The 17 January 1994, Northridge, California, earthquake produced strong ground shaking at the Cedar Hills Nursery (referred to here as the Tarzana site) within the city of Tarzana, California, approximately 6 km from the epicenter of the mainshock. Although the Tarzana site is on a hill and is a rock site, accelerations of approximately 1.78 g horizontally and 1.2 g vertically at the Tarzana site are among the highest ever instrumentally recorded for an earthquake. To investigate possible site effects at the Tarzana site, we used explosive-source seismic refraction data to determine the shallow (<70 m) P-and S-wave velocity structure. Our seismic velocity models for the Tarzana site indicate that the local velocity structure may have contributed significantly to the observed shaking. P-wave velocities range from 0.9 to 1.65 km/sec, and S-wave velocities range from 0.20 and 0.6 km/sec for the upper 70 m. We also found evidence for a local S-wave low-velocity zone (LVZ) beneath the top of the hill. The LVZ underlies a CDMG strong-motion recording site at depths between 25 and 60 m below ground surface (BGS). Our velocity model is consistent with the near-surface (<30 m) P- and S-wave velocities and Poisson's ratios measured in a nearby (<30 m) borehole. High Poisson's ratios (0.477 to 0.494) and S-wave attenuation within the LVZ suggest that the LVZ may be composed of highly saturated shales of the Modelo Formation. Because the lateral dimensions of the LVZ approximately correspond to the areas of strongest shaking, we suggest that the highly saturated zone may have contributed to localized strong shaking. Rock sites are generally considered to be ideal locations for site response in urban areas; however, localized, highly saturated rock sites may be a hazard in urban areas that requires further investigation.
Bouldery debris fans and sandy alluvial terraces of the Colorado River developed contemporaneously during the late Holocene at the mouths of nine major tributaries in eastern Grand Canyon. The age of the debris fans and alluvial terraces contributes to understanding river hydraulics and to the history of human activity along the river, which has been concentrated on these surfaces for at least two to three millennia. Poorly sorted, coarse-grained debris-flow deposits of several ages are interbedded with, overlie, or are overlapped by three terrace-forming alluviums. The alluvial deposits are of three age groups: the striped alluvium, deposited from before 770 b.c. to about a.d. 300; the alluvium of Pueblo II age deposited from about a.d. 700 to December 1900; and the alluvium of the upper mesquite terrace, deposited from about a.d. 1400 to 1880. Two elements define the geomorphology of a typical debris fan: the large, inactive surface of the fan and a smaller, entrenched, active debris-flow channel and fan that is about one-sixth the area of the inactive fan. The inactive fan is segmented into at least three surfaces with distinctive weathering characteristics. These surfaces are conformable with underlying debris-flow deposits that date from before 770 b.c. to around a.d. 660, a.d. 660 to before a.d. 1200, and from a.d. 1200 to slightly before 1890, respectively, based on late-19th-century photographs, radiocarbon and archaeologic dating of the three stratigraphically related alluviums, and radiocarbon dating of fine-grained debris-flow deposits. These debris flows aggraded the fans in at least three stages beginning about 2.8 ka, if not earlier in the late Holocene. Several main-stem floods eroded the margin of the segmented fans, reducing fan symmetry. The entrenched, active debris-flow channels contain deposits <100 yr old, which form debris fans at the mouth of the channel adjacent to the river. Early and middle Holocene debris-flow and alluvial deposits have not been recognized, as they were evidently not preserved adjacent to the river or are buried by younger deposits.
Chrysotile-bearing serpentinite is a constituent of the San Andreas fault zone in central and northern California. At room temperature, chrysotile gouge has a very low coefficient of friction (μ ≈ 0.2), raising the possibility that under hydrothermal conditions μ might be reduced sufficiently (to ≤0.1) to explain the apparent weakness of the fault. To test this hypothesis, we measured the frictional strength of a pure chrysotile gouge at temperatures to 290 °C and axial-shortening velocities as low as 0.001 μm/s. As temperature increases to ≈ 100 °C, the strength of the chrysotile gouge decreases slightly at low velocities, but at temperatures ≥200 °C, it is substantially stronger and essentially independent of velocity at the lowest velocities tested. We estimate that pure chrysotile gouge at hydrostatic fluid pressure and appropriate temperatures would have shear strength averaged over a depth of 14 km of 50 MPa. Thus, on the sole basis of its strength, chrysotile cannot be the cause of a weak San Andreas fault. However, chrysotile may also contribute to low fault strength by forming mineral seals that promote the development of high fluid pressures.
