{"pageNumber":"1149","pageRowStart":"28700","pageSize":"25","recordCount":40884,"records":[{"id":70024706,"text":"70024706 - 2002 - Probability of nitrate contamination of recently recharged groundwaters in the conterminous United States","interactions":[{"subject":{"id":70046294,"text":"70046294 - 1998 - A national look at nitrate contamination of ground water","indexId":"70046294","publicationYear":"1998","noYear":false,"title":"A national look at nitrate contamination of ground water"},"predicate":"SUPERSEDED_BY","object":{"id":70024706,"text":"70024706 - 2002 - Probability of nitrate contamination of recently recharged groundwaters in the conterminous United States","indexId":"70024706","publicationYear":"2002","noYear":false,"title":"Probability of nitrate contamination of recently recharged groundwaters in the conterminous United States"},"id":1}],"lastModifiedDate":"2013-06-17T10:42:52","indexId":"70024706","displayToPublicDate":"2002-01-01T00:00:00","publicationYear":"2002","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":"Probability of nitrate contamination of recently recharged groundwaters in the conterminous United States","docAbstract":"A new logistic regression (LR) model was used to predict the probability of nitrate contamination exceeding 4 mg/L in predominantly shallow, recently recharged ground waters of the United States. The new model contains variables representing (1) N fertilizer loading (p < 0.001) , (2) percent cropland-pasture (p < 0.001), (3) natural log of human population density (p < 0.001), (4) percent well-drained soils (p < 0.001), (5) depth to the seasonally high water table (p <0.001), and (6) presence or absence of unconsolidated sand and gravel aquifers (p = 0.002). Observed and average predicted probabilities associated with deciles of risk are well correlated (r<sup>2</sup> = 0.875), indicating that the LR model fits the data well. The likelihood of nitrate contamination is greater in areas with high N loading and well-drained surficial soils over unconsolidated sand and gravels. The LR model correctly predicted the status of nitrate contamination in 75% of wells in a validation data set. Considering all wells used in both calibration and validation, observed median nitrate concentration increased from 0.24 to 8.30 mg/L as the mapped probability of nitrate exceeding 4 mg/L increased from less than or equal to 0.17 to > 0.83.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Environmental Science and Technology","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1021/es0113854","issn":"0013936X","usgsCitation":"Nolan, B.T., Hitt, K., and Ruddy, B.C., 2002, Probability of nitrate contamination of recently recharged groundwaters in the conterminous United States: Environmental Science & Technology, v. 36, no. 10, p. 2138-2145, https://doi.org/10.1021/es0113854.","startPage":"2138","endPage":"2145","numberOfPages":"8","costCenters":[],"links":[{"id":207804,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1021/es0113854"},{"id":233028,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":273804,"type":{"id":16,"text":"Metadata"},"url":"https://water.usgs.gov/GIS/metadata/usgswrd/XML/gwrisk.xml"}],"volume":"36","issue":"10","noUsgsAuthors":false,"publicationDate":"2002-04-09","publicationStatus":"PW","scienceBaseUri":"505a8cb7e4b0c8380cd7e84d","contributors":{"authors":[{"text":"Nolan, B. T.","contributorId":21565,"corporation":false,"usgs":true,"family":"Nolan","given":"B.","email":"","middleInitial":"T.","affiliations":[{"id":595,"text":"U.S. Geological Survey","active":false,"usgs":true}],"preferred":false,"id":402344,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Hitt, K.J.","contributorId":85985,"corporation":false,"usgs":true,"family":"Hitt","given":"K.J.","email":"","affiliations":[],"preferred":false,"id":402346,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Ruddy, B. C.","contributorId":65098,"corporation":false,"usgs":true,"family":"Ruddy","given":"B.","email":"","middleInitial":"C.","affiliations":[],"preferred":false,"id":402345,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}}
,{"id":70024704,"text":"70024704 - 2002 - Geology and origin of Europa's \"Mitten\" feature (Murias Chaos)","interactions":[],"lastModifiedDate":"2022-08-02T22:48:26.56362","indexId":"70024704","displayToPublicDate":"2002-01-01T00:00:00","publicationYear":"2002","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":"Geology and origin of Europa's \"Mitten\" feature (Murias Chaos)","docAbstract":"<p><span>The “Mitten” (provisionally named Murias Chaos by the International Astronomical Union) is a region of elevated chaos-like terrain in the leading hemisphere of Europa. Its origin had been explained under the currently debated theories of melting through a thin lithosphere or convection within a thick one. Galileo observations reveal several characteristics that suggest that the Mitten is distinct from typical chaos terrain and point to a different formational process. Photoclinometric elevation estimates suggest that the Mitten is slightly elevated with respect to the surrounding terrain; geologic relations indicate that it must have raised significantly from the plains in its past, resembling disrupted domes on Europa's trailing hemisphere. Moreover, the Mitten material appears to have extruded onto the plains and flowed for tens of kilometers. The area subsequently subsided as a result of isostatic adjustment, viscous relaxation, and/or plains loading. Using plate flexure models, we estimated the elastic lithosphere in the area to be several kilometers thick. We propose that the Mitten originated by the ascent and extrusion of a large thermal diapir. Thermal-mechanical modeling shows that a Mitten-sized plume would remain sufficiently warm and buoyant to pierce through the crust and flow unconfined on the surface. Such a diapir probably had an initial radius between 5 and 8 km and an initial depth of 20–40 km, consistent with a thick-lithosphere model. In this scenario the Mitten appears to represent the surface expression of the rare ascent of a large diapir, in contrast to lenticulae and chaos terrain, which may form by isolated and clustered small diapirs, respectively.</span></p>","language":"English","publisher":"American Geophysical Union","doi":"10.1029/2001JE001591","usgsCitation":"Figueredo, P.H., Chuang, F.C., Rathbun, J., Kirk, R.L., and Greeley, R., 2002, Geology and origin of Europa's \"Mitten\" feature (Murias Chaos): Journal of Geophysical Research E: Planets, v. 107, no. E5, p. 2-1-2-13, https://doi.org/10.1029/2001JE001591.","productDescription":"13 p.","startPage":"2-1","endPage":"2-13","costCenters":[],"links":[{"id":487462,"rank":1,"type":{"id":40,"text":"Open Access Publisher Index Page"},"url":"https://doi.org/10.1029/2001je001591","text":"Publisher Index Page"},{"id":232989,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"otherGeospatial":"Europa","volume":"107","issue":"E5","noUsgsAuthors":false,"publicationDate":"2002-05-09","publicationStatus":"PW","scienceBaseUri":"505a2412e4b0c8380cd57d89","contributors":{"authors":[{"text":"Figueredo, P. H.","contributorId":82499,"corporation":false,"usgs":false,"family":"Figueredo","given":"P.","email":"","middleInitial":"H.","affiliations":[],"preferred":false,"id":402335,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Chuang, F. C.","contributorId":105452,"corporation":false,"usgs":false,"family":"Chuang","given":"F.","email":"","middleInitial":"C.","affiliations":[],"preferred":false,"id":402337,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Rathbun, J.","contributorId":9814,"corporation":false,"usgs":true,"family":"Rathbun","given":"J.","affiliations":[],"preferred":false,"id":402334,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Kirk, R. L.","contributorId":94698,"corporation":false,"usgs":true,"family":"Kirk","given":"R.","email":"","middleInitial":"L.","affiliations":[],"preferred":false,"id":402336,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Greeley, R.","contributorId":6538,"corporation":false,"usgs":true,"family":"Greeley","given":"R.","email":"","affiliations":[],"preferred":false,"id":402333,"contributorType":{"id":1,"text":"Authors"},"rank":5}]}}
,{"id":70024697,"text":"70024697 - 2002 - Geochemical evidence for diversity of dust sources in the southwestern United States","interactions":[],"lastModifiedDate":"2012-03-12T17:20:14","indexId":"70024697","displayToPublicDate":"2002-01-01T00:00:00","publicationYear":"2002","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1759,"text":"Geochimica et Cosmochimica Acta","active":true,"publicationSubtype":{"id":10}},"title":"Geochemical evidence for diversity of dust sources in the southwestern United States","docAbstract":"Several potential dust sources, including generic sources of sparsely vegetated alluvium, playa deposits, and anthropogenic emissions, as well as the area around Owens Lake, California, affect the composition of modern dust in the southwestern United States. A comparison of geochemical analyses of modern and old (a few thousand years) dust with samples of potential local sources suggests that dusts reflect four primary sources: (1) alluvial sediments (represented by Hf, K, Rb, Zr, and rare-earth elements, (2) playas, most of which produce calcareous dust (Sr, associated with Ca), (3) the area of Owens (dry) Lake, a human-induced playa (As, Ba, Li, Pb, Sb, and Sr), and (4) anthropogenic and/or volcanic emissions (As, Cr, Ni, and Sb). A comparison of dust and source samples with previous analyses shows that Owens (dry) Lake and mining wastes from the adjacent Cerro Gordo mining district are the primary sources of As, Ba, Li, and Pb in dusts from Owens Valley. Decreases in dust contents of As, Ba, and Sb with distance from Owens Valley suggest that dust from southern Owens Valley is being transported at least 400 km to the east. Samples of old dust that accumulated before European settlement are distinctly lower in As, Ba, and Sb abundances relative to modern dust, likely due to modern transport of dust from Owens Valley. Thus, southern Owens Valley appears to be an important, geochemically distinct, point source for regional dust in the southwestern United States. Copyright ?? 2002 Elsevier Science Ltd.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Geochimica et Cosmochimica Acta","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1016/S0016-7037(01)00864-X","issn":"00167037","usgsCitation":"Reheis, M., Budahn, J., and Lamothe, P.J., 2002, Geochemical evidence for diversity of dust sources in the southwestern United States: Geochimica et Cosmochimica Acta, v. 66, no. 9, p. 1569-1587, https://doi.org/10.1016/S0016-7037(01)00864-X.","startPage":"1569","endPage":"1587","numberOfPages":"19","costCenters":[],"links":[{"id":207717,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/S0016-7037(01)00864-X"},{"id":232886,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"66","issue":"9","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a162ee4b0c8380cd55098","contributors":{"authors":[{"text":"Reheis, M.C. 0000-0002-8359-323X","orcid":"https://orcid.org/0000-0002-8359-323X","contributorId":36128,"corporation":false,"usgs":true,"family":"Reheis","given":"M.C.","affiliations":[],"preferred":false,"id":402313,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Budahn, J. R. 0000-0001-9794-8882","orcid":"https://orcid.org/0000-0001-9794-8882","contributorId":83914,"corporation":false,"usgs":true,"family":"Budahn","given":"J. R.","affiliations":[],"preferred":false,"id":402315,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Lamothe, P. J.","contributorId":45672,"corporation":false,"usgs":true,"family":"Lamothe","given":"P.","email":"","middleInitial":"J.","affiliations":[],"preferred":false,"id":402314,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}}
,{"id":70024696,"text":"70024696 - 2002 - Hazard assessment of selenium to endangered razorback suckers (Xyrauchen texanus)","interactions":[],"lastModifiedDate":"2017-05-24T15:53:17","indexId":"70024696","displayToPublicDate":"2002-01-01T00:00:00","publicationYear":"2002","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":3352,"text":"Science of the Total Environment","active":true,"publicationSubtype":{"id":10}},"title":"Hazard assessment of selenium to endangered razorback suckers (Xyrauchen texanus)","docAbstract":"<p><span>A hazard assessment was conducted based on information derived from two reproduction studies conducted with endangered razorback suckers (</span><i>Xyrauchen texanus</i><span>) at three sites near Grand Junction, CO, USA. Selenium contamination of the upper and lower Colorado River basin has been documented in water, sediment, and biota in studies by US Department of the Interior agencies and academia. Concern has been raised that this selenium contamination may be adversely affecting endangered fish in the upper Colorado River basin. The reproduction studies with razorback suckers revealed that adults readily accumulated selenium in various tissues including eggs, and that 4.6 μg/g of selenium in food organisms caused increased mortality of larvae. The selenium hazard assessment protocol resulted in a moderate hazard at the Horsethief site and high hazards at the Adobe Creek and North Pond sites. The selenium hazard assessment was considered conservative because an on-site toxicity test with razorback sucker larvae using 4.6 μg/g selenium in zooplankton caused nearly complete mortality, in spite of the moderate hazard at Horsethief. Using the margin of uncertainty ratio also suggested a high hazard for effects on razorback suckers from selenium exposure. Both assessment approaches suggested that selenium in the upper Colorado River basin adversely affects the reproductive success of razorback suckers.</span></p>","language":"English","publisher":"Elsevier","doi":"10.1016/S0048-9697(01)01080-4","issn":"00489697","usgsCitation":"Hamilton, S.J., Holley, K., and Buhl, K., 2002, Hazard assessment of selenium to endangered razorback suckers (Xyrauchen texanus): Science of the Total Environment, v. 291, no. 1-3, p. 111-121, https://doi.org/10.1016/S0048-9697(01)01080-4.","productDescription":"11 p.","startPage":"111","endPage":"121","numberOfPages":"11","costCenters":[{"id":192,"text":"Columbia Environmental Research Center","active":true,"usgs":true}],"links":[{"id":232885,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":207716,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/S0048-9697(01)01080-4"}],"volume":"291","issue":"1-3","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a2fc4e4b0c8380cd5d077","contributors":{"authors":[{"text":"Hamilton, S. J.","contributorId":27817,"corporation":false,"usgs":false,"family":"Hamilton","given":"S.","email":"","middleInitial":"J.","affiliations":[],"preferred":false,"id":402312,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Holley, K.M.","contributorId":13405,"corporation":false,"usgs":true,"family":"Holley","given":"K.M.","email":"","affiliations":[],"preferred":false,"id":402310,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Buhl, K.J.","contributorId":19728,"corporation":false,"usgs":true,"family":"Buhl","given":"K.J.","email":"","affiliations":[],"preferred":false,"id":402311,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}}
