{"pageNumber":"1237","pageRowStart":"30900","pageSize":"25","recordCount":40904,"records":[{"id":70162440,"text":"70162440 - 1999 - Individual-based modelling as an integrative approach in theoretical and applied population dynamics and food web studies","interactions":[],"lastModifiedDate":"2016-01-25T11:20:17","indexId":"70162440","displayToPublicDate":"1999-01-01T00:00:00","publicationYear":"1999","noYear":false,"publicationType":{"id":24,"text":"Conference Paper"},"publicationSubtype":{"id":19,"text":"Conference Paper"},"title":"Individual-based modelling as an integrative approach in theoretical and applied population dynamics and food web studies","docAbstract":"<p>No abstract available.</p>","largerWorkType":{"id":24,"text":"Conference Paper"},"largerWorkTitle":"Herbivores : between plants and predators","largerWorkSubtype":{"id":19,"text":"Conference Paper"},"conferenceTitle":"38th symposium of the British Ecological Society in cooperation with the Netherlands Ecological Society","conferenceDate":"1997","conferenceLocation":"Netherlands","language":"English","publisher":"Blackwell Science","usgsCitation":"Mooij, W.M., and DeAngelis, D., 1999, Individual-based modelling as an integrative approach in theoretical and applied population dynamics and food web studies, <i>in</i> Herbivores : between plants and predators, Netherlands, 1997, p. 551-575.","productDescription":"25 p.","startPage":"551","endPage":"575","onlineOnly":"N","additionalOnlineFiles":"N","costCenters":[{"id":566,"text":"Southeast Ecological Science Center","active":true,"usgs":true}],"links":[{"id":314754,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"56a7555fe4b0b28f1184d850","contributors":{"editors":[{"text":"Olff, Han","contributorId":152505,"corporation":false,"usgs":false,"family":"Olff","given":"Han","affiliations":[],"preferred":false,"id":589579,"contributorType":{"id":2,"text":"Editors"},"rank":1},{"text":"Brown, V. K.","contributorId":152506,"corporation":false,"usgs":false,"family":"Brown","given":"V.","email":"","middleInitial":"K.","affiliations":[],"preferred":false,"id":589580,"contributorType":{"id":2,"text":"Editors"},"rank":2},{"text":"Drent, R. H.","contributorId":152507,"corporation":false,"usgs":false,"family":"Drent","given":"R.","email":"","middleInitial":"H.","affiliations":[],"preferred":false,"id":589581,"contributorType":{"id":2,"text":"Editors"},"rank":3}],"authors":[{"text":"Mooij, Wolf M.","contributorId":94169,"corporation":false,"usgs":true,"family":"Mooij","given":"Wolf","email":"","middleInitial":"M.","affiliations":[],"preferred":false,"id":589577,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"DeAngelis, Donald L. 0000-0002-1570-4057 don_deangelis@usgs.gov","orcid":"https://orcid.org/0000-0002-1570-4057","contributorId":147289,"corporation":false,"usgs":true,"family":"DeAngelis","given":"Donald L.","email":"don_deangelis@usgs.gov","affiliations":[{"id":566,"text":"Southeast Ecological Science Center","active":true,"usgs":true}],"preferred":false,"id":589578,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}}
,{"id":70021908,"text":"70021908 - 1999 - Reconstructing late Quaternary deep-water masses in the eastern Arctic Ocean using benthonic Ostracoda","interactions":[],"lastModifiedDate":"2012-03-12T17:19:38","indexId":"70021908","displayToPublicDate":"1999-01-01T00:00:00","publicationYear":"1999","noYear":false,"publicationType":{"id":24,"text":"Conference Paper"},"publicationSubtype":{"id":19,"text":"Conference Paper"},"title":"Reconstructing late Quaternary deep-water masses in the eastern Arctic Ocean using benthonic Ostracoda","docAbstract":"The distribution of Ostracoda in three long cores from the deep eastern Arctic Ocean was studied to determine the palaeoceanographical history of the Eurasian Basin during the late Quaternary. The samples for this study were obtained from the Lomonosov Ridge, Morris Jesup Rise and Yermak Plateau during the Arctic 91 expedition. Ostracoda previously studied in coretops at the same sites as the present study have shown that individual species have a strong association with different water masses and bathymetry. Throughout the late Quaternary, cores exhibit ostracod-rich layers separated by barren intervals. On the basis of biostratigraphical, isotopic and palaeomagnetic data the fossiliferous levels are interpreted as representing interglacial stages. The twenty most significant species were selected for subsequent quantitative investigation using Cluster and Factor analyses, in order to determine similarity and variance between the assemblages. An additional statistical method employing Modern Analogues and the Squared Chord Distance dissimilarity coefficient was utilized to compare the present late Quaternary fossil samples with a modern Arctic database. The results reveal a major faunal division within the Arctic Ocean Deep Water (AODW). Highly abundant and diverse assemblages within the cores were found to group and have good analogues with the Recent bathyal depth (1000-2500 m) upper AODW assemblages. Conversely, assemblages with low abundance and diversity correlate well with abyssal depth (> 3000 m) lower AODW assemblages. The palaeoceanographical history is complicated by the influence of adjacent water masses such as Canada Basin Deep Water (CBDW), Greenland Sea Deep Water (GSDW) and most importantly, Arctic Intermediate Water (AIW), which all had an influence on the ostracod assemblages during the late Quaternary. An enhanced flow of warm saline AIW into the Eurasian Basin results in species-rich upper AODW assemblages having good analogues down to 2750 m in the water column. In contrast, lower AODW assemblages influenced by cold well-oxygenated GSDW give analogues at depths as shallow as 1000 m. The faunal changes are the consequence of rapid climatic fluctuations in the eastern Arctic Ocean during the late Quaternary that are intrinsically linked to palaeoceanographical alternations in warm and cold current inflow from adjacent basins.","largerWorkTitle":"Marine Micropaleontology","language":"English","doi":"10.1016/S0377-8398(99)00022-5","issn":"03778398","usgsCitation":"Jones, R.L., Whatley, R., Cronin, T.M., and Dowsett, H., 1999, Reconstructing late Quaternary deep-water masses in the eastern Arctic Ocean using benthonic Ostracoda, <i>in</i> Marine Micropaleontology, v. 37, no. 3-4, p. 251-272, https://doi.org/10.1016/S0377-8398(99)00022-5.","startPage":"251","endPage":"272","numberOfPages":"22","costCenters":[],"links":[{"id":206288,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/S0377-8398(99)00022-5"},{"id":229311,"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":"50e4a250e4b0e8fec6cdb573","contributors":{"authors":[{"text":"Jones, R. Ll","contributorId":50678,"corporation":false,"usgs":true,"family":"Jones","given":"R.","email":"","middleInitial":"Ll","affiliations":[],"preferred":false,"id":391638,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Whatley, R.C.","contributorId":85211,"corporation":false,"usgs":true,"family":"Whatley","given":"R.C.","affiliations":[],"preferred":false,"id":391639,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Cronin, T. M. 0000-0002-2643-0979","orcid":"https://orcid.org/0000-0002-2643-0979","contributorId":42613,"corporation":false,"usgs":true,"family":"Cronin","given":"T.","email":"","middleInitial":"M.","affiliations":[{"id":40020,"text":"Florence Bascom Geoscience Center","active":true,"usgs":true}],"preferred":false,"id":391637,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Dowsett, H.J. 0000-0003-1983-7524","orcid":"https://orcid.org/0000-0003-1983-7524","contributorId":87924,"corporation":false,"usgs":true,"family":"Dowsett","given":"H.J.","affiliations":[],"preferred":false,"id":391640,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}}
,{"id":70021911,"text":"70021911 - 1999 - Deaggregation of probabilistic ground motions in the central and eastern United States","interactions":[],"lastModifiedDate":"2023-10-18T10:52:54.727588","indexId":"70021911","displayToPublicDate":"1999-01-01T00:00:00","publicationYear":"1999","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":"Deaggregation of probabilistic ground motions in the central and eastern United States","docAbstract":"<p>Probabilistic seismic hazard analysis<span>&nbsp;</span><span class=\"small-caps\">(PSHA)</span><span>&nbsp;</span>is a technique for estimating the annual rate of exceedance of a specified ground motion at a site due to known and suspected earthquake sources. The relative contributions of the various sources to the total seismic hazard are determined as a function of their occurrence rates and their ground-motion potential. The separation of the exceedance contributions into bins whose base dimensions are magnitude and distance is called<span>&nbsp;</span><i>deaggregation</i>. We have deaggregated the hazard analyses for the new USGS national probabilistic ground-motion hazard maps (Frankel<span>&nbsp;</span><i>et al.</i>, 1996). For points on a 0.2° grid in the central and eastern United States<span>&nbsp;</span><span class=\"small-caps\">(CEUS)</span>, we show color maps of the geographical variation of mean and modal magnitudes (<i><span class=\"overline\">M</span>, Mˇ</i>) and distances (<i><span class=\"overline\">D</span>, Dˇ</i>) for ground motions having a 2% chance of exceedance in 50 years. These maps are displayed for peak horizontal acceleration and for spectral response accelerations of 0.2, 0.3, and 1.0 sec. We tabulate<span>&nbsp;</span><i><span class=\"overline\">M</span>,<span>&nbsp;</span><span class=\"overline\">D</span>, Mˇ</i>, and<span>&nbsp;</span><i>Dˇ</i><span>&nbsp;</span>for 49 CEUS cities for 0.2- and 1.0-sec response. Thus, these maps and tables are PSHA-derived estimates of the potential earthquakes that dominate seismic hazard at short and intermediate periods in the CEUS.</p>","language":"English","publisher":"Seismological Society of America","doi":"10.1785/BSSA0890010001","issn":"00371106","usgsCitation":"Harmsen, S., Perkins, D., and Frankel, A., 1999, Deaggregation of probabilistic ground motions in the central and eastern United States: Bulletin of the Seismological Society of America, v. 89, no. 1, p. 1-13, https://doi.org/10.1785/BSSA0890010001.","productDescription":"13 p.","startPage":"1","endPage":"13","numberOfPages":"13","costCenters":[],"links":[{"id":421943,"rank":2,"type":{"id":15,"text":"Index Page"},"url":"https://pubs.geoscienceworld.org/ssa/bssa/article/89/1/1/120360/Deaggregation-of-probabilistic-ground-motions-in"},{"id":229343,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"country":"United States","geographicExtents":"{\n  \"type\": \"FeatureCollection\",\n  \"features\": [\n    {\n      \"type\": \"Feature\",\n      \"properties\": {},\n      \"geometry\": {\n        \"coordinates\": [\n          [\n            [\n              -98.35529324972059,\n              50.267706320710346\n            ],\n            [\n              -98.35529324972059,\n              24.81584356675542\n            ],\n            [\n              -66.01154324972084,\n              24.81584356675542\n            ],\n            [\n              -66.01154324972084,\n              50.267706320710346\n            ],\n            [\n              -98.35529324972059,\n              50.267706320710346\n            ]\n          ]\n        ],\n        \"type\": \"Polygon\"\n      }\n    }\n  ]\n}","volume":"89","issue":"1","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"5059fdeae4b0c8380cd4e9f1","contributors":{"authors":[{"text":"Harmsen, S.","contributorId":79600,"corporation":false,"usgs":true,"family":"Harmsen","given":"S.","affiliations":[],"preferred":false,"id":391653,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Perkins, D.","contributorId":83589,"corporation":false,"usgs":true,"family":"Perkins","given":"D.","affiliations":[],"preferred":false,"id":391654,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Frankel, A. 0000-0001-9119-6106","orcid":"https://orcid.org/0000-0001-9119-6106","contributorId":41593,"corporation":false,"usgs":true,"family":"Frankel","given":"A.","affiliations":[],"preferred":false,"id":391652,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}}
