minimally 2.2 ?? 106 km2 in eastern North America and 6.9 ?? 105 km2 in northwestern Europe, and represents the coeval accumulation of plinian and co-ignimbrite ash on both Laurentia and Baltica during the closure of the Iapetus Ocean. The three most widespread beds are the Deicke and Millbrig K-bentonites in North America and the Kinnekulle K-bentonite in northwestern Europe. The vents were located near the Laurentian margin of Iapetus on an arc or microplate undergoing collision with Laurentia. The volume of ash preserved in the stratigraphic record converted to dense rock equivalent (DRE) of silicic magma is minimally estimated to be 943 km3 for the Deicke, 1509 km3 for the Millbrig and 972 km3 for the Kinnekulle. The Millbrig and Kinnekulle beds are coeval and possibly equivalent, yielding a combined DRE volume of nearly 2500 km3. Some unknown but probably large amount of additional ash fell into oceanic regions of the Iapetus, but these areas became subducted and the ash is not preserved in the geologic record. The symmetry of the thickness contours is suggestive that one or more ash clouds interacting with equatorial stratospheric and tropospheric wind patterns dispersed pyroclastic material to both the northwest and southeast in terms of Ordovician paleogeography. Based on grain size measurements and thickness/area1/2 plots we conclude the three beds were each formed from co-ignimbrite or possibly phreatoplinian eruption columns. Analyses of melt inclusions in primary quartz crystals indicate the parental magma contained approximately 4% dissolved water at the time of the eruption. This water provided the explosive energy during the initial gas thrust phase. The implied fragmentation pressure on the magma would have reduced much of the ejecta to small particles, forming a deposit composed largely of single crystals and glassy dust. Conversion of the ash to K-bentonite resulted in a mass loss of approximately 35%, mostly in the form of Si with lesser amounts of Na and K.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Journal of Volcanology and Geothermal Research","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","issn":"03770273","usgsCitation":"Huff, W., Kolata, D.R., Bergstrom, S., and Zhang, Y., 1996, Large-magnitude Middle Ordovician volcanic ash falls in North America and Europe: Dimensions, emplacement and post-emplacement characteristics: Journal of Volcanology and Geothermal Research, v. 73, no. 3-4, p. 285-301.","startPage":"285","endPage":"301","numberOfPages":"17","costCenters":[],"links":[{"id":228917,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"73","issue":"3-4","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a448ee4b0c8380cd66be3","contributors":{"authors":[{"text":"Huff, W.D.","contributorId":48327,"corporation":false,"usgs":true,"family":"Huff","given":"W.D.","email":"","affiliations":[],"preferred":false,"id":378328,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Kolata, Dennis R.","contributorId":79495,"corporation":false,"usgs":false,"family":"Kolata","given":"Dennis","email":"","middleInitial":"R.","affiliations":[],"preferred":false,"id":378329,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Bergstrom, Stig M.","contributorId":80832,"corporation":false,"usgs":true,"family":"Bergstrom","given":"Stig M.","affiliations":[],"preferred":false,"id":378330,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Zhang, Y.-S.","contributorId":94057,"corporation":false,"usgs":true,"family":"Zhang","given":"Y.-S.","email":"","affiliations":[],"preferred":false,"id":378331,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}}
,{"id":70018049,"text":"70018049 - 1996 - Intraguild predation and cannibalism among larvae of detritivorous caddisflies in subalpine wetlands","interactions":[],"lastModifiedDate":"2023-12-14T17:12:53.018043","indexId":"70018049","displayToPublicDate":"1996-01-01T00:00:00","publicationYear":"1996","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1465,"text":"Ecology","active":true,"publicationSubtype":{"id":10}},"title":"Intraguild predation and cannibalism among larvae of detritivorous caddisflies in subalpine wetlands","docAbstract":"<p><span>Comparative data from subalpine wetlands in Colorado indicate that larvae of the limnephilid caddisflies, Asynarchus nigriculus and Limnephilus externus, are reciprocally abundant among habitats–Limnephilus larvae dominate in permanent waters, whereas Asynarchus larvae dominate in temporary basins. The purpose of this paper is to report on field and laboratory experiments that link this pattern of abundance to biotic interactions among larvae. In the first field experiment, growth and survival were compared in single and mixed species treatments in littoral enclosures. Larvae, which eat mainly vascular plant detritus, grew at similar rates among treatments in both temporary and permanent habitats suggesting that exploitative competition is not important under natural food levels and caddisfly densities. However, the survival of Limnephilus larvae was reduced in the presence of Asynarchus larvae. Subsequent behavioral studies in laboratory arenas revealed that Asynarchus larvae are extremely aggressive predators on Limnephilus larvae. In a second field experiment we manipulated the relative sizes of larvae and found that Limnephilus larvae were preyed on only when Asynarchus larvae had the same size advantage observed in natural populations. Our data suggest that the dominance of Asynarchus larvae in temporary habitats is due to asymmetric intraguild predation (IGP) facilitated by a phenological head start in development. These data do not explain the dominance of Limnephilus larvae in permanent basins, which we show elsewhere to be an indirect effect of salamander predation. Behavioral observations also revealed that Asynarchus larvae are cannibalistic. In contrast to the IGP on Limnephilus larvae, Asynarchus cannibalism occurs among same—sized larvae and often involves the mobbing of one victim by several conspecifics. In a third field experiment, we found that Asynarchus cannibalism was not density—dependent and occurred even at low larval densities. We hypothesize that Asynarchus IGP and cannibalism provide a dietary supplement to detritus that may be necessary for the timely completion of development in these nutrient—poor, high—elevation wetlands.</span></p>","language":"English","publisher":"Ecological Society of America","doi":"10.2307/2265743","usgsCitation":"Wissinger, S., Sparks, G.B., Rouse, G.L., Brown, W.S., and Steltzer, H., 1996, Intraguild predation and cannibalism among larvae of detritivorous caddisflies in subalpine wetlands: Ecology, v. 77, no. 8, p. 2421-2430, https://doi.org/10.2307/2265743.","productDescription":"10 p.","startPage":"2421","endPage":"2430","numberOfPages":"10","costCenters":[],"links":[{"id":228831,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"77","issue":"8","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a3dc5e4b0c8380cd6381f","contributors":{"authors":[{"text":"Wissinger, Scott A","contributorId":279574,"corporation":false,"usgs":false,"family":"Wissinger","given":"Scott A","affiliations":[{"id":57292,"text":"Biology and Environmental Science Departments, Allegheny College, Meadville, PA 16335, USA","active":true,"usgs":false}],"preferred":false,"id":378311,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Sparks, G. B.","contributorId":9788,"corporation":false,"usgs":true,"family":"Sparks","given":"G.","email":"","middleInitial":"B.","affiliations":[],"preferred":false,"id":378308,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Rouse, G. L.","contributorId":105069,"corporation":false,"usgs":true,"family":"Rouse","given":"G.","email":"","middleInitial":"L.","affiliations":[],"preferred":false,"id":378312,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Brown, W. S.","contributorId":14466,"corporation":false,"usgs":true,"family":"Brown","given":"W.","email":"","middleInitial":"S.","affiliations":[],"preferred":false,"id":378309,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Steltzer, Heidi","contributorId":72735,"corporation":false,"usgs":true,"family":"Steltzer","given":"Heidi","email":"","affiliations":[],"preferred":false,"id":378310,"contributorType":{"id":1,"text":"Authors"},"rank":5}]}}
,{"id":70017798,"text":"70017798 - 1996 - Development of gypsum alteration on marble and limestone","interactions":[],"lastModifiedDate":"2023-03-06T17:04:56.391699","indexId":"70017798","displayToPublicDate":"1996-01-01T00:00:00","publicationYear":"1996","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":620,"text":"ASTM Special Technical Publication","active":true,"publicationSubtype":{"id":10}},"title":"Development of gypsum alteration on marble and limestone","docAbstract":"Blackened alteration crusts of gypsum plus particulates that form on sheltered areas on marble and limestone buildings pose a challenge for rehabilitation and cleaning. Fresh marble and limestone samples exposed at monitored exposure sites present conditions of simple geometry and well-documented exposures but have short exposure histories (one to five years). The gypsum alteration crusts that develop on these samples provide insight into the early stages and rate of alteration crust formation. Alteration crusts from buildings give a longer, but less well known exposure history and present much more complex surfaces for gypsum accumulation. Integrated observations and measurements of alteration crusts from exposure samples and from buildings identify four factors that are important in the formation and development of alteration crusts on marble and limestone: (1) pollution levels, (2) exposure to rain or washing, (3) geometry of exposure of the stone surface, and (4) permeability of the stone. The combination of these factors contributes to both the distribution and the physical characteristics of the gypsum crusts which may affect cleaning decisions.","language":"English","publisher":"ASTM","doi":"10.1520/STP15450S","usgsCitation":"McGee, E.S., 1996, Development of gypsum alteration on marble and limestone: ASTM Special Technical Publication, v. 1258, p. 376-397, https://doi.org/10.1520/STP15450S.","productDescription":"22 p.","startPage":"376","endPage":"397","numberOfPages":"22","costCenters":[],"links":[{"id":229044,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"1258","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a0058e4b0c8380cd4f6ed","contributors":{"authors":[{"text":"McGee, E. S.","contributorId":75927,"corporation":false,"usgs":true,"family":"McGee","given":"E.","email":"","middleInitial":"S.","affiliations":[],"preferred":false,"id":377590,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}}
,{"id":70017799,"text":"70017799 - 1996 - Source and tectonic implications of tonalite-trondhjemite magmatism in the Klamath Mountains","interactions":[],"lastModifiedDate":"2023-09-22T16:15:29.997708","indexId":"70017799","displayToPublicDate":"1996-01-01T00:00:00","publicationYear":"1996","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1336,"text":"Contributions to Mineralogy and Petrology","active":true,"publicationSubtype":{"id":10}},"title":"Source and tectonic implications of tonalite-trondhjemite magmatism in the Klamath Mountains","docAbstract":"<p><span>In the Klamath Mountains, voluminous tonalite-trondhjemite magmatism was characteristic of a short period of time from about 144 to 136 Ma (Early Cretaceous). It occurred about 5 to 10 m.y. after the ∼165 to 159 Ma Josephine ophiolite was thrust beneath older parts of the province during the Nevadan orogeny (thrusting from ∼155 to 148 Ma). The magmatism also corresponds to a period of slow or no subduction. Most of the plutons crop out in the south-central Klamath Mountains in California, but one occurs in Oregon at the northern end of the province. Compositionally extended members of the suite consist of precursor gabbroic to dioritic rocks followed by later, more voluminous tonalitic and trondhjemitic intrusions. Most plutons consist almost entirely of tonalite and trondhjemite. Poorly-defined concentric zoning is common. Tonalitic rocks are typically of the low-Al type but trondhjemites are generally of the high-Al type, even those that occur in the same pluton as low-Al tonalite. The suite is characterized by low abundances of K</span><sub>2</sub><span>O, Rb, Zr, and heavy rare earth elements. Sr contents are generally moderate (∼450 ppm) by comparison with Sr-rich arc lavas interpreted to be slab melts (up to 2000 ppm). Initial</span><sup><span>&nbsp;</span>87</sup><span>Sr/</span><sup>86</sup><span>Sr,&nbsp;</span><i>δ</i><span>&nbsp;</span><sup>18</sup><span>O, and&nbsp;</span><i>ɛ</i><span>&nbsp;</span><sub>Nd</sub><span>&nbsp;are typical of mantle-derived magmas or of crustally-derived magmas with a metabasic source. Compositional variation within plutons can be modeled by variable degrees of partial melting of a heterogeneous metabasaltic source (transitional mid-ocean ridge to island arc basalt), but not by fractional crystallyzation of a basaltic parent. Melting models require a residual assemblage of clinopyroxene+garnet±plagioclase±amphibole; residual plagioclase suggests a deep crustal origin rather than melting of a subducted slab. Such models are consistent with the metabasic part of the Josephine ophiolite as the source. Because the Josephine ophiolite was at low&nbsp;</span><i>T</i><span>&nbsp;during Nevadan thrusting, an external heat source was probably necessary to achieve significant degrees of melting; heat was probably extracted from mantle-derived basaltic melts, which were parental to the mafic precursors of the tonalite-trondhjemite suite. Thus, under appropriate tectonic and thermal conditions, heterogeneous mafic crustal rocks can melt to form both low- and high-Al tonalitic and trondhjemitic magmas; slab melting is not necessary.