,{"id":70024689,"text":"70024689 - 2002 - The Emerson Lake Body: A link between the Landers and Hector Mine earthquakes, southern California, as inferred from gravity and magnetic anomalies","interactions":[],"lastModifiedDate":"2023-04-24T15:36:32.651976","indexId":"70024689","displayToPublicDate":"2002-01-01T00:00:00","publicationYear":"2002","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1135,"text":"Bulletin of the Seismological Society of America","onlineIssn":"1943-3573","printIssn":"0037-1106","active":true,"publicationSubtype":{"id":10}},"title":"The Emerson Lake Body: A link between the Landers and Hector Mine earthquakes, southern California, as inferred from gravity and magnetic anomalies","docAbstract":"<p>Gravity and magnetic data indicate a mafic crustal heterogeneity that lies between the Hector Mine 16 October 1999 (<i>M<sub>w</sub></i> 7.1) and Landers 28 June 1992 (<i>M<sub>w</sub></i> 7.3) epicenters. The aftershocks and ruptures of these two events avoided the interior of the body. Two- and three-dimensional modeling of the potential-field anomalies shows that the source, here named the Emerson Lake body (ELB), extends to a depth of approximately 15 km. The source of the gravity and magnetic anomaly is most likely Jurassic diorite because exposures of these rocks coincide with both gravity and magnetic highs west of Emerson Lake. Seismic tomography also shows higher velocities within the region of the ELB. We propose that the ELB was an important influence on the rupture geometry of the Landers and Hector Mine ruptures and that the ELB may have played a role in transferring of stress from the Landers earthquake to the Hector Mine hypocenter. Seismicity before the Landers earthquake also tended to avoid the ELB, suggesting that the ELB affects how strain is distributed in this part of the Mojave Desert. Thus, faults within the body should have limited rupture sizes and lower seismic hazard than faults bounding or outside this mafic crustal heterogeneity.</p>","language":"English","publisher":"Seismological Society of America","doi":"10.1785/0120000906","usgsCitation":"Langenheim, V., and Jachens, R., 2002, The Emerson Lake Body: A link between the Landers and Hector Mine earthquakes, southern California, as inferred from gravity and magnetic anomalies: Bulletin of the Seismological Society of America, v. 92, no. 4, p. 1606-1620, https://doi.org/10.1785/0120000906.","productDescription":"15 p.","startPage":"1606","endPage":"1620","numberOfPages":"15","costCenters":[{"id":312,"text":"Geology, Minerals, Energy, and Geophysics Science Center","active":true,"usgs":true}],"links":[{"id":232775,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"country":"United States","state":"California","otherGeospatial":"Emerson Lake","geographicExtents":"{\n  \"type\": \"FeatureCollection\",\n  \"features\": [\n    {\n      \"type\": \"Feature\",\n      \"properties\": {},\n      \"geometry\": {\n        \"coordinates\": [\n          [\n            [\n              -117,\n              35\n            ],\n            [\n              -117,\n              33.625\n            ],\n            [\n              -115.75,\n              33.625\n            ],\n            [\n              -115.75,\n              35\n            ],\n            [\n              -117,\n              35\n            ]\n          ]\n        ],\n        \"type\": \"Polygon\"\n      }\n    }\n  ]\n}","volume":"92","issue":"4","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505ba71ae4b08c986b32136d","contributors":{"authors":[{"text":"Langenheim, V.E. 0000-0003-2170-5213","orcid":"https://orcid.org/0000-0003-2170-5213","contributorId":54956,"corporation":false,"usgs":true,"family":"Langenheim","given":"V.E.","affiliations":[{"id":312,"text":"Geology, Minerals, Energy, and Geophysics Science Center","active":true,"usgs":true}],"preferred":false,"id":402261,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Jachens, R.C.","contributorId":55433,"corporation":false,"usgs":true,"family":"Jachens","given":"R.C.","email":"","affiliations":[],"preferred":false,"id":402262,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}}
,{"id":70024687,"text":"70024687 - 2002 - The geohydrologic setting of Yucca Mountain, Nevada","interactions":[],"lastModifiedDate":"2012-03-12T17:20:06","indexId":"70024687","displayToPublicDate":"2002-01-01T00:00:00","publicationYear":"2002","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":"The geohydrologic setting of Yucca Mountain, Nevada","docAbstract":"This paper provides a geologic and hydrologic framework of the Yucca Mountain region for the geochemical papers in this volume. The regional geologic units, which range in age from late Precambrian through Holocene, are briefly described. Yucca Mountain is composed of dominantly pyroclastic units that range in age from 11.4 to 15.2 Ma. The principal focus of study has been on the Paintbrush Group, which includes two major zoned and welded ash-flow tuffs separated by an important hydrogeologic unit referred to as the Paintbrush non-welded (PTn). The regional structural setting is currently one of extension, and the major local tectonic domains are presented together with a tectonic model that is consistent with the known structures at Yucca Mountain. Streamflow in this arid to semi-arid region occurs principally in intermittent or ephemeral channels. Near Yucca Mountain, the channels of Fortymile Wash and Amargosa River collect infrequent runoff from tributary basins, ultimately draining to Death Valley. Beneath the surface, large-scale interbasin flow of groundwater from one valley to another occurs commonly in the region. Regional groundwater flow beneath Yucca Mountain originates in the high mesas to the north and returns to the surface either in southern Amargosa Desert or in Death Valley, where it is consumed by evapotranspiration. The water table is very deep beneath the upland areas such as Yucca Mountain, where it is 500-750 m below the land surface, providing a large thickness of unsaturated rocks that are potentially suitable to host a nuclear-waste repository. The nature of unsaturated flow processes, which are important for assessing radionuclide migration, are inferred mainly from hydrochemical or isotopic evidence, from pneumatic tests of the fracture systems, and from the results of in situ experiments. Water seeping down through the unsaturated zone flows rapidly through fractures and more slowly through the pores of the rock matrix. Although capillary forces are expected to divert much of the flow around repository openings, some may drip onto waste packages, ultimately causing release of radionuclides, followed by transport down to the water table. ?? 2002 Elsevier Science Ltd. All rights reserved.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Applied Geochemistry","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1016/S0883-2927(02)00029-X","issn":"08832927","usgsCitation":"Stuckless, J., and Dudley, W.W., 2002, The geohydrologic setting of Yucca Mountain, Nevada: Applied Geochemistry, v. 17, no. 6, p. 659-682, https://doi.org/10.1016/S0883-2927(02)00029-X.","startPage":"659","endPage":"682","numberOfPages":"24","costCenters":[],"links":[{"id":207979,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/S0883-2927(02)00029-X"},{"id":233313,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"17","issue":"6","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505bac53e4b08c986b323412","contributors":{"authors":[{"text":"Stuckless, J. S.","contributorId":6060,"corporation":false,"usgs":true,"family":"Stuckless","given":"J. S.","affiliations":[],"preferred":false,"id":402252,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Dudley, W. W.","contributorId":101941,"corporation":false,"usgs":true,"family":"Dudley","given":"W.","email":"","middleInitial":"W.","affiliations":[],"preferred":false,"id":402253,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}}
,{"id":70024680,"text":"70024680 - 2002 - Complex earthquake rupture and local tsunamis","interactions":[],"lastModifiedDate":"2022-07-22T16:42:09.304213","indexId":"70024680","displayToPublicDate":"2002-01-01T00:00:00","publicationYear":"2002","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2314,"text":"Journal of Geophysical Research B: Solid Earth","active":true,"publicationSubtype":{"id":10}},"title":"Complex earthquake rupture and local tsunamis","docAbstract":"<p><span>In contrast to far-field tsunami amplitudes that are fairly well predicted by the seismic moment of subduction zone earthquakes, there exists significant variation in the scaling of local tsunami amplitude with respect to seismic moment. From a global catalog of tsunami runup observations this variability is greatest for the most frequently occurring tsunamigenic subduction zone earthquakes in the magnitude range of 7 &lt;&nbsp;</span><i>M</i><sub><i>w</i></sub><span>&nbsp;&lt; 8.5. Variability in local tsunami runup scaling can be ascribed to tsunami source parameters that are independent of seismic moment: variations in the water depth in the source region, the combination of higher slip and lower shear modulus at shallow depth, and rupture complexity in the form of heterogeneous slip distribution patterns. The focus of this study is on the effect that rupture complexity has on the local tsunami wave field. A wide range of slip distribution patterns are generated using a stochastic, self-affine source model that is consistent with the falloff of far-field seismic displacement spectra at high frequencies. The synthetic slip distributions generated by the stochastic source model are discretized and the vertical displacement fields from point source elastic dislocation expressions are superimposed to compute the coseismic vertical displacement field. For shallow subduction zone earthquakes it is demonstrated that self-affine irregularities of the slip distribution result in significant variations in local tsunami amplitude. The effects of rupture complexity are less pronounced for earthquakes at greater depth or along faults with steep dip angles. For a test region along the Pacific coast of central Mexico, peak nearshore tsunami amplitude is calculated for a large number (</span><i>N</i><span>&nbsp;= 100) of synthetic slip distribution patterns, all with identical seismic moment (</span><i>M</i><sub><i>w</i></sub><span>&nbsp;= 8.1). Analysis of the results indicates that for earthquakes of a fixed location, geometry, and seismic moment, peak nearshore tsunami amplitude can vary by a factor of 3 or more. These results indicate that there is substantially more variation in the local tsunami wave field derived from the inherent complexity subduction zone earthquakes than predicted by a simple elastic dislocation model. Probabilistic methods that take into account variability in earthquake rupture processes are likely to yield more accurate assessments of tsunami hazards.</span></p>","language":"English","publisher":"American Geophysical Union","doi":"10.1029/2000JB000139","usgsCitation":"Geist, E.L., 2002, Complex earthquake rupture and local tsunamis: Journal of Geophysical Research B: Solid Earth, v. 107, no. B5, p. ESE 2-1-ESE 2-15, https://doi.org/10.1029/2000JB000139.","productDescription":"15 p.","startPage":"ESE 2-1","endPage":"ESE 2-15","costCenters":[],"links":[{"id":478717,"rank":1,"type":{"id":40,"text":"Open Access Publisher Index Page"},"url":"https://doi.org/10.1029/2000jb000139","text":"Publisher Index Page"},{"id":233203,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"107","issue":"B5","noUsgsAuthors":false,"publicationDate":"2002-05-02","publicationStatus":"PW","scienceBaseUri":"5059f90de4b0c8380cd4d3db","contributors":{"authors":[{"text":"Geist, Eric L","contributorId":118729,"corporation":false,"usgs":true,"family":"Geist","given":"Eric","email":"","middleInitial":"L","affiliations":[],"preferred":false,"id":402212,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}}
