{"pageNumber":"3373","pageRowStart":"84300","pageSize":"25","recordCount":184914,"records":[{"id":70021868,"text":"70021868 - 1999 - Evaluation of bursal depth as an indicator of age class of harlequin ducks","interactions":[],"lastModifiedDate":"2018-05-13T12:03:32","indexId":"70021868","displayToPublicDate":"1999-01-01T00:00:00","publicationYear":"1999","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2284,"text":"Journal of Field Ornithology","active":true,"publicationSubtype":{"id":10}},"title":"Evaluation of bursal depth as an indicator of age class of harlequin ducks","docAbstract":"We contrasted the estimated age class of recaptured Harlequin Ducks (Histrionicus histrionicus) (n = 255) based on bursal depth with expected age class based on bursal depth at first capture and time since first capture. Although neither estimated nor expected ages can be assumed to be correct, rates of discrepancies between the two for within-year recaptures indicate sampling error, while between-year recaptures test assumptions about rates of bursal involution. Within-year, between-year, and overall discrepancy rates were 10%, 24%, and 18%, respectively. Most (86%) between-year discrepancies occurred for birds expected to be after-third-year (ATY) but estimated to be third-year (TY). Of these ATY-TY discrepancies, 22 of 25 (88%) birds had bursal depths of 2 or 3 mm. Further, five of six between-year recaptures that were known to be ATY but estimated to be TY had 2 mm bursas. Reclassifying birds with 2 or 3 mm bursas as ATY resulted in reduction in between-year (24% to 10%) and overall (18% to 11%) discrepancy rates. We conclude that age determination of Harlequin Ducks based on bursal depth, particularly using our modified criteria, is a relatively consistent and reliable technique.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Journal of Field Ornithology","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","issn":"02738570","usgsCitation":"Mather, D., and Esler, D., 1999, Evaluation of bursal depth as an indicator of age class of harlequin ducks: Journal of Field Ornithology, v. 70, no. 2, p. 200-205.","startPage":"200","endPage":"205","numberOfPages":"6","costCenters":[],"links":[{"id":229412,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"70","issue":"2","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a0c61e4b0c8380cd52b0c","contributors":{"authors":[{"text":"Mather, D.D.","contributorId":67680,"corporation":false,"usgs":true,"family":"Mather","given":"D.D.","email":"","affiliations":[],"preferred":false,"id":391494,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Esler, Daniel 0000-0001-5501-4555 desler@usgs.gov","orcid":"https://orcid.org/0000-0001-5501-4555","contributorId":5465,"corporation":false,"usgs":true,"family":"Esler","given":"Daniel","email":"desler@usgs.gov","affiliations":[{"id":12437,"text":"Simon Fraser University, Centre for Wildlife Ecology","active":true,"usgs":false},{"id":116,"text":"Alaska Science Center Biology MFEB","active":true,"usgs":true},{"id":114,"text":"Alaska Science Center","active":true,"usgs":true}],"preferred":true,"id":391493,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}}
,{"id":70021804,"text":"70021804 - 1999 - Voluminous volcanism on early mars revealed in valles marineris","interactions":[],"lastModifiedDate":"2012-03-12T17:19:37","indexId":"70021804","displayToPublicDate":"1999-01-01T00:00:00","publicationYear":"1999","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2840,"text":"Nature","active":true,"publicationSubtype":{"id":10}},"title":"Voluminous volcanism on early mars revealed in valles marineris","docAbstract":"The relative rates and importance of impact cratering, volcanism, erosion, and the deposition of sediments to the early geological history of Mars are poorly known. That history is recorded in the upper crust of the planet, which is best exposed along the 4,000km-long canyon system called Valles Marineris. Previous studies of the stratigraphy of this region have assumed that it consists of megabreccia and fractured bedrock resulting from impacts, overlain by or interbedded with relatively thin layers of lava, and with the layering restricted to the uppermost level of the crust. Here we report new high-resolution images that reveal ubiquitous horizontal layering to depths of at least 8 km in the canyons. Megabreccia should be only coarsely layered and fractured bedrock should be unlayered, so these observations indicate that volcanic or sedimentary processes were much more important in early martian history than previously believed. Morphological and compositional data suggest that the layers were formed mainly by volcanic flood lavas. Mars was therefore probably very volcanically active during at least the first billion years and after the period when the heaviest impact bombardment had ended.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Nature","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1038/17539","issn":"00280836","usgsCitation":"McEwen, A.S., Malin, M.C., Carr, M.H., and Hartmann, W., 1999, Voluminous volcanism on early mars revealed in valles marineris: Nature, v. 397, no. 6720, p. 584-586, https://doi.org/10.1038/17539.","startPage":"584","endPage":"586","numberOfPages":"3","costCenters":[],"links":[{"id":206345,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1038/17539"},{"id":229489,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"397","issue":"6720","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505bc36de4b08c986b32b18c","contributors":{"authors":[{"text":"McEwen, A. S.","contributorId":11317,"corporation":false,"usgs":true,"family":"McEwen","given":"A.","email":"","middleInitial":"S.","affiliations":[],"preferred":false,"id":391244,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Malin, M. C.","contributorId":68830,"corporation":false,"usgs":false,"family":"Malin","given":"M.","email":"","middleInitial":"C.","affiliations":[],"preferred":false,"id":391245,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Carr, M. H.","contributorId":84727,"corporation":false,"usgs":true,"family":"Carr","given":"M.","email":"","middleInitial":"H.","affiliations":[{"id":131,"text":"Astrogeology Science Center","active":true,"usgs":true}],"preferred":false,"id":391246,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Hartmann, W.K.","contributorId":96002,"corporation":false,"usgs":true,"family":"Hartmann","given":"W.K.","email":"","affiliations":[],"preferred":false,"id":391247,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}}
,{"id":70021803,"text":"70021803 - 1999 - Methane flux in subalpine wetland and unsaturated soils in the southern Rocky Mountains","interactions":[],"lastModifiedDate":"2018-01-30T20:56:06","indexId":"70021803","displayToPublicDate":"1999-01-01T00:00:00","publicationYear":"1999","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1836,"text":"Global Biogeochemical Cycles","active":true,"publicationSubtype":{"id":10}},"title":"Methane flux in subalpine wetland and unsaturated soils in the southern Rocky Mountains","docAbstract":"Methane exchange between the atmosphere and subalpine wetland and unsaturated soils was evaluated over a 15-month period during 1995-1996. Four vegetation community types along a moisture gradient (wetland, moist-grassy, moist-mossy, and dry) were included in a 100 m sampling transect situated at 3200 m elevation in Rocky Mountain National Park, Colorado. Methane fluxes and soil temperature were measured during snow-free and snow-covered periods, and soil moisture content was measured during snow-free periods. The range of mean measured fluxes through all seasons (a positive value represents CH4 efflux to the atmosphere) were: 0.3 to 29.2 mmol CH4 m-2 d-1 wetland area; 0.1 to 1.8 mmol CH4 m-2 d-1, moist-grassy area; -0.04 to 0.7 mmol CH4 m-2 d-1, moist-mossy area; and -0.6 to 0 mmol CH4 m-2 d-1, dry area. Methane efflux was significantly correlated with soil temperature (5 cm) at the continuously saturated wetland area during snow-free periods. Consumption of atmospheric methane was significantly correlated with moisture content in the upper 5 cm of soil at the dry area. A model based on the wetland flux-temperature relationship estimated an annual methane emission of 2.53 mol CH4 m-2 from the wetland. Estimates of annual methane flux based on field measurements at the other sites were 0.12 mol CH4 m-2, moist-grassy area; 0.03 mol CH4 m-2, moist-mossy area; and -0.04 mol CH4 m-2, dry area. Methane fluxes during snow-covered periods were responsible for 25, 73, 23, and 43% of the annual fluxes at the wetland, moist-grassy, moist-mossy, and dry sites, respectively.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Global Biogeochemical Cycles","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1029/1998GB900003","issn":"08866236","usgsCitation":"Wickland, K., Striegl, R.G., Schmidt, S., and Mast, M., 1999, Methane flux in subalpine wetland and unsaturated soils in the southern Rocky Mountains: Global Biogeochemical Cycles, v. 13, no. 1, p. 101-113, https://doi.org/10.1029/1998GB900003.","startPage":"101","endPage":"113","numberOfPages":"13","costCenters":[],"links":[{"id":479650,"rank":10000,"type":{"id":40,"text":"Open Access Publisher Index Page"},"url":"https://doi.org/10.1029/1998gb900003","text":"Publisher Index Page"},{"id":229488,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":206344,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1029/1998GB900003"}],"volume":"13","issue":"1","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a5524e4b0c8380cd6d13a","contributors":{"authors":[{"text":"Wickland, K.P. 0000-0002-6400-0590","orcid":"https://orcid.org/0000-0002-6400-0590","contributorId":10786,"corporation":false,"usgs":true,"family":"Wickland","given":"K.P.","affiliations":[],"preferred":false,"id":391240,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Striegl, Robert G. 0000-0002-8251-4659 rstriegl@usgs.gov","orcid":"https://orcid.org/0000-0002-8251-4659","contributorId":1630,"corporation":false,"usgs":true,"family":"Striegl","given":"Robert","email":"rstriegl@usgs.gov","middleInitial":"G.","affiliations":[{"id":36183,"text":"Hydro-Ecological Interactions Branch","active":true,"usgs":true},{"id":200,"text":"Coop Res Unit Seattle","active":true,"usgs":true},{"id":5044,"text":"National Research Program - Central Branch","active":true,"usgs":true},{"id":37277,"text":"WMA - Earth System Processes Division","active":true,"usgs":true}],"preferred":false,"id":391242,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Schmidt, S.K.","contributorId":58412,"corporation":false,"usgs":true,"family":"Schmidt","given":"S.K.","email":"","affiliations":[],"preferred":false,"id":391241,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Mast, M.A.","contributorId":67871,"corporation":false,"usgs":true,"family":"Mast","given":"M.A.","affiliations":[],"preferred":false,"id":391243,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}}
,{"id":70021869,"text":"70021869 - 1999 - Female-biased sex ratios of hatchling hawksbill sea turtles from a Caribbean nesting beach","interactions":[],"lastModifiedDate":"2024-11-13T17:58:05.815568","indexId":"70021869","displayToPublicDate":"1999-01-01T00:00:00","publicationYear":"1999","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2334,"text":"Journal of Herpetology","active":true,"publicationSubtype":{"id":10}},"title":"Female-biased sex ratios of hatchling hawksbill sea turtles from a Caribbean nesting beach","docAbstract":"<p>No abstract available.</p>","language":"English","publisher":"Society for the Study of Amphibians and Reptiles","doi":"10.2307/1565556","issn":"00221511","usgsCitation":"Wibbels, T., Hillis-Starr, Z., and Phillips, B., 1999, Female-biased sex ratios of hatchling hawksbill sea turtles from a Caribbean nesting beach: Journal of Herpetology, v. 33, no. 1, p. 142-144, https://doi.org/10.2307/1565556.","productDescription":"3 p.","startPage":"142","endPage":"144","numberOfPages":"3","costCenters":[],"links":[{"id":229413,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"33","issue":"1","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a0f7de4b0c8380cd5390b","contributors":{"authors":[{"text":"Wibbels, T.","contributorId":18721,"corporation":false,"usgs":true,"family":"Wibbels","given":"T.","affiliations":[],"preferred":false,"id":391495,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Hillis-Starr, Z.-M.","contributorId":84524,"corporation":false,"usgs":true,"family":"Hillis-Starr","given":"Z.-M.","email":"","affiliations":[],"preferred":false,"id":391496,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Phillips, B.","contributorId":86512,"corporation":false,"usgs":true,"family":"Phillips","given":"B.","affiliations":[],"preferred":false,"id":391497,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}}