,{"id":70021912,"text":"70021912 - 1999 - Historical trends of metals in the sediments of San Francisco Bay, California","interactions":[],"lastModifiedDate":"2020-01-05T15:04:20","indexId":"70021912","displayToPublicDate":"1999-01-01T00:00:00","publicationYear":"1999","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2662,"text":"Marine Chemistry","active":true,"publicationSubtype":{"id":10}},"title":"Historical trends of metals in the sediments of San Francisco Bay, California","docAbstract":"<div id=\"abstracts\" class=\"Abstracts u-font-serif\"><div id=\"aep-abstract-id14\" class=\"abstract author\"><div id=\"aep-abstract-sec-id15\"><p>Concentrations of Ag, Al, Cr, Cu, Fe, Hg, Mn, Ni, Pb, V and Zn were determined in six sediment cores from San Francisco Bay (SFB) and one sediment core in Tomales Bay (TB), a reference estuary. SFB cores were collected from between the head of the estuary and its mouth (Grizzly Bay, GB; San Pablo Bay, SP; Central Bay, CB; Richardson Bay, RB, respectively) and ranged in length from 150 to 250 cm. Concentrations of Cr, V and Ni are greater than mean crustal content in SFB and TB sediments, and greater than found in many other coastal sediments. However, erosion of ultramafic rock formations in the watershed appears to be the predominant source. Baseline concentrations of other metals were determined from horizons deposited before sediments were influenced by human activities and by comparing concentrations to those in TB. Baseline concentrations of Cu co-varied with Al in the SFB sediments and ranged from 23.7±1.2 μg/g to 41.4±2.4 μg/g. Baseline concentrations of other metals were less variable: Ag, 0.09±0.02 μg/g; Pb, 5.2±0.7 μg/g; Hg, 0.06±0.01 μg/g; Zn, 78±7 μg/g. The earliest anthropogenic influence on metal concentrations appeared as Hg contamination (0.3–0.4 μg/g) in sediments deposited at SP between 1850 and 1880, apparently associated with debris from hydraulic gold mining. Maximum concentrations of Hg within the cores were 20 times baseline. Greater inventories of Hg at SP and GB than at RB verified the importance of mining in the watershed as a source. Enrichment of Ag, Pb, Cu and Zn first appeared after 1910 in the RB core, later than is observed in Europe or eastern North America. Maximum concentrations of Ag and Pb were 5–10 times baseline and Cu and Zn concentrations were less than three times baseline. Large inventories of Pb to the sediments in the GB and SP cores appeared to be the result of the proximity to a large Pb smelter. Inventories of Pb at RB are similar to those typical of atmospheric inputs, although influence from the Pb smelter is also suspected. Concentrations of Hg and Pb have decreased since the 1970s (to 0.30 μg/g and 25 μg/g, respectively) and were similar among all cores in 1990. Early Ag contamination was perhaps a byproduct of the Pb smelting process, but a modern source of Ag is also indicated, especially at RB and CB.</p></div></div></div>","language":"English","publisher":"Elsevier","doi":"10.1016/S0304-4203(98)80083-2","issn":"03044203","usgsCitation":"Hornberger, M.I., Luoma, S., VanGeen, A., Fuller, C., and Anima, R., 1999, Historical trends of metals in the sediments of San Francisco Bay, California: Marine Chemistry, v. 64, no. 1-2, p. 39-55, https://doi.org/10.1016/S0304-4203(98)80083-2.","productDescription":"17 p.","startPage":"39","endPage":"55","numberOfPages":"17","onlineOnly":"N","additionalOnlineFiles":"N","costCenters":[{"id":552,"text":"San Francisco Bay-Delta","active":false,"usgs":true},{"id":589,"text":"Toxic Substances Hydrology Program","active":true,"usgs":true}],"links":[{"id":229344,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"country":"United States","state":"California","otherGeospatial":"San Francisco Bay","geographicExtents":"{\n  \"type\": \"FeatureCollection\",\n  \"features\": [\n    {\n      \"type\": \"Feature\",\n      \"properties\": {},\n      \"geometry\": {\n        \"type\": \"Polygon\",\n        \"coordinates\": [\n          [\n            [\n              -123.81591796875,\n              36.56260003738545\n            ],\n            [\n              -120.234375,\n              36.56260003738545\n            ],\n            [\n              -120.234375,\n              39.40224434029275\n            ],\n            [\n              -123.81591796875,\n              39.40224434029275\n            ],\n            [\n              -123.81591796875,\n              36.56260003738545\n            ]\n          ]\n        ]\n      }\n    }\n  ]\n}","volume":"64","issue":"1-2","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a31abe4b0c8380cd5e114","contributors":{"authors":[{"text":"Hornberger, Michelle I. 0000-0002-7787-3446","orcid":"https://orcid.org/0000-0002-7787-3446","contributorId":23574,"corporation":false,"usgs":true,"family":"Hornberger","given":"Michelle","email":"","middleInitial":"I.","affiliations":[],"preferred":false,"id":391655,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Luoma, S. N.","contributorId":86353,"corporation":false,"usgs":true,"family":"Luoma","given":"S. N.","affiliations":[],"preferred":false,"id":391658,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"VanGeen, A.","contributorId":84086,"corporation":false,"usgs":true,"family":"VanGeen","given":"A.","email":"","affiliations":[],"preferred":false,"id":391657,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Fuller, C.","contributorId":106640,"corporation":false,"usgs":true,"family":"Fuller","given":"C.","affiliations":[],"preferred":false,"id":391659,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Anima, R.","contributorId":77304,"corporation":false,"usgs":true,"family":"Anima","given":"R.","affiliations":[],"preferred":false,"id":391656,"contributorType":{"id":1,"text":"Authors"},"rank":5}]}}
,{"id":70021914,"text":"70021914 - 1999 - Active Volcanism on Io: Global Distribution and Variations in Activity","interactions":[],"lastModifiedDate":"2012-03-12T17:19:37","indexId":"70021914","displayToPublicDate":"1999-01-01T00:00:00","publicationYear":"1999","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1963,"text":"Icarus","active":true,"publicationSubtype":{"id":10}},"title":"Active Volcanism on Io: Global Distribution and Variations in Activity","docAbstract":"Io's volcanic activity has been monitored by instruments aboard the Galileo spacecraft since June 28, 1996. We present results from observations by the near-infrared mapping spectrometer (NIMS) for the first 10 orbits of Galileo, correlate them with results from the Solid State Imaging System (SSI) and from groundbased observations, and compare them to what was known about Io's volcanic activity from observations made during the two Voyager flybys in 1979. A total of 61 active volcanic centers have been identified from Voyager, groundbased, and Galileo observations. Of these, 41 are hot spots detected by NIMS and/or SSI. Another 25 locations were identified as possible active volcanic centers, mostly on the basis of observed surface changes. Hot spots are correlated with surface colors, particularly dark and red deposits, and generally anti-correlated with white, SO2-rich areas. Surface features corresponding to the hot spots, mostly calderas or flows, were identified from Galileo and Voyager images. Hot spot temperatures obtained from both NIMS and SSI are consistent with silicate volcanism, which appears to be widespread on Io. Two types of hot spot activity are present: persistent-type activity, lasting from months to years, and sporadic events, which may represent either short-lived activity or low-level activity that occasionally flares up. Sporadic events are not often detected, but may make an important contribution to Io's heat flow and resurfacing. The distribution of active volcanic centers on the surface does not show any clear correlation with latitude, longitude, Voyager-derived global topography, or heat flow patterns predicted by the asthenosphere and deep mantle tidal dissipation models. However, persistent hot spots and active plumes are concentrated toward lower latitudes, and this distribution favors the asthenosphere rather than the deep mantle tidal dissipation model. ?? 1999 Academic Press.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Icarus","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1006/icar.1999.6129","issn":"00191035","usgsCitation":"Lopes-Gautier, R., McEwen, A.S., Smythe, W., Geissler, P., Kamp, L., Davies, A.G., Spencer, J., Keszthelyi, L., Carlson, R., Leader, F., Mehlman, R., and Soderblom, L., 1999, Active Volcanism on Io: Global Distribution and Variations in Activity: Icarus, v. 140, no. 2, p. 243-264, https://doi.org/10.1006/icar.1999.6129.","startPage":"243","endPage":"264","numberOfPages":"22","costCenters":[],"links":[{"id":206312,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1006/icar.1999.6129"},{"id":229376,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"140","issue":"2","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"5059e6a9e4b0c8380cd4757c","contributors":{"authors":[{"text":"Lopes-Gautier, R.","contributorId":13763,"corporation":false,"usgs":true,"family":"Lopes-Gautier","given":"R.","affiliations":[],"preferred":false,"id":391664,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"McEwen, A. S.","contributorId":11317,"corporation":false,"usgs":true,"family":"McEwen","given":"A.","email":"","middleInitial":"S.","affiliations":[],"preferred":false,"id":391663,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Smythe, W.B.","contributorId":83689,"corporation":false,"usgs":true,"family":"Smythe","given":"W.B.","email":"","affiliations":[],"preferred":false,"id":391670,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Geissler, P.E.","contributorId":67636,"corporation":false,"usgs":true,"family":"Geissler","given":"P.E.","email":"","affiliations":[],"preferred":false,"id":391668,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Kamp, L.","contributorId":32312,"corporation":false,"usgs":true,"family":"Kamp","given":"L.","email":"","affiliations":[],"preferred":false,"id":391666,"contributorType":{"id":1,"text":"Authors"},"rank":5},{"text":"Davies, A. G.","contributorId":72538,"corporation":false,"usgs":true,"family":"Davies","given":"A.","middleInitial":"G.","affiliations":[],"preferred":false,"id":391669,"contributorType":{"id":1,"text":"Authors"},"rank":6},{"text":"Spencer, J.R.","contributorId":106270,"corporation":false,"usgs":true,"family":"Spencer","given":"J.R.","email":"","affiliations":[],"preferred":false,"id":391674,"contributorType":{"id":1,"text":"Authors"},"rank":7},{"text":"Keszthelyi, L.","contributorId":42691,"corporation":false,"usgs":true,"family":"Keszthelyi","given":"L.","affiliations":[],"preferred":false,"id":391667,"contributorType":{"id":1,"text":"Authors"},"rank":8},{"text":"Carlson, R.","contributorId":30773,"corporation":false,"usgs":true,"family":"Carlson","given":"R.","affiliations":[],"preferred":false,"id":391665,"contributorType":{"id":1,"text":"Authors"},"rank":9},{"text":"Leader, F.E.","contributorId":94048,"corporation":false,"usgs":true,"family":"Leader","given":"F.E.","email":"","affiliations":[],"preferred":false,"id":391672,"contributorType":{"id":1,"text":"Authors"},"rank":10},{"text":"Mehlman, R.","contributorId":88499,"corporation":false,"usgs":true,"family":"Mehlman","given":"R.","email":"","affiliations":[],"preferred":false,"id":391671,"contributorType":{"id":1,"text":"Authors"},"rank":11},{"text":"Soderblom, L.","contributorId":106244,"corporation":false,"usgs":true,"family":"Soderblom","given":"L.","affiliations":[],"preferred":false,"id":391673,"contributorType":{"id":1,"text":"Authors"},"rank":12}]}}