,{"id":70024678,"text":"70024678 - 2002 - Uranium-series disequilibrium in tuffs from Yucca Mountain, Nevada, as evidence of pore-fluid flow over the last million years","interactions":[],"lastModifiedDate":"2012-03-12T17:20:07","indexId":"70024678","displayToPublicDate":"2002-01-01T00:00:00","publicationYear":"2002","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":"Uranium-series disequilibrium in tuffs from Yucca Mountain, Nevada, as evidence of pore-fluid flow over the last million years","docAbstract":"Samples of tuff from boreholes drilled into fault zones in the Exploratory Studies Facility (ESF) and relatively unfractured rock of the Cross Drift tunnels, at Yucca Mountain, Nevada, have been analysed by U-series methods. This work is part of a project to verify the finding of fast flow-paths through the tuff to ESF level, indicated by the presence of 'bomb' 36Cl in pore fluids. Secular radioactive equilibrium in the U decay series, (i.e. when the radioactivity ratios 234U/238U, 230Th/234U and 226Ra/230Th all equal 1.00) might be expected if the tuff samples have not experienced radionuclide loss due to rock-water interaction occurring within the last million years. However, most fractured and unfractured samples were found to have a small deficiency of 234U (weighted mean 234U/238U=0.95??0.01) and a small excess of 230Th (weighted mean 230Th/234U 1.10??0.02). The 226Ra/230Th ratios are close to secular equilibrium (weighted mean = 0.94??0.07). These data indicate that 234U has been removed from the rock samples in the last ???350 ka, probably by pore fluids. Within the precision of the measurement, it would appear that 226Ra has not been mobilized and removed from the tuff, although there may be some localised 226Ra redistribution as suggested by a few ratio values that are significantly different from 1.0. Because both fractured and unfractured tuffs show approximately the same deficiency of 234U, this indicates that pore fluids are moving equally through fractured and unfractured rock, More importantly, fractured rock appears not to be a dominant pathway for groundwater flow (otherwise the ratio would be more strongly affected and the Th and Ra isotopic ratios would likely also show disequilibrium). Application of a simple mass-balance model suggests that surface infiltration rate is over an order of magnitude greater than the rate indicated by other infiltration models and that residence time of pore fluids at ESF level is about 400 a. Processes of U sorption, precipitation and re-solution are believed to be occurring and would account for these anomalous results but have not been included in the model. Despite the difficulties, the U-series data suggest that fractured rock, specifically the Sundance and Drill Hole Wash faults, are not preferred flow paths for groundwater flowing through the Topopah Spring tuff and, by implication, rapid-flow, within 50 a, from the surface to the level of the ESF is improbable. ?? 2002 Elsevier Science Ltd. All rights reserved.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Applied Geochemistry","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1016/S0883-2927(02)00038-0","issn":"08832927","usgsCitation":"Gascoyne, M., Miller, N., and Neymark, L., 2002, Uranium-series disequilibrium in tuffs from Yucca Mountain, Nevada, as evidence of pore-fluid flow over the last million years: Applied Geochemistry, v. 17, no. 6, p. 781-792, https://doi.org/10.1016/S0883-2927(02)00038-0.","startPage":"781","endPage":"792","numberOfPages":"12","costCenters":[],"links":[{"id":233170,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":207891,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/S0883-2927(02)00038-0"}],"volume":"17","issue":"6","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505bbe00e4b08c986b329362","contributors":{"authors":[{"text":"Gascoyne, M.","contributorId":74918,"corporation":false,"usgs":true,"family":"Gascoyne","given":"M.","affiliations":[],"preferred":false,"id":402209,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Miller, N.H.","contributorId":37117,"corporation":false,"usgs":true,"family":"Miller","given":"N.H.","email":"","affiliations":[],"preferred":false,"id":402207,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Neymark, L.A. 0000-0003-4190-0278","orcid":"https://orcid.org/0000-0003-4190-0278","contributorId":56673,"corporation":false,"usgs":true,"family":"Neymark","given":"L.A.","affiliations":[],"preferred":false,"id":402208,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}}
,{"id":70024673,"text":"70024673 - 2002 - Influence of fracture anisotropy on ground water ages and chemistry, Valley and Ridge province, Pennsylvania","interactions":[],"lastModifiedDate":"2018-11-28T10:23:23","indexId":"70024673","displayToPublicDate":"2002-01-01T00:00:00","publicationYear":"2002","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1861,"text":"Ground Water","active":true,"publicationSubtype":{"id":10}},"title":"Influence of fracture anisotropy on ground water ages and chemistry, Valley and Ridge province, Pennsylvania","docAbstract":"Model ground water ages based on chlorofluorocarbons (CFCs) and tritium/helium-3 (3H/3He) data were obtained from two arrays of nested piezometers located on the north limb of an anticline in fractured sedimentary rocks in the Valley and Ridge geologic province of Pennsylvania. The fracture geometry of the gently east plunging fold is very regular and consists predominately of south dipping to subhorizontal to north dipping bedding-plane parting and east striking, steeply dipping axial-plane spaced cleavage. In the area of the piezometer arrays, which trend north-south on the north limb of the fold, north dipping bedding-plane parting is a more dominant fracture set than is steeply south dipping axial-plane cleavage. The dating of ground water from the piezometer arrays reveals that ground water traveling along paths parallel to the dip direction of bedding-plane parting has younger 3H/3He and CFC model ages, or a greater component of young water, than does ground water traveling along paths opposite to the dip direction. In predominantly unmixed samples there is a strong positive correlation between age of the young fraction of water and dissolved sodium concentration. The travel times inferred from the model ages are significantly longer than those previously calculated by a ground water flow model, which assumed isotropically fractured layers parallel to topography. A revised model factors in the directional anisotropy to produce longer travel times. Ground water travel times in the watershed therefore appear to be more influenced by anisotropic fracture geometry than previously realized. This could have significant implications for ground water models in other areas underlain by similarly tilted or folded sedimentary rock, such as elsewhere in the Valley and Ridge or the early Mesozoic basins.","language":"English","publisher":"Wiley","doi":"10.1111/j.1745-6584.2002.tb02652.x","issn":"0017467X","usgsCitation":"Burton, W., Plummer, N., Busenberg, E., Lindsey, B., and Gburek, W., 2002, Influence of fracture anisotropy on ground water ages and chemistry, Valley and Ridge province, Pennsylvania: Ground Water, v. 40, no. 3, p. 242-257, https://doi.org/10.1111/j.1745-6584.2002.tb02652.x.","productDescription":"16 p.","startPage":"242","endPage":"257","costCenters":[{"id":589,"text":"Toxic Substances Hydrology Program","active":true,"usgs":true}],"links":[{"id":233096,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"country":"United States","state":"Pennsylvania","otherGeospatial":"Valley and Ridge Province","volume":"40","issue":"3","noUsgsAuthors":false,"publicationDate":"2005-12-13","publicationStatus":"PW","scienceBaseUri":"505a3b3ae4b0c8380cd6233c","contributors":{"authors":[{"text":"Burton, W.C.","contributorId":41439,"corporation":false,"usgs":true,"family":"Burton","given":"W.C.","email":"","affiliations":[],"preferred":false,"id":402186,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Plummer, Niel 0000-0002-4020-1013 nplummer@usgs.gov","orcid":"https://orcid.org/0000-0002-4020-1013","contributorId":190100,"corporation":false,"usgs":true,"family":"Plummer","given":"Niel","email":"nplummer@usgs.gov","affiliations":[{"id":436,"text":"National Research Program - Eastern Branch","active":true,"usgs":true}],"preferred":true,"id":402189,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Busenberg, E.","contributorId":56796,"corporation":false,"usgs":true,"family":"Busenberg","given":"E.","affiliations":[],"preferred":false,"id":402187,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Lindsey, B.D.","contributorId":89696,"corporation":false,"usgs":true,"family":"Lindsey","given":"B.D.","email":"","affiliations":[],"preferred":false,"id":402190,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Gburek, W.J.","contributorId":76098,"corporation":false,"usgs":true,"family":"Gburek","given":"W.J.","affiliations":[],"preferred":false,"id":402188,"contributorType":{"id":1,"text":"Authors"},"rank":5}]}}
,{"id":70024670,"text":"70024670 - 2002 - U-Pb ages of secondary silica at Yucca Mountain, Nevada: Implications for the paleohydrology of the unsaturated zone","interactions":[],"lastModifiedDate":"2012-03-12T17:20:07","indexId":"70024670","displayToPublicDate":"2002-01-01T00:00:00","publicationYear":"2002","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":"U-Pb ages of secondary silica at Yucca Mountain, Nevada: Implications for the paleohydrology of the unsaturated zone","docAbstract":"Uranium, Th and Pb isotopes were analyzed in layers of opal and chalcedony from individual mm- to cm-thick calcite and silica coatings at Yucca Mountain, Nevada, USA, a site that is being evaluated for a potential high-level nuclear waste repository. These calcite and silica coatings on fractures and in lithophysal cavities in Miocene-age tuffs in the unsaturated zone (UZ) precipitated from descending water and record a long history of percolation through the UZ. Opal and chalcedony have high concentrations of U (10 to 780 ppm) and low concentrations of common Pb as indicated by large values of 206Pb/204Pb (up to 53,806), thus making them suitable for U-Pb age determinations. Interpretations of U-Pb isotope systems in opal samples at Yucca Mountain are complicated by the incorporation of excess 234U at the time of mineral formation, resulting in reverse discordance of U-Pb ages. However, the 207PB/235U ages are much less affected by deviation from initial secular equilibrium and provide reliable ages of most silica deposits between 0.6 and 9.8 Ma. For chalcedony subsamples showing normal age discordance, these ages may represent minimum times of deposition. Typically, 207Pb/235U ages are consistent with the microstratigraphy in the mineral coating samples, such that the youngest ages are for subsamples from outer layers, intermediate ages are from inner layers, and oldest ages are from innermost layers. 234U and 230Th in most silica layers deeper in the coatings are in secular equilibrium with 238U, which is consistent with their old age and closed system behavior during the past -0.5 Ma. The ages for subsamples of silica layers from different microstratigraphic positions in individual calcite and silica coating samples collected from lithophysal cavities in the welded part of the Topopah Spring Tuff yield slow long-term average growth rates of 1 to 5 mm/Ma. These data imply that the deeper parts of the UZ at Yucca Mountain maintained long-term hydrologic stability over the past 10 Ma. despite significant climate variations. U-Pb ages for subsamples of silica layers from different microstratigraphic positions in individual calcite and silica coating samples collected from fractures in the shallower part of the UZ (welded part of the overlying Tiva Canyon Tuff) indicate larger long-term average growth rates up to 23 mm/Ma and an absence of recently deposited materials (ages of outermost layers are 3-5 Ma.). These differences between the characteristics of the coatings for samples from the shallower and deeper parts of the UZ may indicate that the nonwelded tuffs (PTn), located between the welded parts of the Tiva Canyon and Topopah Spring Tuffs, play an important role in moderating UZ flow.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Applied Geochemistry","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1016/S0883-2927(02)00032-X","issn":"08832927","usgsCitation":"Neymark, L., Amelin, Y., Paces, J., and Peterman, Z.E., 2002, U-Pb ages of secondary silica at Yucca Mountain, Nevada: Implications for the paleohydrology of the unsaturated zone: Applied Geochemistry, v. 17, no. 6, p. 709-734, https://doi.org/10.1016/S0883-2927(02)00032-X.","startPage":"709","endPage":"734","numberOfPages":"26","costCenters":[],"links":[{"id":478726,"rank":10000,"type":{"id":41,"text":"Open Access External Repository Page"},"url":"https://digital.library.unt.edu/ark:/67531/metadc740548/","text":"External Repository"},{"id":207826,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/S0883-2927(02)00032-X"},{"id":233061,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"17","issue":"6","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505bb9c3e4b08c986b327dba","contributors":{"authors":[{"text":"Neymark, L.A. 0000-0003-4190-0278","orcid":"https://orcid.org/0000-0003-4190-0278","contributorId":56673,"corporation":false,"usgs":true,"family":"Neymark","given":"L.A.","affiliations":[],"preferred":false,"id":402174,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Amelin, Y.","contributorId":62800,"corporation":false,"usgs":true,"family":"Amelin","given":"Y.","affiliations":[],"preferred":false,"id":402175,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Paces, J.B. 0000-0002-9809-8493","orcid":"https://orcid.org/0000-0002-9809-8493","contributorId":27482,"corporation":false,"usgs":true,"family":"Paces","given":"J.B.","affiliations":[],"preferred":false,"id":402173,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Peterman, Z. E.","contributorId":63781,"corporation":false,"usgs":true,"family":"Peterman","given":"Z.","email":"","middleInitial":"E.","affiliations":[],"preferred":false,"id":402176,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}}