,{"id":70021871,"text":"70021871 - 1999 - Esperanzaite, NaCa2Al2 (As(5+)O4)2F4(OH)2H2O, a new mineral species from the La Esperanza Mine, Mexico; descriptive mineralogy and atomic arrangement","interactions":[],"lastModifiedDate":"2023-11-13T11:42:15.857821","indexId":"70021871","displayToPublicDate":"1999-01-01T00:00:00","publicationYear":"1999","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1177,"text":"Canadian Mineralogist","active":true,"publicationSubtype":{"id":10}},"displayTitle":"Esperanzaite, NaCa<sub>2</sub>Al<sub>2</sub>(As<sup>5+</sup>O<sub>4</sub>)<sub>2</sub>F<sub>4</sub>(OH)*2H<sub>2</sub>O, a new mineral species from the La Esperanza mine, Mexico: descriptive mineralogy and atomic arrangement","title":"Esperanzaite, NaCa2Al2 (As(5+)O4)2F4(OH)2H2O, a new mineral species from the La Esperanza Mine, Mexico; descriptive mineralogy and atomic arrangement","docAbstract":"<p>No abstract available.</p>","language":"English","publisher":"Mineralogical Association of Canada","issn":"00084476","usgsCitation":"Foord, E., Hughes, J., Cureton, F., Maxwell, C.H., Falster, A., Sommer, A., and Hlava, P., 1999, Esperanzaite, NaCa2Al2 (As(5+)O4)2F4(OH)2H2O, a new mineral species from the La Esperanza Mine, Mexico; descriptive mineralogy and atomic arrangement: Canadian Mineralogist, v. 37, no. 1, p. 67-72.","productDescription":"6 p.","startPage":"67","endPage":"72","onlineOnly":"N","additionalOnlineFiles":"N","costCenters":[],"links":[{"id":422525,"rank":2,"type":{"id":15,"text":"Index Page"},"url":"https://pubs.geoscienceworld.org/canmin/article/37/1/67/13107/Esperanzaite-NaCa-2-Al-2-As-super-5-O-4-2-F-4-OH"},{"id":229451,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"country":"Mexico","state":"Durango","otherGeospatial":"La Esperanza Mine","geographicExtents":"{\n  \"type\": \"FeatureCollection\",\n  \"features\": [\n    {\n      \"type\": \"Feature\",\n      \"properties\": {},\n      \"geometry\": {\n        \"coordinates\": [\n          [\n            [\n              -105.68109661629447,\n              23.897629776929676\n            ],\n            [\n              -105.68109661629447,\n              23.769664463009235\n            ],\n            [\n              -105.51229442075162,\n              23.769664463009235\n            ],\n            [\n              -105.51229442075162,\n              23.897629776929676\n            ],\n            [\n              -105.68109661629447,\n              23.897629776929676\n            ]\n          ]\n        ],\n        \"type\": \"Polygon\"\n      }\n    }\n  ]\n}","volume":"37","issue":"1","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a0a5fe4b0c8380cd52318","contributors":{"authors":[{"text":"Foord, E.E.","contributorId":86835,"corporation":false,"usgs":true,"family":"Foord","given":"E.E.","email":"","affiliations":[],"preferred":false,"id":391506,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Hughes, J.M.","contributorId":18911,"corporation":false,"usgs":true,"family":"Hughes","given":"J.M.","email":"","affiliations":[],"preferred":false,"id":391501,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Cureton, F.","contributorId":38729,"corporation":false,"usgs":true,"family":"Cureton","given":"F.","email":"","affiliations":[],"preferred":false,"id":391504,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Maxwell, C. H.","contributorId":35343,"corporation":false,"usgs":true,"family":"Maxwell","given":"C.","email":"","middleInitial":"H.","affiliations":[],"preferred":false,"id":391503,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Falster, A.U.","contributorId":31931,"corporation":false,"usgs":true,"family":"Falster","given":"A.U.","email":"","affiliations":[],"preferred":false,"id":391502,"contributorType":{"id":1,"text":"Authors"},"rank":5},{"text":"Sommer, A.J.","contributorId":86916,"corporation":false,"usgs":true,"family":"Sommer","given":"A.J.","email":"","affiliations":[],"preferred":false,"id":391507,"contributorType":{"id":1,"text":"Authors"},"rank":6},{"text":"Hlava, P.F.","contributorId":64415,"corporation":false,"usgs":true,"family":"Hlava","given":"P.F.","email":"","affiliations":[],"preferred":false,"id":391505,"contributorType":{"id":1,"text":"Authors"},"rank":7}]}}
,{"id":70021802,"text":"70021802 - 1999 - Tectonic and regional metamorphic implications of the discovery of Middle Ordovician conodonts in cover rocks east of the Green Mountain massif, Vermont","interactions":[],"lastModifiedDate":"2023-09-20T03:28:49.366061","indexId":"70021802","displayToPublicDate":"1999-01-01T00:00:00","publicationYear":"1999","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1168,"text":"Canadian Journal of Earth Sciences","active":true,"publicationSubtype":{"id":10}},"title":"Tectonic and regional metamorphic implications of the discovery of Middle Ordovician conodonts in cover rocks east of the Green Mountain massif, Vermont","docAbstract":"<p><span>Middle Ordovician (late Arenigian - early Caradocian) conodonts were recovered from a dolostone lens in carbonaceous schist 30 m below the base of the Pinney Hollow Formation in the Eastern Cover sequence near West Bridgewater, Vermont. These are the first reported fossils from the metamorphic cover sequence rocks east of the Green Mountain, Berkshire, and Housatonic massifs of western New England. The conodonts are recrystallized, coated with graphitic matter, thermally altered to a color alteration index (CAI) of at least 5, and tectonically deformed. The faunule is nearly monospecific, consisting of abundant&nbsp;</span><i>Periodon aculeatus<span>&nbsp;</span></i><span>Hadding? and rare&nbsp;</span><i>Protopanderodus</i><span>. The preponderance of&nbsp;</span><i>Periodon<span>&nbsp;</span></i><span>and the absence of warm, shallow-water species characteristic of the North American Midcontinent Conodont Province suggest a slope or basin depositional setting. The conodont-bearing carbonaceous schist is traceable 3 km southeast to the Plymouth area, where it had been designated the uppermost member of the Plymouth Formation, previously regarded as Early Cambrian in age. The age and structural position of the carbonaceous schist above dolostones of the Plymouth Formation but below the Pinney Hollow Formation (upper Proterozoic and Lower Cambrian?) suggest that this unit may be correlative or time transgressive with the Ira Formation, which underlies the Taconic allochthons in the Vermont Valley. Such a correlation supports the concept of placing the western limit of the root zone of the Taconic allochthons beneath the Pinney Hollow Formation. An approximate absolute age assignment for the conodont-bearing rock is between 470 and 454 Ma. This suggests that dynamothermal metamorphism during the Taconian orogeny on the east flank of the Green Mountains was younger than early Caradocian, which is in accord with the middle Caradocian age of the Ira Formation west of the Green Mountain massif.</span></p>","language":"English","publisher":"Canadian Science Publishing","doi":"10.1139/e99-009","issn":"00084077","usgsCitation":"Ratcliffe, N.M., Harris, A., and Walsh, G., 1999, Tectonic and regional metamorphic implications of the discovery of Middle Ordovician conodonts in cover rocks east of the Green Mountain massif, Vermont: Canadian Journal of Earth Sciences, v. 36, no. 3, p. 371-382, https://doi.org/10.1139/e99-009.","productDescription":"12 p.","startPage":"371","endPage":"382","costCenters":[],"links":[{"id":229487,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"country":"United States","state":"Vermont","otherGeospatial":"Green Mountain Massif","geographicExtents":"{\n  \"type\": \"FeatureCollection\",\n  \"features\": [\n    {\n      \"type\": \"Feature\",\n      \"properties\": {},\n      \"geometry\": {\n        \"coordinates\": [\n          [\n            [\n              -73.27078354898968,\n              42.74121278979263\n            ],\n            [\n              -72.46389730468489,\n              42.72385391244967\n            ],\n            [\n              -72.4909060492644,\n              42.77343781422945\n            ],\n            [\n              -72.53479525920545,\n              42.810599709765626\n            ],\n            [\n              -72.55167572456786,\n              42.862588874493554\n            ],\n            [\n              -72.5111626076986,\n              42.89722401655618\n            ],\n            [\n              -72.51453870077124,\n              42.95655331033336\n            ],\n            [\n              -72.4335124670336,\n              42.983726805246505\n            ],\n            [\n              -72.45714511854044,\n              43.04790733964663\n            ],\n            [\n              -72.47064949083018,\n              43.22282782139749\n            ],\n            [\n              -72.44701683932335,\n              43.326066342279944\n            ],\n            [\n              -72.5111626076986,\n              43.529570189273386\n            ],\n            [\n              -72.83526754264925,\n              43.637174220458775\n            ],\n            [\n              -73.25390308362732,\n              43.529570189273386\n            ],\n            [\n              -73.2809118282068,\n              42.852689548715034\n            ],\n            [\n              -73.30116838664101,\n              42.81802941119153\n            ],\n            [\n              -73.27078354898968,\n              42.74121278979263\n            ]\n          ]\n        ],\n        \"type\": \"Polygon\"\n      }\n    }\n  ]\n}","volume":"36","issue":"3","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505ba452e4b08c986b320256","contributors":{"authors":[{"text":"Ratcliffe, N. M.","contributorId":80691,"corporation":false,"usgs":true,"family":"Ratcliffe","given":"N.","middleInitial":"M.","affiliations":[],"preferred":false,"id":391239,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Harris, A. G.","contributorId":39791,"corporation":false,"usgs":true,"family":"Harris","given":"A. G.","affiliations":[],"preferred":false,"id":391237,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Walsh, G. J. 0000-0003-4264-8836","orcid":"https://orcid.org/0000-0003-4264-8836","contributorId":47409,"corporation":false,"usgs":true,"family":"Walsh","given":"G. J.","affiliations":[],"preferred":false,"id":391238,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}}
,{"id":70175688,"text":"70175688 - 1999 - Proceedings of the Rocky Mountain/Great Basin regional climate-change workshop","interactions":[],"lastModifiedDate":"2018-02-21T15:45:03","indexId":"70175688","displayToPublicDate":"1999-01-01T00:00:00","publicationYear":"1999","noYear":false,"publicationType":{"id":4,"text":"Book"},"publicationSubtype":{"id":12,"text":"Conference publication"},"title":"Proceedings of the Rocky Mountain/Great Basin regional climate-change workshop","docAbstract":"<p>No abstract available.</p>","conferenceTitle":"Rocky Mountain/Great Basin regional climate-change workshop","conferenceDate":"February 16-18, 1998","conferenceLocation":"Salt Lake City, Utah","language":"English","publisher":"U.S. National Assessment of the Consequences of Climate Change","publisherLocation":"Washington, D.C.","usgsCitation":"Wagner, F.H., and Baron, J., 1999, Proceedings of the Rocky Mountain/Great Basin regional climate-change workshop, 151 p.","productDescription":"151 p.","onlineOnly":"N","additionalOnlineFiles":"N","costCenters":[{"id":291,"text":"Fort Collins Science Center","active":true,"usgs":true}],"links":[{"id":326793,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"57b6dc6ae4b03fd6b7d94c78","contributors":{"authors":[{"text":"Wagner, Frederic H.","contributorId":9610,"corporation":false,"usgs":false,"family":"Wagner","given":"Frederic","email":"","middleInitial":"H.","affiliations":[],"preferred":false,"id":646066,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Baron, Jill 0000-0002-5902-6251 jill_baron@usgs.gov","orcid":"https://orcid.org/0000-0002-5902-6251","contributorId":194124,"corporation":false,"usgs":true,"family":"Baron","given":"Jill","email":"jill_baron@usgs.gov","affiliations":[{"id":291,"text":"Fort Collins Science Center","active":true,"usgs":true}],"preferred":true,"id":646067,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}}