The three‐dimensional P and S wave structure of Redoubt Volcano, Alaska, and the underlying crust to depths of 7–8 km is determined from 6219 P wave and 4008 S wave first‐arrival times recorded by a 30‐station seismograph network deployed on and around the volcano. First‐arrival times are calculated using a finite‐difference technique, which allows for flexible parameterization of the slowness model and easy inclusion of topography and source‐receiver geometry. The three‐dimensional P wave velocity structure and hypocenters are determined simultaneously, while the three‐dimensional Swave velocity model is determined using the relocated seismicity and an initial S wave velocity model derived from the P wave velocity model assuming an average Vp/Vs ratio of 1.78. Convergence is steady with approximately 73% and 52% reduction in P and Swave arrival time RMS, respectively, after 10 iterations. The most prominent feature observed in the three‐dimensional velocity models derived for both P and S waves is a relative low‐velocity, near‐vertical, pipelike structure approximately 1 km in diameter that extends from 1 to 6 km beneath sea level. This feature aligns axially with the bulk of seismicity and is interpreted as a highly fractured and altered zone encompassing a magma conduit. The velocity structure beneath the north flank of the volcano between depths of 1 and 6 km is characterized by large lateral velocity variations. High velocities within this region are interpreted as remnant dikes and sills and low velocities as regions along which magma migrates. No large low‐velocity body suggestive of a magma chamber is resolved in the upper 7–8 km of the crust.
","language":"English","publisher":"AGU","doi":"10.1029/95JB03046","issn":"01480227","usgsCitation":"Benz, H., Chouet, B., Dawson, P., Lahr, J., Page, R., and Hole, J., 1996, Three-dimensional P and S wave velocity structure of Redoubt Volcano, Alaska: Journal of Geophysical Research B: Solid Earth, v. 101, no. 4, p. 8111-8128, https://doi.org/10.1029/95JB03046.","productDescription":"18 p.","startPage":"8111","endPage":"8128","costCenters":[{"id":615,"text":"Volcano Hazards Program","active":true,"usgs":true}],"links":[{"id":227302,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"101","issue":"4","noUsgsAuthors":false,"publicationDate":"1996-04-10","publicationStatus":"PW","scienceBaseUri":"505bb31de4b08c986b325bb1","contributors":{"authors":[{"text":"Benz, H.M.","contributorId":21594,"corporation":false,"usgs":true,"family":"Benz","given":"H.M.","email":"","affiliations":[],"preferred":false,"id":379856,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Chouet, B. A.","contributorId":31813,"corporation":false,"usgs":true,"family":"Chouet","given":"B. A.","affiliations":[],"preferred":false,"id":379857,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Dawson, P.B.","contributorId":75934,"corporation":false,"usgs":true,"family":"Dawson","given":"P.B.","email":"","affiliations":[],"preferred":false,"id":379860,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Lahr, J.C.","contributorId":34892,"corporation":false,"usgs":true,"family":"Lahr","given":"J.C.","email":"","affiliations":[],"preferred":false,"id":379858,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Page, R.A.","contributorId":40197,"corporation":false,"usgs":true,"family":"Page","given":"R.A.","email":"","affiliations":[],"preferred":false,"id":379859,"contributorType":{"id":1,"text":"Authors"},"rank":5},{"text":"Hole, J.A.","contributorId":103422,"corporation":false,"usgs":true,"family":"Hole","given":"J.A.","email":"","affiliations":[],"preferred":false,"id":379861,"contributorType":{"id":1,"text":"Authors"},"rank":6}]}} ,{"id":70017683,"text":"70017683 - 1996 - Introduction: Paleozoic applications of sequence stratigraphy","interactions":[],"lastModifiedDate":"2012-03-12T17:19:54","indexId":"70017683","displayToPublicDate":"1996-01-01T00:00:00","publicationYear":"1996","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":3005,"text":"Paleozoic sequence stratigraphy: views from the North American craton","active":true,"publicationSubtype":{"id":10}},"title":"Introduction: Paleozoic applications of sequence stratigraphy","docAbstract":"Despite conceptual origins from studies of the Paleozoic strata of cratonic basins, sequence stratigraphy has largely been developed and applied to post-Paleozoic successions in extracratonic settings. The application of continental-margin sequence stratigraphic concepts to cratonic basinal successions is fraught with problems owing to slower rates of sediment accumulation, and consequently, a more coarsely defined temporal resolution. In addition, some important sequence stratigraphic components are rare or completely missing from cratonic areas. Common usage of genetic sequence stratigraphic terminology can coopt critical evaluation of depositional characters, and must be practiced with extreme caution in order to avoid 'model-driven' approaches to stratigraphic synthesis. The best available tests for evaluating current questions regarding the central role of eustasy in sequence stratigraphy may be through interregional and intercontinental comparisons of cratonic stratigraphic sequences.