</span></p>","language":"English","publisher":"Springer Link","doi":"10.1007/s004100050142","usgsCitation":"Barnes, C., Petersen, S.W., Kistler, R.W., Murray, R., and Kays, M.A., 1996, Source and tectonic implications of tonalite-trondhjemite magmatism in the Klamath Mountains: Contributions to Mineralogy and Petrology, v. 123, no. 1, p. 40-60, https://doi.org/10.1007/s004100050142.","productDescription":"21 p.","startPage":"40","endPage":"60","numberOfPages":"21","costCenters":[],"links":[{"id":228350,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"country":"United States","state":"California, Oregon","otherGeospatial":"Klamath Mountains","geographicExtents":"{\n  \"type\": \"FeatureCollection\",\n  \"features\": [\n    {\n      \"type\": \"Feature\",\n      \"properties\": {},\n      \"geometry\": {\n        \"coordinates\": [\n          [\n            [\n              -124.58423057231622,\n              43.14760111393659\n            ],\n            [\n              -124.58423057231622,\n              40.23260246232101\n            ],\n            [\n              -120.96992289802705,\n              40.23260246232101\n            ],\n            [\n              -120.96992289802705,\n              43.14760111393659\n            ],\n            [\n              -124.58423057231622,\n              43.14760111393659\n            ]\n          ]\n        ],\n        \"type\": \"Polygon\"\n      }\n    }\n  ]\n}","volume":"123","issue":"1","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505b9322e4b08c986b31a2ee","contributors":{"authors":[{"text":"Barnes, C. G.","contributorId":78819,"corporation":false,"usgs":false,"family":"Barnes","given":"C. G.","affiliations":[],"preferred":false,"id":377594,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Petersen, S. W.","contributorId":72946,"corporation":false,"usgs":false,"family":"Petersen","given":"S.","email":"","middleInitial":"W.","affiliations":[],"preferred":false,"id":377593,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Kistler, R. W.","contributorId":36112,"corporation":false,"usgs":true,"family":"Kistler","given":"R.","email":"","middleInitial":"W.","affiliations":[],"preferred":false,"id":377591,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Murray, R.","contributorId":80440,"corporation":false,"usgs":true,"family":"Murray","given":"R.","affiliations":[],"preferred":false,"id":377595,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Kays, M. A.","contributorId":65925,"corporation":false,"usgs":false,"family":"Kays","given":"M.","email":"","middleInitial":"A.","affiliations":[],"preferred":false,"id":377592,"contributorType":{"id":1,"text":"Authors"},"rank":5}]}}
,{"id":70019361,"text":"70019361 - 1996 - Stress/strain changes and triggered seismicity at The Geysers, California","interactions":[],"lastModifiedDate":"2024-11-13T17:44:17.558219","indexId":"70019361","displayToPublicDate":"1996-01-01T00:00:00","publicationYear":"1996","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2314,"text":"Journal of Geophysical Research B: Solid Earth","active":true,"publicationSubtype":{"id":10}},"title":"Stress/strain changes and triggered seismicity at The Geysers, California","docAbstract":"<p><span>The principal results of this study of remotely triggered seismicity in The Geysers geothermal field are the demonstration that triggering (initiation of earthquake failure) depends on a critical strain threshold and that the threshold level increases with decreasing frequency, or, equivalently, depends on strain rate. This threshold function derives from (1) analyses of dynamic strains associated with surface waves of the triggering earthquakes, (2) statistically measured aftershock zone dimensions, and (3) analytic functional representations of strains associated with power production and tides. The threshold is also consistent with triggering by static strain changes and implies that both static and dynamic strains may cause aftershocks. The observation that triggered seismicity probably occurs in addition to background activity also provides an important constraint on the triggering process. Assuming the physical processes underlying earthquake nucleation to be the same,&nbsp;</span><i>Gomberg</i><span>&nbsp;[this issue] discusses seismicity triggered by the&nbsp;</span><i>M<sub>W</sub></i><span>&nbsp;7.3 Landers earthquake, its constraints on the variability of triggering thresholds with site, and the implications of time delays between triggering and triggered earthquakes. Our results enable us to reject the hypothesis that dynamic strains simply nudge prestressed faults over a Coulomb failure threshold sooner than they would have otherwise. We interpret the rate-dependent triggering threshold as evidence of several competing processes with different time constants, the faster one(s) facilitating failure and the other(s) inhibiting it. Such competition is a common feature of theories of slip instability. All these results, not surprisingly, imply that to understand earthquake triggering one must consider not only simple failure criteria requiring exceedence of some constant threshold but also the requirements for generating instabilities.</span></p>","language":"English","publisher":"American Geophysical Union","doi":"10.1029/95JB03250","issn":"01480227","usgsCitation":"Gomberg, J., and Davis, S., 1996, Stress/strain changes and triggered seismicity at The Geysers, California: Journal of Geophysical Research B: Solid Earth, v. 101, no. 1, p. 733-749, https://doi.org/10.1029/95JB03250.","productDescription":"17 p.","startPage":"733","endPage":"749","numberOfPages":"17","costCenters":[],"links":[{"id":226377,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"101","issue":"1","noUsgsAuthors":false,"publicationDate":"1996-01-10","publicationStatus":"PW","scienceBaseUri":"505b9b6ee4b08c986b31cea4","contributors":{"authors":[{"text":"Gomberg, J.","contributorId":95994,"corporation":false,"usgs":true,"family":"Gomberg","given":"J.","email":"","affiliations":[],"preferred":false,"id":382476,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Davis, S.","contributorId":43505,"corporation":false,"usgs":true,"family":"Davis","given":"S.","affiliations":[],"preferred":false,"id":382475,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}}
,{"id":70017810,"text":"70017810 - 1996 - AMS radiocarbon analyses from Lake Baikal, Siberia: Challenges of dating sediments from a large, oligotrophic lake","interactions":[],"lastModifiedDate":"2017-08-16T09:08:37","indexId":"70017810","displayToPublicDate":"1996-01-01T00:00:00","publicationYear":"1996","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":3219,"text":"Quaternary Science Reviews","active":true,"publicationSubtype":{"id":10}},"title":"AMS radiocarbon analyses from Lake Baikal, Siberia: Challenges of dating sediments from a large, oligotrophic lake","docAbstract":"A suite of 146 new accelerator-mass spectrometer (AMS) radiocarbon ages provides the first reliable chronology for late Quaternary sediments in Lake Baikal. In this large, highly oligotrophic lake, biogenic and authigenic carbonate are absent, and plant macrofossils are extremely rare. Total organic carbon is therefore the primary material available for dating. Several problems are associated with the TOC ages. One is the mixture of carbon sources in TOC, not all of which are syndepositional in age. This problem manifests itself in apparent ages for the sediment surface that are greater than zero. However, because most of the organic carbon in Lake Baikal sediments is algal (autochthonous) in origin, this effect is limited to about 1000+500 years, which can be corrected, at least for young deposits. The other major problem with dating Lake Baikal sediments is the very low carbon contents of glacial-age deposits, which makes them extremely susceptible to contamination with modern carbon. This problem can be minimized by careful sampling and handling procedures. The ages show almost an order of magnitude difference in sediment-accumulation rates among different sedimentary environments in Lake Baikal, from about 0.04 mm/year on isolated banks such as Academician Ridge, to nearly 0.3 mm/year in the turbidite depositional areas beneath the deep basin floors, such as the Central Basin. The new AMS ages clearly indicate that the dramatic increase in diatom productivity in the lake, as evidenced by increases in biogenic silica and organic carbon, began about 13 ka, in contrast to previous estimates of 7 ka for the age of this transition. Holocene net sedimentation rates may be less than, equal to, or greater than those in the late Pleistocene, depending on the site. This variability reflects the balance between variable terrigenous sedimentation and increased biogenic sedimentation during interglaciations. The ages reported here, and the temporal and spatial variation in sedimentation rates that they imply, provide opportunities for paleoenvironmental reconstructions at different time scales and resolutions.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Quaternary Science Reviews","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1016/0277-3791(96)00027-3","issn":"02773791","usgsCitation":"Colman, S.M., Jones, G.A., Rubin, M., King, J., Peck, J., and Orem, W., 1996, AMS radiocarbon analyses from Lake Baikal, Siberia: Challenges of dating sediments from a large, oligotrophic lake: Quaternary Science Reviews, v. 15, no. 7, p. 669-684, https://doi.org/10.1016/0277-3791(96)00027-3.","startPage":"669","endPage":"684","numberOfPages":"16","costCenters":[{"id":678,"text":"Woods Hole Coastal and Marine Science Center","active":true,"usgs":true}],"links":[{"id":487268,"rank":10000,"type":{"id":41,"text":"Open Access External Repository Page"},"url":"https://digitalcommons.uri.edu/gsofacpubs/1758","text":"External Repository"},{"id":228487,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":206118,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/0277-3791(96)00027-3"}],"volume":"15","issue":"7","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"5059e62ce4b0c8380cd471ee","contributors":{"authors":[{"text":"Colman, Steven M. 0000-0002-0564-9576","orcid":"https://orcid.org/0000-0002-0564-9576","contributorId":77482,"corporation":false,"usgs":true,"family":"Colman","given":"Steven","email":"","middleInitial":"M.","affiliations":[{"id":678,"text":"Woods Hole Coastal and Marine Science Center","active":true,"usgs":true}],"preferred":false,"id":377631,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Jones, Glenn A.","contributorId":17779,"corporation":false,"usgs":false,"family":"Jones","given":"Glenn","email":"","middleInitial":"A.","affiliations":[{"id":6706,"text":"Woods Hole Oceanographic Institution,","active":true,"usgs":false}],"preferred":false,"id":377628,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Rubin, M.","contributorId":88079,"corporation":false,"usgs":true,"family":"Rubin","given":"M.","email":"","affiliations":[],"preferred":false,"id":377632,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"King, J.W.","contributorId":19265,"corporation":false,"usgs":true,"family":"King","given":"J.W.","email":"","affiliations":[],"preferred":false,"id":377629,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Peck, J.A.","contributorId":26398,"corporation":false,"usgs":true,"family":"Peck","given":"J.A.","email":"","affiliations":[],"preferred":false,"id":377630,"contributorType":{"id":1,"text":"Authors"},"rank":5},{"text":"Orem, W. H. 0000-0003-4990-0539","orcid":"https://orcid.org/0000-0003-4990-0539","contributorId":93084,"corporation":false,"usgs":true,"family":"Orem","given":"W. H.","affiliations":[],"preferred":false,"id":377633,"contributorType":{"id":1,"text":"Authors"},"rank":6}]}}
,{"id":70019338,"text":"70019338 - 1996 - Direct simulation of groundwater age","interactions":[],"lastModifiedDate":"2018-03-08T15:45:15","indexId":"70019338","displayToPublicDate":"1996-01-01T00:00:00","publicationYear":"1996","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":3722,"text":"Water Resources Research","onlineIssn":"1944-7973","printIssn":"0043-1397","active":true,"publicationSubtype":{"id":10}},"title":"Direct simulation of groundwater age","docAbstract":"<p><span>A new method is proposed to simulate groundwater age directly, by use of an advection-dispersion transport equation with a distributed zero-order source of unit (1) strength, corresponding to the rate of aging. The dependent variable in the governing equation is the mean age, a mass-weighted average age. The governing equation is derived from residence-time-distribution concepts for the case of steady flow. For the more general case of transient flow, a transient governing equation for age is derived from mass-conservation principles applied to conceptual “age mass.” The age mass is the product of the water mass and its age, and age mass is assumed to be conserved during mixing. Boundary conditions include zero age mass flux across all noflow and inflow boundaries and no age mass dispersive flux across outflow boundaries. For transient-flow conditions, the initial distribution of age must be known. The solution of the governing transport equation yields the spatial distribution of the mean groundwater age and includes diffusion, dispersion, mixing, and exchange processes that typically are considered only through tracer-specific solute transport simulation. Traditional methods have relied on advective transport to predict point values of groundwater travel time and age. The proposed method retains the simplicity and tracer-independence of advection-only models, but incorporates the effects of dispersion and mixing on volume-averaged age. Example simulations of age in two idealized regional aquifer systems, one homogeneous and the other layered, demonstrate the agreement between the proposed method and traditional particle-tracking approaches and illustrate use of the proposed method to determine the effects of diffusion, dispersion, and mixing on groundwater age.</span></p>","language":"English","publisher":"American Geophysical Union","doi":"10.1029/95WR03401","usgsCitation":"Goode, D., 1996, Direct simulation of groundwater age: Water Resources Research, v. 32, no. 2, p. 289-296, https://doi.org/10.1029/95WR03401.","productDescription":"8 p.","startPage":"289","endPage":"296","costCenters":[{"id":532,"text":"Pennsylvania Water Science Center","active":true,"usgs":true}],"links":[{"id":480178,"rank":1,"type":{"id":40,"text":"Open Access Publisher Index Page"},"url":"https://doi.org/10.1029/95wr03401","text":"Publisher Index Page"},{"id":226693,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"32","issue":"2","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a01b2e4b0c8380cd4fd08","contributors":{"authors":[{"text":"Goode, Daniel J. 0000-0002-8527-2456 djgoode@usgs.gov","orcid":"https://orcid.org/0000-0002-8527-2456","contributorId":2433,"corporation":false,"usgs":true,"family":"Goode","given":"Daniel J.","email":"djgoode@usgs.gov","affiliations":[{"id":532,"text":"Pennsylvania Water Science Center","active":true,"usgs":true}],"preferred":false,"id":382393,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}}