,{"id":70024657,"text":"70024657 - 2002 - Strain accumulation and rotation in western Oregon and southwestern Washington","interactions":[],"lastModifiedDate":"2023-04-24T14:05:53.146701","indexId":"70024657","displayToPublicDate":"2002-01-01T00:00:00","publicationYear":"2002","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2314,"text":"Journal of Geophysical Research B: Solid Earth","active":true,"publicationSubtype":{"id":10}},"title":"Strain accumulation and rotation in western Oregon and southwestern Washington","docAbstract":"<p><span>Velocities of 75 geodetic monuments in western Oregon and southwestern Washington extending from the coast to more than 300 km inland have been determined from GPS surveys over the interval 1992–2000. The average standard deviation in each of the horizontal velocity components is ∼1 mm yr</span><sup>−1</sup><span>. The observed velocity field is approximated by a combination of rigid rotation (Euler vector relative to interior North America: 43.40°N ± 0.14°, 119.33°W ± 0.28°, and 0.822 ± 0.057° Myr</span><sup>−1</sup><span>&nbsp;clockwise; quoted uncertainties are standard deviations), uniform regional strain rate (ε</span><sub>EE</sub><span>&nbsp;= −7.4 ± 1.8, ε</span><sub>EN</sub><span>&nbsp;= −3.4 ± 1.0, and ε</span><sub>NN</sub><span>&nbsp;= −5.0 ± 0.8 nstrain yr</span><sup>−1</sup><span>, extension reckoned positive), and a dislocation model representing subduction of the Juan de Fuca plate beneath North America. Subduction south of 44.5°N was represented by a 40‐km‐wide locked thrust and subduction north of 44.5°N by a 75‐km‐wide locked thrust.</span></p>","language":"English","publisher":"Wiley","doi":"10.1029/2001JB000625","usgsCitation":"Svarc, J.L., Savage, J., Prescott, W., and Murray, M., 2002, Strain accumulation and rotation in western Oregon and southwestern Washington: Journal of Geophysical Research B: Solid Earth, v. 107, no. B5, p. ETG 1-1-ETG 1-8, https://doi.org/10.1029/2001JB000625.","productDescription":"8 p.","startPage":"ETG 1-1","endPage":"ETG 1-8","costCenters":[],"links":[{"id":478768,"rank":2,"type":{"id":40,"text":"Open Access Publisher Index Page"},"url":"https://doi.org/10.1029/2001jb000625","text":"Publisher Index Page"},{"id":232810,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"country":"United States","state":"Oregon, Washington","geographicExtents":"{\n  \"type\": \"FeatureCollection\",\n  \"features\": [\n    {\n      \"type\": \"Feature\",\n      \"properties\": {},\n      \"geometry\": {\n        \"type\": \"Polygon\",\n        \"coordinates\": [\n          [\n            [\n              -126.62841796875,\n              41.52502957323801\n            ],\n            [\n              -114.89501953124999,\n              41.52502957323801\n            ],\n            [\n              -114.89501953124999,\n              48.122101028190805\n            ],\n            [\n              -126.62841796875,\n              48.122101028190805\n            ],\n            [\n              -126.62841796875,\n              41.52502957323801\n            ]\n          ]\n        ]\n      }\n    }\n  ]\n}","volume":"107","issue":"B5","noUsgsAuthors":false,"publicationDate":"2002-05-07","publicationStatus":"PW","scienceBaseUri":"505b9894e4b08c986b31c0ab","contributors":{"authors":[{"text":"Svarc, J. L.","contributorId":75995,"corporation":false,"usgs":true,"family":"Svarc","given":"J.","email":"","middleInitial":"L.","affiliations":[],"preferred":false,"id":402122,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Savage, J.C. 0000-0002-5114-7673","orcid":"https://orcid.org/0000-0002-5114-7673","contributorId":102876,"corporation":false,"usgs":true,"family":"Savage","given":"J.C.","affiliations":[],"preferred":false,"id":402124,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Prescott, W.H.","contributorId":96337,"corporation":false,"usgs":true,"family":"Prescott","given":"W.H.","email":"","affiliations":[],"preferred":false,"id":402123,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Murray, M.H.","contributorId":50171,"corporation":false,"usgs":true,"family":"Murray","given":"M.H.","email":"","affiliations":[],"preferred":false,"id":402121,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}}
,{"id":70024655,"text":"70024655 - 2002 - The western pond turtle (Clemmys marmorata) in the Mojave River, California, USA: Highly adapted survivor or tenuous relict?","interactions":[],"lastModifiedDate":"2022-08-10T15:24:34.308271","indexId":"70024655","displayToPublicDate":"2002-01-01T00:00:00","publicationYear":"2002","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2515,"text":"Journal of Zoology","active":true,"publicationSubtype":{"id":10}},"displayTitle":"The western pond turtle (<i>Clemmys marmorata</i>) in the Mojave River, California, USA: Highly adapted survivor or tenuous relict?","title":"The western pond turtle (Clemmys marmorata) in the Mojave River, California, USA: Highly adapted survivor or tenuous relict?","docAbstract":"<p><span>Aspects of the ecology of populations of the western pond turtle&nbsp;</span><i>Clemmys marmorata</i><span>&nbsp;were investigated in the Mojave River of the central Mojave Desert, California, U.S.A. One population occupied man-made ponds and the other occurred in natural ponds in the flood plain of the Mojave River. Both habitats are severely degraded as a result of ground water depletion from human activities along the river and one is infested with the exotic shrub saltcedar&nbsp;</span><i>Tamarix ramosissima</i><span>. Mean female carapace length (CL) was significantly greater (14.4 cm) than that of males (13.7 cm). Live juveniles were not detected during the period of study. Shelled eggs were visible in X-radiographs from 26 May to 14 July. Mean clutch size was 4.46 and ranged from 3 to 6 eggs. Clutch size did not vary between 1998 and 1999 but was significantly correlated with CL for both years combined, increasing at the rate of 0.548 eggs/cm CL. Gravid female CL ranged from 13.3–16.0 cm. Some females nested in both years. Mean X-ray egg width (21.8 mm) was not significantly correlated with CL or clutch size. X-ray egg width differed more among clutches than within, whether including CL as a co-variate or not. Nesting migrations occurred from 6 June to 8 July with minimum round trip distances ranging from 17.5–585 m with a mean of 195 m. Mean estimated time of departure as measured at the drift fence was 18:13. Most females returned to the ponds in the early morning. Nesting migrations required females to be out of the water for estimated periods of 0.83 to 86 h. The destination of nesting females was typically fluvial sand bars in the channel of the dry riverbed. Overall, the ecology of&nbsp;</span><i>C. marmorata</i><span>&nbsp;in the Mojave River is very similar to that reported for populations in less severe habitats along the west coast of the United States. Notable exceptions include long nesting migrations to sandbars in the dry river channel, a possible result of human modifications to the environment, and an apparent lack of terrestrial overwintering behaviour in Mojave River populations. The general similarity of desert and coastal populations is possibly a reflection of their recent geographic separation. Overall, populations in the Mojave River exhibit few obvious adaptations to living in the desert and are considered to be tenuous relicts of the Pleistocene. The small size and tenuous status of these populations suggests that immediate conservation action is needed, including establishment of satellite populations as a hedge against extirpation.</span></p>","language":"English","publisher":"Zoological Society of London","doi":"10.1017/S0952836902000584","usgsCitation":"Lovich, J., and Meyer, K., 2002, The western pond turtle (Clemmys marmorata) in the Mojave River, California, USA: Highly adapted survivor or tenuous relict?: Journal of Zoology, v. 256, no. 4, p. 537-545, https://doi.org/10.1017/S0952836902000584.","productDescription":"9 p.","startPage":"537","endPage":"545","numberOfPages":"9","costCenters":[],"links":[{"id":232773,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"country":"United States","state":"California","otherGeospatial":"Afton  Canyon area, Camp Cady Wildlife  Area, Mojave River","geographicExtents":"{\n  \"type\": \"FeatureCollection\",\n  \"features\": [\n    {\n      \"type\": \"Feature\",\n      \"properties\": {},\n      \"geometry\": {\n        \"type\": \"Polygon\",\n        \"coordinates\": [\n          [\n            [\n              -116.4935302734375,\n              34.83071390101431\n            ],\n            [\n              -116.17767333984375,\n              34.83071390101431\n            ],\n            [\n              -116.17767333984375,\n              35.08620310578525\n            ],\n            [\n              -116.4935302734375,\n              35.08620310578525\n            ],\n            [\n              -116.4935302734375,\n              34.83071390101431\n            ]\n          ]\n        ]\n      }\n    }\n  ]\n}","volume":"256","issue":"4","noUsgsAuthors":false,"publicationDate":"2006-02-28","publicationStatus":"PW","scienceBaseUri":"505bb1dae4b08c986b325459","contributors":{"authors":[{"text":"Lovich, J.","contributorId":30944,"corporation":false,"usgs":true,"family":"Lovich","given":"J.","affiliations":[],"preferred":false,"id":402119,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Meyer, K.","contributorId":28204,"corporation":false,"usgs":true,"family":"Meyer","given":"K.","email":"","affiliations":[],"preferred":false,"id":402118,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}}
,{"id":70024649,"text":"70024649 - 2002 - Comparison of an algebraic multigrid algorithm to two iterative solvers used for modeling ground water flow and transport","interactions":[],"lastModifiedDate":"2022-01-21T16:15:53.988876","indexId":"70024649","displayToPublicDate":"2002-01-01T00:00:00","publicationYear":"2002","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1861,"text":"Ground Water","active":true,"publicationSubtype":{"id":10}},"title":"Comparison of an algebraic multigrid algorithm to two iterative solvers used for modeling ground water flow and transport","docAbstract":"Numerical solution of large-scale ground water flow and transport problems is often constrained by the convergence behavior of the iterative solvers used to solve the resulting systems of equations. We demonstrate the ability of an algebraic multigrid algorithm (AMG) to efficiently solve the large, sparse systems of equations that result from computational models of ground water flow and transport in large and complex domains. Unlike geometric multigrid methods, this algorithm is applicable to problems in complex flow geometries, such as those encountered in pore-scale modeling of two-phase flow and transport. We integrated AMG into MODFLOW 2000 to compare two- and three-dimensional flow simulations using AMG to simulations using PCG2, a preconditioned conjugate gradient solver that uses the modified incomplete Cholesky preconditioner and is included with MODFLOW 2000. CPU times required for convergence with AMG were up to 140 times faster than those for PCG2. The cost of this increased speed was up to a nine-fold increase in required random access memory (RAM) for the three-dimensional problems and up to a four-fold increase in required RAM for the two-dimensional problems. We also compared two-dimensional numerical simulations of steady-state transport using AMG and the generalized minimum residual method with an incomplete LU-decomposition preconditioner. For these transport simulations, AMG yielded increased speeds of up to 17 times with only a 20% increase in required RAM. The ability of AMG to solve flow and transport problems in large, complex flow systems and its ready availability make it an ideal solver for use in both field-scale and pore-scale modeling.","language":"English","publisher":"Wiley","doi":"10.1111/j.1745-6584.2002.tb02654.x","usgsCitation":"Detwiler, R., Mehl, S., Rajaram, H., and Cheung, W., 2002, Comparison of an algebraic multigrid algorithm to two iterative solvers used for modeling ground water flow and transport: Ground Water, v. 40, no. 3, p. 267-272, https://doi.org/10.1111/j.1745-6584.2002.tb02654.x.","productDescription":"6 p.","startPage":"267","endPage":"272","costCenters":[],"links":[{"id":233238,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"40","issue":"3","noUsgsAuthors":false,"publicationDate":"2005-12-13","publicationStatus":"PW","scienceBaseUri":"5059f84ee4b0c8380cd4cfec","contributors":{"authors":[{"text":"Detwiler, R.L.","contributorId":51952,"corporation":false,"usgs":true,"family":"Detwiler","given":"R.L.","email":"","affiliations":[],"preferred":false,"id":402097,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Mehl, S.","contributorId":20114,"corporation":false,"usgs":true,"family":"Mehl","given":"S.","affiliations":[],"preferred":false,"id":402095,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Rajaram, H.","contributorId":39547,"corporation":false,"usgs":true,"family":"Rajaram","given":"H.","affiliations":[],"preferred":false,"id":402096,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Cheung, W.W.","contributorId":63202,"corporation":false,"usgs":true,"family":"Cheung","given":"W.W.","email":"","affiliations":[],"preferred":false,"id":402098,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}}