,{"id":70021851,"text":"70021851 - 1999 - Early evolution of a stratospheric volcanic eruption cloud as observed with TOMS and AVHRR","interactions":[],"lastModifiedDate":"2017-04-07T15:12:28","indexId":"70021851","displayToPublicDate":"1999-01-01T00:00:00","publicationYear":"1999","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2316,"text":"Journal of Geophysical Research D: Atmospheres","active":true,"publicationSubtype":{"id":10}},"title":"Early evolution of a stratospheric volcanic eruption cloud as observed with TOMS and AVHRR","docAbstract":"<p><span>This paper is a detailed study of remote sensing data from the total ozone mapping spectrometer (TOMS) and the advanced very high resolution radiometer (AVHRR) satellite detectors, of the 1982 eruption of El Chichón, Mexico. The volcanic cloud/atmosphere interactions in the first four days of this eruption were investigated by combining ultraviolet retrievals to estimate the mass of sulfur dioxide in the volcanic cloud [</span><i>Krueger et al.</i><span>, 1995] with thermal infrared retrievals of the size, optical depth, and mass of fine-grained (1–10 μm radius) volcanic ash [</span><i>Wen and Rose</i><span>, 1994]. Our study provides the first direct evidence of gravitational separation of ash from a stratospheric, gas-rich, plinian eruption column and documents the marked differences in residence times of volcanic ash and sulfur dioxide in volcanic clouds. The eruption column reached as high as 32 km [</span><i>Carey and Sigurdsson</i><span>, 1986] and was injected into an atmosphere with a strong wind shear, which allowed for an observation of the separation of sulfur dioxide and volcanic ash. The upper, more sulfur dioxide-rich part of the cloud was transported to the west in the stratosphere, while the fine-grained ash traveled to the south in the troposphere. The mass of sulfur dioxide released was estimated at 7.1 × 10</span><sup>9</sup><span> kg with the mass decreasing by approximately 4% 1 day after the peak. The mass of fine-grained volcanic ash detected was estimated at 6.5 × 10</span><sup>9</sup><span> kg, amounting to about 0.7% of the estimated mass of the ash which fell out in the mapped ash blanket close to the volcano. Over the following days, 98% of this remaining fine ash was removed from the volcanic cloud, and the effective radius of ash in the volcanic cloud decreased from about 8 μm to about 4 μm.</span></p>","language":"English","publisher":"AGU","doi":"10.1029/1998JD200073","issn":"01480227","usgsCitation":"Schneider, D., Rose, W.I., Coke, L., Bluth, G., Sprod, I., and Krueger, A., 1999, Early evolution of a stratospheric volcanic eruption cloud as observed with TOMS and AVHRR: Journal of Geophysical Research D: Atmospheres, v. 104, no. D4, p. 4037-4050, https://doi.org/10.1029/1998JD200073.","productDescription":"14 p.","startPage":"4037","endPage":"4050","numberOfPages":"14","costCenters":[{"id":222,"text":"Earth Resources Observation and Science (EROS) Center","active":true,"usgs":true}],"links":[{"id":229119,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"104","issue":"D4","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a0486e4b0c8380cd50a2e","contributors":{"authors":[{"text":"Schneider, D.J.","contributorId":12997,"corporation":false,"usgs":true,"family":"Schneider","given":"D.J.","email":"","affiliations":[],"preferred":false,"id":391410,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Rose, William I. Jr.","contributorId":71556,"corporation":false,"usgs":true,"family":"Rose","given":"William","suffix":"Jr.","email":"","middleInitial":"I.","affiliations":[],"preferred":false,"id":391412,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Coke, L.R.","contributorId":84934,"corporation":false,"usgs":true,"family":"Coke","given":"L.R.","email":"","affiliations":[],"preferred":false,"id":391415,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Bluth, G.J.S.","contributorId":79258,"corporation":false,"usgs":true,"family":"Bluth","given":"G.J.S.","email":"","affiliations":[],"preferred":false,"id":391414,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Sprod, I.E.","contributorId":17391,"corporation":false,"usgs":true,"family":"Sprod","given":"I.E.","email":"","affiliations":[],"preferred":false,"id":391411,"contributorType":{"id":1,"text":"Authors"},"rank":5},{"text":"Krueger, A.J.","contributorId":73764,"corporation":false,"usgs":true,"family":"Krueger","given":"A.J.","email":"","affiliations":[],"preferred":false,"id":391413,"contributorType":{"id":1,"text":"Authors"},"rank":6}]}}
,{"id":70021979,"text":"70021979 - 1999 - Late Pleistocene channel-levee development on Monterey submarine fan, central California","interactions":[],"lastModifiedDate":"2023-11-16T16:49:28.913951","indexId":"70021979","displayToPublicDate":"1999-01-01T00:00:00","publicationYear":"1999","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1742,"text":"Geo-Marine Letters","active":true,"publicationSubtype":{"id":10}},"title":"Late Pleistocene channel-levee development on Monterey submarine fan, central California","docAbstract":"<p><span>Much of the modern upper (proximal) Monterey fan is a channel–levee complex, the Upper Turbidite Sequence (UTS), that was deeply eroded after the channel breached a volcanic ridge to reach a deeper base level. Ages of sediment samples collected with the ALVIN submersible from the deepest outcrop within the channel–levee system, 390 m below the adjacent western levee crest, indicate that the UTS deposits accumulated at ≥1 m ka</span><sup>−1</sup><span>&nbsp;during the last 500 ka. Neogene and Early Pleistocene sediment accumulation on the fan prior to the UTS was much slower (&lt;0.03 m ka</span><sup>−1</sup><span>), and underlying turbidite systems(?) had substantially different morphologic expression(s).</span></p>","language":"English","publisher":"Springer","doi":"10.1007/s003670050066","usgsCitation":"Normark, W.R., 1999, Late Pleistocene channel-levee development on Monterey submarine fan, central California: Geo-Marine Letters, v. 18, no. 3, p. 179-188, https://doi.org/10.1007/s003670050066.","productDescription":"10 p.","startPage":"179","endPage":"188","numberOfPages":"10","costCenters":[],"links":[{"id":489138,"rank":2,"type":{"id":41,"text":"Open Access External Repository Page"},"url":"https://zenodo.org/record/1232699","text":"External Repository"},{"id":229157,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"country":"United States","state":"California","otherGeospatial":"Monterey fan","geographicExtents":"{\n  \"type\": \"FeatureCollection\",\n  \"features\": [\n    {\n      \"type\": \"Feature\",\n      \"properties\": {},\n      \"geometry\": {\n        \"coordinates\": [\n          [\n            [\n              -121.6856342263831,\n              37.10209851973849\n            ],\n            [\n              -123.7968195975298,\n              37.10209851973849\n            ],\n            [\n              -123.7968195975298,\n              35.299385520898596\n            ],\n            [\n              -121.6856342263831,\n              35.299385520898596\n            ],\n            [\n              -121.6856342263831,\n              37.10209851973849\n            ]\n          ]\n        ],\n        \"type\": \"Polygon\"\n      }\n    }\n  ]\n}","volume":"18","issue":"3","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a450de4b0c8380cd66fcd","contributors":{"authors":[{"text":"Normark, W. R.","contributorId":87137,"corporation":false,"usgs":true,"family":"Normark","given":"W.","email":"","middleInitial":"R.","affiliations":[],"preferred":false,"id":391923,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}}
,{"id":70021800,"text":"70021800 - 1999 - ENSO and hydrologic extremes in the western United States","interactions":[],"lastModifiedDate":"2016-07-27T10:35:46","indexId":"70021800","displayToPublicDate":"1999-01-01T00:00:00","publicationYear":"1999","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2216,"text":"Journal of Climate","active":true,"publicationSubtype":{"id":10}},"title":"ENSO and hydrologic extremes in the western United States","docAbstract":"<p>Frequency distributions of daily precipitation in winter and daily stream flow from late winter to early summer, at several hundred sites in the western United States, exhibit strong and systematic responses to the two phases of ENSO. Most of the stream flows considered are driven by snowmelt. The Southern Oscillation index (SOI) is used as the ENSO phase indicator. Both modest (median) and larger (90th percentile) events were considered. In years with negative SOI values (El Nino), days with high daily precipitation and stream flow are more frequent than average over the Southwest and less frequent over the Northwest. During years with positive SOI values (La Nina), a nearly opposite pattern is seen. A more pronounced increase is seen in the number of days exceeding climatological 90th percentile values than in the number exceeding climatological 50th percentile values, for both precipitation and stream flow. Stream flow responses to ENSO extremes are accentuated over precipitation responses. Evidence suggests that the mechanism for this amplification involves ENSO-phase differences in the persistence and duration of wet episodes, affecting the efficiency of the process by which precipitation is converted to runoff. The SOI leads the precipitation events by several months, and hydrologic lags (mostly through snowmelt) dealy the stream flow response by several more months. The combined 6-12 month predictive aspect of this relationship should be of significant benefit in responding to flood (or drought) risk and in improving overall water management in the western states.Frequency distributions of daily precipitation in winter and daily stream flow from late winter to early summer, at several hundred sites in the western United States, exhibit strong and systematic responses to the two phases of ENSO. Most of the stream flows considered are driven by snowmelt. The Southern Oscillation index (SOI) is used as the ENSO phase indicator. Both modest (median) and larger (90th percentile) events were considered. In years with negative SOI values (El Nino), days with high daily precipitation and stream flow are more frequent than average over the Southwest and less frequent over the Northwest. During years with positive SOI values (La Nina), a nearly opposite pattern is seen. A more pronounced increase is seen in the number of days exceeding climatological 90th percentile values than in the number exceeding climatological 50th percentile values, for both precipitation and stream flow. Stream flow responses to ENSO extremes are accentuated over precipitation responses. Evidence suggests that the mechanism for this amplification involves ENSO-phase differences in the persistence and duration of wet episodes, affecting the efficiency of the process by which precipitation is converted to runoff. The SOI leads the precipitation events by several months, and hydrologic lags (mostly through snowmelt) delay the stream flow response by several more months. The combined 6-12-month predictive aspect of this relationship should be of significant benefit in responding to flood (or drought) risk and in improving overall water management in the western states.</p>","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Journal of Climate","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","publisher":"American Meteorological Soc","publisherLocation":"Boston, MA, United States","issn":"08948755","usgsCitation":"Cayan, D., Redmond, K., and Riddle, L., 1999, ENSO and hydrologic extremes in the western United States: Journal of Climate, v. 12, no. 9, p. 2881-2893.","startPage":"2881","endPage":"2893","numberOfPages":"13","onlineOnly":"N","additionalOnlineFiles":"N","costCenters":[{"id":552,"text":"San Francisco Bay-Delta","active":false,"usgs":true},{"id":5079,"text":"Pacific Regional Director's Office","active":true,"usgs":true}],"links":[{"id":229446,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"12","issue":"9","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a0461e4b0c8380cd50952","contributors":{"authors":[{"text":"Cayan, D.R.","contributorId":25961,"corporation":false,"usgs":false,"family":"Cayan","given":"D.R.","email":"","affiliations":[{"id":16196,"text":"Scripps Institution of Oceanography, La Jolla, CA","active":true,"usgs":false}],"preferred":false,"id":391230,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Redmond, K.T.","contributorId":12865,"corporation":false,"usgs":true,"family":"Redmond","given":"K.T.","email":"","affiliations":[],"preferred":false,"id":391229,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Riddle, L.G.","contributorId":66439,"corporation":false,"usgs":true,"family":"Riddle","given":"L.G.","email":"","affiliations":[],"preferred":false,"id":391231,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}}