,{"id":70021037,"text":"70021037 - 1999 - Calculation of broadband time histories of ground motion: Comparison of methods and validation using strong-ground motion from the 1994 Northridge earthquake","interactions":[],"lastModifiedDate":"2023-10-18T23:34:07.47916","indexId":"70021037","displayToPublicDate":"1999-01-01T00:00:00","publicationYear":"1999","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":"Calculation of broadband time histories of ground motion: Comparison of methods and validation using strong-ground motion from the 1994 Northridge earthquake","docAbstract":"<div id=\"135253931\" class=\"article-section-wrapper js-article-section js-content-section  \" data-section-parent-id=\"0\"><p>This article compares techniques for calculating broadband time histories of ground motion in the near field of a finite fault by comparing synthetics with the strong-motion data set for the 1994 Northridge earthquake. Based on this comparison, a preferred methodology is presented. Ground-motion-simulation techniques are divided into two general methods: kinematic- and composite-fault models. Green's functions of three types are evaluated: stochastic, empirical, and theoretical. A hybrid scheme is found to give the best fit to the Northridge data. Low frequencies (&lt; 1 Hz) are calculated using a kinematic-fault model and a 3D finite-difference code to propagate energy through a realistic 3D velocity structure. High frequencies (&gt; 1 Hz) are calculated using a composite-fault model with a fractal subevent size distribution and stochastic, bandlimited, white-noise Green's functions. At frequencies below 1 Hz, theoretical elastic-wave-propagation synthetics introduce proper seismic-phase arrivals of body waves and surface waves. The 3D velocity structure more accurately reproduces record durations for the deep sedimentary basin structures found in the Los Angeles region. At frequencies above 1 Hz, scattering effects become important and wave propagation is more accurately represented by stochastic Green's functions. A fractal subevent size distribution for the composite fault model ensures an ω<sup>−2</sup><span>&nbsp;</span>spectral shape over the entire frequency band considered (0.1-20 Hz).</p></div>","language":"English","publisher":"Seismological Society of America","doi":"10.1785/BSSA0890061484","issn":"00371106","usgsCitation":"Hartzell, S., Harmsen, S., Frankel, A., and Larsen, S., 1999, Calculation of broadband time histories of ground motion: Comparison of methods and validation using strong-ground motion from the 1994 Northridge earthquake: Bulletin of the Seismological Society of America, v. 89, no. 6, p. 1484-1504, https://doi.org/10.1785/BSSA0890061484.","productDescription":"21 p.","startPage":"1484","endPage":"1504","numberOfPages":"21","costCenters":[],"links":[{"id":230209,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"country":"United States","state":"California","otherGeospatial":"Northridge","geographicExtents":"{\n  \"type\": \"FeatureCollection\",\n  \"features\": [\n    {\n      \"type\": \"Feature\",\n      \"properties\": {},\n      \"geometry\": {\n        \"coordinates\": [\n          [\n            [\n              -119.0,\n              34.5\n            ],\n            [\n              -119.0,\n              33.57705855378293\n            ],\n            [\n              -118.0,\n              33.57705855378293\n            ],\n            [\n              -118.0,\n              34.5\n            ],\n            [\n              -119.0,\n              34.5\n            ]\n          ]\n        ],\n        \"type\": \"Polygon\"\n      }\n    }\n  ]\n}","volume":"89","issue":"6","noUsgsAuthors":false,"publicationDate":"1999-12-01","publicationStatus":"PW","scienceBaseUri":"5059f301e4b0c8380cd4b542","contributors":{"authors":[{"text":"Hartzell, S.","contributorId":12603,"corporation":false,"usgs":true,"family":"Hartzell","given":"S.","email":"","affiliations":[],"preferred":false,"id":388374,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Harmsen, S.","contributorId":79600,"corporation":false,"usgs":true,"family":"Harmsen","given":"S.","affiliations":[],"preferred":false,"id":388377,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Frankel, A. 0000-0001-9119-6106","orcid":"https://orcid.org/0000-0001-9119-6106","contributorId":41593,"corporation":false,"usgs":true,"family":"Frankel","given":"A.","affiliations":[],"preferred":false,"id":388376,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Larsen, S.","contributorId":37087,"corporation":false,"usgs":true,"family":"Larsen","given":"S.","email":"","affiliations":[],"preferred":false,"id":388375,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}}
,{"id":70021761,"text":"70021761 - 1999 - Present-day deformation across the Basin and Range Province, western United States","interactions":[],"lastModifiedDate":"2012-03-12T17:19:41","indexId":"70021761","displayToPublicDate":"1999-01-01T00:00:00","publicationYear":"1999","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":3338,"text":"Science","active":true,"publicationSubtype":{"id":10}},"title":"Present-day deformation across the Basin and Range Province, western United States","docAbstract":"The distribution of deformation within the Basin and Range province was determined from 1992, 1996, and 1998 surveys of a dense, 800-kilometer- aperture, Global Positioning System network, Internal deformation generally follows the pattern of Holocene fault distribution and is concentrated near the western extremity of the province, with lesser amounts focused near the eastern boundary. Little net deformation occurs across the central 500 kilometers of the network in western Utah and eastern Nevada. Concentration of deformation adjacent to the rigid Sierra Nevada block indicates that external plate-driving forces play an important role in driving deformation, modulating the extensional stress field generated by internal buoyancy forces that are due to lateral density gradients and topography near the province boundaries.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Science","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1126/science.283.5408.1714","issn":"00368075","usgsCitation":"Thatcher, W., Foulger, G., Julian, B., Svarc, J., Quilty, E., and Bawden, G., 1999, Present-day deformation across the Basin and Range Province, western United States: Science, v. 283, no. 5408, p. 1714-1718, https://doi.org/10.1126/science.283.5408.1714.","startPage":"1714","endPage":"1718","numberOfPages":"5","costCenters":[],"links":[{"id":206316,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1126/science.283.5408.1714"},{"id":229405,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"283","issue":"5408","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a8b4be4b0c8380cd7e1e9","contributors":{"authors":[{"text":"Thatcher, W.","contributorId":32669,"corporation":false,"usgs":true,"family":"Thatcher","given":"W.","email":"","affiliations":[],"preferred":false,"id":391052,"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":391051,"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":391055,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Svarc, J.","contributorId":85731,"corporation":false,"usgs":true,"family":"Svarc","given":"J.","affiliations":[],"preferred":false,"id":391054,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Quilty, E.","contributorId":12633,"corporation":false,"usgs":true,"family":"Quilty","given":"E.","email":"","affiliations":[],"preferred":false,"id":391050,"contributorType":{"id":1,"text":"Authors"},"rank":5},{"text":"Bawden, G.W.","contributorId":61139,"corporation":false,"usgs":true,"family":"Bawden","given":"G.W.","email":"","affiliations":[],"preferred":false,"id":391053,"contributorType":{"id":1,"text":"Authors"},"rank":6}]}}
,{"id":70021554,"text":"70021554 - 1999 - Paleomagnetism of an east-west transect across the Cascade arc in southern Washington: Implications for regional tectonism","interactions":[],"lastModifiedDate":"2024-07-17T15:09:19.852927","indexId":"70021554","displayToPublicDate":"1999-01-01T00:00:00","publicationYear":"1999","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":"Paleomagnetism of an east-west transect across the Cascade arc in southern Washington: Implications for regional tectonism","docAbstract":"<p><span>Paleomagnetic data from a transect across the Cascade arc in southern Washington were collected to test models of vertical axis rotations for this part of the Pacific Northwest and to provide information on the tectonic history of the St. Helens seismic zone. The 75 site-mean directions are divided into three groups based on isotopic, fission track, and stratigraphic ages. Group 1 consists of samples from rocks deposited between 39 and 30 Ma and shows a mean clockwise vertical axis rotation of 34° ± 13°, group 2 consists of samples from rocks deposited between 30 and 24 Ma and shows a mean clockwise rotation of 17° ± 11°, and group 3 consists of samples from rocks between 24 and 16 Ma and shows a mean clockwise rotation of 20° ± 12°. Although these three values of rotation are statistically indistinguishable at the 95% confidence level, we interpret them in combination with other data to indicate differential rotation across the St. Helens seismic zone (SHZ). The available paleomagnetic data for Eocene-Oligocene rocks west of the seismic zone show clockwise vertical axis rotations of 30° ± 8° and 35° ± 9° consistent with the value for group 1. The rotational values for groups 2 and 3 and the intrusive suite of Kidd Creek (13 Ma), despite their different ages, have similar values east of the SHZ. Comparing these groups of data east and west of the seismic zone indicates a differential rotation of 10° ± 3° across it. In addition, the rates of rotation in southern Washington are similar to those for rocks in the western Cascades of Oregon and indicate that rotational deformation of Miocene age extends northward into southern Washington and eastward into the axis of the arc.</span></p>","language":"English","publisher":"American Geophysical Union","doi":"10.1029/1999JB900077","issn":"01480227","usgsCitation":"Hagstrum, J., Swanson, D.A., and Evarts, R., 1999, Paleomagnetism of an east-west transect across the Cascade arc in southern Washington: Implications for regional tectonism: Journal of Geophysical Research B: Solid Earth, v. 104, no. B6, p. 12853-12863, https://doi.org/10.1029/1999JB900077.","productDescription":"11 p.","startPage":"12853","endPage":"12863","numberOfPages":"11","costCenters":[],"links":[{"id":489149,"rank":2,"type":{"id":40,"text":"Open Access Publisher Index Page"},"url":"https://doi.org/10.1029/1999jb900077","text":"Publisher Index Page"},{"id":229547,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"104","issue":"B6","noUsgsAuthors":false,"publicationDate":"1999-06-10","publicationStatus":"PW","scienceBaseUri":"505a7426e4b0c8380cd77489","contributors":{"authors":[{"text":"Hagstrum, J.T.","contributorId":75922,"corporation":false,"usgs":true,"family":"Hagstrum","given":"J.T.","email":"","affiliations":[],"preferred":false,"id":390282,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Swanson, D. A.","contributorId":34102,"corporation":false,"usgs":true,"family":"Swanson","given":"D.","email":"","middleInitial":"A.","affiliations":[],"preferred":false,"id":390280,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Evarts, R.C.","contributorId":74766,"corporation":false,"usgs":true,"family":"Evarts","given":"R.C.","affiliations":[],"preferred":false,"id":390281,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}}