,{"id":70019324,"text":"70019324 - 1996 - A one-pot procedure for the quantitative conversion of glycosides into acetylated glycosyl fluorides","interactions":[],"lastModifiedDate":"2012-03-12T17:19:11","indexId":"70019324","displayToPublicDate":"1996-01-01T00:00:00","publicationYear":"1996","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1181,"text":"Carbohydrate Research","active":true,"publicationSubtype":{"id":10}},"title":"A one-pot procedure for the quantitative conversion of glycosides into acetylated glycosyl fluorides","docAbstract":"[No abstract available]","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Carbohydrate Research","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1016/0008-6215(95)00328-2","issn":"00086215","usgsCitation":"Bergamaschi, B., and Hedges, J.I., 1996, A one-pot procedure for the quantitative conversion of glycosides into acetylated glycosyl fluorides: Carbohydrate Research, v. 280, no. 2, p. 345-350, https://doi.org/10.1016/0008-6215(95)00328-2.","startPage":"345","endPage":"350","numberOfPages":"6","costCenters":[],"links":[{"id":205721,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/0008-6215(95)00328-2"},{"id":226424,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"280","issue":"2","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"5059e4cee4b0c8380cd4693b","contributors":{"authors":[{"text":"Bergamaschi, B.A. 0000-0002-9610-5581","orcid":"https://orcid.org/0000-0002-9610-5581","contributorId":22401,"corporation":false,"usgs":true,"family":"Bergamaschi","given":"B.A.","affiliations":[],"preferred":false,"id":382353,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Hedges, J. I.","contributorId":30757,"corporation":false,"usgs":true,"family":"Hedges","given":"J.","email":"","middleInitial":"I.","affiliations":[],"preferred":false,"id":382354,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}}
,{"id":70019299,"text":"70019299 - 1996 - The accuracy of seismic estimates of dynamic strains: an evaluation using strainmeter and seismometer data from Piñon Flat Observatory, California","interactions":[],"lastModifiedDate":"2023-10-22T14:16:21.258696","indexId":"70019299","displayToPublicDate":"1996-01-01T00:00:00","publicationYear":"1996","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1135,"text":"Bulletin of the Seismological Society of America","onlineIssn":"1943-3573","printIssn":"0037-1106","active":true,"publicationSubtype":{"id":10}},"title":"The accuracy of seismic estimates of dynamic strains: an evaluation using strainmeter and seismometer data from Piñon Flat Observatory, California","docAbstract":"<div id=\"136841857\" class=\"article-section-wrapper js-article-section js-content-section  \" data-section-parent-id=\"0\"><p>The dynamic strains associated with seismic waves may play a significant role in earthquake triggering, hydrological and magmatic changes, earthquake damage, and ground failure. We determine how accurately dynamic strains may be estimated from seismometer data and elastic-wave theory by comparing such estimated strains with strains measured on a three-component long-base strainmeter system at Piñon Flat, California. We quantify the uncertainties and errors through cross-spectral analysis of data from three regional earthquakes (the<span>&nbsp;</span><i>M</i><sub>0</sub><span>&nbsp;</span>= 4 × 10<sup>17</sup><span>&nbsp;</span>N-m St. George, Utah;<span>&nbsp;</span><i>M</i><sub>0</sub><span>&nbsp;</span>= 4 × 10<sup>17</sup><span>&nbsp;</span>N-m Little Skull Mountain, Nevada; and<span>&nbsp;</span><i>M</i><sub>0</sub><span>&nbsp;</span>= 1 × 10<sup>19</sup><span>&nbsp;</span>N-m Northridge, California, events at distances of 470, 345, and 206 km, respectively). Our analysis indicates that in most cases the phase of the estimated strain matches that of the observed strain quite well (to within the uncertainties, which are about ±0.1 to ±0.2 cycles). However, the amplitudes are often systematically off, at levels exceeding the uncertainties (about 20%); in one case, the predicted strain amplitudes are nearly twice those observed. We also observe significant<span>&nbsp;</span><i>ɛ<sub>φφ</sub></i><span>&nbsp;</span>strains (<i>φ</i><span>&nbsp;</span>= tangential direction), which should be zero theoretically; in the worst case, the rms<span>&nbsp;</span><i>ɛ<sub>φφ</sub></i><span>&nbsp;</span>strain exceeds the other nonzero components. These nonzero<span>&nbsp;</span><i>ɛ<sub>φφ</sub></i><span>&nbsp;</span>strains cannot be caused by deviations of the surface-wave propagation paths from the expected azimuth or by departures from the plane-wave approximation. We believe that distortion of the strain field by topography or material heterogeneities give rise to these complexities.</p></div>","language":"English","publisher":"Seismological Society of America","doi":"10.1785/BSSA08601A0212","issn":"00371106","usgsCitation":"Gomberg, J.S., and Agnew, D., 1996, The accuracy of seismic estimates of dynamic strains: an evaluation using strainmeter and seismometer data from Piñon Flat Observatory, California: Bulletin of the Seismological Society of America, v. 86, no. 1 SUPPL. A, p. 212-220, https://doi.org/10.1785/BSSA08601A0212.","productDescription":"9 p.","startPage":"212","endPage":"220","onlineOnly":"N","additionalOnlineFiles":"N","costCenters":[],"links":[{"id":226691,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"country":"United States","state":"California","otherGeospatial":"Piñon Flat Observatory","geographicExtents":"{\n  \"type\": \"FeatureCollection\",\n  \"features\": [\n    {\n      \"type\": \"Feature\",\n      \"properties\": {},\n      \"geometry\": {\n        \"coordinates\": [\n          [\n            [\n              -114.4208087174198,\n              35.82058748907717\n            ],\n            [\n              -118.96914856116959,\n              35.82058748907717\n            ],\n            [\n              -118.96914856116959,\n              32.90091090249189\n            ],\n            [\n              -114.4208087174198,\n              32.90091090249189\n            ],\n            [\n              -114.4208087174198,\n              35.82058748907717\n            ]\n          ]\n        ],\n        \"type\": \"Polygon\"\n      }\n    }\n  ]\n}","volume":"86","issue":"1 SUPPL. A","noUsgsAuthors":false,"publicationDate":"1996-02-01","publicationStatus":"PW","scienceBaseUri":"505ba99de4b08c986b3223ad","contributors":{"authors":[{"text":"Gomberg, Joan S. 0000-0002-0134-2606 gomberg@usgs.gov","orcid":"https://orcid.org/0000-0002-0134-2606","contributorId":1269,"corporation":false,"usgs":true,"family":"Gomberg","given":"Joan","email":"gomberg@usgs.gov","middleInitial":"S.","affiliations":[{"id":237,"text":"Earthquake Science Center","active":true,"usgs":true}],"preferred":true,"id":382291,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Agnew, Duncan Carr","contributorId":53686,"corporation":false,"usgs":true,"family":"Agnew","given":"Duncan Carr","affiliations":[],"preferred":false,"id":382290,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}}
,{"id":70017853,"text":"70017853 - 1996 - Inelastic models of lithospheric stress - II. Implications for outer-rise seismicity and dynamics","interactions":[],"lastModifiedDate":"2024-02-08T12:08:05.077229","indexId":"70017853","displayToPublicDate":"1996-01-01T00:00:00","publicationYear":"1996","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1803,"text":"Geophysical Journal International","active":true,"publicationSubtype":{"id":10}},"title":"Inelastic models of lithospheric stress - II. Implications for outer-rise seismicity and dynamics","docAbstract":"<div class=\"u-mb-1\"><div>Outer-rise seismicity and dynamics are examined using inelastic models of lithospheric deformation, which allow a more realistic characterization of stress distributions and failure behaviour. We conclude that thrust- and normal-faulting outer-rise earthquakes represent substantially different states of stress within the oceanic lithosphere. Specifically, the normal-faulting events occur in response to downward plate bending, which establishes the ‘standard’, bending-dominated state of outer-rise stress, and the thrust-faulting events occur in response to an elevated level of in-plane compression, which develops only in response to exceptional circumstances. This interpretation accounts for the observation that normal-faulting outer-rise earthquakes occur more frequently and are more widely distributed than their thrust-faulting counterparts, an observation for which the simple bending model offers no explanation. In addition, attributing both thrust- and normal-faulting outer-rise earthquakes to plate bending implies that both classes of events should occur within relatively close lateral proximity to one another because both are allegedly a manifestation of the same bendingdominated stress distribution, whereas, in reality, this is not observed. We propose that the tendency for thrust-faulting outer-rise earthquakes to exhibit greater source depths than their normal-faulting counterparts (an observation that is frequently cited in support of the bending interpretation of the former) is merely a consequence of the fact that bending-induced tension is confined to the upper lithosphere. Our model predicts that outer-rise in-plane-force variations may promote thrust-faulting outerrise activity prior to an underthrusting interplate subduction earthquake and normalfaulting outer-rise activity following such an earthquake, but that both forms of outerrise activity are unlikely to be associated with the same subduction earthquake. A corollary implication of our model is t...</div></div>","language":"English","publisher":"IEEE","doi":"10.1111/j.1365-246X.1996.tb06534.x","issn":"0956540X","usgsCitation":"Mueller, S., Spence, W., and Choy, G.L., 1996, Inelastic models of lithospheric stress - II. Implications for outer-rise seismicity and dynamics: Geophysical Journal International, v. 125, no. 1, p. 54-72, https://doi.org/10.1111/j.1365-246X.1996.tb06534.x.","productDescription":"19 p.","startPage":"54","endPage":"72","numberOfPages":"19","costCenters":[],"links":[{"id":228400,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"125","issue":"1","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a3ac4e4b0c8380cd61f65","contributors":{"authors":[{"text":"Mueller, S.","contributorId":68899,"corporation":false,"usgs":true,"family":"Mueller","given":"S.","affiliations":[],"preferred":false,"id":377760,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Spence, W.","contributorId":7721,"corporation":false,"usgs":true,"family":"Spence","given":"W.","email":"","affiliations":[],"preferred":false,"id":377759,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Choy, G. L. 0000-0002-0217-5555","orcid":"https://orcid.org/0000-0002-0217-5555","contributorId":78322,"corporation":false,"usgs":true,"family":"Choy","given":"G.","email":"","middleInitial":"L.","affiliations":[],"preferred":false,"id":377761,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}}