,{"id":70021978,"text":"70021978 - 1999 - Streamflow trends in the United States","interactions":[],"lastModifiedDate":"2024-02-08T12:20:47.998826","indexId":"70021978","displayToPublicDate":"1999-01-01T00:00:00","publicationYear":"1999","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1807,"text":"Geophysical Research Letters","active":true,"publicationSubtype":{"id":10}},"title":"Streamflow trends in the United States","docAbstract":"<div class=\"\"><div class=\"article-section__content en main\"><p>Secular trends in streamflow are evaluated for 395 climate-sensitive streamgaging stations in the conterminous United States using the non-parametric Mann-Kendall test. Trends are calculated for selected quantiles of discharge, from the 0<sup>th</sup><span>&nbsp;</span>to the 100<sup>th</sup><span>&nbsp;</span>percentile, to evaluate differences between low-, medium-, and high-flow regimes during the twentieth century. Two general patterns emerge; trends are most prevalent in the annual minimum (Q<sub>0</sub>) to median (Q<sub>50</sub>) flow categories and least prevalent in the annual maximum (Q<sub>100</sub>) category; and, at all but the highest quantiles, streamflow has increased across broad sections of the United States. Decreases appear only in parts of the Pacific Northwest and the Southeast. Systematic patterns are less apparent in the Q<sub>100</sub><span>&nbsp;</span>flow. Hydrologically, these results indicate that the conterminous U.S. is getting wetter, but less extreme.</p></div></div>","language":"English","publisher":"American Geophysical Union","doi":"10.1029/1998GL900291","issn":"00948276","usgsCitation":"Lins, H., and Slack, J.R., 1999, Streamflow trends in the United States: Geophysical Research Letters, v. 26, no. 2, p. 227-230, https://doi.org/10.1029/1998GL900291.","productDescription":"4 p.","startPage":"227","endPage":"230","numberOfPages":"4","costCenters":[],"links":[{"id":479620,"rank":2,"type":{"id":40,"text":"Open Access Publisher Index Page"},"url":"https://doi.org/10.1029/1998gl900291","text":"Publisher Index Page"},{"id":229125,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"26","issue":"2","noUsgsAuthors":false,"publicationDate":"1999-01-15","publicationStatus":"PW","scienceBaseUri":"505b9b25e4b08c986b31cce1","contributors":{"authors":[{"text":"Lins, H.F.","contributorId":81508,"corporation":false,"usgs":true,"family":"Lins","given":"H.F.","affiliations":[],"preferred":false,"id":391922,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Slack, J. R.","contributorId":40205,"corporation":false,"usgs":true,"family":"Slack","given":"J.","email":"","middleInitial":"R.","affiliations":[],"preferred":false,"id":391921,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}}
,{"id":70021977,"text":"70021977 - 1999 - Degradation of 1,1,2,2-tetrachloroethane in a freshwater tidal wetland: Field and laboratory evidence","interactions":[],"lastModifiedDate":"2012-03-12T17:19:55","indexId":"70021977","displayToPublicDate":"1999-01-01T00:00:00","publicationYear":"1999","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":"Degradation of 1,1,2,2-tetrachloroethane in a freshwater tidal wetland: Field and laboratory evidence","docAbstract":"Degradation reactions controlling the fate of 1,1,2,2-tetrachloroethane (PCA) in a freshwater tidal wetland that is a discharge area for a contaminated aquifer were investigated by a combined field and laboratory study. Samples from nested piezometers and porous-membrane sampling devices (peepers) showed that PCA concentrations decreased and that less chlorinated daughter products formed as the groundwater became increasingly reducing along upward flow paths through the wetland sediments. The cis and trans isomers of 1,2-dichloroethylene (12DCE) and vinyl chloride (VC) were the predominant daughter products detected from degradation of PCA in the field and in microcosms constructed under methanogenic conditions. Significantly lower ratios of cis-12DCE to trans-12DCE were produced by PCA degradation than by degradation of trichloroethylene, a common co-contaminant with PCA. 1,1,2-Trichloroethane (112TCA) and 1,2-dichloroethane (12DCA) occurred simultaneously with 12DCE, indicating simultaneous hydrogenolysis and dichloroelimination of PCA. From an initial PCA concentration of about 1.5 ??mol/L, concentrations of PCA and its daughter products decreased to below detection within a 1.0-m vertical distance in the wetland sediments and within 34 days in the microcosms. The results indicate that natural attenuation of PCA through complete anaerobic biodegradation can occur in wetlands before sensitive surface water receptors are reached.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Environmental Science and Technology","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1021/es980503t","issn":"0013936X","usgsCitation":"Lorah, M., and Olsen, L., 1999, Degradation of 1,1,2,2-tetrachloroethane in a freshwater tidal wetland: Field and laboratory evidence: Environmental Science & Technology, v. 33, no. 2, p. 227-234, https://doi.org/10.1021/es980503t.","startPage":"227","endPage":"234","numberOfPages":"8","costCenters":[],"links":[{"id":206209,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1021/es980503t"},{"id":229124,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"33","issue":"2","noUsgsAuthors":false,"publicationDate":"1998-12-05","publicationStatus":"PW","scienceBaseUri":"5059fe55e4b0c8380cd4ec97","contributors":{"authors":[{"text":"Lorah, M.M.","contributorId":29002,"corporation":false,"usgs":true,"family":"Lorah","given":"M.M.","affiliations":[],"preferred":false,"id":391919,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Olsen, L.D.","contributorId":97520,"corporation":false,"usgs":true,"family":"Olsen","given":"L.D.","email":"","affiliations":[],"preferred":false,"id":391920,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}}
,{"id":70022054,"text":"70022054 - 1999 - Seismic subduction of the Nazca Ridge as shown by the 1996-97 Peru earthquakes","interactions":[],"lastModifiedDate":"2012-03-12T17:19:45","indexId":"70022054","displayToPublicDate":"1999-01-01T00:00:00","publicationYear":"1999","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":3208,"text":"Pure and Applied Geophysics","active":true,"publicationSubtype":{"id":10}},"title":"Seismic subduction of the Nazca Ridge as shown by the 1996-97 Peru earthquakes","docAbstract":"By rupturing more than half of the shallow subduction interface of the Nazca Ridge, the great November 12, 1996 Peruvian earthquake contradicts the hypothesis that oceanic ridges subduct aseismically. The mainshock's rupture has a length of about 200 km and has an average slip of about 1.4 m. Its moment is 1.5 x 1028 dyne-cm and the corresponding M(w) is 8.0. The mainshock registered three major episodes of moment release as shown by a finite fault inversion of teleseismically recorded broadband body waves. About 55% of the mainshock's total moment release occurred south of the Nazca Ridge, and the remaining moment release occurred at the southern half of the subduction interface of the Nazca Ridge. The rupture south of the Nazca Ridge was elongated parallel to the ridge axis and extended from a shallow depth to about 65 km depth. Because the axis of the Nazca Ridge is at a high angle to the plate convergence direction, the subducting Nazca Ridge has a large southwards component of motion, 5 cm/yr parallel to the coast. The 900-1200 m relief of the southwards sweeping Nazca Ridge is interpreted to act as a 'rigid indenter,' causing the greatest coupling south of the ridge's leading edge and leading to the large observed slip. The mainshock and aftershock hypocenters were relocated using a new procedure that simultaneously inverts local and teleseismic data. Most aftershocks were within the outline of the Nazca Ridge. A three-month delayed aftershock cluster' occurred at the northern part of the subducting Nazca Ridge. Aftershocks were notably lacking at the zone of greatest moment release, to the south of the Nazca Ridge. However, a lone foreshock at the southern end of this zone, some 140 km downstrike of the mainshock's epicenter, implies that conditions existed for rupture into that zone. The 1996 earthquake ruptured much of the inferred source zone of the M(w) 7.9-8.2 earthquake of 1942, although the latter was a slightly larger earthquake. The rupture zone of the 1996 earthquake is immediately north of the seismic gap left by the great earthquakes (M(w) ~8.8-9.1) of 1868 and 1877. The M(w) 8.0 Antofagasta earthquake of 1995 occurred at the southern end of this great seismic gap. The M(w) 8.2 deep-focus Bolivian earthquake of 1994 occurred directly downdip of the 1868 portion of that gap. The recent occurrence of three significant earthquakes on the periphery of the great seismic gap of the 1868 and 1877 events, among other factors, may signal an increased seismic potential for that zone.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Pure and Applied Geophysics","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","issn":"00334553","usgsCitation":"Spence, W., Mendoza, C., Engdahl, E., Choy, G.L., and Norabuena, E., 1999, Seismic subduction of the Nazca Ridge as shown by the 1996-97 Peru earthquakes: Pure and Applied Geophysics, v. 154, no. 3-4, p. 753-776.","startPage":"753","endPage":"776","numberOfPages":"24","costCenters":[],"links":[{"id":230735,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"154","issue":"3-4","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505b8b6be4b08c986b3177fe","contributors":{"authors":[{"text":"Spence, W.","contributorId":7721,"corporation":false,"usgs":true,"family":"Spence","given":"W.","email":"","affiliations":[],"preferred":false,"id":392188,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Mendoza, C.","contributorId":82059,"corporation":false,"usgs":true,"family":"Mendoza","given":"C.","email":"","affiliations":[],"preferred":false,"id":392191,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Engdahl, E.R.","contributorId":22906,"corporation":false,"usgs":true,"family":"Engdahl","given":"E.R.","email":"","affiliations":[],"preferred":false,"id":392189,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"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":392190,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Norabuena, E.","contributorId":6619,"corporation":false,"usgs":true,"family":"Norabuena","given":"E.","email":"","affiliations":[],"preferred":false,"id":392187,"contributorType":{"id":1,"text":"Authors"},"rank":5}]}}
,{"id":70021798,"text":"70021798 - 1999 - Accretion in the wake of terrane collision: The Neogene accretionary wedge off Kenai Peninsula, Alaska","interactions":[],"lastModifiedDate":"2018-01-08T12:44:46","indexId":"70021798","displayToPublicDate":"1999-01-01T00:00:00","publicationYear":"1999","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":3524,"text":"Tectonics","active":true,"publicationSubtype":{"id":10}},"title":"Accretion in the wake of terrane collision: The Neogene accretionary wedge off Kenai Peninsula, Alaska","docAbstract":"Subduction accretion and repeated terrane collision shaped the Alaskan convergent margin. The Yakutat Terrane is currently colliding with the continental margin below the central Gulf of Alaska. During the Neogene the terrane's western part was subducted after which a sediment wedge accreted along the northeast Aleutian Trench. This wedge incorporates sediment eroded from the continental margin and marine sediments carried into the subduction zone on the Pacific plate. Prestack depth migration was performed on six seismic reflection lines to resolve the structure within this accretionary wedge and its backstop. The lateral extent of the structures is constrained by high-resolution swath bathymetry and seismic lines collected along strike. Accretionary structure consists of variably sized thrust slices that were deformed against a backstop during frontal accretion and underplating. Toward the northeast the lower slope steepens, the wedge narrows, and the accreted volume decreases notwith-standing a doubling of sediments thickness in the trench. In the northeasternmost transect, near the area where the terrane's trailing edge subducts, no frontal accretion is observed and the slope is eroded. The structures imaged along the seismic lines discussed here most likely result from progressive evolution from erosion to accretion, as the trailing edge of the Yakutat Terrane is subducting.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Tectonics","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1029/1998TC900021","issn":"02787407","usgsCitation":"Fruehn, J., von Huene, R.E., and Fisher, M.A., 1999, Accretion in the wake of terrane collision: The Neogene accretionary wedge off Kenai Peninsula, Alaska: Tectonics, v. 18, no. 2, p. 263-277, https://doi.org/10.1029/1998TC900021.","startPage":"263","endPage":"277","numberOfPages":"15","costCenters":[],"links":[{"id":487417,"rank":10000,"type":{"id":40,"text":"Open Access Publisher Index Page"},"url":"https://doi.org/10.1029/1998tc900021","text":"Publisher Index Page"},{"id":229407,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":206318,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1029/1998TC900021"}],"volume":"18","issue":"2","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"5059e670e4b0c8380cd4741a","contributors":{"authors":[{"text":"Fruehn, J.","contributorId":92007,"corporation":false,"usgs":true,"family":"Fruehn","given":"J.","email":"","affiliations":[],"preferred":false,"id":391224,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"von Huene, Roland E. 0000-0003-1301-3866 rvonhuene@usgs.gov","orcid":"https://orcid.org/0000-0003-1301-3866","contributorId":191070,"corporation":false,"usgs":true,"family":"von Huene","given":"Roland","email":"rvonhuene@usgs.gov","middleInitial":"E.","affiliations":[{"id":7065,"text":"USGS emeritus","active":true,"usgs":false},{"id":237,"text":"Earthquake Science Center","active":true,"usgs":true}],"preferred":false,"id":391223,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Fisher, M. A.","contributorId":69972,"corporation":false,"usgs":true,"family":"Fisher","given":"M.","email":"","middleInitial":"A.","affiliations":[],"preferred":false,"id":391222,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}}