,{"id":70021676,"text":"70021676 - 1999 - Factors controlling the establishment of Fremont cottonwood seedlings on the Upper Green River, USA","interactions":[],"lastModifiedDate":"2018-02-23T14:34:26","indexId":"70021676","displayToPublicDate":"1999-01-01T00:00:00","publicationYear":"1999","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":3246,"text":"Regulated Rivers: Research & Management","printIssn":"0886-9375","active":false,"publicationSubtype":{"id":10}},"title":"Factors controlling the establishment of Fremont cottonwood seedlings on the Upper Green River, USA","docAbstract":"<p><span>Declines in cottonwood (</span><i>Populus</i><span><span>&nbsp;</span>spp.) recruitment along alluvial reaches of large rivers in arid regions of the western United States have been attributed to modified flow regimes, lack of suitable substrate, insufficient seed rain, and increased interspecific competition. We evaluated whether and how these factors were operating during 1993–1996 to influence demographics of Fremont cottonwood (</span><i>P. deltoides</i><span><span>&nbsp;</span>Marshall subsp.<span>&nbsp;</span></span><i>wislizenii</i><span><span>&nbsp;</span>(Watson) Eckenwalder) along reaches of the Green and Yampa Rivers near their confluence in northwestern Colorado. We examined seedling establishment, defined as survival through three growing seasons, at three alluvial reaches that differed primarily in the level of flow regulation: a site on the unregulated Yampa, an upper Green River site regulated by Flaming Gorge Dam, and a lower Green River site below the Green–Yampa confluence. Seed rain was abundant in all sites, and led to large numbers of germinants (first-year seedlings) appearing each year at all sites. The regulated flow in the upper Green River reach restricted germination to islands and cut banks that were later inundated or eroded; no seedlings survived there. Mortality at the lower Green River site was due largely to desiccation or substrate erosion; 23% of 1993 germinants survived their first growing season, but at most 2% survived through their second. At the Yampa River site, germinants appeared on vegetated and unvegetated surfaces up to 2.5 m above base flow stage, but survived to autumn only on bare surfaces at least 1.25 m above base flow stage, and where at least 10 of the upper 40 cm of the alluvium was fine-textured. Our studies of rooting depths and the stable isotopic composition of xylem water showed that seedlings in the most favorable locations for establishment at the Yampa site do not become phreatophytic until their third or fourth growing season. Further, the results of experimental field studies examining effects of shade and competition supported the hypothesis that insufficient soil moisture, possibly in combination with insufficient light, restricts establishment to unvegetated sites. Collectively, the demographic and experimental studies suggest that, in arid regions, soil water availability is at least as important as light level in limiting establishment of Fremont cottonwood seedlings. We hypothesize that in cases where arid land rivers experience large spring stage changes, recruitment is further constrained within bare areas to those sites that contain sufficient fine-textured alluvium, saturated during the spring flood, to provide the flood-derived soil moisture normally necessary for late-summer seedling survival.</span></p>","language":"English","publisher":"Wiley","doi":"10.1002/(SICI)1099-1646(199909/10)15:5<419::AID-RRR555>3.0.CO;2-Y","usgsCitation":"Cooper, D.J., Merritt, D.M., Andersen, D., and Chimner, R.A., 1999, Factors controlling the establishment of Fremont cottonwood seedlings on the Upper Green River, USA: Regulated Rivers: Research & Management, v. 15, no. 5, p. 419-440, https://doi.org/10.1002/(SICI)1099-1646(199909/10)15:5<419::AID-RRR555>3.0.CO;2-Y.","productDescription":"22 p.","startPage":"419","endPage":"440","costCenters":[],"links":[{"id":229078,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"country":"United States","otherGeospatial":"Upper Green River","volume":"15","issue":"5","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a0ebde4b0c8380cd535d7","contributors":{"authors":[{"text":"Cooper, David J.","contributorId":196510,"corporation":false,"usgs":false,"family":"Cooper","given":"David","email":"","middleInitial":"J.","affiliations":[{"id":13017,"text":"Department of Forest and Rangeland Stewardship, Colorado State University","active":true,"usgs":false}],"preferred":false,"id":390683,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Merritt, David M.","contributorId":192229,"corporation":false,"usgs":false,"family":"Merritt","given":"David","email":"","middleInitial":"M.","affiliations":[{"id":24595,"text":"USDA Forest Service, Fort Collins CO","active":true,"usgs":false}],"preferred":false,"id":390680,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Andersen, Douglas C. doug_andersen@usgs.gov","contributorId":2216,"corporation":false,"usgs":true,"family":"Andersen","given":"Douglas C.","email":"doug_andersen@usgs.gov","affiliations":[{"id":291,"text":"Fort Collins Science Center","active":true,"usgs":true}],"preferred":false,"id":390681,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Chimner, Rodney A.","contributorId":53346,"corporation":false,"usgs":false,"family":"Chimner","given":"Rodney","email":"","middleInitial":"A.","affiliations":[{"id":17860,"text":"Colorado State University, Fort Collins, Colorado","active":true,"usgs":false}],"preferred":false,"id":390682,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}}
,{"id":70021576,"text":"70021576 - 1999 - Cooling rates and crystallization dynamics of shallow level pegmatite-aplite dikes, San Diego County, California","interactions":[],"lastModifiedDate":"2013-10-29T14:41:08","indexId":"70021576","displayToPublicDate":"1999-01-01T00:00:00","publicationYear":"1999","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":738,"text":"American Mineralogist","active":true,"publicationSubtype":{"id":10}},"title":"Cooling rates and crystallization dynamics of shallow level pegmatite-aplite dikes, San Diego County, California","docAbstract":"Pegmatites of the Pala and Mesa Grande Pegmatite Districts, San Diego County, California are typically thin, sheet-like composite pegmatite-aplite dikes. Aplitic portions of many dikes display pronounced mineralogical layering referred to as \"line rock,\" characterized by fine-grained, garnet-rich bands alternating with albite- and quartz-rich bands. Thermal modeling was performed for four dikes in San Diego County including the 1 m thick Himalaya dike, the 2 m thick Mission dike, the 8 m thick George Ashley dike, and the 25 m thick Stewart dike. Calculations were based on conductive cooling equations accounting for latent heat of crystallization, a melt emplacement temperature of 650 °C into 150 °C fractured, gabbroic country rock at a depth of 5 km, and an estimated 3 wt% initial H<sub>2</sub>O content in the melt. Cooling to <550 °C at the center of each dike occurred in ~9 years for the Stewart dike, ~340 days for the George Ashley dike, ~22 days for the Mission dike, and ~5 days for the Himalaya dike. Based on these calculations, growth rates for large pegmatitic minerals such as the 10 cm long Himalaya hanging wall tourmaline crystals may have been on the order of 10<sup>-5</sup> cm/s. Crystal size distribution (CSD) studies of garnet from layered aplites suggest growth rates of about 10<sup>-6</sup> cm/s. These results indicate that the dikes cooled and crystallized rapidly, with variable nucleation rates but high overall crystal-growth rates. Initial high nucleation rates coincident with emplacement and strong undercooling can account for the millimeter-size aplite grains. Lower nucleation rates coupled with high growth rates can explain the decimeter-size minerals in the hanging walls, cores, and miarolitic cavities of the pegmatites. The presence of tourmaline and/or lepidolite throughout these dikes suggests that although the melts were initially H<sub>2</sub>O-undersaturated, high melt concentrations of incompatible (or fluxing) components such as B, F, and Li (&plusmn;H<sub>2</sub>O), aided in the development of large pegmatitic crystals that grew rapidly in the short times suggested by the conductive cooling models.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"American Mineralogist","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","publisher":"American Geological Institute","issn":"0003004X","usgsCitation":"Webber, K.L., Simmons, W.B., Falster, A.U., and Foord, E.E., 1999, Cooling rates and crystallization dynamics of shallow level pegmatite-aplite dikes, San Diego County, California: American Mineralogist, v. 84, no. 5-6, p. 708-717.","startPage":"708","endPage":"717","numberOfPages":"10","costCenters":[],"links":[{"id":229323,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"84","issue":"5-6","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"5059fbe1e4b0c8380cd4e002","contributors":{"authors":[{"text":"Webber, Karen L.","contributorId":42739,"corporation":false,"usgs":true,"family":"Webber","given":"Karen","email":"","middleInitial":"L.","affiliations":[],"preferred":false,"id":390350,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Simmons, William B.","contributorId":47110,"corporation":false,"usgs":true,"family":"Simmons","given":"William","email":"","middleInitial":"B.","affiliations":[],"preferred":false,"id":390351,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Falster, Alexander U.","contributorId":29593,"corporation":false,"usgs":true,"family":"Falster","given":"Alexander","email":"","middleInitial":"U.","affiliations":[],"preferred":false,"id":390349,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Foord, Eugene E.","contributorId":96319,"corporation":false,"usgs":true,"family":"Foord","given":"Eugene","email":"","middleInitial":"E.","affiliations":[],"preferred":false,"id":390352,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}}
,{"id":70021432,"text":"70021432 - 1999 - Elastic-wave velocity in marine sediments with gas hydrates: Effective medium modeling","interactions":[],"lastModifiedDate":"2024-02-09T00:00:24.594203","indexId":"70021432","displayToPublicDate":"1999-01-01T00:00:00","publicationYear":"1999","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1807,"text":"Geophysical Research Letters","active":true,"publicationSubtype":{"id":10}},"title":"Elastic-wave velocity in marine sediments with gas hydrates: Effective medium modeling","docAbstract":"<div class=\"\"><div class=\"article-section__content en main\"><p>We offer a first-principle-based effective medium model for elastic-wave velocity in unconsolidated, high porosity, ocean bottom sediments containing gas hydrate. The dry sediment frame elastic constants depend on porosity, elastic moduli of the solid phase, and effective pressure. Elastic moduli of saturated sediment are calculated from those of the dry frame using Gassmann's equation. To model the effect of gas hydrate on sediment elastic moduli we use two separate assumptions: (a) hydrate modifies the pore fluid elastic properties without affecting the frame; (b) hydrate becomes a component of the solid phase, modifying the elasticity of the frame. The goal of the modeling is to predict the amount of hydrate in sediments from sonic or seismic velocity data. We apply the model to sonic and VSP data from ODP Hole 995 and obtain hydrate concentration estimates from assumption (b) consistent with estimates obtained from resistivity, chlorinity and evolved gas data.</p></div></div>","language":"English","publisher":"American Geophysical Union","doi":"10.1029/1999GL900421","issn":"00948276","usgsCitation":"Helgerud, M., Dvorkin, J., Nur, A., Sakai, A., and Collett, T., 1999, Elastic-wave velocity in marine sediments with gas hydrates: Effective medium modeling: Geophysical Research Letters, v. 26, no. 13, p. 2021-2024, https://doi.org/10.1029/1999GL900421.","productDescription":"4 p.","startPage":"2021","endPage":"2024","numberOfPages":"4","costCenters":[],"links":[{"id":229793,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"26","issue":"13","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a0884e4b0c8380cd51b62","contributors":{"authors":[{"text":"Helgerud, M.B.","contributorId":10946,"corporation":false,"usgs":true,"family":"Helgerud","given":"M.B.","affiliations":[],"preferred":false,"id":389850,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Dvorkin, J.","contributorId":77686,"corporation":false,"usgs":true,"family":"Dvorkin","given":"J.","affiliations":[],"preferred":false,"id":389854,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Nur, A.","contributorId":31114,"corporation":false,"usgs":true,"family":"Nur","given":"A.","email":"","affiliations":[],"preferred":false,"id":389851,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Sakai, A.","contributorId":76899,"corporation":false,"usgs":true,"family":"Sakai","given":"A.","email":"","affiliations":[],"preferred":false,"id":389853,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Collett, T. 0000-0002-7598-4708","orcid":"https://orcid.org/0000-0002-7598-4708","contributorId":62780,"corporation":false,"usgs":true,"family":"Collett","given":"T.","affiliations":[],"preferred":false,"id":389852,"contributorType":{"id":1,"text":"Authors"},"rank":5}]}}