,{"id":70024639,"text":"70024639 - 2002 - Web-based distribution of geo-scientific models","interactions":[],"lastModifiedDate":"2012-03-12T17:20:06","indexId":"70024639","displayToPublicDate":"2002-01-01T00:00:00","publicationYear":"2002","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1315,"text":"Computers & Geosciences","printIssn":"0098-3004","active":true,"publicationSubtype":{"id":10}},"title":"Web-based distribution of geo-scientific models","docAbstract":"[No abstract available]","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Computers and Geosciences","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1016/S0098-3004(01)00090-5","issn":"00983004","usgsCitation":"Markstrom, S., McCabe, G., and David, O., 2002, Web-based distribution of geo-scientific models: Computers & Geosciences, v. 28, no. 4, p. 577-581, https://doi.org/10.1016/S0098-3004(01)00090-5.","startPage":"577","endPage":"581","numberOfPages":"5","costCenters":[],"links":[{"id":207873,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/S0098-3004(01)00090-5"},{"id":233131,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"28","issue":"4","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505bcfc5e4b08c986b32eac7","contributors":{"authors":[{"text":"Markstrom, S.L.","contributorId":76807,"corporation":false,"usgs":true,"family":"Markstrom","given":"S.L.","email":"","affiliations":[],"preferred":false,"id":402062,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"McCabe, G.","contributorId":77637,"corporation":false,"usgs":true,"family":"McCabe","given":"G.","affiliations":[],"preferred":false,"id":402063,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"David, O.","contributorId":7468,"corporation":false,"usgs":true,"family":"David","given":"O.","email":"","affiliations":[],"preferred":false,"id":402061,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}}
,{"id":70024630,"text":"70024630 - 2002 - Material-balance assessment of the New Albany-Chesterian petroleum system of the Illinois basin","interactions":[],"lastModifiedDate":"2021-12-03T16:55:13.785237","indexId":"70024630","displayToPublicDate":"2002-01-01T00:00:00","publicationYear":"2002","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":701,"text":"American Association of Petroleum Geologists Bulletin","active":true,"publicationSubtype":{"id":10}},"title":"Material-balance assessment of the New Albany-Chesterian petroleum system of the Illinois basin","docAbstract":"The New Albany-Chesterian petroleum system of the Illinois basin is a well-constrained system from which petroleum charges and losses were quantified through a material-balance assessment. This petroleum system has nearly 90,000 wells penetrating the Chesterian section, a single New Albany Shale source rock accounting for more than 99% of the produced oil, well-established stratigraphic and structural frameworks, and accessible source rock samples at various maturity levels. A hydrogen index (HI) map based on Rock-Eval analyses of source rock samples of New Albany Shale defines the pod of active source rock and extent of oil generation. Based on a buoyancy-drive model, the system was divided into seven secondary-migration catchments. Each catchment contains a part of the active pod of source rock from which it derives a petroleum charge, and this charge is confined to carrier beds and reservoirs within these catchments as accountable petroleum, petroleum losses, or undiscovered petroleum. A well-constrained catchment with no apparent erosional or leakage losses is used to determine an actual petroleum charge from accountable petroleum and residual migration losses. This actual petroleum charge is used to calibrate the other catchments in which erosional petroleum losses have occurred. Petroleum charges determined by laboratory pyrolysis are exaggerated relative to the actual petroleum charge. Rock-Eval charges are exaggerated by a factor of 4-14, and hydrouspyrolysis charges are exaggerated by a factor of 1.7. The actual petroleum charge provides a more meaningful material balance and more realistic estimates of petroleum losses and remaining undiscovered petroleum. The total petroleum charge determined for the New Albany-Chesterian system is 78 billion bbl, of which 11.4 billion bbl occur as a accountable in place petroleum, 9 billion bbl occur as residual migration losses, and 57.6 billion bbl occur as erosional losses. Of the erosional losses, 40 billion bbl were lost from two catchments that have highly faulted and extensively eroded sections. Anomalies in the relationship between erosional losses and degree of erosion suggest there is potential for undiscovered petroleum in one of the catchments. These results demonstrate that a material-balance assessment of migration catchments provides a useful means to evaluate and rank areas within a petroleum system. The article provides methodologies for obtaining more realistic petroleum charges and losses that can be applied to less data-rich petroleum systems.","language":"English","publisher":"AAPG","doi":"10.1306/61EEDB8E-173E-11D7-8645000102C1865D","usgsCitation":"Lewan, M.D., Henry, M.E., Higley, D., and Pitman, J.K., 2002, Material-balance assessment of the New Albany-Chesterian petroleum system of the Illinois basin: American Association of Petroleum Geologists Bulletin, v. 86, no. 5, p. 745-778, https://doi.org/10.1306/61EEDB8E-173E-11D7-8645000102C1865D.","productDescription":"34 p.","startPage":"745","endPage":"778","costCenters":[{"id":164,"text":"Central Energy Resources Science Center","active":true,"usgs":true}],"links":[{"id":232984,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"country":"United States","state":"Illinois, Indiana, Kentucky","geographicExtents":"{\n  \"type\": \"FeatureCollection\",\n  \"features\": [\n    {\n      \"type\": \"Feature\",\n      \"properties\": {},\n      \"geometry\": {\n        \"type\": \"Polygon\",\n        \"coordinates\": [\n          [\n            [\n              -89.384765625,\n              36.98500309285596\n            ],\n            [\n              -87.8466796875,\n              37.405073750176925\n            ],\n            [\n              -86.572265625,\n              37.37015718405753\n            ],\n            [\n              -87.1875,\n              40.212440718286466\n            ],\n            [\n              -89.033203125,\n              40.88029480552824\n            ],\n            [\n              -91.0546875,\n              40.91351257612758\n            ],\n            [\n              -89.384765625,\n              36.98500309285596\n            ]\n          ]\n        ]\n      }\n    }\n  ]\n}","volume":"86","issue":"5","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a5277e4b0c8380cd6c432","contributors":{"authors":[{"text":"Lewan, M. D.","contributorId":46540,"corporation":false,"usgs":true,"family":"Lewan","given":"M.","email":"","middleInitial":"D.","affiliations":[],"preferred":false,"id":402013,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Henry, M. E.","contributorId":103734,"corporation":false,"usgs":true,"family":"Henry","given":"M.","email":"","middleInitial":"E.","affiliations":[],"preferred":false,"id":402016,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Higley, D.K. 0000-0001-8024-9954","orcid":"https://orcid.org/0000-0001-8024-9954","contributorId":90261,"corporation":false,"usgs":true,"family":"Higley","given":"D.K.","affiliations":[{"id":164,"text":"Central Energy Resources Science Center","active":true,"usgs":true}],"preferred":false,"id":402014,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Pitman, Janet K. 0000-0002-0441-779X jpitman@usgs.gov","orcid":"https://orcid.org/0000-0002-0441-779X","contributorId":767,"corporation":false,"usgs":true,"family":"Pitman","given":"Janet","email":"jpitman@usgs.gov","middleInitial":"K.","affiliations":[{"id":164,"text":"Central Energy Resources Science Center","active":true,"usgs":true},{"id":241,"text":"Eastern Energy Resources Science Center","active":true,"usgs":true}],"preferred":true,"id":402015,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}}
,{"id":70024627,"text":"70024627 - 2002 - Geology and geochemistry of Carlin-type gold deposits in China","interactions":[],"lastModifiedDate":"2012-03-12T17:20:13","indexId":"70024627","displayToPublicDate":"2002-01-01T00:00:00","publicationYear":"2002","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2746,"text":"Mineralium Deposita","active":true,"publicationSubtype":{"id":10}},"title":"Geology and geochemistry of Carlin-type gold deposits in China","docAbstract":"The Carlin-type gold deposits in China lie mostly near the margins of the Proterozoic Yangtze and Aba cratons. Submicron-sized gold in micron-sized arsenian pyrite is disseminated in fractured Cambrian through Triassic carbonaceous shale and carbonate rocks, and is associated with anomalous Hg, Sb, As, U, and Tl. Alteration typically includes silicification, argilization, and sulfidation. Aqueous fluid inclusions contain CO2, have relatively low temperatures of homogenization (250-150 ??C), and salinities (8-2 wt% equiv. NaCl) that typically decrease from early to later stages. The indicated pressures of 105-330x105 Pa correspond to depths in excess of 1.0 to 3.0 km, assuming hydrostatic conditions. The ??D values of fluid inclusions (-87 to -47%) and the calculated ??18 values for water in ore fluids (-2.1 to 16.2%) reflect interactions between meteoric water and sedimentary rocks. The ??13C values of calcite (-9 to 2%) and ??34S values of sulfides (-24 to 17%) suggest that C and S were derived from marine carbonate (and organic carbon) and diagenetic sulfides (and organic sulfur) in the vicinity of the deposits. Geologic relationships and geochronologic evidence indicate the deposits formed during a late phase of the Yanshanian orogeny (140-75 Ma). These gold deposits share much in common with the Carlin-type gold deposits in Nevada, USA. Both occur in carbonaceous, pyritic, sedimentary rocks deposited on extended margins of Precambrian cratons. The smaller Chinese deposits are generally in more siliceous rocks and the larger Nevada deposits in more calcareous rocks. In both countries, the host rocks prior to mineralization were affected by contractional deformation that produced many of the ore-controlling structures and the deposits do not show consistent spatial or genetic relationships with epizonal plutons. However, the Nevada deposits show broad spatial and temporal relationships with shifting patterns of calc-alkaline magmatism. The ore and alteration mineral assemblages, residence of gold, geochemical signatures, paragenetic sequence, and fluid inclusions are remarkably similar, which indicates that the deposits formed from low salinity, moderately acidic, CO2 and H2S-rich in the crust similar processes at relatively shallow levels in the crust (<5 km). However, the deposits in China are associated with large Hg, Sb, As, U, and Tl deposits, which may reflect higher background abundances of these elements. Stable isotopic data suggest meteoric water evolved to become ore fluids through interactions with sedimentary rocks, although contributions of volatiles or metals from deeper levels are present in some deposits in Nevada. In both countries, the deposits appear to have formed in an area of high paleothermal gradients after a change in stress regime during the later phases of orogenic activity.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Mineralium Deposita","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1007/s00126-001-0242-7","issn":"00264598","usgsCitation":"Rui-Zhong, H., Wen-Chao, S., Xian-Wu, B., Guang-Zhi, T., and Hofstra, A., 2002, Geology and geochemistry of Carlin-type gold deposits in China: Mineralium Deposita, v. 37, no. 3-4, p. 378-392, https://doi.org/10.1007/s00126-001-0242-7.","startPage":"378","endPage":"392","numberOfPages":"15","costCenters":[],"links":[{"id":207737,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1007/s00126-001-0242-7"},{"id":232917,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"37","issue":"3-4","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a22d7e4b0c8380cd573a6","contributors":{"authors":[{"text":"Rui-Zhong, H.","contributorId":20512,"corporation":false,"usgs":true,"family":"Rui-Zhong","given":"H.","email":"","affiliations":[],"preferred":false,"id":402000,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Wen-Chao, S.","contributorId":96050,"corporation":false,"usgs":true,"family":"Wen-Chao","given":"S.","email":"","affiliations":[],"preferred":false,"id":402003,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Xian-Wu, B.","contributorId":11800,"corporation":false,"usgs":true,"family":"Xian-Wu","given":"B.","email":"","affiliations":[],"preferred":false,"id":401999,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Guang-Zhi, T.","contributorId":86936,"corporation":false,"usgs":true,"family":"Guang-Zhi","given":"T.","email":"","affiliations":[],"preferred":false,"id":402002,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Hofstra, A. H. 0000-0002-2450-1593","orcid":"https://orcid.org/0000-0002-2450-1593","contributorId":41426,"corporation":false,"usgs":true,"family":"Hofstra","given":"A. H.","affiliations":[],"preferred":false,"id":402001,"contributorType":{"id":1,"text":"Authors"},"rank":5}]}}