,{"id":70022055,"text":"70022055 - 1999 - A new multistage groundwater transport inverse method: presentation, evaluation, and implications","interactions":[],"lastModifiedDate":"2018-03-20T15:34:00","indexId":"70022055","displayToPublicDate":"1999-01-01T00:00:00","publicationYear":"1999","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":"A new multistage groundwater transport inverse method: presentation, evaluation, and implications","docAbstract":"<p><span>More computationally efficient methods of using concentration data are needed to estimate groundwater flow and transport parameters. This work introduces and evaluates a three‐stage nonlinear‐regression‐based iterative procedure in which trial advective‐front locations link decoupled flow and transport models. Method accuracy and efficiency are evaluated by comparing results to those obtained when flow‐ and transport‐model parameters are estimated simultaneously. The new method is evaluated as conclusively as possible by using a simple test case that includes distinct flow and transport parameters, but does not include any approximations that are problem dependent. The test case is analytical; the only flow parameter is a constant velocity, and the transport parameters are longitudinal and transverse dispersivity. Any difficulties detected using the new method in this ideal situation are likely to be exacerbated in practical problems. Monte‐Carlo analysis of observation error ensures that no specific error realization obscures the results. Results indicate that, while this, and probably other, multistage methods do not always produce optimal parameter estimates, the computational advantage may make them useful in some circumstances, perhaps as a precursor to using a simultaneous method.</span></p>","language":"English","publisher":"American Geophysical Union","doi":"10.1029/1998WR900114","usgsCitation":"Anderman, E.R., and Hill, M.C., 1999, A new multistage groundwater transport inverse method: presentation, evaluation, and implications: Water Resources Research, v. 35, no. 4, p. 1053-1063, https://doi.org/10.1029/1998WR900114.","productDescription":"11 p.","startPage":"1053","endPage":"1063","costCenters":[],"links":[{"id":479539,"rank":1,"type":{"id":40,"text":"Open Access Publisher Index Page"},"url":"https://doi.org/10.1029/1998wr900114","text":"Publisher Index Page"},{"id":230736,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"35","issue":"4","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"5059e4abe4b0c8380cd4681e","contributors":{"authors":[{"text":"Anderman, Evan R.","contributorId":95505,"corporation":false,"usgs":true,"family":"Anderman","given":"Evan","email":"","middleInitial":"R.","affiliations":[],"preferred":false,"id":392193,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Hill, Mary C. mchill@usgs.gov","contributorId":974,"corporation":false,"usgs":true,"family":"Hill","given":"Mary","email":"mchill@usgs.gov","middleInitial":"C.","affiliations":[{"id":5044,"text":"National Research Program - Central Branch","active":true,"usgs":true}],"preferred":true,"id":392192,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}}
,{"id":70021873,"text":"70021873 - 1999 - Restoring marsh elevation in a rapidly subsiding salt marsh by thin-layer deposition of dredged material","interactions":[],"lastModifiedDate":"2012-03-12T17:19:38","indexId":"70021873","displayToPublicDate":"1999-01-01T00:00:00","publicationYear":"1999","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1454,"text":"Ecological Engineering","active":true,"publicationSubtype":{"id":10}},"title":"Restoring marsh elevation in a rapidly subsiding salt marsh by thin-layer deposition of dredged material","docAbstract":"Thin-layer deposition of dredged material on coastal marsh by means of high-pressure spray dredging (Jet-Spray??2) technology has been proposed as a mechanism to minimize wetland impacts associated with traditional bucket dredging technologies and to restore soil elevations in deteriorated marshes of the Mississippi River delta. The impact of spray dredging on vegetated marsh and adjacent shallow-water habitat (formerly vegetated marsh that deteriorated to open water) was evaluated in a 0.5-ha Spartina alterniflora-dominated salt marsh in coastal Louisiana. The thickness of dredged sediment deposits was determined from artificial soil marker horizons and soil elevation change was determined from sedimentation-erosion tables (SET) established prior to spraying in both sprayed and reference marshes. The vertical accretion and elevation change measurements were made simultaneously to allow for calculation of shallow (~5 m depth) subsidence (accretion minus elevation change). Measurements made immediately following spraying in July 1996 revealed that stems of S. alterniflora were knocked down by the force of the spray and covered with 23 mm of dredged material. Stems of S. alterniflora soon recovered, and by July 1997 the percent cover of S. alterniflora had increased three-fold over pre-project conditions. Thus, the layer of dredged material was thin enough to allow for survival of the S. alterniflora plants, with no subsequent colonization by plant species typical of higher marsh zones. By February 1998, 62 mm of vertical accretion accumulated at this site, and little indication of disturbance was noted. Although not statistically significant, soil elevation change was greater than accretion on average at both the spray and reference marshes, suggesting that subsurface expansion caused by increased root biomass production and/or pore water storage influence elevation in this marsh region. In the adjacent shallow water pond, 129 mm of sediment was deposited in July 1996 as a result of spraying, and despite initial shallow subsidence and continual erosion through February 1998, water bottom elevation was raised sufficiently to allow S. alterniflora to invade via rhizome growth from the adjacent marsh. Hence, thin-layer deposition of dredged material at this site was effective at restoring and maintaining marsh elevation after 1.5 years. However, if the open water sediment deposits are not soon completely stabilized via further vegetative colonization, erosion may eventually lower elevations to the level where emergent vegetation cannot persist.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Ecological Engineering","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1016/S0925-8574(98)00061-5","issn":"09258574","usgsCitation":"Ford, M., Cahoon, D.R., and Lynch, J., 1999, Restoring marsh elevation in a rapidly subsiding salt marsh by thin-layer deposition of dredged material: Ecological Engineering, v. 12, no. 3-4, p. 189-205, https://doi.org/10.1016/S0925-8574(98)00061-5.","startPage":"189","endPage":"205","numberOfPages":"17","costCenters":[],"links":[{"id":206348,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/S0925-8574(98)00061-5"},{"id":229492,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"12","issue":"3-4","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505aaae4e4b0c8380cd865ac","contributors":{"authors":[{"text":"Ford, M.A.","contributorId":42315,"corporation":false,"usgs":true,"family":"Ford","given":"M.A.","email":"","affiliations":[],"preferred":false,"id":391511,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Cahoon, Donald R. 0000-0002-2591-5667","orcid":"https://orcid.org/0000-0002-2591-5667","contributorId":65424,"corporation":false,"usgs":true,"family":"Cahoon","given":"Donald","email":"","middleInitial":"R.","affiliations":[{"id":531,"text":"Patuxent Wildlife Research Center","active":true,"usgs":true},{"id":455,"text":"National Wetlands Research Center","active":true,"usgs":true}],"preferred":false,"id":391512,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Lynch, J.C.","contributorId":25104,"corporation":false,"usgs":true,"family":"Lynch","given":"J.C.","email":"","affiliations":[],"preferred":false,"id":391510,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}}
,{"id":70021797,"text":"70021797 - 1999 - Comparing global models of terrestrial net primary productivity (NPP): Global pattern and differentiation by major biomes","interactions":[],"lastModifiedDate":"2012-03-12T17:19:41","indexId":"70021797","displayToPublicDate":"1999-01-01T00:00:00","publicationYear":"1999","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1837,"text":"Global Change Biology","active":true,"publicationSubtype":{"id":10}},"title":"Comparing global models of terrestrial net primary productivity (NPP): Global pattern and differentiation by major biomes","docAbstract":"Annual and seasonal net primary productivity estimates (NPP) of 15 global models across latitudinal zones and biomes are compared. The models simulated NPP for contemporary climate using common, spatially explicit data sets for climate, soil texture, and normalized difference vegetation index (NDVI). Differences among NPP estimates varied over space and time. The largest differences occur during the summer months in boreal forests (50??to 60??N) and during the dry seasons of tropical evergreen forests. Differences in NPP estimates are related to model assumptions about vegetation structure, model parameterizations, and input data sets.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Global Change Biology","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1046/j.1365-2486.1999.00003.x","issn":"13541013","usgsCitation":"Kicklighter, D., Bondeau, A., Schloss, A.L., Kaduk, J., and McGuire, A., 1999, Comparing global models of terrestrial net primary productivity (NPP): Global pattern and differentiation by major biomes: Global Change Biology, v. 5, no. SUPPL. 1, p. 16-24, https://doi.org/10.1046/j.1365-2486.1999.00003.x.","startPage":"16","endPage":"24","numberOfPages":"9","costCenters":[],"links":[{"id":206317,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1046/j.1365-2486.1999.00003.x"},{"id":229406,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"5","issue":"SUPPL. 1","noUsgsAuthors":false,"publicationDate":"2001-12-24","publicationStatus":"PW","scienceBaseUri":"5059f833e4b0c8380cd4cf36","contributors":{"authors":[{"text":"Kicklighter, D. W.","contributorId":31537,"corporation":false,"usgs":false,"family":"Kicklighter","given":"D. W.","affiliations":[{"id":13627,"text":"Woods Hole Oceanographic Institution, Woods Hole, MA","active":true,"usgs":false}],"preferred":false,"id":391219,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Bondeau, A.","contributorId":72151,"corporation":false,"usgs":true,"family":"Bondeau","given":"A.","email":"","affiliations":[],"preferred":false,"id":391220,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Schloss, A. L.","contributorId":15774,"corporation":false,"usgs":false,"family":"Schloss","given":"A.","email":"","middleInitial":"L.","affiliations":[],"preferred":false,"id":391217,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Kaduk, J.","contributorId":105462,"corporation":false,"usgs":true,"family":"Kaduk","given":"J.","email":"","affiliations":[],"preferred":false,"id":391221,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"McGuire, A. D.","contributorId":16552,"corporation":false,"usgs":true,"family":"McGuire","given":"A. D.","affiliations":[],"preferred":false,"id":391218,"contributorType":{"id":1,"text":"Authors"},"rank":5}]}}