,{"id":70020979,"text":"70020979 - 1999 - Management of groundwater supply and water quality in the Los Angeles Basin, California","interactions":[],"lastModifiedDate":"2012-03-12T17:19:47","indexId":"70020979","displayToPublicDate":"1999-01-01T00:00:00","publicationYear":"1999","noYear":false,"publicationType":{"id":24,"text":"Conference Paper"},"publicationSubtype":{"id":19,"text":"Conference Paper"},"title":"Management of groundwater supply and water quality in the Los Angeles Basin, California","docAbstract":"Water use and water needs in the coastal Los Angeles Basin in California have been very closely tied to the development of the region during the last 150 years. The first water wells were drilled in the mid-1800s. Currently about 40% of the water supply (9.4 m3 s-1) in the region is provided by groundwater. Other sources of water supply include reclaimed water and surface water imported from Owens Valley, the Colorado River, and northern California. Increasing groundwater use in the basin led to over-abstraction and seawater instrusion. Because of this, an important component of water management in the area has been the artificial recharge of local, imported, and reclaimed water which is spread in ponds and injected in wells to recharge the aquifer system and control seawater intrusion. The US Geological Survey (USGS) is working co-operatively with the Water Replenishment District of Southern California to evaluate the hydraulic and water-quality effects of these recharge operations and to assess the potential impacts of alternative water-management strategies, including changes in pumping and increases in the use of reclaimed water. As part of this work, the USGS has developed a geographic information system (GIS), collected water-quality and geohydrological data from new and existing wells, and developed a multi-aquifer regional groundwater flow model. Chemical and isotopic data were used to identify the age and source of recharge to groundwater throughout the study area. This information is key to understanding the fate of artificially recharged water and helps define the three-dimensional groundwater flow system. The geohydrological data, especially the geophysical and geological data collected from 11 newly installed multi-completion monitoring wells, were used to redefine the regional hydrostratigraphy. The groundwater flow model is being used to enhance the understanding of the geohydrological system and to quantitatively evaluate new water-management strategies.As part of the work aimed at evaluating the hydraulic and water-quality effects of recharge operations and to assess the potential impacts of alternative water-management strategies, the US Geological Survey (USGS), has developed a geographic information system (GIS), collected water-quality and geohydrological data from new and existing wells, and developed a multi-aquifer regional groundwater flow model. At present, the developed model is being used to enhance the understanding of the geohydrological system and to quantitatively evaluate new water-management strategies.","largerWorkTitle":"IAHS-AISH Publication","conferenceTitle":"The 2nd International Symposium on Assessing and Managing Health Risks from Drinking Water Contamination: Approaches and Applications","conferenceDate":"7 September 1998 through 10 September 1998","conferenceLocation":"Santiago, Chile","language":"English","publisher":"IAHS","publisherLocation":"Houston, TX, United States","issn":"01447815","usgsCitation":"Reichard, E., Crawford, S., Land, M., and Paybins, K., 1999, Management of groundwater supply and water quality in the Los Angeles Basin, California, <i>in</i> IAHS-AISH Publication, no. 260, Santiago, Chile, 7 September 1998 through 10 September 1998, p. 91-92.","startPage":"91","endPage":"92","numberOfPages":"2","costCenters":[],"links":[{"id":229968,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"issue":"260","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a4c71e4b0c8380cd69c79","contributors":{"authors":[{"text":"Reichard, E.G. 0000-0002-7310-3866","orcid":"https://orcid.org/0000-0002-7310-3866","contributorId":40635,"corporation":false,"usgs":true,"family":"Reichard","given":"E.G.","affiliations":[],"preferred":false,"id":388179,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Crawford, S.M.","contributorId":39418,"corporation":false,"usgs":true,"family":"Crawford","given":"S.M.","email":"","affiliations":[],"preferred":false,"id":388178,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Land, M.T. 0000-0001-5141-0307","orcid":"https://orcid.org/0000-0001-5141-0307","contributorId":14459,"corporation":false,"usgs":true,"family":"Land","given":"M.T.","affiliations":[],"preferred":false,"id":388177,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Paybins, K.S.","contributorId":11359,"corporation":false,"usgs":true,"family":"Paybins","given":"K.S.","affiliations":[],"preferred":false,"id":388176,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}}
,{"id":70021168,"text":"70021168 - 1999 - Survival of greater white-fronted geese: Effects of year, season, sex, and body condition","interactions":[],"lastModifiedDate":"2024-07-30T11:26:30.926239","indexId":"70021168","displayToPublicDate":"1999-01-01T00:00:00","publicationYear":"1999","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2508,"text":"Journal of Wildlife Management","active":true,"publicationSubtype":{"id":10}},"title":"Survival of greater white-fronted geese: Effects of year, season, sex, and body condition","docAbstract":"Information regarding the magnitude and variation in survival rates is necessary for understanding the causes of large changes in population size. We examined survival of greater white-fronted geese (Anser albifrons frontalis) in the Pacific Flyway during 1979-82. The population declined by 75% in the decade preceding our study but was stable during our investigation. Annual survival of adults (0.749, SE = 0.045) was 7% higher than during an earlier study. We developed a simple population model which suggests that recent (1985-96) survival rates may be as much as 10% higher in adults than the 1979-82 rate, which corresponds to population increases observed since 1985. Survival of adult females varied seasonally; monthly survival during a period of winter when no hunting or migration occurred was higher (0.986, SE = 0.015) than monthly survival at other times (0.964, SE = 0.006). Survival of adult males varied among years and with a general seasonal trend inverse to that for females. An index of body condition was positively related to survival of adult females in fall and spring, but not for adult males or immature geese. Monthly survival of immatures was lower during their first hunting season (0.886, SE = 0.026) than during all subsequent seasons (0.963, SE = 0.007). Annual survival of immatures beginning 1 October, immediately before the hunting season, was 0.471. Corresponding variations in survival rates, population numbers, and hunting regulations suggest that hunting may have influenced survival in this population of greater white-fronted geese.","language":"English","publisher":"Wildlife Society","issn":"0022541X","usgsCitation":"Schmutz, J.A., and Ely, C.R., 1999, Survival of greater white-fronted geese: Effects of year, season, sex, and body condition: Journal of Wildlife Management, v. 63, no. 4, p. 1239-1249.","productDescription":"11 p.","startPage":"1239","endPage":"1249","numberOfPages":"11","costCenters":[],"links":[{"id":229855,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"63","issue":"4","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505ba2d0e4b08c986b31f9a1","contributors":{"authors":[{"text":"Schmutz, Joel A. 0000-0002-6516-0836 jschmutz@usgs.gov","orcid":"https://orcid.org/0000-0002-6516-0836","contributorId":1805,"corporation":false,"usgs":true,"family":"Schmutz","given":"Joel","email":"jschmutz@usgs.gov","middleInitial":"A.","affiliations":[{"id":114,"text":"Alaska Science Center","active":true,"usgs":true},{"id":117,"text":"Alaska Science Center Biology WTEB","active":true,"usgs":true}],"preferred":true,"id":388869,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Ely, Craig R. 0000-0003-4262-0892 cely@usgs.gov","orcid":"https://orcid.org/0000-0003-4262-0892","contributorId":3214,"corporation":false,"usgs":true,"family":"Ely","given":"Craig","email":"cely@usgs.gov","middleInitial":"R.","affiliations":[{"id":651,"text":"Western Ecological Research Center","active":true,"usgs":true},{"id":117,"text":"Alaska Science Center Biology WTEB","active":true,"usgs":true}],"preferred":true,"id":388870,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}}