,{"id":70017775,"text":"70017775 - 1996 - Extension across Tempe Terra, Mars, from measurements of fault scarp widths and deformed craters","interactions":[],"lastModifiedDate":"2024-08-01T13:28:57.358214","indexId":"70017775","displayToPublicDate":"1996-01-01T00:00:00","publicationYear":"1996","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2317,"text":"Journal of Geophysical Research E: Planets","active":true,"publicationSubtype":{"id":10}},"title":"Extension across Tempe Terra, Mars, from measurements of fault scarp widths and deformed craters","docAbstract":"<p><span>Two independent methods, with no common assumptions, have been used to estimate the extension across the heavily deformed Tempe Terra province of the Tharsis region of Mars. One method uses measurements of normal fault scarp width with average scarp slope data for simple grabens and rifts on Mars to estimate the fault throw, which, combined with sparse fault dip data, can be used to estimate extension. Formal uncertainties in this method are only slightly greater than those in other methods, given that the total uncertainty is dominated by the likely uncertainty in the fault dip (assumed to be 60° ± 15°). Measurement of normal fault scarp widths along two N25°–50°W directed traverses across Tempe Terra both yield about 22 ± 16 km of extension (or ∼2% strain across the northern traverse and nearly 3% across the southern one). About three quarters of the extension has occurred during the two main phases of Tharsis-related deformation from Middle/Late Noachian to Early Hesperian and from Late Hesperian to Early Amazonian, with more extension closer to the center of Tharsis during the first phase. Extension across the region was also determined by measuring the elongation and elongation direction of all ancient Noachian impact craters without ejecta blankets, which predate most of the deformation. Results have been corrected for initial non circularity of craters, established from similar measurements of young (post deformation) impact craters, yielding a statistically significant mean strain of 1.96 ± 0.35% in a N38° ± 10°W direction across Tempe Terra (extension of ∼20 ± 4, comparable in magnitude and direction to the average result from the scarp measurement method). Both methods indicate an average extension for single normal fault scarps (and shortening across wrinkle ridges for the crater method) of ∼100 m. The agreement between the results of the two independent methods in overall extension and average single normal fault extension argues that the average scarp slope and fault dip data in the fault scarp width method accurately represent the actual extension across the observed structures. This conclusion supports existing geometric and kinematic models for structural features on Mars. A preliminary estimate of the total circumferential extension around Tharsis (at a radius of ∼2500 km) is roughly 60 ± 42 km; total hoop strain is about 0.4% distributed heterogeneously (Tempe Terra is the most highly strained region on Mars).</span></p>","language":"English","publisher":"American Geophysical Union","doi":"10.1029/96JE02709","issn":"01480227","usgsCitation":"Golombek, M., Tanaka, K.L., and Franklin, B., 1996, Extension across Tempe Terra, Mars, from measurements of fault scarp widths and deformed craters: Journal of Geophysical Research E: Planets, v. 101, no. E11, p. 26119-26130, https://doi.org/10.1029/96JE02709.","productDescription":"12 p.","startPage":"26119","endPage":"26130","numberOfPages":"12","costCenters":[],"links":[{"id":228772,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"otherGeospatial":"Mars","volume":"101","issue":"E11","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a0e41e4b0c8380cd53384","contributors":{"authors":[{"text":"Golombek, M.P.","contributorId":52696,"corporation":false,"usgs":true,"family":"Golombek","given":"M.P.","email":"","affiliations":[],"preferred":false,"id":377535,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Tanaka, K. L.","contributorId":31394,"corporation":false,"usgs":false,"family":"Tanaka","given":"K.","email":"","middleInitial":"L.","affiliations":[],"preferred":false,"id":377533,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Franklin, B.J.","contributorId":48358,"corporation":false,"usgs":true,"family":"Franklin","given":"B.J.","email":"","affiliations":[],"preferred":false,"id":377534,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}}
,{"id":70017849,"text":"70017849 - 1996 - Geomagnetic storms, the Dst ring-current myth and lognormal distributions","interactions":[],"lastModifiedDate":"2013-02-23T13:22:06","indexId":"70017849","displayToPublicDate":"1996-01-01T00:00:00","publicationYear":"1996","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2188,"text":"Journal of Atmospheric and Terrestrial Physics","active":true,"publicationSubtype":{"id":10}},"title":"Geomagnetic storms, the Dst ring-current myth and lognormal distributions","docAbstract":"The definition of geomagnetic storms dates back to the turn of the century when researchers recognized the unique shape of the H-component field change upon averaging storms recorded at low latitude observatories. A generally accepted modeling of the storm field sources as a magnetospheric ring current was settled about 30 years ago at the start of space exploration and the discovery of the Van Allen belt of particles encircling the Earth. The Dst global 'ring-current' index of geomagnetic disturbances, formulated in that period, is still taken to be the definitive representation for geomagnetic storms. Dst indices, or data from many world observatories processed in a fashion paralleling the index, are used widely by researchers relying on the assumption of such a magnetospheric current-ring depiction. Recent in situ measurements by satellites passing through the ring-current region and computations with disturbed magnetosphere models show that the Dst storm is not solely a main-phase to decay-phase, growth to disintegration, of a massive current encircling the Earth. Although a ring current certainly exists during a storm, there are many other field contributions at the middle-and low-latitude observatories that are summed to show the 'storm' characteristic behavior in Dst at these observatories. One characteristic of the storm field form at middle and low latitudes is that Dst exhibits a lognormal distribution shape when plotted as the hourly value amplitude in each time range. Such distributions, common in nature, arise when there are many contributors to a measurement or when the measurement is a result of a connected series of statistical processes. The amplitude-time displays of Dst are thought to occur because the many time-series processes that are added to form Dst all have their own characteristic distribution in time. By transforming the Dst time display into the equivalent normal distribution, it is shown that a storm recovery can be predicted with remarkable accuracy from measurements made during the Dst growth phase. In the lognormal formulation, the mean, standard deviation and field count within standard deviation limits become definitive Dst storm parameters.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Journal of Atmospheric and Terrestrial Physics","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","publisher":"Elsevier","doi":"10.1016/0021-9169(95)00103-4","issn":"00219169","usgsCitation":"Campbell, W., 1996, Geomagnetic storms, the Dst ring-current myth and lognormal distributions: Journal of Atmospheric and Terrestrial Physics, v. 58, no. 10, p. 1171-1187, https://doi.org/10.1016/0021-9169(95)00103-4.","startPage":"1171","endPage":"1187","numberOfPages":"17","costCenters":[],"links":[{"id":268032,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/0021-9169(95)00103-4"},{"id":229003,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"58","issue":"10","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a2762e4b0c8380cd59831","contributors":{"authors":[{"text":"Campbell, W.H.","contributorId":30749,"corporation":false,"usgs":true,"family":"Campbell","given":"W.H.","email":"","affiliations":[],"preferred":false,"id":377732,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}}
,{"id":70017844,"text":"70017844 - 1996 - Modeling impact of small Kansas landfills on underlying aquifers","interactions":[],"lastModifiedDate":"2024-04-22T15:01:37.657099","indexId":"70017844","displayToPublicDate":"1996-01-01T00:00:00","publicationYear":"1996","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2255,"text":"Journal of Environmental Engineering","active":true,"publicationSubtype":{"id":10}},"title":"Modeling impact of small Kansas landfills on underlying aquifers","docAbstract":"<p><span>Small landfills are exempt from compliance with Resource Conservation and Recovery Act Subtitle D standards for liner and leachate collection. We investigate the ramifications of this exemption under western Kansas semiarid environments and explore the conditions under which naturally occurring geologic settings provide sufficient protection against ground-water contamination. The methodology we employed was to run water budget simulations using the Hydrologic Evaluation of Landfill Performance (HELP) model, and fate and transport simulations using the Multimedia Exposure Assessment Model (MULTIMED) for several western Kansas small landfill scenarios in combination with extensive sensitivity analyses. We demonstrate that requiring landfill cover, leachate collection system (LCS), and compacted soil liner will reduce leachate production by 56%, whereas requiring only a cover without LCS and liner will reduce leachate by half as much. The most vulnerable small landfills are shown to be the ones with no vegetative cover underlain by both a relatively thin vadose zone and aquifer and which overlie an aquifer characterized by cool temperatures and low hydraulic gradients. The aquifer-related physical and chemical parameters proved to be more important than vadose zone and biodegradation parameters in controlling leachate concentrations at the point of compliance.</span></p>","language":"English","publisher":"ASCE","doi":"10.1061/(ASCE)0733-9372(1996)122:12(1067)","issn":"07339372","usgsCitation":"Sophocleous, M., Stadnyk, N., and Stotts, M., 1996, Modeling impact of small Kansas landfills on underlying aquifers: Journal of Environmental Engineering, v. 122, no. 12, p. 1067-1077, https://doi.org/10.1061/(ASCE)0733-9372(1996)122:12(1067).","productDescription":"11 p.","startPage":"1067","endPage":"1077","numberOfPages":"11","costCenters":[],"links":[{"id":228952,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"122","issue":"12","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a5c04e4b0c8380cd6f987","contributors":{"authors":[{"text":"Sophocleous, M.","contributorId":13373,"corporation":false,"usgs":true,"family":"Sophocleous","given":"M.","email":"","affiliations":[],"preferred":false,"id":377721,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Stadnyk, N.G.","contributorId":98484,"corporation":false,"usgs":true,"family":"Stadnyk","given":"N.G.","email":"","affiliations":[],"preferred":false,"id":377723,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Stotts, M.","contributorId":21306,"corporation":false,"usgs":true,"family":"Stotts","given":"M.","email":"","affiliations":[],"preferred":false,"id":377722,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}}
,{"id":70019060,"text":"70019060 - 1996 - Isolation of Geobacter species from diverse sedimentary environments","interactions":[],"lastModifiedDate":"2023-01-17T18:08:16.749165","indexId":"70019060","displayToPublicDate":"1996-01-01T00:00:00","publicationYear":"1996","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":850,"text":"Applied and Environmental Microbiology","active":true,"publicationSubtype":{"id":10}},"displayTitle":"Isolation of <i>Geobacter</i> species from diverse sedimentary environments","title":"Isolation of Geobacter species from diverse sedimentary environments","docAbstract":"<p>In an attempt to better understand the microorganisms responsible for Fe(III) reduction in sedimentary environments, Fe(III)-reducing microorganisms were enriched for and isolated from freshwater aquatic sediments, a pristine deep aquifer, and a petroleum-contaminated shallow aquifer. Enrichments were initiated with acetate or toluene as the electron donor and Fe(III) as the electron acceptor. Isolations were made with acetate or benzoate. Five new strains which could obtain energy for growth by dissimilatory Fe(III) reduction were isolated. All five isolates are gram- negative strict anaerobes which grow with acetate as the electron donor and Fe(III) as the electron acceptor. Analysis of the 16S rRNA sequence of the isolated organisms demonstrated that they all belonged to the genus <i>Geobacter</i> in the delta subdivision of the <i>Proteobacteria</i>. Unlike the type strain, <i>Geobacter</i> <i>metallireducens</i>, three of the five isolates could use H<sub>2</sub> as an electron donor for Fe(III) reduction. The deep subsurface isolate is the first Fe(III) reducer shown to completely oxidize lactate to carbon dioxide, while one of the freshwater sediment isolates is only the second Fe(III) reducer known that can oxidize toluene. The isolation of these organisms demonstrates that <i>Geobacter</i> species are widely distributed in a diversity of sedimentary environments in which Fe(III) reduction is an important process.</p>","language":"English","publisher":"American Society for Microbiology","doi":"10.1128/aem.62.5.1531-1536.1996","issn":"00992240","usgsCitation":"Coaxes, J., Phillips, E.J., Lonergan, D., Jenter, H., and Lovley, D.R., 1996, Isolation of Geobacter species from diverse sedimentary environments: Applied and Environmental Microbiology, v. 62, no. 5, p. 1531-1536, https://doi.org/10.1128/aem.62.5.1531-1536.1996.","productDescription":"6 p.","startPage":"1531","endPage":"1536","costCenters":[],"links":[{"id":479068,"rank":2,"type":{"id":40,"text":"Open Access Publisher Index Page"},"url":"https://doi.org/10.1128/aem.62.5.1531-1536.1996","text":"Publisher Index Page"},{"id":226577,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"62","issue":"5","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a3f4ee4b0c8380cd64427","contributors":{"authors":[{"text":"Coaxes, J.D.","contributorId":89012,"corporation":false,"usgs":true,"family":"Coaxes","given":"J.D.","email":"","affiliations":[],"preferred":false,"id":381554,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Phillips, Elizabeth J.P.","contributorId":37475,"corporation":false,"usgs":true,"family":"Phillips","given":"Elizabeth","middleInitial":"J.P.","affiliations":[],"preferred":false,"id":381552,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Lonergan, D.J.","contributorId":86110,"corporation":false,"usgs":true,"family":"Lonergan","given":"D.J.","email":"","affiliations":[],"preferred":false,"id":381553,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Jenter, H.","contributorId":23022,"corporation":false,"usgs":true,"family":"Jenter","given":"H.","affiliations":[],"preferred":false,"id":381551,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Lovley, Derek R.","contributorId":107852,"corporation":false,"usgs":true,"family":"Lovley","given":"Derek","middleInitial":"R.","affiliations":[],"preferred":false,"id":381555,"contributorType":{"id":1,"text":"Authors"},"rank":5}]}}