,{"id":70021875,"text":"70021875 - 1999 - The evolutionary history of steelhead (<i>Oncorhynchus mykiss</i>) along the US Pacific Coast: Developing a conservation strategy using genetic diversity","interactions":[],"lastModifiedDate":"2017-02-27T14:59:15","indexId":"70021875","displayToPublicDate":"1999-01-01T00:00:00","publicationYear":"1999","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1936,"text":"ICES Journal of Marine Science","active":true,"publicationSubtype":{"id":10}},"title":"The evolutionary history of steelhead (<i>Oncorhynchus mykiss</i>) along the US Pacific Coast: Developing a conservation strategy using genetic diversity","docAbstract":"<p>Changes in genetic variation across a species range may indicate patterns of population structure resulting from past ecological and demographic events that are otherwise difficult to infer and thus provide insight into evolutionary development. Genetic data is used, drawn from 11 microsatellite loci amplified from anadromous steelhead (<i>Oncorhynchus mykiss</i>) sampled throughout its range in the eastern Pacific Ocean, to explore population structure at the southern edge in California. Steelhead populations in this region represent less than 10% of their reported historic abundance and survive in very small populations found in fragmented habitats. Genetic data derived from three independent molecular systems (allozymes, mtDNA, and microsatellites) have shown that the southernmost populations are characterized by a relatively high genetic diversity. Two hypothetical models supporting genetic population substructure such as observed were considered: (1) range expansion with founder-flush effects and subsequent population decline; (2) a second Pleistocene radiation from the Gulf of California. Using genetic and climatic data, a second Pleistocene refugium contributing to a southern ecotone seems more feasible. These data support strong conservation measures based on genetic diversity be developed to ensure the survival of this uniquely diverse gene pool.</p>","language":"English","publisher":"Oxford Academic","doi":"10.1006/jmsc.1999.0452","issn":"10543139","usgsCitation":"Nielsen, J., 1999, The evolutionary history of steelhead (<i>Oncorhynchus mykiss</i>) along the US Pacific Coast: Developing a conservation strategy using genetic diversity: ICES Journal of Marine Science, v. 56, no. 4, p. 449-458, https://doi.org/10.1006/jmsc.1999.0452.","productDescription":"10 p.","startPage":"449","endPage":"458","costCenters":[{"id":114,"text":"Alaska Science Center","active":true,"usgs":true}],"links":[{"id":479649,"rank":1,"type":{"id":40,"text":"Open Access Publisher Index Page"},"url":"https://doi.org/10.1006/jmsc.1999.0452","text":"Publisher Index Page"},{"id":229530,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"country":"United States","volume":"56","issue":"4","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505babebe4b08c986b323174","contributors":{"authors":[{"text":"Nielsen, J.L.","contributorId":105665,"corporation":false,"usgs":true,"family":"Nielsen","given":"J.L.","email":"","affiliations":[],"preferred":false,"id":391517,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}}
,{"id":70021876,"text":"70021876 - 1999 - Quantification of aerobic biodegradation and volatilization rates of gasoline hydrocarbons near the water table under natural attenuation conditions","interactions":[],"lastModifiedDate":"2018-12-19T09:13:11","indexId":"70021876","displayToPublicDate":"1999-01-01T00:00:00","publicationYear":"1999","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":"Quantification of aerobic biodegradation and volatilization rates of gasoline hydrocarbons near the water table under natural attenuation conditions","docAbstract":"<p><span>Aerobic biodegradation and volatilization near the water table constitute a coupled pathway that contributes significantly to the natural attenuation of hydrocarbons at gasoline spill sites. Rates of hydrocarbon biodegradation and volatilization were quantified by analyzing vapor transport in the unsaturated zone at a gasoline spill site in Beaufort, South Carolina. Aerobic biodgradation rates decreased with distance above the water table, ranging from 0.20 to 1.5 g m</span><sup>−3</sup><span><span>&nbsp;</span>d</span><sup>−1</sup><span><span>&nbsp;</span>for toluene, from 0.24 to 0.38 g m</span><sup>−3</sup><span><span>&nbsp;</span>d</span><sup>−1</sup><span>for xylene, from 0.09 to 0.24 g m</span><sup>−3</sup><span><span>&nbsp;</span>d</span><sup>−1</sup><span><span>&nbsp;</span>for cyclohexene, from 0.05 to 0.22 g m</span><sup>−3</sup><span><span>&nbsp;</span>d</span><sup>−1</sup><span><span>&nbsp;</span>for ethylbenzene, and from 0.02 to 0.08 g m</span><sup>−3</sup><span><span>&nbsp;</span>d</span><sup>−1</sup><span><span>&nbsp;</span>for benzene. Rates were highest in the capillary zone, where 68% of the total hydrocarbon mass that volatilized from the water table was estimated to have been biodegraded. Hydrocarbons were nearly completely degraded within 1m above the water table. This large loss underscores the importance of aerobic biodradation in limiting the transport of hydrocarbon vapors in the unsaturated zone and implies that vapor‐plume migration to basements and other points of contact may only be significant if a source of free product is present. Furthermore, because transport of the hydrocarbon in the unsaturated zone can be limited relative to that of oxygen and carbon dioxide, soil‐gas surveys conducted at hydrocarbon‐spill sites would benefit by the inclusion of oxygen‐ and carbon‐dioxide‐gas concentration measurements. Aerobic degradation kinetics in the unsaturated zone were approximately first‐order. First‐order rate constants near the water table were highest for cyclohexene (0.21–0.65 d</span><sup>−1</sup><span>) and nearly equivalent for ethylbenzene (0.11–0.31 d</span><sup>−1</sup><span>), xylenes (0.10–0.31 d</span><sup>−1</sup><span>), toluene (0.09–0.30 d</span><sup>−1</sup><span>), and benzene (0.07–0.31 d</span><sup>−1</sup><span>). Hydrocarbon mass loss rates at the water table resulting from the coupled aerobic biodgradation and volatilization process were determined by extrapolating gas transport rates through the capillary zone. Mass loss rates from groundwater were highest for toluene (0.20–0.84 g m</span><sup>−2</sup><span><span>&nbsp;</span>d</span><sup>−1</sup><span>), followed by xylenes (0.12–0.69 g m</span><sup>−2</sup><span><span>&nbsp;</span>d</span><sup>−1</sup><span>), cyclohexene (0.05–0.15 g m</span><sup>−2</sup><span><span>&nbsp;</span>d</span><sup>−1</sup><span>), ethylbenzene (0.02–0.12 g m</span><sup>−2</sup><span><span>&nbsp;</span>d</span><sup>−1</sup><span>), and benzene (0.01–0.04 g m</span><sup>−2</sup><span><span>&nbsp;</span>d</span><sup>−1</sup><span>). These rates exceed predicted rates of solubilization to groundwater, demonstrating the effectiveness of aerobic biodgradation and volatilization as a combined natural attenuation pathway.</span></p>","language":"English","publisher":"American Geophysical Union","doi":"10.1029/1998WR900087","usgsCitation":"Lahvis, M.A., Baehr, A.L., and Baker, R.J., 1999, Quantification of aerobic biodegradation and volatilization rates of gasoline hydrocarbons near the water table under natural attenuation conditions: Water Resources Research, v. 35, no. 3, p. 753-765, https://doi.org/10.1029/1998WR900087.","productDescription":"13 p.","startPage":"753","endPage":"765","costCenters":[{"id":589,"text":"Toxic Substances Hydrology Program","active":true,"usgs":true}],"links":[{"id":479647,"rank":1,"type":{"id":40,"text":"Open Access Publisher Index Page"},"url":"https://doi.org/10.1029/1998wr900087","text":"Publisher Index Page"},{"id":229531,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"35","issue":"3","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a91a8e4b0c8380cd803a7","contributors":{"authors":[{"text":"Lahvis, Matthew A.","contributorId":104522,"corporation":false,"usgs":true,"family":"Lahvis","given":"Matthew","email":"","middleInitial":"A.","affiliations":[],"preferred":false,"id":391520,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Baehr, Arthur L.","contributorId":104523,"corporation":false,"usgs":true,"family":"Baehr","given":"Arthur","email":"","middleInitial":"L.","affiliations":[],"preferred":false,"id":391518,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Baker, Ronald J. rbaker@usgs.gov","contributorId":1436,"corporation":false,"usgs":true,"family":"Baker","given":"Ronald","email":"rbaker@usgs.gov","middleInitial":"J.","affiliations":[{"id":470,"text":"New Jersey Water Science Center","active":true,"usgs":true}],"preferred":true,"id":391519,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}}
,{"id":70021877,"text":"70021877 - 1999 - Mobility of pyroclastic flows and surges at the Soufriere Hills Volcano, Montserrat","interactions":[],"lastModifiedDate":"2024-02-08T23:53:52.272196","indexId":"70021877","displayToPublicDate":"1999-01-01T00:00:00","publicationYear":"1999","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1807,"text":"Geophysical Research Letters","active":true,"publicationSubtype":{"id":10}},"title":"Mobility of pyroclastic flows and surges at the Soufriere Hills Volcano, Montserrat","docAbstract":"<div class=\"\"><div class=\"article-section__content en main\"><p>The Soufriere Hills Volcano on Montserrat has produced avalanche-like pyroclastic flows formed by collapse of the unstable lava dome or explosive activity. Pyroclastic flows associated with dome collapse generate overlying dilute surges which detach from and travel beyond their parent flows. The largest surges partially transform by rapid sedimentation into dense secondary pyroclastic flows that pose significant hazards to distal areas. Different kinds of pyroclastic density currents display contrasting mobilities indicated by ratios of total height of fall<span>&nbsp;</span><i>H</i>, run-out distance<span>&nbsp;</span><i>L</i>, area inundated<span>&nbsp;</span><i>A</i><span>&nbsp;</span>and volume transported<span>&nbsp;</span><i>V</i>. Dome-collapse flow mobilities (characterised by either<span>&nbsp;</span><i>L/H</i><span>&nbsp;</span>or<span>&nbsp;</span><i>A/V</i><sup>2/3</sup>) resemble those of terrestrial and extraterrestrial cold-rockfalls (Dade and Huppert, 1998). In contrast, fountain-fed pumice flows and fine-grained, secondary pyroclastic flows travel slower but, for comparable initial volumes and heights, can inundate greater areas.</p></div></div>","language":"English","publisher":"American Geophysical Union","doi":"10.1029/1999GL900051","issn":"00948276","usgsCitation":"Calder, E., Cole, P., Dade, W., Druitt, T.H., Hoblitt, R., Huppert, H., Ritchie, L., Sparks, R.S., and Young, S., 1999, Mobility of pyroclastic flows and surges at the Soufriere Hills Volcano, Montserrat: Geophysical Research Letters, v. 26, no. 5, p. 537-540, https://doi.org/10.1029/1999GL900051.","productDescription":"4 p.","startPage":"537","endPage":"540","numberOfPages":"4","costCenters":[],"links":[{"id":229566,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"26","issue":"5","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a5b94e4b0c8380cd6f661","contributors":{"authors":[{"text":"Calder, E.S.","contributorId":90494,"corporation":false,"usgs":true,"family":"Calder","given":"E.S.","email":"","affiliations":[],"preferred":false,"id":391529,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Cole, P.D.","contributorId":9022,"corporation":false,"usgs":true,"family":"Cole","given":"P.D.","email":"","affiliations":[],"preferred":false,"id":391521,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Dade, W.B.","contributorId":70951,"corporation":false,"usgs":true,"family":"Dade","given":"W.B.","email":"","affiliations":[],"preferred":false,"id":391525,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Druitt, T. H.","contributorId":60662,"corporation":false,"usgs":true,"family":"Druitt","given":"T.","email":"","middleInitial":"H.","affiliations":[],"preferred":false,"id":391524,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Hoblitt, R.","contributorId":89536,"corporation":false,"usgs":true,"family":"Hoblitt","given":"R.","affiliations":[],"preferred":false,"id":391528,"contributorType":{"id":1,"text":"Authors"},"rank":5},{"text":"Huppert, H.E.","contributorId":47111,"corporation":false,"usgs":true,"family":"Huppert","given":"H.E.","email":"","affiliations":[],"preferred":false,"id":391523,"contributorType":{"id":1,"text":"Authors"},"rank":6},{"text":"Ritchie, L.","contributorId":79653,"corporation":false,"usgs":true,"family":"Ritchie","given":"L.","email":"","affiliations":[],"preferred":false,"id":391526,"contributorType":{"id":1,"text":"Authors"},"rank":7},{"text":"Sparks, R. S. J.","contributorId":46686,"corporation":false,"usgs":false,"family":"Sparks","given":"R.","email":"","middleInitial":"S. J.","affiliations":[],"preferred":false,"id":391522,"contributorType":{"id":1,"text":"Authors"},"rank":8},{"text":"Young, S.R.","contributorId":83643,"corporation":false,"usgs":true,"family":"Young","given":"S.R.","email":"","affiliations":[],"preferred":false,"id":391527,"contributorType":{"id":1,"text":"Authors"},"rank":9}]}}