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Paleozoic sequence stratigraphy: views from the North American craton","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","publisher":"Geological Society of America; Special Paper","publisherLocation":"306","usgsCitation":"Witzke, B., Ludvigson, G.A., and Day, J., 1996, Introduction: Paleozoic applications of sequence stratigraphy: Paleozoic sequence stratigraphy: views from the North American craton, p. 1-6.","startPage":"1","endPage":"6","numberOfPages":"6","costCenters":[],"links":[{"id":228809,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a3e0be4b0c8380cd63a67","contributors":{"editors":[{"text":"Witzke B.J.","contributorId":128402,"corporation":true,"usgs":false,"organization":"Witzke B.J.","id":536372,"contributorType":{"id":2,"text":"Editors"},"rank":1}],"authors":[{"text":"Witzke, B.J.","contributorId":12976,"corporation":false,"usgs":true,"family":"Witzke","given":"B.J.","affiliations":[],"preferred":false,"id":377258,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Ludvigson, Greg A.","contributorId":80803,"corporation":false,"usgs":true,"family":"Ludvigson","given":"Greg","email":"","middleInitial":"A.","affiliations":[],"preferred":false,"id":377260,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Day, J.","contributorId":62357,"corporation":false,"usgs":true,"family":"Day","given":"J.","affiliations":[],"preferred":false,"id":377259,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70018702,"text":"70018702 - 1996 - The origin of the Bering Sea basalt province, western Alaska","interactions":[],"lastModifiedDate":"2012-03-12T17:19:16","indexId":"70018702","displayToPublicDate":"1996-01-01T00:00:00","publicationYear":"1996","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1798,"text":"Geology of the Pacific Ocean","active":true,"publicationSubtype":{"id":10}},"title":"The origin of the Bering Sea basalt province, western Alaska","docAbstract":"Bering Sea basalt province consists of at least 15 late Cenozoic (less than 6 Ma) volcanic fields that occur on islands in the Bering Sea and along the adjacent west coast of Alaska. The fields are composed of widespread flows of tholeiitic and alkali olivine basalt and small cones, flows, and maar craters of more alkalic basalt, basanite, and rare nephelinite. Although the volcanic fields do not lie along a hot-spot trace, the rocks are compositionally similar to ocean island basalts. Although the rocks show some evidence for fractionation, the dominant control on composition is by varying degrees of partial melting of a mantle source. Trace-element and isotopic data further constrain the mantle source.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Geology of the Pacific Ocean","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","issn":"8755755X","usgsCitation":"Moll-Stalcup, E.J., 1996, The origin of the Bering Sea basalt province, western Alaska: Geology of the Pacific Ocean, v. 12, no. 4, p. 671-689.","startPage":"671","endPage":"689","numberOfPages":"19","costCenters":[],"links":[{"id":227004,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"12","issue":"4","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505bae6fe4b08c986b3240cc","contributors":{"authors":[{"text":"Moll-Stalcup, E. J.","contributorId":26698,"corporation":false,"usgs":true,"family":"Moll-Stalcup","given":"E.","email":"","middleInitial":"J.","affiliations":[],"preferred":false,"id":380492,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}} ,{"id":70017824,"text":"70017824 - 1996 - Production of activated char from Illinois coal for flue gas cleanup","interactions":[],"lastModifiedDate":"2012-03-12T17:19:55","indexId":"70017824","displayToPublicDate":"1996-01-01T00:00:00","publicationYear":"1996","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":611,"text":"ACS Division of Fuel Chemistry, Preprints","active":true,"publicationSubtype":{"id":10}},"title":"Production of activated char from Illinois coal for flue gas cleanup","docAbstract":"[No abstract available]","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"ACS Division of Fuel Chemistry, Preprints","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","issn":"05693772","usgsCitation":"Lizzio, A., and DeBarr, J., 