,{"id":1002972,"text":"1002972 - 1999 - Behavioral responses to disturbance in freshwater mussels with implications for conservation and management","interactions":[],"lastModifiedDate":"2024-05-31T11:14:56.674864","indexId":"1002972","displayToPublicDate":"1999-01-01T00:00:00","publicationYear":"1999","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2564,"text":"Journal of the North American Benthological Society","onlineIssn":"1937-237X","printIssn":"0887-3593","active":true,"publicationSubtype":{"id":10}},"title":"Behavioral responses to disturbance in freshwater mussels with implications for conservation and management","docAbstract":"<div class=\"col-lg-9 article__content\"><div class=\"article__body show-references \"><div class=\"hlFld-Abstract\"><div class=\"abstractSection abstractInFull\"><p>Knowledge about the ability of freshwater unionid mussels to recover from physical disturbance is important to their conservation and management. Threatened species may be disturbed by relocation to refugia as a conservation measure, and some species are disturbed by size- and species-selective harvesting of shells for use in the production of cultured pearls. The activity of freshwater unionid mussels generally decreases with water temperature, but intra- and interspecific differences in the frequency and distribution of recovery behaviors following disturbances at specific water temperatures have not been previously quantified. We observed righting, moving, and burrowing behavior of 4 mussel species, Amblema plicata plicata, Potamilus alatus, Fusconaia flava, and Lampsilis cardium, at 3 water temperatures (7, 14, and 21°C). The temporal frequency (intensity) and times-to-1st-event of behaviors were analyzed using proportional hazards models. Righting events and consecutive movements occurred at different intensities among temperatures and species. For righting, intensity increased by 8%/°C within the range of 7-21°C. Subsequent movements increased in intensity by 10%/°C. Amblema plicata was the slowest to respond, and had an intensity of turning upright only 27% of that for P. alatus. The intensities of movements for A. plicata and F. flava were 16% of those for P. alatus. Lampsilis cardium righted themselves most quickly, and had an intensity of righting 124% of that for P. alatus. The distribution of the 3 behaviors among treatment groups at 1 wk was analyzed with a proportional odds model. The distribution of righting, moving, and burrowing 1 wk after disturbance was described entirely by high-order interactions in our proportional odds model. Therefore, that model revealed little interpretable pattern in the endpoint data and it was less sensitive than our analysis of time-to-event data for measuring the effects of disturbance. We attributed the difference in sensitivity between the 2 models to the greater information content of time-until-event data. For similar studies of occurrences of key events, times to events should be recorded and interpreted whenever feasible and consistent with study objectives. Our results suggest that water temperature has an important effect on the outcome of mussel conservation projects and commercial harvesting activities. Our modeling approach, applied to other species, could help guide decisions about which species can safely be disturbed and the optimal seasonal timing of those disturbances.</p></div></div></div></div>","language":"English","publisher":"University of Chicago Press","doi":"10.2307/1468451","issn":"08873593","usgsCitation":"Waller, D.L., Gutreuter, S., and Rach, J., 1999, Behavioral responses to disturbance in freshwater mussels with implications for conservation and management: Journal of the North American Benthological Society, v. 18, no. 3, p. 381-390, https://doi.org/10.2307/1468451.","productDescription":"10 p.","startPage":"381","endPage":"390","numberOfPages":"10","costCenters":[{"id":606,"text":"Upper Midwest Environmental Sciences Center","active":true,"usgs":true}],"links":[{"id":165683,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"18","issue":"3","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4a54e4b07f02db62c2cb","contributors":{"authors":[{"text":"Waller, D. L.","contributorId":43704,"corporation":false,"usgs":true,"family":"Waller","given":"D.","email":"","middleInitial":"L.","affiliations":[],"preferred":false,"id":312464,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Gutreuter, S.","contributorId":79829,"corporation":false,"usgs":true,"family":"Gutreuter","given":"S.","email":"","affiliations":[],"preferred":false,"id":312466,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Rach, J.J.","contributorId":73948,"corporation":false,"usgs":true,"family":"Rach","given":"J.J.","email":"","affiliations":[],"preferred":false,"id":312465,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}}
,{"id":1002976,"text":"1002976 - 1999 - Evaluation of the flood-pulse concept based on statistical models of growth of selected fishes of the upper Mississippi River system","interactions":[],"lastModifiedDate":"2012-02-02T00:04:09","indexId":"1002976","displayToPublicDate":"1999-01-01T00:00:00","publicationYear":"1999","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1169,"text":"Canadian Journal of Fisheries and Aquatic Sciences","active":true,"publicationSubtype":{"id":10}},"title":"Evaluation of the flood-pulse concept based on statistical models of growth of selected fishes of the upper Mississippi River system","docAbstract":"The flood-pulse concept (FPC) states that annual inundation is the principal force responsible for productivity and biotic interactions in river-floodplain systems. Somatic growth is one component of production, and we hypothesized that, if the FPC applies, growth of fishes that use the moving littoral zone should differ among years with differing flood pattern, whereas nonlittoral fishes would show no such response. Growth of largemouth bass (Micropterus salmoides) and bluegill (Lepomis macrochirus), species that exploit littoral resources, increased during a year having an unusual warm-season flood in the Upper Mississippi River system and was reduced during low-water years. Growth of white bass (Morone chrysops), which do not rely heavily on the littoral zone, did not differ significantly between the extreme-flood and low-water years. Patterns of growth of black crappie (Pomoxis nigromaculatus), which have intermediate dependence on the moving littoral zone, were somewhat ambiguous. These results are consistent with the hypothesis that the FPC applies, at least under certain conditions, to this temperate river system. Our results can also provide an important basis from which to assess some costs and benefits of water level management strategies in large regulated temperate rivers.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Canadian Journal of Fisheries and Aquatic Sciences","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","usgsCitation":"Gutreuter, S., Bartels, A., Irons, K., and Sandheinrich, M., 1999, Evaluation of the flood-pulse concept based on statistical models of growth of selected fishes of the upper Mississippi River system: Canadian Journal of Fisheries and Aquatic Sciences, v. 56, no. 12, p. 2282-2291.","productDescription":"pp. 2282-2291","startPage":"2282","endPage":"2291","numberOfPages":"10","costCenters":[{"id":606,"text":"Upper Midwest Environmental Sciences Center","active":true,"usgs":true}],"links":[{"id":129462,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":15622,"rank":100,"type":{"id":15,"text":"Index Page"},"url":"https://rparticle.web-p.cisti.nrc.ca/rparticle/AbstractTemplateServlet?journal=cjfas&volume=56&year=1999&issue=56&msno=f99-161&calyLang=eng","linkFileType":{"id":5,"text":"html"},"description":"7112.000000000000000"}],"volume":"56","issue":"12","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4a08e4b07f02db5fa3ab","contributors":{"authors":[{"text":"Gutreuter, S.","contributorId":79829,"corporation":false,"usgs":true,"family":"Gutreuter","given":"S.","email":"","affiliations":[],"preferred":false,"id":312474,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Bartels, A.D.","contributorId":81841,"corporation":false,"usgs":true,"family":"Bartels","given":"A.D.","email":"","affiliations":[],"preferred":false,"id":312475,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Irons, K.","contributorId":20282,"corporation":false,"usgs":true,"family":"Irons","given":"K.","email":"","affiliations":[],"preferred":false,"id":312472,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Sandheinrich, M.B.","contributorId":76263,"corporation":false,"usgs":true,"family":"Sandheinrich","given":"M.B.","affiliations":[],"preferred":false,"id":312473,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}}
,{"id":70021238,"text":"70021238 - 1999 - Applied historical ecology: Using the past to manage for the future","interactions":[],"lastModifiedDate":"2018-01-23T13:42:56","indexId":"70021238","displayToPublicDate":"1999-01-01T00:00:00","publicationYear":"1999","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1450,"text":"Ecological Applications","active":true,"publicationSubtype":{"id":10}},"title":"Applied historical ecology: Using the past to manage for the future","docAbstract":"Applied historical ecology is the use of historical knowledge in the management of ecosystems. Historical perspectives increase our understanding of the dynamic nature of landscapes and provide a frame of reference for assessing modern patterns and processes. Historical records, however, are often too brief or fragmentary to be useful, or they are not obtainable for the process or structure of interest. Even where long historical time series can be assembled, selection of appropriate reference conditions may be complicated by the past influence of humans and the many potential reference conditions encompassed by nonequilibrium dynamics. These complications, however, do not lessen the value of history; rather they underscore the need for multiple, comparative histories from many locations for evaluating both cultural and natural causes of variability, as well as for characterizing the overall dynamical properties of ecosystems. Historical knowledge may not simplify the task of setting management goals and making decisions, but 20th century trends, such as increasingly severe wildfires, suggest that disregarding history can be perilous. We describe examples from our research in the southwestern United States to illustrate some of the values and limitations of applied historical ecology. Paleoecological data from packrat middens and other natural archives have been useful for defining baseline conditions of vegetation communities, determining histories and rates of species range expansions and contractions, and discriminating between natural and cultural causes of environmental change. We describe a montane grassland restoration project in northern New Mexico that was justified and guided by an historical sequence of aerial photographs showing progressive tree invasion during the 20th century. Likewise, fire scar chronologies have been widely used to justify and guide fuel reduction and natural five reintroduction in forests. A southwestern network of fire histories illustrates the power of aggregating historical time series across spatial scales. Regional fire patterns evident in these aggregations point to the key role of interannual lags in responses of fuels and fire regimes to the El Nino-Southern Oscillation (wet/dry cycles), with important implications for long-range fire hazard forecasting. These examples of applied historical ecology emphasize that detection and explanation of historical trends and variability are essential to informed management.","language":"English","publisher":"Ecological Society of America","doi":"10.1890/1051-0761(1999)009[1189:AHEUTP]2.0.CO;2","usgsCitation":"Swetnam, T.W., Allen, C.D., and Betancourt, J.L., 1999, Applied historical ecology: Using the past to manage for the future: Ecological Applications, v. 9, no. 4, p. 1189-1206, https://doi.org/10.1890/1051-0761(1999)009[1189:AHEUTP]2.0.CO;2.","productDescription":"18 p.","startPage":"1189","endPage":"1206","costCenters":[{"id":291,"text":"Fort Collins Science Center","active":true,"usgs":true}],"links":[{"id":229743,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":350525,"rank":2,"type":{"id":22,"text":"Related Work"},"url":"https://pubs.usgs.gov/publication/70194846","text":"USGS Publications Warehouse citation page for republication","linkHelpText":"This article was republished in the book <i>Wildfire: A century of failed forest policy</i> (Island Press, 2006)"}],"volume":"9","issue":"4","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"5059eccde4b0c8380cd494d2","contributors":{"authors":[{"text":"Swetnam, Thomas W.","contributorId":191872,"corporation":false,"usgs":false,"family":"Swetnam","given":"Thomas","email":"","middleInitial":"W.","affiliations":[],"preferred":false,"id":389168,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Allen, Craig D. 0000-0002-8777-5989 craig_allen@usgs.gov","orcid":"https://orcid.org/0000-0002-8777-5989","contributorId":2597,"corporation":false,"usgs":true,"family":"Allen","given":"Craig","email":"craig_allen@usgs.gov","middleInitial":"D.","affiliations":[{"id":290,"text":"Forest and Rangeland Ecosystem Science Center","active":false,"usgs":true},{"id":291,"text":"Fort Collins Science Center","active":true,"usgs":true}],"preferred":true,"id":389166,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Betancourt, Julio L. 0000-0002-7165-0743 jlbetanc@usgs.gov","orcid":"https://orcid.org/0000-0002-7165-0743","contributorId":3376,"corporation":false,"usgs":true,"family":"Betancourt","given":"Julio","email":"jlbetanc@usgs.gov","middleInitial":"L.","affiliations":[{"id":436,"text":"National Research Program - Eastern Branch","active":true,"usgs":true},{"id":438,"text":"National Research Program - Western Branch","active":true,"usgs":true},{"id":554,"text":"Science and Decisions Center","active":true,"usgs":true}],"preferred":true,"id":389167,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}}