,{"id":70021779,"text":"70021779 - 1999 - Imager for Mars Pathfinder (IMP) image calibration","interactions":[],"lastModifiedDate":"2018-12-04T08:35:17","indexId":"70021779","displayToPublicDate":"1999-01-01T00:00:00","publicationYear":"1999","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":"Imager for Mars Pathfinder (IMP) image calibration","docAbstract":"<p>The Imager for Mars Pathfinder returned over 16,000 high-quality images from the surface of Mars. The camera was well-calibrated in the laboratory, with &lt;5% radiometric uncertainty. The photometric properties of two radiometric targets were also measured with 3% uncertainty. Several data sets acquired during the cruise and on Mars confirm that the system operated nominally throughout the course of the mission. Image calibration algorithms were developed for landed operations to correct instrumental sources of noise and to calibrate images relative to observations of the radiometric targets. The uncertainties associated with these algorithms as well as current improvements to image calibration are discussed.</p>","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Journal of Geophysical Research E: Planets","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","publisher":"American Geophysical Union","publisherLocation":"Washington, D.C.","doi":"10.1029/1998JE900011","issn":"01480227","usgsCitation":"Reid, R., Smith, P.H., Lemmon, M., Tanner, R., Burkland, M., Wegryn, E., Weinberg, J., Marcialis, R., Britt, D., Thomas, N., Kramm, R., Dummel, A., Crowe, D., Bos, B., Bell, J., Rueffer, P., Gliem, F., Johnson, J.R., Maki, J., Herkenhoff, K.E., and Singer, R.B., 1999, Imager for Mars Pathfinder (IMP) image calibration: Journal of Geophysical Research E: Planets, v. 104, no. E4, p. 8907-8925, https://doi.org/10.1029/1998JE900011.","productDescription":"19p.","startPage":"8907","endPage":"8925","numberOfPages":"19","costCenters":[{"id":131,"text":"Astrogeology Science Center","active":true,"usgs":true}],"links":[{"id":479455,"rank":1,"type":{"id":40,"text":"Open Access Publisher Index Page"},"url":"https://doi.org/10.1029/1998je900011","text":"Publisher Index Page"},{"id":229115,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"otherGeospatial":"Mars","volume":"104","issue":"E4","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a387ae4b0c8380cd615a3","contributors":{"authors":[{"text":"Reid, R.J.","contributorId":88899,"corporation":false,"usgs":true,"family":"Reid","given":"R.J.","email":"","affiliations":[],"preferred":false,"id":391136,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Smith, P. H.","contributorId":94058,"corporation":false,"usgs":false,"family":"Smith","given":"P.","email":"","middleInitial":"H.","affiliations":[],"preferred":false,"id":391139,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Lemmon, M.","contributorId":65628,"corporation":false,"usgs":true,"family":"Lemmon","given":"M.","affiliations":[],"preferred":false,"id":391128,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Tanner, R.","contributorId":93229,"corporation":false,"usgs":true,"family":"Tanner","given":"R.","email":"","affiliations":[],"preferred":false,"id":391138,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Burkland, M.","contributorId":18126,"corporation":false,"usgs":true,"family":"Burkland","given":"M.","email":"","affiliations":[],"preferred":false,"id":391124,"contributorType":{"id":1,"text":"Authors"},"rank":5},{"text":"Wegryn, E.","contributorId":92449,"corporation":false,"usgs":true,"family":"Wegryn","given":"E.","email":"","affiliations":[],"preferred":false,"id":391137,"contributorType":{"id":1,"text":"Authors"},"rank":6},{"text":"Weinberg, J.","contributorId":10183,"corporation":false,"usgs":true,"family":"Weinberg","given":"J.","email":"","affiliations":[],"preferred":false,"id":391121,"contributorType":{"id":1,"text":"Authors"},"rank":7},{"text":"Marcialis, R.","contributorId":79648,"corporation":false,"usgs":true,"family":"Marcialis","given":"R.","email":"","affiliations":[],"preferred":false,"id":391133,"contributorType":{"id":1,"text":"Authors"},"rank":8},{"text":"Britt, D.T.","contributorId":72150,"corporation":false,"usgs":true,"family":"Britt","given":"D.T.","email":"","affiliations":[],"preferred":false,"id":391130,"contributorType":{"id":1,"text":"Authors"},"rank":9},{"text":"Thomas, N.","contributorId":72490,"corporation":false,"usgs":true,"family":"Thomas","given":"N.","email":"","affiliations":[],"preferred":false,"id":391131,"contributorType":{"id":1,"text":"Authors"},"rank":10},{"text":"Kramm, R.","contributorId":78105,"corporation":false,"usgs":true,"family":"Kramm","given":"R.","email":"","affiliations":[],"preferred":false,"id":391132,"contributorType":{"id":1,"text":"Authors"},"rank":11},{"text":"Dummel, A.","contributorId":82872,"corporation":false,"usgs":true,"family":"Dummel","given":"A.","affiliations":[],"preferred":false,"id":391134,"contributorType":{"id":1,"text":"Authors"},"rank":12},{"text":"Crowe, D.","contributorId":27215,"corporation":false,"usgs":true,"family":"Crowe","given":"D.","email":"","affiliations":[],"preferred":false,"id":391125,"contributorType":{"id":1,"text":"Authors"},"rank":13},{"text":"Bos, B.J.","contributorId":54756,"corporation":false,"usgs":true,"family":"Bos","given":"B.J.","email":"","affiliations":[],"preferred":false,"id":391126,"contributorType":{"id":1,"text":"Authors"},"rank":14},{"text":"Bell, J.F. III","contributorId":97612,"corporation":false,"usgs":true,"family":"Bell","given":"J.F.","suffix":"III","email":"","affiliations":[],"preferred":false,"id":391141,"contributorType":{"id":1,"text":"Authors"},"rank":15},{"text":"Rueffer, P.","contributorId":94059,"corporation":false,"usgs":true,"family":"Rueffer","given":"P.","email":"","affiliations":[],"preferred":false,"id":391140,"contributorType":{"id":1,"text":"Authors"},"rank":16},{"text":"Gliem, F.","contributorId":86133,"corporation":false,"usgs":true,"family":"Gliem","given":"F.","email":"","affiliations":[],"preferred":false,"id":391135,"contributorType":{"id":1,"text":"Authors"},"rank":17},{"text":"Johnson, J. R.","contributorId":69278,"corporation":false,"usgs":true,"family":"Johnson","given":"J.","email":"","middleInitial":"R.","affiliations":[],"preferred":false,"id":391129,"contributorType":{"id":1,"text":"Authors"},"rank":18},{"text":"Maki, J.N.","contributorId":11356,"corporation":false,"usgs":true,"family":"Maki","given":"J.N.","affiliations":[],"preferred":false,"id":391122,"contributorType":{"id":1,"text":"Authors"},"rank":19},{"text":"Herkenhoff, Kenneth E. 0000-0002-3153-6663 kherkenhoff@usgs.gov","orcid":"https://orcid.org/0000-0002-3153-6663","contributorId":2275,"corporation":false,"usgs":true,"family":"Herkenhoff","given":"Kenneth","email":"kherkenhoff@usgs.gov","middleInitial":"E.","affiliations":[{"id":131,"text":"Astrogeology Science Center","active":true,"usgs":true}],"preferred":true,"id":391127,"contributorType":{"id":1,"text":"Authors"},"rank":20},{"text":"Singer, Robert B.","contributorId":16166,"corporation":false,"usgs":true,"family":"Singer","given":"Robert","email":"","middleInitial":"B.","affiliations":[],"preferred":false,"id":391123,"contributorType":{"id":1,"text":"Authors"},"rank":21}]}}
,{"id":70021778,"text":"70021778 - 1999 - Grenville age of basement rocks in Cape May NJ well: New evidence for Laurentian crust in U.S. Atlantic Coastal Plain basement Chesapeake terrane","interactions":[],"lastModifiedDate":"2012-03-12T17:19:54","indexId":"70021778","displayToPublicDate":"1999-01-01T00:00:00","publicationYear":"1999","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2304,"text":"Journal of Geodynamics","active":true,"publicationSubtype":{"id":10}},"title":"Grenville age of basement rocks in Cape May NJ well: New evidence for Laurentian crust in U.S. Atlantic Coastal Plain basement Chesapeake terrane","docAbstract":"The Chesapeake terrane of the U.S. mid-Atlantic Coastal Plain basement is bounded on the northwest by the Salisbury positive gravity and magnetic anomaly and extends to the southeast as far as the Atlantic coast. It underlies the Coastal Plain of Virginia, Maryland, Delaware and southern New Jersey. Rubidium/Strontium dating of the Chesapeake terrane basement yields an age of 1.025 ?? 0.036 Ga. This age is typical of Grenville province rocks of the Middle to Late Proterozoic Laurentian continent. The basement lithologies are similar to some exposed Grenville-age rocks of the Appalachians. The TiO2 and Zr/P2O5 composition of the metagabbro from the Chesapeake terrane basement is overlapped by those of the Proterozoic mafic dikes in the New Jersey Highlands. These new findings support the interpretation that Laurentian basement extends southeast as far as the continental shelf in the U.S. mid-Atlantic region. The subcrop of Laurentian crust under the mid-Atlantic Coastal Plain implies unroofing by erosion of the younger Carolina (Avalon) supracrustal terrane. Dextral-transpression fault duplexes may have caused excessive uplift in the Salisbury Embayment area during the Alleghanian orogeny. This extra uplift in the Salisbury area may have caused the subsequent greater subsidence of the Coastal Plain basement in the embayment.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Journal of Geodynamics","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1016/S0264-3707(98)00015-5","issn":"02643707","usgsCitation":"Sheridan, R.E., Maguire, T., Feigenson, M., Patino, L., and Volkert, R., 1999, Grenville age of basement rocks in Cape May NJ well: New evidence for Laurentian crust in U.S. Atlantic Coastal Plain basement Chesapeake terrane: Journal of Geodynamics, v. 27, no. 4-5, p. 623-633, https://doi.org/10.1016/S0264-3707(98)00015-5.","startPage":"623","endPage":"633","numberOfPages":"11","costCenters":[],"links":[{"id":206193,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/S0264-3707(98)00015-5"},{"id":229083,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"27","issue":"4-5","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a2a6ee4b0c8380cd5b18c","contributors":{"authors":[{"text":"Sheridan, R. E.","contributorId":36681,"corporation":false,"usgs":true,"family":"Sheridan","given":"R.","email":"","middleInitial":"E.","affiliations":[],"preferred":false,"id":391116,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Maguire, T.J.","contributorId":82512,"corporation":false,"usgs":true,"family":"Maguire","given":"T.J.","email":"","affiliations":[],"preferred":false,"id":391119,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Feigenson, M.D.","contributorId":65641,"corporation":false,"usgs":true,"family":"Feigenson","given":"M.D.","email":"","affiliations":[],"preferred":false,"id":391118,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Patino, L.C.","contributorId":59208,"corporation":false,"usgs":true,"family":"Patino","given":"L.C.","email":"","affiliations":[],"preferred":false,"id":391117,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Volkert, R.A.","contributorId":90799,"corporation":false,"usgs":true,"family":"Volkert","given":"R.A.","affiliations":[],"preferred":false,"id":391120,"contributorType":{"id":1,"text":"Authors"},"rank":5}]}}