,{"id":70019037,"text":"70019037 - 1996 - Recent volcanism in the Siqueiros transform fault: Picritic basalts and implications for MORB magma genesis","interactions":[],"lastModifiedDate":"2023-12-09T00:38:00.386052","indexId":"70019037","displayToPublicDate":"1996-01-01T00:00:00","publicationYear":"1996","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1427,"text":"Earth and Planetary Science Letters","active":true,"publicationSubtype":{"id":10}},"title":"Recent volcanism in the Siqueiros transform fault: Picritic basalts and implications for MORB magma genesis","docAbstract":"Small constructional volcanic landforms and very fresh-looking lava flows are present along one of the inferred active strike-slip faults that connect two small spreading centers (A and B) in the western portion of the Siqueiros transform domain. The most primitive lavas (picritic and olivine-phyric basalts), exclusively recovered from the young-looking flows within the A-B strike-slip fault, contain millimeter-sized olivine phenocrysts (up to 20 modal%) that have a limited compositional range (Fo91.5-Fo89.5) and complexly zoned Cr-Al spinels. High-MgO (9.5-10.6 wt%) glasses sampled from the young lava flows contain 1-7% olivine phenocrysts (Fo90.5-Fo89) that could have formed by equilibrium crystallization from basaltic melts with Mg# values between 71 and 74. These high MgO (and high Al2O3) glasses may be near-primary melts from incompatible-element depleted oceanic mantle and little modified by crustal mixing and/or fractionation processes. Phase chemistry and major element systematics indicate that the picritic basalts are not primary liquids and formed by the accumulation of olivine and minor spinel from high-MgO melts (10% < MgO < 14%). Compared to typical N-MORB from the East Pacific Rise, the Siqueiros lavas are more primitive and depleted in incompatible elements. Phase equilibria calculations and comparisons with experimental data and trace element modeling support this hypothesis. They indicate such primary mid-ocean ridge basalt magmas formed by 10-18% accumulative decompression melting in the spinel peridotite field (but small amounts of melting in the garnet peridotite field are not precluded). The compositional variations of the primitive magmas may result from the accumulation of different small batch melt fractions from a polybaric melting column.","language":"English","publisher":"Elsevier","doi":"10.1016/0012-821X(96)00052-0","issn":"0012821X","usgsCitation":"Perfit, M., Fornari, D., Ridley, W., Kirk, P., Casey, J.F., Kastens, K., Reynolds, J., Edwards, M., Desonie, D., Shuster, R., and Paradis, S., 1996, Recent volcanism in the Siqueiros transform fault: Picritic basalts and implications for MORB magma genesis: Earth and Planetary Science Letters, v. 141, no. 1-4, p. 91-108, https://doi.org/10.1016/0012-821X(96)00052-0.","productDescription":"18 p.","startPage":"91","endPage":"108","numberOfPages":"18","costCenters":[],"links":[{"id":226943,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"141","issue":"1-4","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a9659e4b0c8380cd81f41","contributors":{"authors":[{"text":"Perfit, M.R.","contributorId":45467,"corporation":false,"usgs":true,"family":"Perfit","given":"M.R.","email":"","affiliations":[],"preferred":false,"id":381479,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Fornari, D.J.","contributorId":49520,"corporation":false,"usgs":true,"family":"Fornari","given":"D.J.","email":"","affiliations":[],"preferred":false,"id":381481,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Ridley, W.I.","contributorId":72122,"corporation":false,"usgs":true,"family":"Ridley","given":"W.I.","email":"","affiliations":[],"preferred":false,"id":381484,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Kirk, P.D.","contributorId":30769,"corporation":false,"usgs":true,"family":"Kirk","given":"P.D.","email":"","affiliations":[],"preferred":false,"id":381478,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Casey, John F.","contributorId":29550,"corporation":false,"usgs":true,"family":"Casey","given":"John","email":"","middleInitial":"F.","affiliations":[],"preferred":false,"id":381477,"contributorType":{"id":1,"text":"Authors"},"rank":5},{"text":"Kastens, K.A.","contributorId":70917,"corporation":false,"usgs":true,"family":"Kastens","given":"K.A.","email":"","affiliations":[],"preferred":false,"id":381483,"contributorType":{"id":1,"text":"Authors"},"rank":6},{"text":"Reynolds, J.R.","contributorId":72942,"corporation":false,"usgs":true,"family":"Reynolds","given":"J.R.","email":"","affiliations":[],"preferred":false,"id":381485,"contributorType":{"id":1,"text":"Authors"},"rank":7},{"text":"Edwards, M.","contributorId":8627,"corporation":false,"usgs":true,"family":"Edwards","given":"M.","affiliations":[],"preferred":false,"id":381476,"contributorType":{"id":1,"text":"Authors"},"rank":8},{"text":"Desonie, D.","contributorId":78099,"corporation":false,"usgs":true,"family":"Desonie","given":"D.","email":"","affiliations":[],"preferred":false,"id":381486,"contributorType":{"id":1,"text":"Authors"},"rank":9},{"text":"Shuster, R.","contributorId":69725,"corporation":false,"usgs":true,"family":"Shuster","given":"R.","email":"","affiliations":[],"preferred":false,"id":381482,"contributorType":{"id":1,"text":"Authors"},"rank":10},{"text":"Paradis, S.","contributorId":46704,"corporation":false,"usgs":true,"family":"Paradis","given":"S.","email":"","affiliations":[],"preferred":false,"id":381480,"contributorType":{"id":1,"text":"Authors"},"rank":11}]}}
,{"id":70018967,"text":"70018967 - 1996 - Integrated borehole logging methods for wellhead protection applications","interactions":[],"lastModifiedDate":"2019-03-04T20:08:56","indexId":"70018967","displayToPublicDate":"1996-01-01T00:00:00","publicationYear":"1996","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1517,"text":"Engineering Geology","active":true,"publicationSubtype":{"id":10}},"title":"Integrated borehole logging methods for wellhead protection applications","docAbstract":"Modeling of ground water infiltration and movement in the wellhead area is a critical part of an effective wellhead protection program. Such models depend on an accurate description of the aquifer in the wellhead area so that reliable estimates of contaminant travel times can be used in defining a protection area. Geophysical and hydraulic measurements in boreholes provide one of the most important methods for obtaining the data needed to specify wellhead protection measures. Most effective characterization of aquifers in the wellhead vicinity results when a variety of geophysical and hydraulic measurements are made where geophysical measurements can be calibrated in terms of hydraulic variables, and where measurements are made at somewhat different scales of investigation. The application of multiple geophysical measurements to ground water flow in the wellhead area is illustrated by examples in alluvial, fractured sedimentary, and fractured crystalline rock aquifers. Data obtained from a single test well are useful, but cannot indicate how conductive elements in the aquifer are connected to form large-scale flow paths. Geophysical and hydraulic measurements made in arrays of observation boreholes can provide information about such large-scale flow paths, and are especially useful in specifying aquifer properties in wellhead protection studies.","language":"English","publisher":"Elsevier","doi":"10.1016/0013-7952(95)00077-1","issn":"00137952","usgsCitation":"Paillet, F.L., and Pedler, W., 1996, Integrated borehole logging methods for wellhead protection applications: Engineering Geology, v. 42, no. 2-3, p. 155-165, https://doi.org/10.1016/0013-7952(95)00077-1.","productDescription":"11 p.","startPage":"155","endPage":"165","costCenters":[{"id":589,"text":"Toxic Substances Hydrology Program","active":true,"usgs":true}],"links":[{"id":226396,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"42","issue":"2-3","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a3c5de4b0c8380cd62ca7","contributors":{"authors":[{"text":"Paillet, Frederick L.","contributorId":63820,"corporation":false,"usgs":true,"family":"Paillet","given":"Frederick","email":"","middleInitial":"L.","affiliations":[],"preferred":false,"id":381233,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Pedler, W.H.","contributorId":26456,"corporation":false,"usgs":true,"family":"Pedler","given":"W.H.","affiliations":[],"preferred":false,"id":381232,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}}
,{"id":70018929,"text":"70018929 - 1996 - Outburst floods from glacier-dammed lakes: The effect of mode of lake drainage on flood magnitude","interactions":[],"lastModifiedDate":"2019-04-17T08:26:26","indexId":"70018929","displayToPublicDate":"1996-01-01T00:00:00","publicationYear":"1996","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1425,"text":"Earth Surface Processes and Landforms","active":true,"publicationSubtype":{"id":10}},"title":"Outburst floods from glacier-dammed lakes: The effect of mode of lake drainage on flood magnitude","docAbstract":"<p><span>Published accounts of outburst floods from glacier‐dammed lakes show that a significant number of such floods are associated&nbsp;</span><i>not</i><span>&nbsp;with drainage through a tunnel incised into the basal ice—the process generally assumed—but rather with ice‐marginal drainage, mechanical failure of part of the ice dam, or both. Non‐tunnel floods are strongly correlated with formation of an ice dam by a glacier advancing from a tributary drainage into either a main river valley or a pre‐existing body of water (lake or fiord). For a given lake volume, non‐tunnel floods tend to have significantly higher peak discharges than tunnel‐drainage floods. Statistical analysis of data for floods associated with subglacial tunnels yields the following empirical relation between lake volume&nbsp;</span><i>V</i><span>&nbsp;and peak discharge&nbsp;</span><i>Q</i><sub>p</sub><span> : </span><i>Q</i><sub>p</sub><span> = 46</span><i>V</i><sup>0.66</sup><span>&nbsp;(</span><i>r</i><sup>2</sup><span> = 0.70), when&nbsp;</span><i>Q</i><sub>p</sub><span>&nbsp;is expressed in metres per second and&nbsp;</span><i>V</i><span>&nbsp;in millions of cubic metres. This updates the so‐called Clague–Mathews relation. For non‐tunnel floods, the analogous relation is&nbsp;</span><i>Q</i><sub>p</sub><span> = 1100</span><i>V</i><sup>0.44</sup><span>&nbsp;(</span><i>r</i><sup>2</sup><span> = 0.58). The latter relation is close to one found by Costa (1988) for failure of constructed earthen dams. This closeness is probably not coincidental but rather reflects similarities in modes of dam failure and lake drainage.  We develop a simple physical model of the breach‐widening process for non‐tunnel floods, assuming that (1) the rate of breach widening is controlled by melting of the ice, (2) outflow from the lake is regulated by the hydraulic condition of critical flow where water enters the breach, and (3) the effect of lake temperature may be dealt with as done by Clarke (1982). Calculations based on the model simulate quite well outbursts from Lake George, Alaska. Dimensional analysis leads to two approximations of the form&nbsp;</span><i>Q</i><sub>p</sub><span> ∝ </span><i>V</i><sup><i>q</i></sup><i>f</i><span>(</span><i>h</i><sub>i</sub><span>, θ</span><sub>0</sub><span>), where&nbsp;</span><i>q</i><span> = 0.5 to 0.6,&nbsp;</span><i>h</i><sub>i</sub><span>&nbsp;is initial lake depth, θ</span><sub>0</sub><span>&nbsp;is lake temperature, and the form of&nbsp;</span><i>f</i><span> (</span><i>h</i><sub>i</sub><span>, θ</span><sub>0</sub><span>) depends on the relative importance of viscous dissipation and the lake's thermal energy in determining the rate of breach opening. These expressions, along with the regression relations, should prove useful for assessing the probable magnitude of breach‐type outburst floods.</span></p>","language":"English","publisher":"Wiley","doi":"10.1002/(SICI)1096-9837(199608)21:8<701::AID-ESP615>3.0.CO;2-2","issn":"01979337","usgsCitation":"Walder, J.S., and Costa, J.E., 1996, Outburst floods from glacier-dammed lakes: The effect of mode of lake drainage on flood magnitude: Earth Surface Processes and Landforms, v. 21, no. 8, p. 701-723, https://doi.org/10.1002/(SICI)1096-9837(199608)21:8<701::AID-ESP615>3.0.CO;2-2.","productDescription":"23 p.","startPage":"701","endPage":"723","costCenters":[{"id":615,"text":"Volcano Hazards Program","active":true,"usgs":true}],"links":[{"id":226529,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"21","issue":"8","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a71a6e4b0c8380cd766ca","contributors":{"authors":[{"text":"Walder, Joseph S. jswalder@usgs.gov","contributorId":2046,"corporation":false,"usgs":true,"family":"Walder","given":"Joseph","email":"jswalder@usgs.gov","middleInitial":"S.","affiliations":[{"id":617,"text":"Volcano Science Center","active":true,"usgs":true}],"preferred":true,"id":381120,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Costa, John E.","contributorId":105743,"corporation":false,"usgs":true,"family":"Costa","given":"John","email":"","middleInitial":"E.","affiliations":[],"preferred":false,"id":381119,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}}