1996, Production of activated char from Illinois coal for flue gas cleanup: ACS Division of Fuel Chemistry, Preprints, v. 41, no. 1, p. 427-430.","startPage":"427","endPage":"430","numberOfPages":"4","costCenters":[],"links":[{"id":228677,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"41","issue":"1","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a8ddbe4b0c8380cd7ee8b","contributors":{"authors":[{"text":"Lizzio, A.A.","contributorId":70937,"corporation":false,"usgs":true,"family":"Lizzio","given":"A.A.","email":"","affiliations":[],"preferred":false,"id":377669,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"DeBarr, J.A.","contributorId":20078,"corporation":false,"usgs":true,"family":"DeBarr","given":"J.A.","affiliations":[],"preferred":false,"id":377668,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70018644,"text":"70018644 - 1996 - On the central muscle attachment scar pattern of Suchonella Spizharsky 1939","interactions":[],"lastModifiedDate":"2012-03-12T17:19:25","indexId":"70018644","displayToPublicDate":"1996-01-01T00:00:00","publicationYear":"1996","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2735,"text":"Micropaleontology","active":true,"publicationSubtype":{"id":10}},"title":"On the central muscle attachment scar pattern of Suchonella Spizharsky 1939","docAbstract":"The fortuitous spalling of a carapace of the nonmarine Permian Suchonella typica Spizharsky 1939 disclosed the adductor muscle attachment scar as well as two accessory scars on both the right side of the steinkern and the inside of the spalled right valve. This central muscle field is illustrated and discussed. An objective list of species described in or referred to Suchonella Spizharsky 1939 is appended.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Micropaleontology","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","issn":"00262803","usgsCitation":"Sohn, I.G., 1996, On the central muscle attachment scar pattern of Suchonella Spizharsky 1939: Micropaleontology, v. 42, no. 4, p. 380-386.","startPage":"380","endPage":"386","numberOfPages":"7","costCenters":[],"links":[{"id":227484,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"42","issue":"4","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a6db9e4b0c8380cd752b9","contributors":{"authors":[{"text":"Sohn, I. G.","contributorId":70751,"corporation":false,"usgs":true,"family":"Sohn","given":"I.","email":"","middleInitial":"G.","affiliations":[],"preferred":false,"id":380309,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}} ,{"id":70018172,"text":"70018172 - 1996 - Use of liquefaction-induced features for paleoseismic analysis","interactions":[],"lastModifiedDate":"2023-12-16T13:28:29.058569","indexId":"70018172","displayToPublicDate":"1996-01-01T00:00:00","publicationYear":"1996","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1517,"text":"Engineering Geology","active":true,"publicationSubtype":{"id":10}},"title":"Use of liquefaction-induced features for paleoseismic analysis","docAbstract":"Liquefaction features can be used in many field settings to estimate the recurrence interval and magnitude of strong earthquakes through much of the Holocene. These features include dikes, craters, vented sand, sills, and laterally spreading landslides. The relatively high seismic shaking level required for their formation makes them particularly valuable as records of strong paleo-earthquakes. This state-of-the-art summary for using liquefaction-induced features for paleoseismic interpretation and analysis takes into account both geological and geotechnical engineering perspectives. The driving mechanism for formation of the features is primarily the increased pore-water pressure associated with liquefaction of sand-rich sediment. The role of this mechanism is often supplemented greatly by the direct action of seismic shaking at the ground surface, which strains and breaks the clay-rich cap that lies immediately above the sediment that liquefied. Discussed in the text are the processes involved in formation of the features, as well as their morphology and characteristics in field settings. Whether liquefaction occurs is controlled mainly by sediment grain size, sediment packing, depth to the water table, and strength and duration of seismic shaking. Formation of recognizable features in the field generally requires a low-permeability cap above the sediment that liquefied. Field manifestations are controlled largely by the severity of liquefaction and the thickness and properties of the low-permeability cap. Criteria are presented for determining whether observed sediment deformation in the field originated by seismically induced liquefaction. These criteria have been developed mainly by observing historic effects of liquefaction in varied field settings. The most important criterion is that a seismic liquefaction origin requires