,{"id":70024624,"text":"70024624 - 2002 - Seismic anisotropy and mantle creep in young orogens","interactions":[],"lastModifiedDate":"2023-04-20T15:20:38.386388","indexId":"70024624","displayToPublicDate":"2002-01-01T00:00:00","publicationYear":"2002","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1803,"text":"Geophysical Journal International","active":true,"publicationSubtype":{"id":10}},"title":"Seismic anisotropy and mantle creep in young orogens","docAbstract":"<p>Seismic anisotropy provides evidence for the physical state and tectonic evolution of the lithosphere. We discuss the origin of anisotropy at various depths, and relate it to tectonic stress, geotherms and rheology. The anisotropy of the uppermost mantle is controlled by the orthorhombic mineral olivine, and may result from ductile deformation, dynamic recrystallization or annealing. Anisotropy beneath young orogens has been measured for the seismic phase Pn that propagates in the uppermost mantle. This anisotropy is interpreted as being caused by deformation during the most recent thermotectonic event, and thus provides information on the process of mountain building. Whereas tectonic stress and many structural features in the upper crust are usually orientated perpendicular to the structural axis of mountain belts, Pn anisotropy is aligned parallel to the structural axis. We interpret this to indicate mountain-parallel ductile (i.e. creeping) deformation in the uppermost mantle that is a consequence of mountain-perpendicular compressive stresses. The preferred orientation of the fast axes of some anisotropic minerals, such as olivine, is known to be in the creep direction, a consequence of the anisotropy of strength and viscosity of orientated minerals. In order to explain the anisotropy of the mantle beneath young orogens we extend the concept of crustal 'escape' (or 'extrusion') tectonics to the uppermost mantle. We present rheological model calculations to support this hypothesis. Mountain-perpendicular horizontal stress (determined in the upper crust) and mountain-parallel seismic anisotropy (in the uppermost mantle) require a zone of ductile decoupling in the middle or lower crust of young mountain belts. Examples for stress and mountain-parallel <i>Pn</i> anisotropy are given for Tibet, the Alpine chains, and young mountain ranges in the Americas. Finally, we suggest a simple model for initiating mountain parallel creep.</p>","language":"English","publisher":"Oxford Academic","doi":"10.1046/j.1365-246X.2002.01628.x","usgsCitation":"Meissner, R., Mooney, T.C., and Artemieva, I., 2002, Seismic anisotropy and mantle creep in young orogens: Geophysical Journal International, v. 149, no. 1, p. 1-14, https://doi.org/10.1046/j.1365-246X.2002.01628.x.","productDescription":"14 p.","startPage":"1","endPage":"14","numberOfPages":"14","costCenters":[{"id":237,"text":"Earthquake Science Center","active":true,"usgs":true}],"links":[{"id":478611,"rank":2,"type":{"id":40,"text":"Open Access Publisher Index Page"},"url":"https://doi.org/10.1046/j.1365-246x.2002.01628.x","text":"Publisher Index Page"},{"id":232848,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"149","issue":"1","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505b8af1e4b08c986b3174a2","contributors":{"authors":[{"text":"Meissner, R.","contributorId":53563,"corporation":false,"usgs":true,"family":"Meissner","given":"R.","email":"","affiliations":[],"preferred":false,"id":401965,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Mooney, Thomas C.","contributorId":18010,"corporation":false,"usgs":true,"family":"Mooney","given":"Thomas","email":"","middleInitial":"C.","affiliations":[],"preferred":false,"id":401966,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Artemieva, I.","contributorId":41624,"corporation":false,"usgs":true,"family":"Artemieva","given":"I.","email":"","affiliations":[],"preferred":false,"id":401964,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}}
,{"id":70024623,"text":"70024623 - 2002 - Crustal structure beneath western and eastern Iceland from surface waves and receiver functions","interactions":[],"lastModifiedDate":"2012-03-12T17:20:14","indexId":"70024623","displayToPublicDate":"2002-01-01T00:00:00","publicationYear":"2002","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1803,"text":"Geophysical Journal International","active":true,"publicationSubtype":{"id":10}},"title":"Crustal structure beneath western and eastern Iceland from surface waves and receiver functions","docAbstract":"We determine the crustal structures beneath 14 broad-band seismic stations, deployed in western, eastern, central and southern Iceland, using surface wave dispersion curves and receiver functions. We implement a method to invert receiver functions using constraints obtained from genetic algorithm inversion of surface waves. Our final models satisfy both data sets. The thickness of the upper crust, as defined by the velocity horizon Vs = 3.7 km s-1, is fairly uniform at ???6.5-9 km beneath the Tertiary intraplate areas of western and eastern Iceland, and unusually thick at 11 km beneath station HOT22 in the far south of Iceland. The depth to the base of the lower crust, as defined by the velocity horizon Vs = 4.1 km s-1 is ???20-26 km in western Iceland and ???27-33 km in eastern Iceland. These results agree with those of explosion profiles that detect a thinner crust beneath western Iceland than beneath eastern Iceland. An earlier report of a substantial low-velocity zone beneath the Middle Volcanic Zone in the lower crust is confirmed by a similar observation beneath an additional station there. As was found in previous receiver function studies, the most reliable feature of the results is the clear division into an upper sequence that is a few kilometres thick where velocity gradients are high, and a lower, thicker sequence where velocity gradients are low. The transition to typical mantle velocities is variable, and may range from being very gradational to being relatively sharp and clear. A clear Moho, by any definition, is rarely seen, and there is thus uncertainty in estimates of the thickness of the crust in many areas. Although a great deal of seismic data are now available constraining the structures of the crust and upper mantle beneath Iceland, their geological nature is not well understood.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Geophysical Journal International","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1046/j.1365-246X.2002.01642.x","issn":"0956540X","usgsCitation":"Du, Z., Foulger, G., Julian, B., Allen, R.M., Nolet, G., Morgan, W.J., Bergsson, B.H., Erlendsson, P., Jakobsdottir, S., Ragnarsson, S., Stefansson, R., and Vogfjord, K., 2002, Crustal structure beneath western and eastern Iceland from surface waves and receiver functions: Geophysical Journal International, v. 149, no. 2, p. 349-363, https://doi.org/10.1046/j.1365-246X.2002.01642.x.","startPage":"349","endPage":"363","numberOfPages":"15","costCenters":[],"links":[{"id":478694,"rank":10000,"type":{"id":41,"text":"Open Access External Repository Page"},"url":"https://doi.org/10.1046/j.1365-246x.2002.01642.x","text":"External Repository"},{"id":207689,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1046/j.1365-246X.2002.01642.x"},{"id":232847,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"149","issue":"2","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"5059fce8e4b0c8380cd4e4dc","contributors":{"authors":[{"text":"Du, Z.","contributorId":40765,"corporation":false,"usgs":true,"family":"Du","given":"Z.","email":"","affiliations":[],"preferred":false,"id":401959,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Foulger, G.R.","contributorId":14439,"corporation":false,"usgs":false,"family":"Foulger","given":"G.R.","email":"","affiliations":[],"preferred":false,"id":401955,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Julian, B.R.","contributorId":101272,"corporation":false,"usgs":true,"family":"Julian","given":"B.R.","email":"","affiliations":[],"preferred":false,"id":401963,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Allen, R. M.","contributorId":36170,"corporation":false,"usgs":false,"family":"Allen","given":"R.","email":"","middleInitial":"M.","affiliations":[],"preferred":false,"id":401958,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Nolet, G.","contributorId":26448,"corporation":false,"usgs":true,"family":"Nolet","given":"G.","email":"","affiliations":[],"preferred":false,"id":401957,"contributorType":{"id":1,"text":"Authors"},"rank":5},{"text":"Morgan, W. J.","contributorId":10573,"corporation":false,"usgs":false,"family":"Morgan","given":"W.","email":"","middleInitial":"J.","affiliations":[],"preferred":false,"id":401952,"contributorType":{"id":1,"text":"Authors"},"rank":6},{"text":"Bergsson, B. H.","contributorId":19320,"corporation":false,"usgs":false,"family":"Bergsson","given":"B.","email":"","middleInitial":"H.","affiliations":[],"preferred":false,"id":401956,"contributorType":{"id":1,"text":"Authors"},"rank":7},{"text":"Erlendsson, P.","contributorId":95638,"corporation":false,"usgs":true,"family":"Erlendsson","given":"P.","email":"","affiliations":[],"preferred":false,"id":401962,"contributorType":{"id":1,"text":"Authors"},"rank":8},{"text":"Jakobsdottir, S.","contributorId":64828,"corporation":false,"usgs":true,"family":"Jakobsdottir","given":"S.","email":"","affiliations":[],"preferred":false,"id":401960,"contributorType":{"id":1,"text":"Authors"},"rank":9},{"text":"Ragnarsson, S.","contributorId":12644,"corporation":false,"usgs":true,"family":"Ragnarsson","given":"S.","email":"","affiliations":[],"preferred":false,"id":401953,"contributorType":{"id":1,"text":"Authors"},"rank":10},{"text":"Stefansson, R.","contributorId":81650,"corporation":false,"usgs":true,"family":"Stefansson","given":"R.","email":"","affiliations":[],"preferred":false,"id":401961,"contributorType":{"id":1,"text":"Authors"},"rank":11},{"text":"Vogfjord, K.","contributorId":13768,"corporation":false,"usgs":true,"family":"Vogfjord","given":"K.","email":"","affiliations":[],"preferred":false,"id":401954,"contributorType":{"id":1,"text":"Authors"},"rank":12}]}}
,{"id":70024619,"text":"70024619 - 2002 - Development and evaluation of a local grid refinement method for block-centered finite-difference groundwater models using shared nodes","interactions":[],"lastModifiedDate":"2012-03-12T17:20:05","indexId":"70024619","displayToPublicDate":"2002-01-01T00:00:00","publicationYear":"2002","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":664,"text":"Advances in Water Resources","active":true,"publicationSubtype":{"id":10}},"title":"Development and evaluation of a local grid refinement method for block-centered finite-difference groundwater models using shared nodes","docAbstract":"A new method of local grid refinement for two-dimensional block-centered finite-difference meshes is presented in the context of steady-state groundwater-flow modeling. The method uses an iteration-based feedback with shared nodes to couple two separate grids. The new method is evaluated by comparison with results using a uniform fine mesh, a variably spaced mesh, and a traditional method of local grid refinement without a feedback. Results indicate: (1) The new method exhibits quadratic convergence for homogeneous systems and convergence equivalent to uniform-grid refinement for heterogeneous systems. (2) Coupling the coarse grid with the refined grid in a numerically rigorous way allowed for improvement in the coarse-grid results. (3) For heterogeneous systems, commonly used linear interpolation of heads from the large model onto the boundary of the refined model produced heads that are inconsistent with the physics of the flow field. (4) The traditional method works well in situations where the better resolution of the locally refined grid has little influence on the overall flow-system dynamics, but if this is not true, lack of a feedback mechanism produced errors in head up to 3.6% and errors in cell-to-cell flows up to 25%. ?? 2002 Elsevier Science Ltd. All rights reserved.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Advances in Water Resources","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1016/S0309-1708(02)00021-0","issn":"03091708","usgsCitation":"Mehl, S., and Hill, M.C., 2002, Development and evaluation of a local grid refinement method for block-centered finite-difference groundwater models using shared nodes: Advances in Water Resources, v. 25, no. 5, p. 497-511, https://doi.org/10.1016/S0309-1708(02)00021-0.","startPage":"497","endPage":"511","numberOfPages":"15","costCenters":[],"links":[{"id":207977,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/S0309-1708(02)00021-0"},{"id":233309,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"25","issue":"5","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a0020e4b0c8380cd4f5d7","contributors":{"authors":[{"text":"Mehl, S.","contributorId":20114,"corporation":false,"usgs":true,"family":"Mehl","given":"S.","affiliations":[],"preferred":false,"id":401935,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Hill, M. C.","contributorId":48993,"corporation":false,"usgs":true,"family":"Hill","given":"M.","email":"","middleInitial":"C.","affiliations":[],"preferred":false,"id":401936,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}}