,{"id":1001797,"text":"1001797 - 1999 - Effects of fire retardant chemical and fire suppressant foam on shrub steppe vegetation in northern Nevada","interactions":[],"lastModifiedDate":"2018-01-02T12:33:46","indexId":"1001797","displayToPublicDate":"1999-01-01T00:00:00","publicationYear":"1999","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2083,"text":"International Journal of Wildland Fire","active":true,"publicationSubtype":{"id":10}},"title":"Effects of fire retardant chemical and fire suppressant foam on shrub steppe vegetation in northern Nevada","docAbstract":"<p><span>The objectives of this study were to determine the effects of fire retardantchemical (Phos-Chek G75-F</span><sup>*</sup><span>) and fire suppressant foam (Silv-Ex) application,alone and in combination with fire, on Great Basin shrub steppe vegetation. Wemeasured growth, resprouting, flowering, and incidence of galling insects on</span><i>Chrysothamnus viscidiflorus</i><span>and</span><i>Artemisia tridentata</i><span>. These characteristics were notaffected by any chemical treatment. We measured community characteristics,including species richness, evenness, and diversity, and number of stems ofwoody and herbaceous plants in riparian and upland plots. Of these characteristics, only species richness and number ofstems/m</span><sup>2</sup><span> clearly responded to the chemicaltreatments, and the response was modified by fire. In general, speciesrichness declined, especially after Phos-Chek application. However, by the endof the growing season, species richness did not differ between treated andcontrol plots. Acanonical variate analysis suggested that burning had agreater influence on community composition than did the chemical treatments.In general, riparian areas showed more significant responses to the treatmentsthan did upland areas, and June applications produced greater changes inspecies richness and stem density than did July applications.</span></p>","language":"English","publisher":"International Association of Wildland Fire","doi":"10.1071/WF00013","usgsCitation":"Larson, D.L., Newton, W.E., Anderson, P.J., and Stein, S.J., 1999, Effects of fire retardant chemical and fire suppressant foam on shrub steppe vegetation in northern Nevada: International Journal of Wildland Fire, v. 9, no. 2, p. 115-127, https://doi.org/10.1071/WF00013.","productDescription":"13 p.","startPage":"115","endPage":"127","costCenters":[{"id":480,"text":"Northern Prairie Wildlife Research Center","active":true,"usgs":true}],"links":[{"id":129234,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"9","issue":"2","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4a2ee4b07f02db6158e8","contributors":{"authors":[{"text":"Larson, Diane L. 0000-0001-5202-0634 dlarson@usgs.gov","orcid":"https://orcid.org/0000-0001-5202-0634","contributorId":2120,"corporation":false,"usgs":true,"family":"Larson","given":"Diane","email":"dlarson@usgs.gov","middleInitial":"L.","affiliations":[{"id":480,"text":"Northern Prairie Wildlife Research Center","active":true,"usgs":true}],"preferred":true,"id":311802,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Newton, Wesley E. 0000-0002-1377-043X wnewton@usgs.gov","orcid":"https://orcid.org/0000-0002-1377-043X","contributorId":3661,"corporation":false,"usgs":true,"family":"Newton","given":"Wesley","email":"wnewton@usgs.gov","middleInitial":"E.","affiliations":[{"id":480,"text":"Northern Prairie Wildlife Research Center","active":true,"usgs":true}],"preferred":true,"id":311800,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Anderson, Patrick J. 0000-0003-2281-389X andersonpj@usgs.gov","orcid":"https://orcid.org/0000-0003-2281-389X","contributorId":3590,"corporation":false,"usgs":true,"family":"Anderson","given":"Patrick","email":"andersonpj@usgs.gov","middleInitial":"J.","affiliations":[{"id":291,"text":"Fort Collins Science Center","active":true,"usgs":true}],"preferred":true,"id":311803,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Stein, Steven J.","contributorId":174613,"corporation":false,"usgs":false,"family":"Stein","given":"Steven","email":"","middleInitial":"J.","affiliations":[],"preferred":false,"id":311801,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}}
,{"id":70021719,"text":"70021719 - 1999 - Seafloor environments in the Long Island Sound estuarine system","interactions":[],"lastModifiedDate":"2012-03-12T17:19:37","indexId":"70021719","displayToPublicDate":"1999-01-01T00:00:00","publicationYear":"1999","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2667,"text":"Marine Geology","active":true,"publicationSubtype":{"id":10}},"title":"Seafloor environments in the Long Island Sound estuarine system","docAbstract":"Four categories of modern seafloor sedimentary environments have been identified and mapped across the large, glaciated, topographically complex Long Island Sound estuary by means of an extensive regional set of sidescan sonographs, bottom samples, and video-camera observations and supplemental marine-geologic and modeled physical-oceanographic data. (1) Environments of erosion or nondeposition contain sediments which range from boulder fields to gravelly coarse-to-medium sands and appear on the sonographs either as patterns with isolated reflections (caused by outcrops of glacial drift and bedrock) or as patterns of strong backscatter (caused by coarse lag deposits). Areas of erosion or nondeposition were found across the rugged seafloor at the eastern entrance of the Sound and atop bathymetric highs and within constricted depressions in other parts of the basin. (2) Environments of bedload transport contain mostly coarse-to-fine sand with only small amounts of mud and are depicted by sonograph patterns of sand ribbons and sand waves. Areas of bedload transport were found primarily in the eastern Sound where bottom currents have sculptured the surface of a Holocene marine delta and are moving these sediments toward the WSW into the estuary. (3) Environments of sediment sorting and reworking comprise variable amounts of fine sand and mud and are characterized either by patterns of moderate backscatter or by patterns with patches of moderate-to-weak backscatter that reflect a combination of erosion and deposition. Areas of sediment sorting and reworking were found around the periphery of the zone of bedload transport in the eastern Sound and along the southern nearshore margin. They also are located atop low knolls, on the flanks of shoal complexes, and within segments of the axial depression in the western Sound. (4) Environments of deposition are blanketed by muds and muddy fine sands that produce patterns of uniformly weak backscatter. Depositional areas occupy broad areas of the basin floor in the western part of the Sound. The regional distribution of seafloor environments reflects fundamental differences in marine-geologic conditions between the eastern and western parts of the Sound. In the funnel-shaped eastern part, a gradient of strong tidal currents coupled with the net nontidal (estuarine) bottom drift produce a westward progression of environments ranging from erosion or nondeposition at the narrow entrance to the Sound, through an extensive area of bedload transport, to a peripheral zone of sediment sorting. In the generally broader western part of the Sound, a weak tidal-current regime combined with the production of particle aggregates by biologic or chemical processes, cause large areas of deposition that are locally interrupted by a patchy distribution of various other environments where the bottom currents are enhanced by and interact with the seafloor topography.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Marine Geology","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1016/S0025-3227(98)00129-7","issn":"00253227","usgsCitation":"Knebel, H., Signell, R.P., Rendigs, R., Poppe, L., and List, J.H., 1999, Seafloor environments in the Long Island Sound estuarine system: Marine Geology, v. 155, no. 3-4, p. 277-318, https://doi.org/10.1016/S0025-3227(98)00129-7.","startPage":"277","endPage":"318","numberOfPages":"42","costCenters":[],"links":[{"id":229260,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":206264,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/S0025-3227(98)00129-7"}],"volume":"155","issue":"3-4","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505b882ae4b08c986b31682c","contributors":{"authors":[{"text":"Knebel, H.J.","contributorId":79092,"corporation":false,"usgs":true,"family":"Knebel","given":"H.J.","affiliations":[],"preferred":false,"id":390899,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Signell, R. P.","contributorId":89147,"corporation":false,"usgs":true,"family":"Signell","given":"R.","email":"","middleInitial":"P.","affiliations":[],"preferred":false,"id":390900,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Rendigs, R.R.","contributorId":50506,"corporation":false,"usgs":true,"family":"Rendigs","given":"R.R.","affiliations":[],"preferred":false,"id":390896,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Poppe, L.J.","contributorId":72782,"corporation":false,"usgs":true,"family":"Poppe","given":"L.J.","affiliations":[],"preferred":false,"id":390898,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"List, J. H.","contributorId":70406,"corporation":false,"usgs":true,"family":"List","given":"J.","email":"","middleInitial":"H.","affiliations":[],"preferred":false,"id":390897,"contributorType":{"id":1,"text":"Authors"},"rank":5}]}}