widespread, regional development of features around a core area where the effects are most severe. In addition, the features must have a morphology that is consistent with a very sudden application of a large hydraulic force. This article discusses case studies in widely separated and different geological settings: coastal South Carolina, the New Madrid seismic zone, the Wabash Valley seismic zone, and coastal Washington State. These studies encompass most of the range of settings and the types of liquefaction-induced features likely to be encountered anywhere. The case studies describe the observed features and the logic for assigning a seismic liquefaction origin to them. Also discussed are some types of sediment deformations that can be misinterpreted as having a seismic origin. Two independent methods for estimating prehistoric magnitude are discussed briefly. One method is based on determination of the maximum distance from the epicenter over which liquefaction-induced effects have formed. The other method is based on use of geotechnical engineering techniques at sites of marginal liquefaction, in order to bracket the peak accelerations as a function of epicentral distance; these accelerations can then be compared with predictions from seismological models.","language":"English","publisher":"Elsevier","doi":"10.1016/S0074-6142(96)80074-X","issn":"00137952","usgsCitation":"Obermeier, S., 1996, Use of liquefaction-induced features for paleoseismic analysis: Engineering Geology, v. 44, no. 1-4, p. 1-76, https://doi.org/10.1016/S0074-6142(96)80074-X.","productDescription":"76 p.","startPage":"1","endPage":"76","numberOfPages":"76","costCenters":[],"links":[{"id":227631,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"44","issue":"1-4","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505bbf38e4b08c986b329a20","contributors":{"authors":[{"text":"Obermeier, S. F.","contributorId":17602,"corporation":false,"usgs":true,"family":"Obermeier","given":"S. F.","affiliations":[],"preferred":false,"id":378759,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}} ,{"id":70018453,"text":"70018453 - 1996 - Neotype designations and synonyms of some Texas caddisflies (Trichoptera)","interactions":[],"lastModifiedDate":"2012-03-12T17:19:14","indexId":"70018453","displayToPublicDate":"1996-01-01T00:00:00","publicationYear":"1996","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2556,"text":"Journal of the Kansas Entomological Society","active":true,"publicationSubtype":{"id":10}},"title":"Neotype designations and synonyms of some Texas caddisflies (Trichoptera)","docAbstract":"The uncertain taxonomic status of five species of caddisflies previously recorded from Texas is resolved. Neotypes are designated for Cheumatopsyche comis Edwards and Arnold, Polyplectropus proditus (Edwards), and Protoptila arca Edwards and Arnold. Polyplectropus proditus and C. flinti Gordon are reduced to junior synonym status with P. santiago Ross and C. comis, respectively.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Journal of the Kansas Entomological Society","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","issn":"00228567","usgsCitation":"Moulton, S., 1996, Neotype designations and synonyms of some Texas caddisflies (Trichoptera): Journal of the Kansas Entomological Society, v. 69, no. 3, p. 272-273.","startPage":"272","endPage":"273","numberOfPages":"2","costCenters":[],"links":[{"id":226987,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"69","issue":"3","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a6471e4b0c8380cd729b9","contributors":{"authors":[{"text":"Moulton, S.R. II","contributorId":26460,"corporation":false,"usgs":true,"family":"Moulton","given":"S.R.","suffix":"II","email":"","affiliations":[],"preferred":false,"id":379627,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}} ,{"id":70018779,"text":"70018779 - 1996 - Little Ice Age evidence from a south-central North American ice core, U.S.A.","interactions":[],"lastModifiedDate":"2019-02-19T06:00:22","indexId":"70018779","displayToPublicDate":"1996-01-01T00:00:00","publicationYear":"1996","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":898,"text":"Arctic and Alpine Research","active":true,"publicationSubtype":{"id":10}},"title":"Little Ice Age evidence from a south-central North American ice core, U.S.A.","docAbstract":"In the past, ice-core records from mid-latitude glaciers in alpine areas of the continental United States were considered to be poor candidates for paleoclimate records because of the influence of meltwater on isotopic stratigraphy. To evaluate the existence of reliable paleoclimatic records, a 160-m ice core, containing about 250 yr of record was obtained from Upper Fremont Glacier, at an altitude of 4000 m in the Wind River Range of south-central North America. The δ18O (SMOW) profile from the