,{"id":70024618,"text":"70024618 - 2002 - Parasite (Ribeiroia ondatrae) infection linked to amphibian malformations in the western United States","interactions":[],"lastModifiedDate":"2018-11-28T08:41:07","indexId":"70024618","displayToPublicDate":"2002-01-01T00:00:00","publicationYear":"2002","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1459,"text":"Ecological Monographs","active":true,"publicationSubtype":{"id":10}},"title":"Parasite (Ribeiroia ondatrae) infection linked to amphibian malformations in the western United States","docAbstract":"<p>Parasites and pathogens can influence the survivorship, behavior, and very structure of their host species. For example, experimental studies have shown that trematode parasites can cause high frequencies of severe limb malformations in amphibians. In a broad-scale field survey covering parts of California, Oregon, Washington, Idaho, and Montana, we examined relationships between the frequency and types of morphological abnormalities in amphibians and the abundance of trematode parasite infection, pH, concentrations of 61 pesticides, and levels of orthophosphate and total nitrate. We recorded severe malformations at frequencies ranging from 1% to 90% in nine amphibian species from 53 aquatic systems. Infection of larvae by the trematode Ribeiroia ondatrae was associated with, and functionally related to, higher frequencies of amphibian limb malformations than found in uninfected populations (≤5%). Parasites were concentrated around the basal tissue of hind limbs in infected anurans, and malformations associated with infection included skin webbings, supernumerary limbs and digits, and missing or malformed hind limbs. In the absence of Ribeiroia, amphibian populations exhibited low (0-5%) frequencies of abnormalities involving missing digits or distal portions of a hind limb. Species were affected differentially by the parasite, and Ambystoma macrodactylum, Hyla regilla, Rand aurora, R. luteiventris, and Taricha torosa typically exhibited the highest frequencies of abnormalities. None of the water-quality variables measured was associated with malformed amphibians, but aquatic snail hosts (Planorbella spp.) were significant predictors of the presence and abundance of Ribeiroia infection. Morphological comparisons of adult specimens of Ribeiroia collected from different sites and raised in experimental definitive hosts suggested that all samples represented the same species - R. ondatrae. These field results, coupled with experimental research on the effects of Ribeiroia on amphibians, demonstrate that Ribeiroia infection is an important and widespread cause of amphibian limb malformations in the western United States. The relevance of trematode infection to declines of amphibian populations and the influence of habitat modification on the pathology and life cycle of Ribeiroia are emphasized as areas requiring further research.</p>","language":"English","publisher":"ESA","doi":"10.1890/0012-9615(2002)072[0151:PROILT]2.0.CO;2","issn":"00129615","usgsCitation":"Johnson, P., Lunde, K., Thurman, E., Ritchie, E., Wray, S., Sutherland, D., Kapfer, J., Frest, T., Bowerman, J., and Blaustein, A., 2002, Parasite (Ribeiroia ondatrae) infection linked to amphibian malformations in the western United States: Ecological Monographs, v. 72, no. 2, p. 151-168, https://doi.org/10.1890/0012-9615(2002)072[0151:PROILT]2.0.CO;2.","productDescription":"18 p.","startPage":"151","endPage":"168","costCenters":[{"id":589,"text":"Toxic Substances Hydrology Program","active":true,"usgs":true}],"links":[{"id":502602,"rank":1,"type":{"id":41,"text":"Open Access External Repository Page"},"url":"https://figshare.com/articles/journal_contribution/Parasite_Ribeiroia_ondatrae_infection_linked_to_amphibian_malformations_in_the_western_United_States/20877172","text":"External Repository"},{"id":233308,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"country":"United States","volume":"72","issue":"2","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a74d6e4b0c8380cd77867","contributors":{"authors":[{"text":"Johnson, P.T.J.","contributorId":104255,"corporation":false,"usgs":true,"family":"Johnson","given":"P.T.J.","email":"","affiliations":[],"preferred":false,"id":401934,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Lunde, K.B.","contributorId":10200,"corporation":false,"usgs":true,"family":"Lunde","given":"K.B.","email":"","affiliations":[],"preferred":false,"id":401925,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Thurman, E.M.","contributorId":102864,"corporation":false,"usgs":true,"family":"Thurman","given":"E.M.","affiliations":[],"preferred":false,"id":401933,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Ritchie, E.G.","contributorId":97285,"corporation":false,"usgs":true,"family":"Ritchie","given":"E.G.","email":"","affiliations":[],"preferred":false,"id":401932,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Wray, S.N.","contributorId":90505,"corporation":false,"usgs":true,"family":"Wray","given":"S.N.","email":"","affiliations":[],"preferred":false,"id":401930,"contributorType":{"id":1,"text":"Authors"},"rank":5},{"text":"Sutherland, D.R.","contributorId":15376,"corporation":false,"usgs":true,"family":"Sutherland","given":"D.R.","email":"","affiliations":[],"preferred":false,"id":401926,"contributorType":{"id":1,"text":"Authors"},"rank":6},{"text":"Kapfer, J.M.","contributorId":68505,"corporation":false,"usgs":true,"family":"Kapfer","given":"J.M.","email":"","affiliations":[],"preferred":false,"id":401928,"contributorType":{"id":1,"text":"Authors"},"rank":7},{"text":"Frest, T.J.","contributorId":70964,"corporation":false,"usgs":true,"family":"Frest","given":"T.J.","email":"","affiliations":[],"preferred":false,"id":401929,"contributorType":{"id":1,"text":"Authors"},"rank":8},{"text":"Bowerman, J.","contributorId":94824,"corporation":false,"usgs":true,"family":"Bowerman","given":"J.","email":"","affiliations":[],"preferred":false,"id":401931,"contributorType":{"id":1,"text":"Authors"},"rank":9},{"text":"Blaustein, A.R.","contributorId":40325,"corporation":false,"usgs":true,"family":"Blaustein","given":"A.R.","affiliations":[],"preferred":false,"id":401927,"contributorType":{"id":1,"text":"Authors"},"rank":10}]}}
,{"id":70024616,"text":"70024616 - 2002 - Subsurface geometry and evolution of the Seattle fault zone and the Seattle Basin, Washington","interactions":[],"lastModifiedDate":"2017-11-18T10:14:37","indexId":"70024616","displayToPublicDate":"2002-01-01T00:00:00","publicationYear":"2002","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1135,"text":"Bulletin of the Seismological Society of America","onlineIssn":"1943-3573","printIssn":"0037-1106","active":true,"publicationSubtype":{"id":10}},"title":"Subsurface geometry and evolution of the Seattle fault zone and the Seattle Basin, Washington","docAbstract":"The Seattle fault, a large, seismically active, east-west-striking fault zone under Seattle, is the best-studied fault within the tectonically active Puget Lowland in western Washington, yet its subsurface geometry and evolution are not well constrained. We combine several analysis and modeling approaches to study the fault geometry and evolution, including depth-converted, deep-seismic-reflection images, P-wave-velocity field, gravity data, elastic modeling of shoreline uplift from a late Holocene earthquake, and kinematic fault restoration. We propose that the Seattle thrust or reverse fault is accompanied by a shallow, antithetic reverse fault that emerges south of the main fault. The wedge enclosed by the two faults is subject to an enhanced uplift, as indicated by the boxcar shape of the shoreline uplift from the last major earthquake on the fault zone. The Seattle Basin is interpreted as a flexural basin at the footwall of the Seattle fault zone. Basin stratigraphy and the regional tectonic history lead us to suggest that the Seattle fault zone initiated as a reverse fault during the middle Miocene, concurrently with changes in the regional stress field, to absorb some of the north-south shortening of the Cascadia forearc. Kingston Arch, 30 km north of the Seattle fault zone, is interpreted as a more recent disruption arising within the basin, probably due to the development of a blind reverse fault.","language":"English","publisher":"Seismological Society of America","doi":"10.1785/0120010229","issn":"00371106","usgsCitation":"ten Brink, U., Molzer, P., Fisher, M.A., Blakely, R., Bucknam, R., Parsons, T., Crosson, R.S., and Creager, K.C., 2002, Subsurface geometry and evolution of the Seattle fault zone and the Seattle Basin, Washington: Bulletin of the Seismological Society of America, v. 92, no. 5, p. 1737-1753, https://doi.org/10.1785/0120010229.","productDescription":"17 p.","startPage":"1737","endPage":"1753","costCenters":[{"id":678,"text":"Woods Hole Coastal and Marine Science Center","active":true,"usgs":true}],"links":[{"id":233270,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"country":"United States","state":"Washington","otherGeospatial":"Seattle Basin","geographicExtents":"{\n  \"type\": \"FeatureCollection\",\n  \"features\": [\n    {\n      \"type\": \"Feature\",\n      \"properties\": {},\n      \"geometry\": {\n        \"type\": \"Polygon\",\n        \"coordinates\": [\n          [\n            [\n              -122.8216552734375,\n              46.89398546092549\n            ],\n            [\n              -122.1185302734375,\n              46.89398546092549\n            ],\n            [\n              -122.1185302734375,\n              48.55297816440071\n            ],\n            [\n              -122.8216552734375,\n              48.55297816440071\n            ],\n            [\n              -122.8216552734375,\n              46.89398546092549\n            ]\n          ]\n        ]\n      }\n    }\n  ]\n}","volume":"92","issue":"5","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505b9d76e4b08c986b31d87c","contributors":{"authors":[{"text":"ten Brink, Uri S. 0000-0001-6858-3001 utenbrink@usgs.gov","orcid":"https://orcid.org/0000-0001-6858-3001","contributorId":127560,"corporation":false,"usgs":true,"family":"ten Brink","given":"Uri S.","email":"utenbrink@usgs.gov","affiliations":[{"id":678,"text":"Woods Hole Coastal and Marine Science Center","active":true,"usgs":true},{"id":186,"text":"Coastal and Marine Geology Program","active":true,"usgs":true}],"preferred":false,"id":401918,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Molzer, P.C.","contributorId":86514,"corporation":false,"usgs":true,"family":"Molzer","given":"P.C.","email":"","affiliations":[],"preferred":false,"id":401919,"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":401916,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Blakely, R.J. 0000-0003-1701-5236","orcid":"https://orcid.org/0000-0003-1701-5236","contributorId":70755,"corporation":false,"usgs":true,"family":"Blakely","given":"R.J.","affiliations":[],"preferred":false,"id":401917,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Bucknam, R.C.","contributorId":35744,"corporation":false,"usgs":true,"family":"Bucknam","given":"R.C.","affiliations":[],"preferred":false,"id":401914,"contributorType":{"id":1,"text":"Authors"},"rank":5},{"text":"Parsons, T.","contributorId":48288,"corporation":false,"usgs":true,"family":"Parsons","given":"T.","email":"","affiliations":[],"preferred":false,"id":401915,"contributorType":{"id":1,"text":"Authors"},"rank":6},{"text":"Crosson, R. S.","contributorId":104987,"corporation":false,"usgs":true,"family":"Crosson","given":"R.","email":"","middleInitial":"S.","affiliations":[],"preferred":false,"id":401920,"contributorType":{"id":1,"text":"Authors"},"rank":7},{"text":"Creager, K. C.","contributorId":105078,"corporation":false,"usgs":true,"family":"Creager","given":"K.","email":"","middleInitial":"C.","affiliations":[],"preferred":false,"id":401921,"contributorType":{"id":1,"text":"Authors"},"rank":8}]}}
,{"id":70024611,"text":"70024611 - 2002 - Lunar prospector epithermal neutrons from impact craters and landing sites: Implications for surface maturity and hydrogen distribution","interactions":[],"lastModifiedDate":"2022-08-02T22:50:53.505412","indexId":"70024611","displayToPublicDate":"2002-01-01T00:00:00","publicationYear":"2002","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":"Lunar prospector epithermal neutrons from impact craters and landing sites: Implications for surface maturity and hydrogen distribution","docAbstract":"<p><span class=\"paraNumber\"><span>&nbsp;</span></span><span>Initial studies of neutron spectrometer data returned by Lunar Prospector concentrated on the discovery of enhanced hydrogen abundances near both lunar poles. However, the nonpolar data exhibit intriguing patterns that appear spatially correlated with surface features such as young impact craters (e.g., Tycho). Such immature crater materials may have low hydrogen contents because of their relative lack of exposure to solar wind-implanted volatiles. We tested this hypothesis by comparing epithermal* neutron counts (i.e., epithermal −0.057 × thermal neutrons) for Copernican-age craters classified as relatively young, intermediate, and old (as determined by previous studies of Clementine optical maturity variations). The epithermal* counts of the crater and continuous ejecta regions suggest that the youngest impact materials are relatively devoid of hydrogen in the upper 1 m of regolith. We also show that the mean hydrogen contents measured in Apollo and Luna landing site samples are only moderately well correlated to the epithermal* neutron counts at the landing sites, likely owing to the effects of rare earth elements. These results suggest that further work is required to define better how hydrogen distribution can be revealed by epithermal neutrons in order to understand more fully the nature and sources (e.g., solar wind, meteorite impacts) of volatiles in the lunar regolith.</span></p>","language":"English","publisher":"American Geophysical Union","doi":"10.1029/2000JE001430","usgsCitation":"Johnson, J.R., Feldman, W.C., Lawrence, D.J., Maurice, S., Swindle, T.D., and Lucey, P.G., 2002, Lunar prospector epithermal neutrons from impact craters and landing sites: Implications for surface maturity and hydrogen distribution: Journal of Geophysical Research E: Planets, v. 107, no. E2, p. 3-1-3-8, https://doi.org/10.1029/2000JE001430.","productDescription":"8 p.","startPage":"3-1","endPage":"3-8","costCenters":[],"links":[{"id":233198,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"otherGeospatial":"Moon","volume":"107","issue":"E2","noUsgsAuthors":false,"publicationDate":"2002-02-28","publicationStatus":"PW","scienceBaseUri":"505a4a95e4b0c8380cd68e9c","contributors":{"authors":[{"text":"Johnson, J. R.","contributorId":69278,"corporation":false,"usgs":true,"family":"Johnson","given":"J.","email":"","middleInitial":"R.","affiliations":[],"preferred":false,"id":401901,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Feldman, W. C.","contributorId":40767,"corporation":false,"usgs":false,"family":"Feldman","given":"W.","email":"","middleInitial":"C.","affiliations":[],"preferred":false,"id":401899,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Lawrence, D. J.","contributorId":84952,"corporation":false,"usgs":false,"family":"Lawrence","given":"D.","email":"","middleInitial":"J.","affiliations":[],"preferred":false,"id":401903,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Maurice, S.","contributorId":18144,"corporation":false,"usgs":true,"family":"Maurice","given":"S.","email":"","affiliations":[],"preferred":false,"id":401898,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Swindle, T. D.","contributorId":68042,"corporation":false,"usgs":false,"family":"Swindle","given":"T.","email":"","middleInitial":"D.","affiliations":[],"preferred":false,"id":401900,"contributorType":{"id":1,"text":"Authors"},"rank":5},{"text":"Lucey, P. G.","contributorId":72532,"corporation":false,"usgs":false,"family":"Lucey","given":"P.","email":"","middleInitial":"G.","affiliations":[],"preferred":false,"id":401902,"contributorType":{"id":1,"text":"Authors"},"rank":6}]}}