,{"id":70018819,"text":"70018819 - 1996 - Pesticides in streams draining agricultural and urban areas in Colorado","interactions":[],"lastModifiedDate":"2012-03-12T17:19:28","indexId":"70018819","displayToPublicDate":"1996-01-01T00:00:00","publicationYear":"1996","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1565,"text":"Environmental Science & Technology","onlineIssn":"1520-5851","printIssn":"0013-936X","active":true,"publicationSubtype":{"id":10}},"title":"Pesticides in streams draining agricultural and urban areas in Colorado","docAbstract":"A study was conducted from April 1993 through April 1994 to describe and compare the occurrence and distribution of pesticides in streams in a small agricultural and a small urban area in Colorado. Twenty-five water samples collected at least monthly at the mouths of two tributary streams of the South Plate River were analyzed for 47 pesticides. The results indicate that both agricultural and urban areas are probable sources for pesticides in streams. In the agricultural area, 30 pesticides were detected, and in the urban area, 22 pesticides were detected in one or more samples. Most often, the more frequently detected pesticides in both areas also were some of the more commonly used pesticides. In both areas, pesticide concentrations were higher during the summer (application period) with maximum concentrations generally occurring in storm runoff. The year-round detection of some pesticides in both areas at consistently low concentrations, regardless of season or streamflow volume, could indicate that these compounds persist in the shallow alluvial aquifer year-round.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Environmental Science and Technology","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1021/es950353b","issn":"0013936X","usgsCitation":"Kimbrough, R.A., and Litke, D.W., 1996, Pesticides in streams draining agricultural and urban areas in Colorado: Environmental Science & Technology, v. 30, no. 3, p. 908-916, https://doi.org/10.1021/es950353b.","startPage":"908","endPage":"916","numberOfPages":"9","costCenters":[],"links":[{"id":205866,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1021/es950353b"},{"id":227187,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"30","issue":"3","noUsgsAuthors":false,"publicationDate":"1996-02-26","publicationStatus":"PW","scienceBaseUri":"505a775de4b0c8380cd7849b","contributors":{"authors":[{"text":"Kimbrough, R. A.","contributorId":21150,"corporation":false,"usgs":true,"family":"Kimbrough","given":"R.","email":"","middleInitial":"A.","affiliations":[],"preferred":false,"id":380843,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Litke, D. W.","contributorId":94346,"corporation":false,"usgs":true,"family":"Litke","given":"D.","email":"","middleInitial":"W.","affiliations":[],"preferred":false,"id":380844,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}}
,{"id":49782,"text":"ofr96192 - 1996 - Level II scour analysis for Bridge 32 (BETHTH00380032) on Town Highway 038, crossing Camp Brook, Bethel, Vermont","interactions":[],"lastModifiedDate":"2013-12-06T15:26:45","indexId":"ofr96192","displayToPublicDate":"1994-01-01T00:00:00","publicationYear":"1996","noYear":false,"publicationType":{"id":18,"text":"Report"},"publicationSubtype":{"id":5,"text":"USGS Numbered Series"},"seriesTitle":{"id":330,"text":"Open-File Report","code":"OFR","onlineIssn":"2331-1258","printIssn":"0196-1497","active":true,"publicationSubtype":{"id":5}},"seriesNumber":"96-192","title":"Level II scour analysis for Bridge 32 (BETHTH00380032) on Town Highway 038, crossing Camp Brook, Bethel, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure \nBETHTH00380032 on town highway 38 crossing Camp Brook, Bethel, Vermont (figures \n1–8). A Level II study is a basic engineering analysis of the site, including a quantitative \nanalysis of stream stability and scour (U.S. Department of Transportation, 1993). A Level \nI study is included in Appendix E of this report. A Level I study provides a qualitative \ngeomorphic characterization of the study site. Information on the bridge available from \nVTAOT files were compiled prior to conducting Level I and Level II analyses and can be \nfound in Appendix D.\nThe site is in the Green Mountain physiographic province of central Vermont in the town of \nBethel. The 7.57-mi<sup>2</sup> drainage area is predominantly rural and forested. In the vicinity of \nthe study site, the banks have dense woody vegetation coverage.\nIn the study area, Camp Brook is an incised, mildly sinuous channel with a slope of \napproximately 0.018 ft/ft, an average channel top width of 50 ft and an average channel \ndepth of 4 ft. The predominant channel bed material is gravel and cobble (D<sub>50</sub> is 66.4 mm or \n0.218 ft). The geomorphic assessment at the time of the Level I and Level II site visit on \nSeptember 29, 1994, indicated that the reach was stable.\nThe town highway 38 crossing of Camp Brook is a 32-ft-long, one-lane bridge consisting of \none 29-foot span steel beam with timber deck (Vermont Agency of Transportation, written \ncommun., August 23, 1994). The bridge is supported by vertical, concrete abutments with \nwingwalls. The channel is skewed approximately 5 degrees to the opening while the \nopening-skew-to-roadway is 0 degrees. \nThe scour protection measures at the site include type-1 stone fill (less than 12 inches) at \nboth of the US wingwalls, type-2 stone fill (less than 36 inches) at the US and DS right and \nDS left road approaches. The US right bank is protected by an artificial levee with a mix of \nstone fill. Additional details describing conditions at the site are included in the Level II \nSummary and Appendices D and E.\nScour depths and rock rip-rap sizes were computed using the general guidelines described \nin Hydraulic Engineering Circular 18 (Richardson and others, 1993). Scour depths were \ncalculated assuming an infinite depth of erosive material and a homogeneous particle-size \ndistribution. The scour analysis results are presented in tables 1 and 2 and a graph of the \nscour depths is presented in figure 8.","language":"English","publisher":"U.S. Geological Survey","doi":"10.3133/ofr96192","collaboration":"Prepared in cooperation with Vermont Agency and Transportation and Federal Highway Administration","usgsCitation":"Ivanoff, M.A., 1996, Level II scour analysis for Bridge 32 (BETHTH00380032) on Town Highway 038, crossing Camp Brook, Bethel, Vermont: U.S. Geological Survey Open-File Report 96-192, iv, 28 p., https://doi.org/10.3133/ofr96192.","productDescription":"iv, 28 p.","numberOfPages":"33","costCenters":[],"links":[{"id":178509,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr96192.png"},{"id":279414,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1996/0192/report.pdf"}],"country":"United States","state":"Vermont","city":"Bethel","otherGeospatial":"Camp Brook","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -72.765979,43.790521 ], [ -72.765979,43.910383 ], [ -72.574443,43.910383 ], [ -72.574443,43.790521 ], [ -72.765979,43.790521 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b19e4b07f02db6a7f69","contributors":{"authors":[{"text":"Ivanoff, Michael A.","contributorId":27105,"corporation":false,"usgs":true,"family":"Ivanoff","given":"Michael","email":"","middleInitial":"A.","affiliations":[],"preferred":false,"id":240253,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}}
,{"id":67935,"text":"ha730I - 1996 - Ground Water Atlas of the United States: Segment 8, Montana, North Dakota, South Dakota, Wyoming","interactions":[{"subject":{"id":67935,"text":"ha730I - 1996 - Ground Water Atlas of the United States: Segment 8, Montana, North Dakota, South Dakota, Wyoming","indexId":"ha730I","publicationYear":"1996","noYear":false,"chapter":"I","title":"Ground Water Atlas of the United States: Segment 8, Montana, North Dakota, South Dakota, Wyoming"},"predicate":"IS_PART_OF","object":{"id":68687,"text":"ha730 - 2000 - Ground Water Atlas of the United States","indexId":"ha730","publicationYear":"2000","noYear":false,"title":"Ground Water Atlas of the United States"},"id":1}],"isPartOf":{"id":68687,"text":"ha730 - 2000 - Ground Water Atlas of the United States","indexId":"ha730","publicationYear":"2000","noYear":false,"title":"Ground Water Atlas of the United States"},"lastModifiedDate":"2017-05-30T16:00:40","indexId":"ha730I","displayToPublicDate":"1994-01-01T00:00:00","publicationYear":"1996","noYear":false,"publicationType":{"id":18,"text":"Report"},"publicationSubtype":{"id":5,"text":"USGS Numbered Series"},"seriesTitle":{"id":318,"text":"Hydrologic Atlas","code":"HA","active":false,"publicationSubtype":{"id":5}},"seriesNumber":"730","chapter":"I","title":"Ground Water Atlas of the United States: Segment 8, Montana, North Dakota, South Dakota, Wyoming","docAbstract":"<p>The States of Montana, North Dakota, South Dakota, and Wyoming compose the 392,764-square-mile area of Segment 8, which is in the north-central part of the continental United States. The area varies topographically from the high rugged mountain ranges of the Rocky Mountains in western Montana and Wyoming to the gently undulating surface of the Central Lowland in eastern North Dakota and South Dakota (fig. 1). The Black Hills in southwestern South Dakota and northeastern Wyoming interrupt the uniformity of the intervening Great Plains. Segment 8 spans the Continental Divide, which is the drainage divide that separates streams that generally flow westward from those that generally flow eastward. The area of Segment 8 is drained by the following major rivers or river systems: the Green River drains southward to join the Colorado River, which ultimately discharges to the Gulf of California; the Clark Fork and the Kootenai Rivers drain generally westward by way of the Columbia River to discharge to the Pacific Ocean; the Missouri River system and the North Platte River drain eastward and southeastward to the Mississippi River, which discharges to the Gulf of Mexico; and the Red River of the North and the Souris River drain northward through Lake Winnipeg to ultimately discharge to Hudson Bay in Canada. </p><p>These rivers and their tributaries are an important source of water for public-supply, domestic and commercial, agricultural, and industrial uses. Much of the surface water has long been appropriated for agricultural use, primarily irrigation, and for compliance with downstream water pacts. Reservoirs store some of the surface water for flood control, irrigation, power generation, and recreational purposes. Surface water is not always available when and where it is needed, and ground water is the only other source of supply. Ground water is obtained primarily from wells completed in unconsolidated-deposit aquifers that consist mostly of sand and gravel, and from wells completed in semi-consolidated- and consolidated-rock aquifers, chiefly sandstone and limestone. Some wells withdraw water from volcanic rocks, igneous and metamorphic rocks, or fractured fine-grained sedimentary rocks, such as shale; however, wells completed in these types of rocks generally yield only small volumes of water. </p><p>Most wells in the four-State area of Segment 8 are on privately owned land (fig. 2). Agriculture, primarily irrigation, is one of the largest uses of ground water. The irrigation generally is on lowlands close to streams (fig. 3). Lowlands within a few miles of major streams usually are irrigated with surface water that is diverted by gravity flow from the main stream or a reservoir and transported through a canal system. Surface water also is pumped to irrigate land that gravity systems cannot supply. In addition, ground water is pumped from large-capacity wells to supplement surface water during times of drought or during seasons of the year when surface water is in short supply. Ground water is the only source of water for irrigation in much of the segment. The thickness and permeability of aquifers in the area of Segment 8 vary considerably, as do yields of wells completed in the aquifers. Ground-water levels and artesian pressures (hydraulic head) have declined significantly in some places as a result of excessive withdrawals by wells. State governments have taken steps to control the declines by enacting programs that either limit the number of additional wells that can be completed in a particular aquifer or prevent further ground-water development altogether. </p><p>The demand for water is directly related to the distribution of people. In 1990, Montana had a population of 799,065; North Dakota, 638,800; South Dakota, 696,004; and Wyoming, 453,588. The more densely populated areas are on lowlands near major streams. Many of the mountain, desert, and upland areas lack major population centers, particularly in Montana and Wyoming, where use of much of the land is controlled by the Federal Government and withdrawal of ground water is restricted.</p><p>Average annual precipitation (1951-80) in Segment 8 ranges from less than 8 inches in parts of Montana and Wyoming to more than 40 inches in some of the mountainous areas (fig. 4). Most storms move eastward through Segment 8 and are particularly common during the winter months. Moisture that evaporates from the Pacific Ocean is absorbed by eastward- moving air. As the moisture-laden air masses move eastward, they rise and cool as they encounter mountain ranges and lose some of their moisture to condensation. Consequently, the western sides of mountain ranges receive the most precipitation, much of it as snow during the winter months. In contrast, the eastern sides of some of the higher mountain ranges are in rain shadows and receive little precipitation. East of the Continental Divide, precipitation that falls during many summer storms results from northward-moving, moisture-laden air masses from the Gulf of Mexico. These air masses move northward when the polar front recedes; accordingly, a major part of the annual precipitation falls on the plains during the growing season. Average annual precipitation minus the total of average annual runoff plus evapotranspiration (the combination of evaporation and transpiration by plants) is the amount of water potentially available for recharge to the aquifers.