core shows a -0.95‰ shift to lighter values in the interval from 101.8 to 150 m below the surface, corresponding to the latter part of the Little Ice Age (LIA). Numerous high-amplitude oscillations in the section of the core from 101.8 to 150 m cannot be explained by site-specific lateral variability and probably reflect increased seasonality or better preservation of annual signals as a result of prolonged cooler temperatures that existed in this alpine setting. An abrupt decrease in these large amplitude oscillations at the 101.8-m depth suggests a sudden termination of this period of lower temperatures which generally coincides with the termination of the LIA. Three common features in the δ18O profiles between Upper Fremont Glacier and the better dated Quelccaya Ice Cap cores indicate a global paleoclimate linkage, further supporting the first documented occurrence of the LIA in an ice-core record from a temperate glacier in south-central North America.
","language":"English","publisher":"INSTAAR, University of Colorado","doi":"10.2307/1552083","issn":"00040851","usgsCitation":"Naftz, D.L., Klusman, R., Michel, R.L., Schuster, P., Ready, M., Taylor, H.E., Yanosky, T., and McConnaughey, E., 1996, Little Ice Age evidence from a south-central North American ice core, U.S.A.: Arctic and Alpine Research, v. 28, no. 1, p. 35-41, https://doi.org/10.2307/1552083.","productDescription":"7 p.","startPage":"35","endPage":"41","costCenters":[{"id":589,"text":"Toxic Substances Hydrology Program","active":true,"usgs":true}],"links":[{"id":227402,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"country":"United States","otherGeospatial":"Upper Fremont Glacier, Wind River Range","volume":"28","issue":"1","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a48b1e4b0c8380cd68066","contributors":{"authors":[{"text":"Naftz, D. L.","contributorId":40624,"corporation":false,"usgs":true,"family":"Naftz","given":"D.","email":"","middleInitial":"L.","affiliations":[],"preferred":false,"id":380734,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Klusman, R.W.","contributorId":93108,"corporation":false,"usgs":true,"family":"Klusman","given":"R.W.","email":"","affiliations":[],"preferred":false,"id":380738,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Michel, R. L.","contributorId":86375,"corporation":false,"usgs":true,"family":"Michel","given":"R.","email":"","middleInitial":"L.","affiliations":[],"preferred":false,"id":380737,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Schuster, P. F.","contributorId":30197,"corporation":false,"usgs":true,"family":"Schuster","given":"P. F.","affiliations":[],"preferred":false,"id":380732,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Ready, M.M.","contributorId":63968,"corporation":false,"usgs":true,"family":"Ready","given":"M.M.","email":"","affiliations":[],"preferred":false,"id":380736,"contributorType":{"id":1,"text":"Authors"},"rank":5},{"text":"Taylor, Howard E. hetaylor@usgs.gov","contributorId":1551,"corporation":false,"usgs":true,"family":"Taylor","given":"Howard","email":"hetaylor@usgs.gov","middleInitial":"E.","affiliations":[{"id":5044,"text":"National Research Program - Central Branch","active":true,"usgs":true}],"preferred":true,"id":380733,"contributorType":{"id":1,"text":"Authors"},"rank":6},{"text":"Yanosky, T.M.","contributorId":42263,"corporation":false,"usgs":true,"family":"Yanosky","given":"T.M.","email":"","affiliations":[],"preferred":false,"id":380735,"contributorType":{"id":1,"text":"Authors"},"rank":7},{"text":"McConnaughey, E.A.","contributorId":97265,"corporation":false,"usgs":true,"family":"McConnaughey","given":"E.A.","email":"","affiliations":[],"preferred":false,"id":380739,"contributorType":{"id":1,"text":"Authors"},"rank":8}]}} ,{"id":70018488,"text":"70018488 - 1996 - A quantitative look at the demise of a basaltic vent: The death of Kupaianaha, Kilauea Volcano, Hawai'i","interactions":[],"lastModifiedDate":"2019-06-06T12:58:13","indexId":"70018488","displayToPublicDate":"1996-01-01T00:00:00","publicationYear":"1996","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1109,"text":"Bulletin of Volcanology","active":true,"publicationSubtype":{"id":10}},"title":"A quantitative look at the demise of a basaltic vent: The death of Kupaianaha, Kilauea Volcano, Hawai'i","docAbstract":"The Kupaianaha vent, the source of the 48th episode of the 1983-to-present Pu'u 'O'o-Kupaianaha eruption, erupted nearly continuously from July 1986 until February 1992. This investigation documents the geophysical and geologic monitoring of the final 10 months of activity at the Kupaianaha vent. Detailed very low frequency (VLF) electromagnetic profiles across the single lava tube transporting lava from the vent were used to determine the cross-sectional area of the molten lava within the tube. Combined with measurements of lava velocity, these