,{"id":70024610,"text":"70024610 - 2002 - A comparison of factors controlling sedimentation rates and wetland loss in fluvial-deltaic systems, Texas Gulf coast","interactions":[],"lastModifiedDate":"2012-03-12T17:20:06","indexId":"70024610","displayToPublicDate":"2002-01-01T00:00:00","publicationYear":"2002","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1801,"text":"Geomorphology","active":true,"publicationSubtype":{"id":10}},"title":"A comparison of factors controlling sedimentation rates and wetland loss in fluvial-deltaic systems, Texas Gulf coast","docAbstract":"Submergence of coastal marshes in areas where rates of relative sea-level rise exceed rates of marsh sedimentation, or vertical accretion, is a global problem that requires detailed examination of the principal processes that establish, maintain, and degrade these biologically productive environments. Using a simple 210Pb-dating model, we measured sedimentation rates in cores from the Trinity, Lavaca-Navidad, and Nueces bayhead fluvial-deltaic systems in Texas where more than 2000 ha of wetlands have been lost since the 1950s. Long-term average rates of fluvial-deltaic aggradation decrease southwestward from 0.514 ?? 0.008 cm year -1 in the Trinity, 0.328 ?? 0.022 cm year -1 in the Lavaca-Navidad, to 0.262 ?? 0.034 cm year -1 in the Nucces. The relative magnitudes of sedimentation and wetland loss correlate with several parameters that define the differing fluvial-deltaic settings, including size of coastal drainage basin, average annual rainfall, suspended sediment load, thickness of Holocene mud in the valley fill, and rates of relative sea-level rise. There is some evidence that upstream reservoirs have reduced wetland sedimentation rates, which are now about one-half the local rates of relative sea-level rise. The extant conditions indicate that fluvial-deltaic marshes in these valleys will continue to be lost as a result of submergence and erosion. ?? 2002 Elsevier Science B.V. All rights reserved.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Geomorphology","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1016/S0169-555X(01)00140-4","issn":"0169555X","usgsCitation":"White, W., Morton, R., and Holmes, C.W., 2002, A comparison of factors controlling sedimentation rates and wetland loss in fluvial-deltaic systems, Texas Gulf coast: Geomorphology, v. 44, no. 1-2, p. 47-66, https://doi.org/10.1016/S0169-555X(01)00140-4.","startPage":"47","endPage":"66","numberOfPages":"20","costCenters":[],"links":[{"id":207888,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/S0169-555X(01)00140-4"},{"id":233165,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"44","issue":"1-2","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"5059e35ae4b0c8380cd45fb8","contributors":{"authors":[{"text":"White, W.A.","contributorId":24489,"corporation":false,"usgs":true,"family":"White","given":"W.A.","email":"","affiliations":[],"preferred":false,"id":401895,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Morton, R.A.","contributorId":53849,"corporation":false,"usgs":true,"family":"Morton","given":"R.A.","email":"","affiliations":[],"preferred":false,"id":401897,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Holmes, C. W.","contributorId":36076,"corporation":false,"usgs":true,"family":"Holmes","given":"C.","email":"","middleInitial":"W.","affiliations":[],"preferred":false,"id":401896,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}}
,{"id":70024609,"text":"70024609 - 2002 - Pathways of nutrient loading and impacts on plant diversity in a New York peatland","interactions":[],"lastModifiedDate":"2022-08-22T15:56:36.477759","indexId":"70024609","displayToPublicDate":"2002-01-01T00:00:00","publicationYear":"2002","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":3750,"text":"Wetlands","onlineIssn":"1943-6246","printIssn":"0277-5212","active":true,"publicationSubtype":{"id":10}},"title":"Pathways of nutrient loading and impacts on plant diversity in a New York peatland","docAbstract":"<p><span>Nutrient loading is a subtle, yet serious threat to the preservation of high diversity wetlands such as peatlands. Pathways of nutrient loading and impacts on plant diversity in a small peatland in New York State, USA were determined by collecting and analyzing a suite of hydrogeological, hydro-chemical, soil, and vegetation data. Piezometer clusters within an intensive network constituted hydro-chemical sampling points and focal points for randomly selected vegetation quadrats and soil-coring locations. Hydrogeological data and nutrient analyses showed that P and K loading occurred chiefly by means of overland flow from an adjacent farm field, whereas N loading occurred predominantly through ground-water flow from the farm field. Redundancy analysis and polynomial regression showed that nutrients, particularly total P in peat, total K in peat, extractable NH</span><sub>4</sub><span>-N, and NO</span><sub>3</sub><span>-N flux in ground water, were strongly negatively correlated with plant diversity measures at the site. No other environmental variables except vegetation measures associated with eutrophication demonstrated such a strong relationship with plant diversity. Nitrate loading over 4 mg m</span><sup>−2</sup><span>&nbsp;day</span><sup>−1</sup><span>&nbsp;was associated with low plant diversity, and Ca fluxes between 80 and 130 mg m</span><sup>−2</sup><span>&nbsp;day</span><sup>−1</sup><span>&nbsp;were associated with high plant diversity. Areas in the site with particularly low vascular plant and bryophyte species richness and Shannon-Wiener diversity (H′) occurred adjacent to the farm field and near a hillside spring. High H′ and species richness of vascular plants and bryophytes occurred in areas that were further removed from agriculture, contained no highly dominant vegetation, and were situated directly along the ground-water flow paths of springs. These areas were characterized by relatively constant water levels and consistent, yet moderate fluxes of base cations and nutrients. Overall, this study demonstrates that knowledge of site hydrogeology is crucial for determining potential pathways of nutrient loading and for developing relationships between nutrient inflows and wetland plant diversity.</span></p>","language":"English","publisher":"Springer Link","doi":"10.1672/0277-5212(2002)022[0263:PONLAI]2.0.CO;2","usgsCitation":"Drexler, J.Z., and Bedford, B.L., 2002, Pathways of nutrient loading and impacts on plant diversity in a New York peatland: Wetlands, v. 22, no. 2, p. 263-281, https://doi.org/10.1672/0277-5212(2002)022[0263:PONLAI]2.0.CO;2.","productDescription":"19 p.","startPage":"263","endPage":"281","numberOfPages":"19","costCenters":[],"links":[{"id":233164,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"country":"United States","state":"New York","otherGeospatial":"McLean Preserve Fen","geographicExtents":"{\n  \"type\": \"FeatureCollection\",\n  \"features\": [\n    {\n      \"type\": \"Feature\",\n      \"properties\": {},\n      \"geometry\": {\n        \"type\": \"Polygon\",\n        \"coordinates\": [\n          [\n            [\n              -76.27017974853516,\n              42.53297077712674\n            ],\n            [\n              -76.26331329345703,\n              42.53297077712674\n            ],\n            [\n              -76.26331329345703,\n              42.537461198323754\n            ],\n            [\n              -76.27017974853516,\n              42.537461198323754\n            ],\n            [\n              -76.27017974853516,\n              42.53297077712674\n            ]\n          ]\n        ]\n      }\n    }\n  ]\n}","volume":"22","issue":"2","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a75afe4b0c8380cd77ca2","contributors":{"authors":[{"text":"Drexler, Judith Z. 0000-0002-0127-3866 jdrexler@usgs.gov","orcid":"https://orcid.org/0000-0002-0127-3866","contributorId":167492,"corporation":false,"usgs":true,"family":"Drexler","given":"Judith","email":"jdrexler@usgs.gov","middleInitial":"Z.","affiliations":[{"id":5044,"text":"National Research Program - Central Branch","active":true,"usgs":true},{"id":154,"text":"California Water Science Center","active":true,"usgs":true}],"preferred":true,"id":401894,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Bedford, B. L.","contributorId":41996,"corporation":false,"usgs":false,"family":"Bedford","given":"B.","email":"","middleInitial":"L.","affiliations":[],"preferred":false,"id":401893,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}}
,{"id":70024601,"text":"70024601 - 2002 - Molecular analysis of a 11 700-year-old rodent midden from the Atacama Desert, Chile","interactions":[],"lastModifiedDate":"2012-03-12T17:20:07","indexId":"70024601","displayToPublicDate":"2002-01-01T00:00:00","publicationYear":"2002","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2774,"text":"Molecular Ecology","active":true,"publicationSubtype":{"id":10}},"title":"Molecular analysis of a 11 700-year-old rodent midden from the Atacama Desert, Chile","docAbstract":"DNA was extracted from an 11 700-year-old rodent midden from the Atacama Desert, Chile and the chloroplast and animal mitochondrial DNA (mtDNA) gene sequences were analysed to investigate the floral environment surrounding the midden, and the identity of the midden agent. The plant sequences, together with the macroscopic identifications, suggest the presence of 13 plant families and three orders that no longer exist today at the midden locality, and thus point to a much more diverse and humid climate 11 700 years ago. The mtDNA sequences suggest the presence of at least four different vertebrates, which have been putatively identified as a camelid (vicuna), two rodents (Phyllotis and Abrocoma), and a cardinal bird (Passeriformes). To identify the midden agent, DNA was extracted from pooled faecal pellets, three small overlapping fragments of the mitochondrial cytochrome b gene were amplified and multiple clones were sequenced. These results were analysed along with complete cytochrome b sequences for several modern Phyllotis species to place the midden sequence phylogenetically. The results identified the midden agent as belonging to an ancestral P. limatus. Today, P. limatus is not found at the midden locality but it can be found 100 km to the north, indicating at least a small range shift. The more extensive sampling of modern Phyllotis reinforces the suggestion that P. limatus is recently derived from a peripheral isolate.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Molecular Ecology","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1046/j.1365-294X.2002.01492.x","issn":"09621083","usgsCitation":"Kuch, M., Rohland, N., Betancourt, J., Latorre, C., Steppan, S., and Poinar, H., 2002, Molecular analysis of a 11 700-year-old rodent midden from the Atacama Desert, Chile: Molecular Ecology, v. 11, no. 5, p. 913-924, https://doi.org/10.1046/j.1365-294X.2002.01492.x.","startPage":"913","endPage":"924","numberOfPages":"12","costCenters":[],"links":[{"id":207779,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1046/j.1365-294X.2002.01492.x"},{"id":232982,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"11","issue":"5","noUsgsAuthors":false,"publicationDate":"2002-04-29","publicationStatus":"PW","scienceBaseUri":"505a5cefe4b0c8380cd7004d","contributors":{"authors":[{"text":"Kuch, M.","contributorId":68502,"corporation":false,"usgs":true,"family":"Kuch","given":"M.","email":"","affiliations":[],"preferred":false,"id":401856,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Rohland, N.","contributorId":56420,"corporation":false,"usgs":true,"family":"Rohland","given":"N.","affiliations":[],"preferred":false,"id":401855,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Betancourt, J.L. 0000-0002-7165-0743","orcid":"https://orcid.org/0000-0002-7165-0743","contributorId":87505,"corporation":false,"usgs":true,"family":"Betancourt","given":"J.L.","affiliations":[{"id":595,"text":"U.S. Geological Survey","active":false,"usgs":true}],"preferred":false,"id":401857,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Latorre, C.","contributorId":101797,"corporation":false,"usgs":true,"family":"Latorre","given":"C.","affiliations":[],"preferred":false,"id":401859,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Steppan, S.","contributorId":90503,"corporation":false,"usgs":true,"family":"Steppan","given":"S.","email":"","affiliations":[],"preferred":false,"id":401858,"contributorType":{"id":1,"text":"Authors"},"rank":5},{"text":"Poinar, H.N.","contributorId":25730,"corporation":false,"usgs":true,"family":"Poinar","given":"H.N.","email":"","affiliations":[],"preferred":false,"id":401854,"contributorType":{"id":1,"text":"Authors"},"rank":6}]}}
]}