</p><p>Average annual runoff (1951-80) in the area of Segment 8 varies greatly, and the distribution of runoff (fig. 5) generally parallels that of precipitation. In arid and semiarid areas of the segment, most precipitation replenishes soil moisture, evaporates, or is transpired by vegetation, and only a small part of the precipitation is left to maintain streamflow or recharge aquifers. In wetter areas of the segment, much of the precipitation runs off the land surface directly to perennial streams. Because a smaller percentage of precipitation in wet areas usually is lost to evapotranspiration than in dry areas, more water is, therefore, available to recharge aquifers where more precipitation falls. Precipitation that falls as snow generally does not become runoff until spring thaws begin. Runoff is affected in some areas by reservoirs that have been constructed on major streams to mitigate flooding and to store water for irrigation, electrical power generation, and recreation. Water stored in reservoirs during times when runoff is great is subsequently released during drier periods to maintain downstream flow.</p>","largerWorkTitle":"Ground Water Atlas of the United States","language":"English","publisher":"U.S. Geological Survey","doi":"10.3133/ha730I","isbn":"0607859741","usgsCitation":"Whitehead, R., 1996, Ground Water Atlas of the United States: Segment 8, Montana, North Dakota, South Dakota, Wyoming: U.S. Geological Survey Hydrologic Atlas 730, 24 p., https://doi.org/10.3133/ha730I.","productDescription":"24 p.","startPage":"I1","endPage":"I24","costCenters":[{"id":595,"text":"U.S. Geological Survey","active":false,"usgs":true}],"links":[{"id":11486,"rank":100,"type":{"id":15,"text":"Index Page"},"url":"https://pubs.usgs.gov/ha/ha730/ch_i/index.html","linkFileType":{"id":5,"text":"html"}},{"id":115245,"rank":300,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/ha/730i/report.pdf","text":"Report","size":"54.91 MB","linkFileType":{"id":1,"text":"pdf"},"description":"Report"},{"id":188155,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/ha/730i/report-thumb.jpg"}],"country":"United States","state":"Montana, North Dakota, South Dakota, Wyoming","geographicExtents":"{\"type\":\"FeatureCollection\",\"features\":[{\"type\":\"Feature\",\"geometry\":{\"type\":\"Polygon\",\"coordinates\":[[[-111.048974,44.474072],[-111.131379,44.499925],[-111.143557,44.535732],[-111.175747,44.552219],[-111.189617,44.571062],[-111.23018,44.587025],[-111.224161,44.623402],[-111.25268,44.651092],[-111.276956,44.655626],[-111.26875,44.668279],[-111.29626,44.702271],[-111.323669,44.724474],[-111.355768,44.727602],[-111.385005,44.755128],[-111.397805,44.746738],[-111.398575,44.723343],[-111.414271,44.710741],[-111.438793,44.720546],[-111.490228,44.700221],[-111.468833,44.679335],[-111.473178,44.665479],[-111.525764,44.604883],[-111.519126,44.582916],[-111.467736,44.544521],[-111.500792,44.540062],[-111.585763,44.562843],[-111.614405,44.548991],[-111.704218,44.560205],[-111.715474,44.543543],[-111.746401,44.540766],[-111.821488,44.509286],[-111.870504,44.564033],[-111.947941,44.556776],[-111.980833,44.536682],[-112.032707,44.546642],[-112.036943,44.530323],[-112.069011,44.537104],[-112.101564,44.520847],[-112.136454,44.539911],[-112.164597,44.541666],[-112.179703,44.533021],[-112.221698,44.543519],[-112.230117,44.562759],[-112.242785,44.568091],[-112.286187,44.568472],[-112.312899,44.553536],[-112.315008,44.5419],[-112.35421,44.535638],[-112.358926,44.48628],[-112.387389,44.448058],[-112.473207,44.480027],[-112.50031,44.463051],[-112.541989,44.483971],[-112.584197,44.481368],[-112.601863,44.491015],[-112.660696,44.485756],[-112.71911,44.504344],[-112.781294,44.484888],[-112.828191,44.442472],[-112.836034,44.422653],[-112.812608,44.392275],[-112.81324,44.378103],[-112.844859,44.358221],[-112.855395,44.359975],[-112.881769,44.380315],[-112.886041,44.395874],[-112.951146,44.416699],[-113.003544,44.450814],[-113.020917,44.493827],[-113.019777,44.528505],[-113.04282,44.546757],[-113.042363,44.565237],[-113.083819,44.60222],[-113.049349,44.62938],[-113.068306,44.656374],[-113.06776,44.679474],[-113.098064,44.697477],[-113.102138,44.729027],[-113.134824,44.752763],[-113.131453,44.772837],[-113.163806,44.778921],[-113.19436,44.802151],[-113.247166,44.82295],[-113.341704,44.784853],[-113.354034,44.791745],[-113.346692,44.798898],[-113.356062,44.819798],[-113.377153,44.834858],[-113.422376,44.842595],[-113.455071,44.865424],[-113.498745,44.942314],[-113.443782,44.95989],[-113.446884,44.998545],[-113.437726,45.006967],[-113.45197,45.059247],[-113.485278,45.063519],[-113.520134,45.093033],[-113.506638,45.107288],[-113.513342,45.115225],[-113.554744,45.112901],[-113.57467,45.128411],[-113.599506,45.191114],[-113.636889,45.212983],[-113.657027,45.241436],[-113.684946,45.253706],[-113.689359,45.28355],[-113.735601,45.325265],[-113.734402,45.392353],[-113.765203,45.410601],[-113.763368,45.427732],[-113.783272,45.451839],[-113.759986,45.480735],[-113.766022,45.520621],[-113.834555,45.520729],[-113.819868,45.566326],[-113.804796,45.580358],[-113.806729,45.602146],[-113.861404,45.62366],[-113.886006,45.61702],[-113.904691,45.622007],[-113.898883,45.644167],[-113.919752,45.658536],[-113.93422,45.682232],[-113.986656,45.704564],[-114.015633,45.696127],[-114.018731,45.648616],[-114.033456,45.648629],[-114.067619,45.627706],[-114.086584,45.59118],[-114.122322,45.58426],[-114.135249,45.557465],[-114.180043,45.551432],[-114.192802,45.536596],[-114.248121,45.545877],[-114.247824,45.524283],[-114.270717,45.486116],[-114.333218,45.459316],[-114.360719,45.474116],[-114.36562,45.490416],[-114.415804,45.509753],[-114.456764,45.543983],[-114.460542,45.561283],[-114.498176,45.555473],[-114.526075,45.570771],[-114.549508,45.56059],[-114.559038,45.565706],[-114.558253,45.585104],[-114.538132,45.606834],[-114.563652,45.637412],[-114.507645,45.658949],[-114.495421,45.703321],[-114.504869,45.722176],[-114.535634,45.739095],[-114.566172,45.773864],[-114.512973,45.828825],[-114.509303,45.845531],[-114.44868,45.858891],[-114.409477,45.85164],[-114.388243,45.88234],[-114.395059,45.901458],[-114.431159,45.935737],[-114.404708,45.9559],[-114.403712,45.967049],[-114.425843,45.984984],[-114.470965,45.995742],[-114.480241,46.030325],[-114.493418,46.03717],[-114.468529,46.062484],[-114.460049,46.097104],[-114.474415,46.112515],[-114.5213,46.125287],[-114.527096,46.146218],[-114.514706,46.167726],[-114.478333,46.160876],[-114.445928,46.173933],[-114.449819,46.237119],[-114.468254,46.248796],[-114.470479,46.26732],[-114.427309,46.283624],[-114.433478,46.305502],[-114.413758,46.335945],[-114.410682,46.360673],[-114.422458,46.387097],[-114.384756,46.411784],[-114.376413,46.442983],[-114.383051,46.466402],[-114.400068,46.47718],[-114.403019,46.498675],[-114.35874,46.505306],[-114.342072,46.519679],[-114.349208,46.529514],[-114.322519,46.611066],[-114.32456,46.653579],[-114.360709,46.669059],[-114.424424,46.660648],[-114.453239,46.649266],[-114.466902,46.631695],[-114.547321,46.644485],[-114.593292,46.632848],[-114.615036,46.639733],[-114.614716,46.655256],[-114.635713,46.659375],[-114.642713,46.673145],[-114.623198,46.691511],[-114.620859,46.707415],[-114.649388,46.73289],[-114.696656,46.740572],[-114.710425,46.717704],[-114.76689,46.696901],[-114.787065,46.711255],[-114.76718,46.738828],[-114.765106,46.758153],[-114.79004,46.778729],[-114.829117,46.782503],[-114.861376,46.81196],[-114.888146,46.808573],[-114.920459,46.827697],[-114.928615,46.854815],[-114.947413,46.859324],[-114.931608,46.876799],[-114.936805,46.897378],[-114.929997,46.919625],[-114.960597,46.93001],[-115.00091,46.967703],[-115.028386,46.975659],[-115.047857,46.969533],[-115.087806,47.045519],[-115.120917,47.061237],[-115.140375,47.093013],[-115.170436,47.106265],[-115.200547,47.139154],[-115.243707,47.150347],[-115.261885,47.181742],[-115.300504,47.188139],[-115.294785,47.220914],[-115.317124,47.233305],[-115.326903,47.255912],[-115.410685,47.264228],[-115.428359,47.278722],[-115.457077,47.277794],[-115.51186,47.295219],[-115.548658,47.332213],[-115.551079,47.349856],[-115.578619,47.367007],[-115.617247,47.382521],[-115.639186,47.378605],[-115.657681,47.400651],[-115.728801,47.428925],[-115.728801,47.445159],[-115.718247,47.45316],[-115.663867,47.456936],[-115.653044,47.476035],[-115.686704,47.485596],[-115.708748,47.51264],[-115.71034,47.52951],[-115.747263,47.543197],[-115.734674,47.567401],[-115.706473,47.577299],[-115.689404,47.595402],[-115.694284,47.62346],[-115.72993,47.642442],[-115.73627,47.654762],[-115.72377,47.696671],[-115.752349,47.716743],[-115.77177,47.717412],[-115.783504,47.729305],[-115.780441,47.743447],[-115.797299,47.75752],[-115.831755,47.755785],[-115.847487,47.785227],[-115.852291,47.827991],[-115.881522,47.849672],[-115.906409,47.846261],[-115.969076,47.914256],[-115.993678,47.926183],[-116.030751,47.973349],[-116.048421,47.97682],[-116.049193,49.000912],[-97.229039,49.000687],[-97.239209,48.968684],[-97.210541,48.90439],[-97.198857,48.899831],[-97.197982,48.880341],[-97.175618,48.853105],[-97.180028,48.81845],[-97.157093,48.790024],[-97.136083,48.727763],[-97.098697,48.687534],[-97.108276,48.634396],[-97.125887,48.626975],[-97.138246,48.609301],[-97.16309,48.543964],[-97.148874,48.534282],[-97.139276,48.48631],[-97.144116,48.469212],[-97.134229,48.461178],[-97.142066,48.42045],[-97.135012,48.406735],[-97.145201,48.395566],[-97.147748,48.359905],[-97.131722,48.341123],[-97.127236,48.291827],[-97.117726,48.283488],[-97.141254,48.234668],[-97.134372,48.210434],[-97.146233,48.186054],[-97.142279,48.148056],[-97.123135,48.109497],[-97.10395,48.096184],[-97.104697,48.073094],[-97.072257,48.048068],[-97.071911,48.021395],[-97.054945,47.992924],[-97.061854,47.96448],[-97.051054,47.943379],[-97.017754,47.919778],[-97.023156,47.874978],[-97.005356,47.870177],[-96.992963,47.837911],[-96.981725,47.830421],[-96.976176,47.801544],[-96.939179,47.768397],[-96.910144,47.691235],[-96.887126,47.666369],[-96.879496,47.620576],[-96.855421,47.60875],[-96.852826,47.597891],[-96.855092,47.53731],[-96.866363,47.525944],[-96.851653,47.497098],[-96.862924,47.422309],[-96.841767,47.39246],[-96.852417,47.366241],[-96.835845,47.335914],[-96.841003,47.311558],[-96.832884,47.307069],[-96.843922,47.29302],[-96.8432,47.270486],[-96.833589,47.238037],[-96.8368,47.195028],[-96.822091,47.165036],[-96.831547,47.142017],[-96.817984,47.106007],[-96.824097,47.070666],[-96.818557,47.035516],[-96.833504,47.01011],[-96.822043,46.971091],[-96.802749,46.965933],[-96.791621,46.931213],[-96.785126,46.925769],[-96.763257,46.935063],[-96.759241,46.918223],[-96.776558,46.895663],[-96.769758,46.877563],[-96.781358,46.879363],[-96.779347,46.843672],[-96.799336,46.815436],[-96.779899,46.722915],[-96.798823,46.658071],[-96.772457,46.601491],[-96.746442,46.574078],[-96.737798,46.489785],[-96.714861,46.459132],[-96.718074,46.438255],[-96.682008,46.40784],[-96.667189,46.375458],[-96.646532,46.36251],[-96.645959,46.353532],[-96.631586,46.353752],[-96.601048,46.331139],[-96.599729,46.262123],[-96.592375,46.246076],[-96.59755,46.227733],[-96.584899,46.204383],[-96.580408,46.151234],[-96.557952,46.102442],[-96.556907,46.06483],[-96.57794,46.026874],[-96.561334,45.945655],[-96.583085,45.820024],[-96.629426,45.784211],[-96.662595,45.738682],[-96.832659,45.651716],[-96.856657,45.609041],[-96.76528,45.521414],[-96.732739,45.458737],[-96.692541,45.417338],[-96.617726,45.408092],[-96.521787,45.375645],[-96.489065,45.357071],[-96.454094,45.301546],[-96.453049,43.500415],[-96.598928,43.500457],[-96.580997,43.481384],[-96.60286,43.450907],[-96.594254,43.434153],[-96.570224,43.428601],[-96.573579,43.419228],[-96.537116,43.395063],[-96.525453,43.396317],[-96.521572,43.38564],[-96.533101,43.328587],[-96.530392,43.300034],[-96.553087,43.29286],[-96.580346,43.298204],[-96.577588,43.2788],[-96.58522,43.268878],[-96.553217,43.259141],[-96.55203,43.251117],[-96.571194,43.238961],[-96.568505,43.231554],[-96.512458,43.218556],[-96.476697,43.222014],[-96.466537,43.150281],[-96.450361,43.142237],[-96.436589,43.120842],[-96.460516,43.09494],[-96.458201,43.067554],[-96.518431,43.042068],[-96.49167,43.009707],[-96.516724,42.981458],[-96.500308,42.959391],[-96.516419,42.935438],[-96.541098,42.924496],[-96.538555,42.904605],[-96.526357,42.891852],[-96.540116,42.889678],[-96.537851,42.878475],[-96.549659,42.870281],[-96.544321,42.851282],[-96.552092,42.836057],[-96.558584,42.839487],[-96.563058,42.831051],[-96.579772,42.838093],[-96.577813,42.828719],[-96.595664,42.810426],[-96.595283,42.792982],[-96.632142,42.770863],[-96.632212,42.761512],[-96.619494,42.754792],[-96.638621,42.734921],[-96.626317,42.725951],[-96.629777,42.708852],[-96.575299,42.682665],[-96.578148,42.672765],[-96.569194,42.675509],[-96.556244,42.664396],[-96.559962,42.658543],[-96.537877,42.655431],[-96.516338,42.630435],[-96.529894,42.610432],[-96.509468,42.61273],[-96.49545,42.579474],[-96.486606,42.576062],[-96.497186,42.571464],[-96.498439,42.560876],[-96.476952,42.556079],[-96.490089,42.512441],[-96.477454,42.509589],[-96.474409,42.491895],[-96.443408,42.489495],[-96.475565,42.480036],[-96.501321,42.482749],[-96.525142,42.510234],[-96.548791,42.520547],[-96.611489,42.506088],[-96.625958,42.513576],[-96.643589,42.557604],[-96.681369,42.574486],[-96.706416,42.599413],[-96.711546,42.614758],[-96.687788,42.645992],[-96.691269,42.6562],[-96.728024,42.666882],[-96.793238,42.666024],[-96.806219,42.704149],[-96.906797,42.7338],[-96.961576,42.719841],[-96.96888,42.754278],[-96.982197,42.760554],[-97.131331,42.771929],[-97.150763,42.795566],[-97.210126,42.809296],[-97.217411,42.843519],[-97.237868,42.853139],[-97.289859,42.855499],[-97.308853,42.867307],[-97.359569,42.854816],[-97.404442,42.86775],[-97.439114,42.84711],[-97.504847,42.858477],[-97.561928,42.847552],[-97.611811,42.858367],[-97.686506,42.842435],[-97.774456,42.849774],[-97.84527,42.867734],[-97.875345,42.858724],[-97.888562,42.817251],[-97.932962,42.778203],[-97.950147,42.769619],[-98.035034,42.764205],[-98.059838,42.772772],[-98.146933,42.839823],[-98.189765,42.841628],[-98.25181,42.872824],[-98.325864,42.8865],[-98.342408,42.900847],[-98.42074,42.931924],[-98.444145,42.929242],[-98.467356,42.947556],[-98.49855,42.99856],[-104.053127,43.000585],[-104.053249,41.001406],[-111.046723,40.997959],[-111.048974,44.474072]]]},\"properties\":{\"name\":\"Montana\",\"nation\":\"USA  \"}}]}","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4ab0e4b07f02db66dd82","contributors":{"authors":[{"text":"Whitehead, R.L.","contributorId":34891,"corporation":false,"usgs":true,"family":"Whitehead","given":"R.L.","email":"","affiliations":[],"preferred":false,"id":277351,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}}