data provide an estimate of the lava output of Kupaianaha. In addition, lava temperatures (calculated from analysis of quenched glass) and bulk-rock chemistry were obtained for samples taken from the tube at the same site. The combined data set shows the lava flux from Kupaianaha vent declining linearly from 250000 m3/day in April 1991 to 54000 m3/day by November 1991. During that time surface breakouts of lava from weak points along the tube occurred progressively closer to the vent, consistent with declining efficiency in lava transport. There were no significant changes in lava temperature or in bulk MgO content during this period. Another eruptive episode (the 49th) began uprift of Kupaianaha on 8 November 1991 and erupted lava concurrently with Kupaianaha for 18 days. Lava flux from Kupaianaha decreased in response to this new episode, but the response was delayed by approximately 1 day. After 14 November 1991, lava velocities were no longer measurable in the tube because the lava stream beneath the skylight had crusted over; however, the VLF-derived electrical conductances documented the decreasing flux of molten lava through the tube. Kupaianaha remained active, but output continued to decrease until early February 1992 when the last active surface flows were seen. In November 1991 we used the linearly decreasing effusion rate to accurately predict the date for the death of the Kupaianaha vent. The linear nature of the decline in lava tube conductance and the delayed and slow response of the Waha'ula tube conductances to the 49th eruptive episode led us to speculate that (a) the Kupaianaha vent shut down because of a decrease in driving pressure and not because of a freeze-up of the vent, and (b) that Pu'u 'O'o, episode 49, and Kupaianaha were fed nearly vertically from a source deep within the rift zone.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Bulletin of Volcanology","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1007/s004450050117","issn":"02588900","usgsCitation":"Kauahikaua, J., Mangan, M., Heliker, C., and Mattox, T., 1996, A quantitative look at the demise of a basaltic vent: The death of Kupaianaha, Kilauea Volcano, Hawai'i: Bulletin of Volcanology, v. 57, no. 8, p. 641-648, https://doi.org/10.1007/s004450050117.","productDescription":"8 p. ","startPage":"641","endPage":"648","costCenters":[{"id":615,"text":"Volcano Hazards Program","active":true,"usgs":true}],"links":[{"id":226988,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"57","issue":"8","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"5059e525e4b0c8380cd46b6b","contributors":{"authors":[{"text":"Kauahikaua, J. 0000-0003-3777-503X","orcid":"https://orcid.org/0000-0003-3777-503X","contributorId":26087,"corporation":false,"usgs":true,"family":"Kauahikaua","given":"J.","affiliations":[],"preferred":false,"id":379779,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Mangan, M.","contributorId":20091,"corporation":false,"usgs":true,"family":"Mangan","given":"M.","affiliations":[],"preferred":false,"id":379778,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Heliker, C.","contributorId":80314,"corporation":false,"usgs":true,"family":"Heliker","given":"C.","affiliations":[],"preferred":false,"id":379781,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Mattox, T.","contributorId":75966,"corporation":false,"usgs":true,"family":"Mattox","given":"T.","affiliations":[],"preferred":false,"id":379780,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}} ,{"id":1014568,"text":"1014568 - 1996 - Ecosystem management and fishery resources of the Antarctic","interactions":[],"lastModifiedDate":"2012-02-02T00:04:28","indexId":"1014568","displayToPublicDate":"1996-01-01T00:00:00","publicationYear":"1996","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1476,"text":"Ecosystem Health","active":true,"publicationSubtype":{"id":10}},"title":"Ecosystem management and fishery resources of the Antarctic","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Ecosystem Health","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","collaboration":"96-066/PY96/TL","usgsCitation":"McKenna, J., 1996, Ecosystem management and fishery resources of the Antarctic: Ecosystem Health, v. 2, no. 2, p. 110-126.","productDescription":"p. 110-126","startPage":"110","endPage":"126","numberOfPages":"17","costCenters":[{"id":365,"text":"Leetown Science Center","active":true,"usgs":true}],"links":[{"id":132323,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"2","issue":"2","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4a4be4b07f02db62593f","contributors":{"authors":[{"text":"McKenna, J.E. Jr.","contributorId":106065,"corporation":false,"usgs":true,"family":"McKenna","given":"J.E.","suffix":"Jr.","email":"","affiliations":[],"preferred":false,"id":320631,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}} ]}