,{"id":70021777,"text":"70021777 - 1999 - Testing earthquake prediction algorithms: Statistically significant advance prediction of the largest earthquakes in the Circum-Pacific, 1992-1997","interactions":[],"lastModifiedDate":"2013-01-22T15:35:48","indexId":"70021777","displayToPublicDate":"1999-01-01T00:00:00","publicationYear":"1999","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":3071,"text":"Physics of the Earth and Planetary Interiors","active":true,"publicationSubtype":{"id":10}},"title":"Testing earthquake prediction algorithms: Statistically significant advance prediction of the largest earthquakes in the Circum-Pacific, 1992-1997","docAbstract":"Algorithms M8 and MSc (i.e., the Mendocino Scenario) were used in a real-time intermediate-term research prediction of the strongest earthquakes in the Circum-Pacific seismic belt. Predictions are made by M8 first. Then, the areas of alarm are reduced by MSc at the cost that some earthquakes are missed in the second approximation of prediction. In 1992-1997, five earthquakes of magnitude 8 and above occurred in the test area: all of them were predicted by M8 and MSc identified correctly the locations of four of them. The space-time volume of the alarms is 36% and 18%, correspondingly, when estimated with a normalized product measure of empirical distribution of epicenters and uniform time. The statistical significance of the achieved results is beyond 99% both for M8 and MSc. For magnitude 7.5 + , 10 out of 19 earthquakes were predicted by M8 in 40% and five were predicted by M8-MSc in 13% of the total volume considered. This implies a significance level of 81% for M8 and 92% for M8-MSc. The lower significance levels might result from a global change in seismic regime in 1993-1996, when the rate of the largest events has doubled and all of them become exclusively normal or reversed faults. The predictions are fully reproducible; the algorithms M8 and MSc in complete formal definitions were published before we started our experiment [Keilis-Borok, V.I., Kossobokov, V.G., 1990. Premonitory activation of seismic flow: Algorithm M8, Phys. Earth and Planet. Inter. 61, 73-83; Kossobokov, V.G., Keilis-Borok, V.I., Smith, S.W., 1990. Localization of intermediate-term earthquake prediction, J. Geophys. Res., 95, 19763-19772; Healy, J.H., Kossobokov, V.G., Dewey, J.W., 1992. A test to evaluate the earthquake prediction algorithm, M8. U.S. Geol. Surv. OFR 92-401]. M8 is available from the IASPEI Software Library [Healy, J.H., Keilis-Borok, V.I., Lee, W.H.K. (Eds.), 1997. Algorithms for Earthquake Statistics and Prediction, Vol. 6. IASPEI Software Library]. ?? 1999 Elsevier Science B.V. All rights reserved.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Physics of the Earth and Planetary Interiors","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","publisher":"Elsevier","publisherLocation":"Amsterdam, Netherlands","doi":"10.1016/S0031-9201(98)00159-9","issn":"00319201","usgsCitation":"Kossobokov, V., Romashkova, L., Keilis-Borok, V.I., and Healy, J.H., 1999, Testing earthquake prediction algorithms: Statistically significant advance prediction of the largest earthquakes in the Circum-Pacific, 1992-1997: Physics of the Earth and Planetary Interiors, v. 111, no. 3-4, p. 187-196, https://doi.org/10.1016/S0031-9201(98)00159-9.","startPage":"187","endPage":"196","numberOfPages":"10","costCenters":[],"links":[{"id":229082,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":266259,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/S0031-9201(98)00159-9"}],"volume":"111","issue":"3-4","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505ba5c2e4b08c986b320c67","contributors":{"authors":[{"text":"Kossobokov, V.G.","contributorId":105449,"corporation":false,"usgs":true,"family":"Kossobokov","given":"V.G.","affiliations":[],"preferred":false,"id":391115,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Romashkova, L.L.","contributorId":47108,"corporation":false,"usgs":true,"family":"Romashkova","given":"L.L.","email":"","affiliations":[],"preferred":false,"id":391113,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Keilis-Borok, V. I.","contributorId":46244,"corporation":false,"usgs":true,"family":"Keilis-Borok","given":"V.","email":"","middleInitial":"I.","affiliations":[],"preferred":false,"id":391112,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Healy, J. H.","contributorId":48968,"corporation":false,"usgs":true,"family":"Healy","given":"J.","email":"","middleInitial":"H.","affiliations":[],"preferred":false,"id":391114,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}}
,{"id":70021878,"text":"70021878 - 1999 - Numerical model of a tracer test on the Santa Clara River, Ventura County, California","interactions":[],"lastModifiedDate":"2018-09-25T10:24:54","indexId":"70021878","displayToPublicDate":"1999-01-01T00:00:00","publicationYear":"1999","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2529,"text":"Journal of the American Water Resources Association","active":true,"publicationSubtype":{"id":10}},"title":"Numerical model of a tracer test on the Santa Clara River, Ventura County, California","docAbstract":"To better understand the flow processes, solute-transport processes, and ground-water/surface-water interactions on the Santa Clara River in Ventura County, California, a 24-hour fluorescent-dye tracer study was performed under steady-state flow conditions on a 45-km reach of the river. The study reach includes perennial (uppermost and lowermost) subreaches and ephemeral subreaches of the lower Piru Creek and the middle Santa Clara River. The tracer-test data were used to calibrate a one-dimensional flow model (DAFLOW) and a solute-transport model (BLTM). The dye-arrival times at each sample location were simulated by calibrating the velocity parameters in DAFLOW. The simulations of dye transport indicated that (1) ground-water recharge explains the loss of mass in the ephemeral middle subreaches, and (2) groundwater recharge does not explain the loss of mass in the perennial uppermost and lowermost subreaches. The observed tracer curves in the perennial subreaches were indicative of sorptive dye losses, transient storage, and (or) photodecay - these phenomena were simulated using a linear decay term. However, analysis of the linear decay terms indicated that photodecay was not a dominant source of dye loss.To better understand the flow processes, solute-transport processes, and ground-water/surface-water interactions on the Santa Clara River in Ventura County, California, a 24-hour fluorescent-dye tracer study was performed under steady-state flow conditions on a 45-km reach of the river. The study reach includes perennial (uppermost and lowermost) subreaches and ephemeral subreaches of the lower Piru Creek and the middle Santa Clara River. The tracer-test data were used to calibrate a one-dimension-al flow model (DAFLOW) and a solute-transport model (BLTM). The dye-arrival times at each sample location were simulated by calibrating the velocity parameters in DAFLOW. The simulations of dye transport indicated that (1) ground-water recharge explains the loss of mass in the ephemeral middle subreaches, and (2) ground-water recharge does not explain the loss of mass in the perennial uppermost and lowermost subreaches. The observed tracer curves in the perennial subreaches were indicative of sorptive dye losses, transient storage, and (or) photodecay - these phenomena were simulated using a linear decay term. However, analysis of the linear decay terms indicated that photodecay was not a dominant source of dye loss.","language":"English","publisher":"American Water Resources Assoc","doi":"10.1111/j.1752-1688.1999.tb05458.x","issn":"1093474X","usgsCitation":"Nishikawa, T., Paybins, K.S., Izbicki, J.A., and Reichard, E.G., 1999, Numerical model of a tracer test on the Santa Clara River, Ventura County, California: Journal of the American Water Resources Association, v. 35, no. 1, p. 133-142, https://doi.org/10.1111/j.1752-1688.1999.tb05458.x.","productDescription":"10 p.","startPage":"133","endPage":"142","numberOfPages":"10","costCenters":[{"id":154,"text":"California Water Science Center","active":true,"usgs":true}],"links":[{"id":229567,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"35","issue":"1","noUsgsAuthors":false,"publicationDate":"2007-06-08","publicationStatus":"PW","scienceBaseUri":"505a68f2e4b0c8380cd73a9a","contributors":{"authors":[{"text":"Nishikawa, Tracy 0000-0002-7348-3838 tnish@usgs.gov","orcid":"https://orcid.org/0000-0002-7348-3838","contributorId":1515,"corporation":false,"usgs":true,"family":"Nishikawa","given":"Tracy","email":"tnish@usgs.gov","affiliations":[{"id":154,"text":"California Water Science Center","active":true,"usgs":true}],"preferred":true,"id":391531,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Paybins, Katherine S. 0000-0002-3967-5043 kpaybins@usgs.gov","orcid":"https://orcid.org/0000-0002-3967-5043","contributorId":2805,"corporation":false,"usgs":true,"family":"Paybins","given":"Katherine","email":"kpaybins@usgs.gov","middleInitial":"S.","affiliations":[{"id":642,"text":"West Virginia Water Science Center","active":true,"usgs":true}],"preferred":true,"id":391530,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Izbicki, John A. 0000-0003-0816-4408 jaizbick@usgs.gov","orcid":"https://orcid.org/0000-0003-0816-4408","contributorId":149374,"corporation":false,"usgs":true,"family":"Izbicki","given":"John","email":"jaizbick@usgs.gov","middleInitial":"A.","affiliations":[],"preferred":false,"id":391532,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Reichard, Eric G. 0000-0002-7310-3866 egreich@usgs.gov","orcid":"https://orcid.org/0000-0002-7310-3866","contributorId":1207,"corporation":false,"usgs":true,"family":"Reichard","given":"Eric","email":"egreich@usgs.gov","middleInitial":"G.","affiliations":[],"preferred":true,"id":391533,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}}
,{"id":70021975,"text":"70021975 - 1999 - Isotopic identification of the source of methane in subsurface sediments of an area surrounded by waste disposal facilities","interactions":[],"lastModifiedDate":"2012-03-12T17:19:56","indexId":"70021975","displayToPublicDate":"1999-01-01T00:00:00","publicationYear":"1999","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":835,"text":"Applied Geochemistry","active":true,"publicationSubtype":{"id":10}},"title":"Isotopic identification of the source of methane in subsurface sediments of an area surrounded by waste disposal facilities","docAbstract":"The major source of methane (CH4) in subsurface sediments on the property of a former hazardous waste treatment facility was determined using isotopic analyses measured on CH4 and associated groundwater. The site, located on an earthen pier built into a shallow wetland lake, has had a history of waste disposal practices and is surrounded by landfills and other waste management facilities. Concentrations of CH4 up to 70% were found in the headspace gases of several piezometers screened at 3 different depths (ranging from 8 to 17 m) in lacustrine and glacial till deposits. Possible sources of the CH4 included a nearby landfill, organic wastes from previous impoundments and microbial gas derived from natural organic matter in the sediments. Isotopic analyses included ??13C, ??D, 14C, and 3H on select CH4 samples and ??D and ??18O on groundwater samples. Methane from the deepest glacial till and intermediate lacustrine deposits had ??13C values from -79 to -82???, typical of natural 'drift gas' generated by microbial CO2-reduction. The CH4 from the shallow lacustrine deposits had ??13C values from -63 to -76???, interpreted as a mixture between CH4 generated by microbial fermentation and the CO2-reduction processes within the subsurface sediments. The ??D values of all the CH4 samples were quite negative ranging from -272 to -299???. Groundwater sampled from the deeper zones also showed quite negative ??D values that explained the light ??D observed for the CH4. Radiocarbon analyses of the CH4 showed decreasing 14C activity with depth, from a high of 58 pMC in the shallow sediments to 2 pMC in the deeper glacial till. The isotopic data indicated the majority of CH4 detected in the fill deposits of this site was microbial CH4 generated from naturally buried organic matter within the subsurface sediments. However, the isotopic data of CH4 from the shallow piezometers was more variable and the possibility of some mixing with oxidized landfill CH4 could not be completely ruled out.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Applied Geochemistry","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","publisher":"Elsevier Sci Ltd","publisherLocation":"Exeter, United Kingdom","doi":"10.1016/S0883-2927(98)00036-5","issn":"08832927","usgsCitation":"Hackley, K.C., Liu, C., and Trainor, D., 1999, Isotopic identification of the source of methane in subsurface sediments of an area surrounded by waste disposal facilities: Applied Geochemistry, v. 14, no. 1, p. 119-131, https://doi.org/10.1016/S0883-2927(98)00036-5.","startPage":"119","endPage":"131","numberOfPages":"13","costCenters":[],"links":[{"id":206199,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/S0883-2927(98)00036-5"},{"id":229094,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"14","issue":"1","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a3fb8e4b0c8380cd64767","contributors":{"authors":[{"text":"Hackley, Keith C.","contributorId":12166,"corporation":false,"usgs":true,"family":"Hackley","given":"Keith","email":"","middleInitial":"C.","affiliations":[],"preferred":false,"id":391909,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Liu, Chao-Li","contributorId":42361,"corporation":false,"usgs":true,"family":"Liu","given":"Chao-Li","email":"","affiliations":[],"preferred":false,"id":391910,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Trainor, D.","contributorId":67776,"corporation":false,"usgs":true,"family":"Trainor","given":"D.","email":"","affiliations":[],"preferred":false,"id":391911,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}}
]}