,{"id":49810,"text":"ofr96312 - 1996 - Level II scour analysis for Bridge 25 (CRAFTH00220025) on Town Highway 22, crossing the Wild Branch Lamoille River, Craftsbury, Vermont","interactions":[],"lastModifiedDate":"2013-12-10T15:56:24","indexId":"ofr96312","displayToPublicDate":"1994-01-01T00:00:00","publicationYear":"1996","noYear":false,"publicationType":{"id":18,"text":"Report"},"publicationSubtype":{"id":5,"text":"USGS Numbered Series"},"seriesTitle":{"id":330,"text":"Open-File Report","code":"OFR","onlineIssn":"2331-1258","printIssn":"0196-1497","active":true,"publicationSubtype":{"id":5}},"seriesNumber":"96-312","title":"Level II scour analysis for Bridge 25 (CRAFTH00220025) on Town Highway 22, crossing the Wild Branch Lamoille River, Craftsbury, Vermont","docAbstract":"<p>This report provides the results of a detailed Level II analysis of scour potential at structure \nCRAFTH00220025 on town highway 22 crossing the Wild Branch Lamoille River, \nCraftsbury, Vermont (figures 1–8). A Level II study is a basic engineering analysis of the \nsite, including a quantitative analysis of stream stability and scour (U.S. Department of \nTransportation, 1993). A Level I study is included in Appendix E of this report. A Level I \nstudy provides a qualitative geomorphic characterization of the study site. Information on \nthe bridge, gleaned from Vermont Agency of Transportation (VTAOT) files, was compiled \nprior to conducting Level I and Level II analyses and can be found in Appendix D.</p>\n<br/>\n<p>The site is in the New England Upland physiographic province of north-central Vermont in \nthe town of Bridgewater. The 9.52-mi<sup>2</sup>\n drainage area is in a predominantly rural basin with \nsome pasture on the valley bottom. In the vicinity of the study site, the banks have less than \n25% woody vegetation coverage.</p>\n<br/>\n<p>In the study area, the Wild Branch Lamoille River has a meandering channel in a low relief \nvalley setting with wide flood plains and a slope of approximately 0.0044 ft/ft, an average \nchannel top width of 35 ft and an average channel depth of 4 ft. The predominant channel \nbed material is gravel (D<sub>50</sub> is 38.6 mm or 0.127 ft). The geomorphic assessment at the time \nof the Level I and Level II site visit on November 9, 1994, indicated that the reach was \nlaterally unstable.</p>\n<br/>\n<p>The town highway 22 crossing of the Wild Branch Lamoille Riveris a 31-ft-long, two-lane\nbridge consisting of one 29-foot span concrete slab superstructure (Vermont Agency of \nTransportation, written commun., August 4, 1994). The bridge is supported by vertical, \nconcrete abutments with wingwalls. The channel is skewed approximately 20 degrees to the \nopening and the opening-skew-to-roadway is 20 degrees.</p>\n<br/>\n<p>A scour hole 1.5 ft deeper than the mean thalweg depth was observed along the left bank \nside of the channel upstream during the Level I assessment. There are tall, steep stone fill \nembankments (artificial levees) that make up both banks between 50 feet upstream and the \nupstream face of the bridge, which straighten and constrict the channel. Type-2 stone fill \n(less than 36 inches diameter) is reported on the banks upstream, the upstream wingwalls,\nthe abutments, the downstream left wingwall, and the downstream left bank. Additional \ndetails describing conditions at the site are included in the Level II Summary and \nAppendices D and E.</p>\n<br/>\n<p>Scour depths and rock rip-rap sizes were computed using the general guidelines described \nin Hydraulic Engineering Circular 18 (Richardson and others, 1995). Total scour at a \nhighway crossing is comprised of three components: 1) long-term streambed degradation; \n2) contraction scour (due to accelerated flow caused by a reduction in flow area at a bridge) \nand; 3) local scour (caused by accelerated flow around piers and abutments). Total scour is \nthe sum of the three components. Equations are available to compute depths for contraction \nand local scour and a summary of the results of these computations follows.</p>\n<br/>\n<p>Contraction scour for all modelled flows ranged from 0.0 to 2.5 ft. The worst-case \ncontraction scour occurred at the incipient overtopping discharge, which was less than the \n100-year discharge. Abutment scour ranged from 4.7 to 8.6 ft. The worst-case abutment \nscour also occurred at the incipient overtopping discharge. Additional information on scour \ndepths and depths to armoring are included in the section titled “Scour Results”. Scoured-streambed elevations, based on the calculated scour depths, are presented in tables 1 and 2. \nA cross-section of the scour computed at the bridge is presented in figure 8. Scour depths \nwere calculated assuming an infinite depth of erosive material and a homogeneous particle-size distribution. </p>\n<br/>\n<p>It is generally accepted that the Froehlich equation (abutment scour) gives “excessively \nconservative estimates of scour depths” (Richardson and others, 1995, p. 47). Many factors, \nincluding historical performance during flood events, the geomorphic assessment, scour \nprotection, and the results of the hydraulic analyses, must be considered to properly assess \nthe validity of abutment scour results. Therefore, scour depths adopted by VTAOT may \ndiffer from the computed values documented herein, based on the consideration of \nadditional contributing factors and experienced engineering judgement.</p>","language":"English","publisher":"U.S. Geological Survey","publisherLocation":"Pembroke, NH","doi":"10.3133/ofr96312","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Boehmler, E.M., and Ivanoff, M.A., 1996, Level II scour analysis for Bridge 25 (CRAFTH00220025) on Town Highway 22, crossing the Wild Branch Lamoille River, Craftsbury, Vermont: U.S. Geological Survey Open-File Report 96-312, iv, 50 p., https://doi.org/10.3133/ofr96312.","productDescription":"iv, 50 p.","numberOfPages":"55","costCenters":[],"links":[{"id":179409,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr96312.GIF"},{"id":279364,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1996/0312/report.pdf"}],"scale":"24000","country":"United States","state":"Vermont","city":"Craftsbury","otherGeospatial":"Wild Branch Lamoille River","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -72.75,43.5 ], [ -72.75,43.625 ], [ -72.625,43.625 ], [ -72.625,43.5 ], [ -72.75,43.5 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b1ae4b07f02db6a808e","contributors":{"authors":[{"text":"Boehmler, Erick M.","contributorId":96303,"corporation":false,"usgs":true,"family":"Boehmler","given":"Erick","email":"","middleInitial":"M.","affiliations":[],"preferred":false,"id":240300,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Ivanoff, Michael A.","contributorId":27105,"corporation":false,"usgs":true,"family":"Ivanoff","given":"Michael","email":"","middleInitial":"A.","affiliations":[],"preferred":false,"id":240299,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}}
,{"id":49816,"text":"ofr96388 - 1996 - Level II scour analysis for Bridge 25 (BRNAVT00120025) on State Highway 12, crossing Locust Creek, Barnard, Vermont","interactions":[],"lastModifiedDate":"2013-12-10T13:29:17","indexId":"ofr96388","displayToPublicDate":"1994-01-01T00:00:00","publicationYear":"1996","noYear":false,"publicationType":{"id":18,"text":"Report"},"publicationSubtype":{"id":5,"text":"USGS Numbered Series"},"seriesTitle":{"id":330,"text":"Open-File Report","code":"OFR","onlineIssn":"2331-1258","printIssn":"0196-1497","active":true,"publicationSubtype":{"id":5}},"seriesNumber":"96-388","title":"Level II scour analysis for Bridge 25 (BRNAVT00120025) on State Highway 12, crossing Locust Creek, Barnard, Vermont","docAbstract":"<p>This report provides the results of a detailed Level II analysis of scour potential at structure \nBRNAVT00120025 on State Highway 12 crossing Locust Creek, Barnard, Vermont \n(figures 1–8). A Level II study is a basic engineering analysis of the site, including a \nquantitative analysis of stream stability and scour (U.S. Department of Transportation, \n1993). A Level I study is included in Appendix E of this report. A Level I study provides \na qualitative geomorphic characterization of the study site. Information on the bridge \navailable from VTAOT files was compiled prior to conducting Level I and Level II \nanalyses and can be found in Appendix D.</p>\n<br/>\n<p>The site is in the Green Mountain physiographic division of central Vermont in the town of \nBarnard. The 11.6-mi<sup>2</sup>\n drainage area is in a predominantly rural and forested basin. In the \nvicinity of the study site, the banks have woody vegetation coverage.</p>\n<br/>\n<p>In the study area, Locust Creek has a sinuous channel with a slope of approximately 0.023 \nft/ft, an average channel top width of 49 ft and an average channel depth of 4 ft. The \npredominant channel bed material is cobble (D<sub>50</sub> is 109 mm or 0.359 ft). The geomorphic \nassessment at the time of the Level I and Level II site visits on September 23 and December \n16, 1994, indicated that the reach was stable.</p>\n<br/>\n<p>The State Highway 12 crossing of Locust Creek is a 41-ft-long, two-lane bridge consisting \nof one 39-foot concrete slab type superstructure (Vermont Agency of Transportation, \nwritten communication, August 23, 1994). The bridge is supported by vertical, concrete\nabutments with wingwalls. The channel is skewed approximately 30 degrees to the opening \nwhile the opening-skew-to-roadway is 45 degrees.</p>\n<br/>\n<p>A scour hole 1 ft deeper than the mean thalweg depth was observed along a bedrock outcrop \nnear the upstream left wingwall during the Level I assessment. The scour protection \nmeasures in place at the site are type-1 stone fill (less than 12 inches diameter) along the left \nabutment, upstream right bank, and both downstream banks; type-2 stone fill (less than 36 \ninches diameter) at the downstream side of the right road approach and upstream left bank; \ntype-3 stone fill (less than 48 inches diameter) at the upstream end of the upstream right \nwingwall and downstream end of downstream left wingwall; type-5 (wall/ artificial levee) \nat the upstream end of the upstream left wingwall. Additional details describing conditions \nat the site are included in the Level II Summary and Appendices D and E.</p>\n<br/>\n<p>Scour depths and rock rip-rap sizes were computed using the general guidelines described \nin Hydraulic Engineering Circular 18 (Richardson and others, 1993). Total scour at a \nhighway crossing is comprised of three components: 1) long-term streambed degradation; \n2) contraction scour (due to accelerated flow caused by a reduction in flow area at a bridge) \nand; 3) local scour (caused by accelerated flow around piers and abutments). Total scour is \nthe sum of the three components. Equations are available to compute depths for contraction \nand local scour and a summary of the results of these computations follows.</p>\n<br/>\n<p>Contraction scour for all modelled flows ranged from 0.0 to 1.4 ft. The worst-case \ncontraction scour occurred at the 100-year discharge. Abutment scour ranged from 8.5 to \n20.9 ft. The worst-case abutment scour occurred at the 500-year discharge. Additional \ninformation on scour depths and depths to armoring are included in the section titled “Scour \nResults”. Scoured-streambed elevations, based on the calculated scour depths, are presented \nin tables 1 and 2. A cross-section of the scour computed at the bridge is presented in figure \n8. Scour depths were calculated assuming an infinite depth of erosive material and a \nhomogeneous particle-size distribution. </p>\n<br/>\n<p>It is generally accepted that the Froehlich equation (abutment scour) gives “excessively \nconservative estimates of scour depths” (Richardson and others, 1993, p. 48). Usually, \ncomputed scour depths are evaluated in combination with other information including (but \nnot limited to) historical performance during flood events, the geomorphic stability \nassessment, existing scour protection measures, and the results of the hydraulic analyses. \nTherefore, scour depths adopted by VTAOT may differ from the computed values \ndocumented herein.</p>","language":"English","publisher":"U.S. Geological Survey","publisherLocation":"Pembroke, NH","doi":"10.3133/ofr96388","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Ivanoff, M.A., and Weber, M.A., 1996, Level II scour analysis for Bridge 25 (BRNAVT00120025) on State Highway 12, crossing Locust Creek, Barnard, Vermont: U.S. Geological Survey Open-File Report 96-388, iv, 28 p., https://doi.org/10.3133/ofr96388.","productDescription":"iv, 28 p.","numberOfPages":"33","costCenters":[],"links":[{"id":178615,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr96388.GIF"},{"id":279352,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1996/0388/report.pdf"}],"scale":"24000","country":"United States","state":"Vermont","city":"Barnard","otherGeospatial":"Locust Creek","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -72.75,43.75 ], [ -72.75,43.875 ], [ -72.625,43.875 ], [ -72.625,43.75 ], [ -72.75,43.75 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b1ae4b07f02db6a8084","contributors":{"authors":[{"text":"Ivanoff, Michael A.","contributorId":27105,"corporation":false,"usgs":true,"family":"Ivanoff","given":"Michael","email":"","middleInitial":"A.","affiliations":[],"preferred":false,"id":240311,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Weber, Matthew A.","contributorId":41483,"corporation":false,"usgs":true,"family":"Weber","given":"Matthew","email":"","middleInitial":"A.","affiliations":[],"preferred":false,"id":240312,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}}
]}