,{"id":70021770,"text":"70021770 - 1999 - Geodetic estimates of fault slip rates in the San Francisco Bay area","interactions":[],"lastModifiedDate":"2024-07-17T15:25:27.312028","indexId":"70021770","displayToPublicDate":"1999-01-01T00:00:00","publicationYear":"1999","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":"Geodetic estimates of fault slip rates in the San Francisco Bay area","docAbstract":"<p><i>Bourne et al.</i><span>&nbsp;[1998] have suggested that the interseismic velocity profile at the surface across a transform plate boundary is a replica of the secular velocity profile at depth in the plastosphere. On the other hand, in the viscoelastic coupling model the shape of the interseismic surface velocity profile is a consequence of plastosphere relaxation following the previous rupture of the faults that make up the plate boundary and is not directly related to the secular flow in the plastosphere. The two models appear to be incompatible. If the plate boundary is composed of several subparallel faults and the interseismic surface velocity profile across the boundary known, each model predicts the secular slip rates on the faults which make up the boundary. As suggested by Bourne et al., the models can then be tested by comparing the predicted secular slip rates to those estimated from long-term offsets inferred from geology. Here we apply that test to the secular slip rates predicted for the principal faults (San Andreas, San Gregorio, Hayward, Calaveras, Rodgers Creek, Green Valley and Greenville faults) in the San Andreas fault system in the San Francisco Bay area. The estimates from the two models generally agree with one another and to a lesser extent with the geologic estimate. Because the viscoelastic coupling model has been equally successful in estimating secular slip rates on the various fault strands at a diffuse plate boundary, the success of the model of&nbsp;</span><i>Bourne et at.</i><span>&nbsp;[1998] in doing the same thing should not be taken as proof that the interseismic velocity profile across the plate boundary at the surface is a replica of the velocity profile at depth in the plastosphere.</span></p>","language":"English","publisher":"American Geophysical Union","doi":"10.1029/1998JB900108","issn":"01480227","usgsCitation":"Savage, J., Svarc, J.L., and Prescott, W., 1999, Geodetic estimates of fault slip rates in the San Francisco Bay area: Journal of Geophysical Research B: Solid Earth, v. 104, no. B3, p. 4995-5002, https://doi.org/10.1029/1998JB900108.","productDescription":"8 p.","startPage":"4995","endPage":"5002","numberOfPages":"8","costCenters":[],"links":[{"id":229523,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"104","issue":"B3","noUsgsAuthors":false,"publicationDate":"1999-03-10","publicationStatus":"PW","scienceBaseUri":"505a173be4b0c8380cd55435","contributors":{"authors":[{"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":391091,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Svarc, J. L.","contributorId":75995,"corporation":false,"usgs":true,"family":"Svarc","given":"J.","email":"","middleInitial":"L.","affiliations":[],"preferred":false,"id":391089,"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":391090,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}}
,{"id":70021758,"text":"70021758 - 1999 - Mesoproterozoic rapakivi granites of the Rondonia Tin Province, southwestern border of the Amazonian craton, Brazil-I. Reconnaissance U-Pb geochronology and regional implications","interactions":[],"lastModifiedDate":"2012-03-12T17:19:41","indexId":"70021758","displayToPublicDate":"1999-01-01T00:00:00","publicationYear":"1999","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":3112,"text":"Precambrian Research","active":true,"publicationSubtype":{"id":10}},"title":"Mesoproterozoic rapakivi granites of the Rondonia Tin Province, southwestern border of the Amazonian craton, Brazil-I. Reconnaissance U-Pb geochronology and regional implications","docAbstract":"Rapakivi granites and associated mafic and ultramafic rocks in the Rondonia Tin Province, southwestern Amazonian craton, Brazil were emplaced during six discrete episodes of magmatism between ca 1600 and 970 Ma. The seven rapakivi granite suites emplaced at this time were the Serra da Providencia Intrusive Suite (U-Pb ages between 1606 and 1532 Ma); Santo Antonio Intrusive Suite (U-Pb age 1406 Ma); Teotonio Intrusive Suite (U-Pb age 1387 Ma); Alto Candeias Intrusive Suite (U-Pb ages between 1346 and 1338 Ma); Sao Lourenco-Caripunas Intrusive Suite (U-Pb ages between 1314 and 1309 Ma); Santa Clara Intrusive Suite (U-Pb ages between 1082 and 1074 Ma); and Younger Granites of Rondonia (U-Pb ages between 998 and 974 Ma). The Serra da Providencia Intrusive Suite intruded the Paleoproterozoic (1.80 to 1.70 Ga) Rio Negro-Juruena crust whereas the other suites were emplaced into the 1.50 to 1.30 Ga Rondonia-San Ignacio crust. Their intrusion was contemporaneous with orogenic activity in other parts of the southwestern Amazonian craton, except for the oldest, Serra da Providencia Intrusive Suite. Orogenic events coeval with emplacement of the Serra da Providencia Intrusive Suite are not clearly recognized in the region. The Santo Antonio, Teotonio, Alto Candeias and Sao Lourenco-Caripunas Intrusive Suites are interpreted to represent extensional anorogenic magmatism associated with the terminal stages of the Rondonian-San Ignacio orogeny. At least the Sao Lourenco-Caripunas rapakivi granites and coeval intra-continental rift sedimentary rocks may, in contrast, represent the products of extensional tectonics and rifting preceding the Sunsas/Aguapei orogeny (1.25 to 1.0 Ga). The two youngest rapakivi suites, the Santa Clara Intrusive Suite and Younger Granites of Rondonia, seemingly represent inboard magmatism in the Rondonian-San Ignacio Province during a younger episode of reworking in the Rio Negro-Juruena Province during the waning stages of the collisional 1.1 to 1.0 Ga Sunsas/Aguapei orogeny. The six intra-plate rapakivi granite episodes in the southwestern part of the Amazonian craton form three broad periods of anorogenic magmatism that have age-correlative events composed of similar rocks and geologic environments in eastern Laurentia and Baltica, although the exact timing of magmatism appears slightly different. Recognition of lithologic and chronological correlations between various cratons provide important constraints to models explaining the interplay between rapakivi granite magmatism and deep crustal evolution of an early Mesoproterozoic supercontinent. They are, furthermore, important to plate tectonic models for the assembly, dispersal and reassembly of Amazonia, Laurentia and Baltica in the Mesoproterozoic and Neoproterozoic.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Precambrian Research","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1016/S0301-9268(98)00126-0","issn":"03019268","usgsCitation":"Bettencourt, J.S., Tosdal, R., Leite, W., and Payolla, B., 1999, Mesoproterozoic rapakivi granites of the Rondonia Tin Province, southwestern border of the Amazonian craton, Brazil-I. Reconnaissance U-Pb geochronology and regional implications: Precambrian Research, v. 95, no. 1-2, p. 41-67, https://doi.org/10.1016/S0301-9268(98)00126-0.","startPage":"41","endPage":"67","numberOfPages":"27","costCenters":[],"links":[{"id":206309,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/S0301-9268(98)00126-0"},{"id":229367,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"95","issue":"1-2","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a5446e4b0c8380cd6cf2b","contributors":{"authors":[{"text":"Bettencourt, Jorge S.","contributorId":97269,"corporation":false,"usgs":true,"family":"Bettencourt","given":"Jorge","email":"","middleInitial":"S.","affiliations":[],"preferred":false,"id":391044,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Tosdal, R. M.","contributorId":54982,"corporation":false,"usgs":true,"family":"Tosdal","given":"R. M.","affiliations":[],"preferred":false,"id":391043,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Leite, W.B. Jr.","contributorId":28763,"corporation":false,"usgs":true,"family":"Leite","given":"W.B.","suffix":"Jr.","email":"","affiliations":[],"preferred":false,"id":391042,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Payolla, B.L.","contributorId":7441,"corporation":false,"usgs":true,"family":"Payolla","given":"B.L.","email":"","affiliations":[],"preferred":false,"id":391041,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}}
,{"id":70021874,"text":"70021874 - 1999 - A digital resource model of the Upper Pennsylvanian Pittsburgh coal bed, Monongahela Group, northern Appalachian basin coal region, USA","interactions":[],"lastModifiedDate":"2012-03-12T17:19:38","indexId":"70021874","displayToPublicDate":"1999-01-01T00:00:00","publicationYear":"1999","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2033,"text":"International Journal of Coal Geology","active":true,"publicationSubtype":{"id":10}},"title":"A digital resource model of the Upper Pennsylvanian Pittsburgh coal bed, Monongahela Group, northern Appalachian basin coal region, USA","docAbstract":"The U.S. Geological Survey is currently conducting a coal resource assessment of the coal beds and zones that are expected to provide the bulk of the Nation's coal resources for the next few decades. The Pittsburgh coal bed is the first bed in the northern and central Appalachian basin coal region to undergo a fully-digital assessment. The bed-specific assessment is being carried out in partnership with the state geologic surveys of West Virginia (WV), Pennsylvania (PA), Ohio (OH), and Maryland (MD). Comprehensive stratigraphic and geochemical databases have been developed for the Pittsburgh coal bed, and areal extent, mined areas, structure contour, isopach, overburden thickness maps of the bed have been released as United States Geological Survey (USGS) Open-File Reports. The resulting resource model indicates that of the original 34 billion short tons (31 billion tonnes) of Pittsburgh coal, 16 billion short tons (14 billion tonnes) remain. Although most of the remaining coal is thinner, deeper, and higher in ash and sulfur (S) than the original resource, there are blocks of extensive thick (6-8 ft or 1.8-2.4 m) coal in southwestern PA and the northern panhandle of WV.The U.S. Geological Survey is currently conducting a coal resource assessment of the coal beds and zones that are expected to provide the bulk of the Nation's coal resources for the next few decades. The Pittsburgh coal bed is the first bed in the northern and central Appalachian basin coal region to undergo a fully-digital assessment. The bed-specific assessment is being carried out in partnership with the state geologic surveys of West Virginia (WV), Pennsylvania (PA), Ohio (OH), and Maryland (MD). Comprehensive stratigraphic and geochemical databases have been developed for the Pittsburgh coal bed, and areal extent, mined areas, structure contour, isopach, overburden thickness maps of the bed have been released as United States Geological Survey (USGS) Open-File Reports. The resulting resource model indicates that of the original 34 billion short tons (31 billion tonnes) of Pittsburgh coal, 16 billion short tons (14 billion tonnes) remain. Although most of the remaining coal is thinner, deeper, and higher in ash and sulfur (S) than the original resource, there are blocks of extensive thick (6-8 ft or 1.8-2.4 m) coal in southwestern PA and the northern panhandle of WV.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"International Journal of Coal Geology","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","publisher":"Elsevier Science Publishers B.V.","publisherLocation":"Amsterdam, Netherlands","doi":"10.1016/S0166-5162(99)00009-9","issn":"01665162","usgsCitation":"Ruppert, L., Tewalt, S., Bragg, L.J., and Wallack, R., 1999, A digital resource model of the Upper Pennsylvanian Pittsburgh coal bed, Monongahela Group, northern Appalachian basin coal region, USA: International Journal of Coal Geology, v. 41, no. 1-2, p. 3-24, https://doi.org/10.1016/S0166-5162(99)00009-9.","startPage":"3","endPage":"24","numberOfPages":"22","costCenters":[],"links":[{"id":229493,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":206349,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/S0166-5162(99)00009-9"}],"volume":"41","issue":"1-2","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"5059e3bde4b0c8380cd461cd","contributors":{"authors":[{"text":"Ruppert, L.F. 0000-0003-4990-0539","orcid":"https://orcid.org/0000-0003-4990-0539","contributorId":59043,"corporation":false,"usgs":true,"family":"Ruppert","given":"L.F.","affiliations":[],"preferred":false,"id":391515,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Tewalt, S.J.","contributorId":55838,"corporation":false,"usgs":true,"family":"Tewalt","given":"S.J.","affiliations":[],"preferred":false,"id":391514,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Bragg, L. J.","contributorId":104055,"corporation":false,"usgs":true,"family":"Bragg","given":"L.","email":"","middleInitial":"J.","affiliations":[],"preferred":false,"id":391516,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Wallack, R.N.","contributorId":34183,"corporation":false,"usgs":true,"family":"Wallack","given":"R.N.","affiliations":[],"preferred":false,"id":391513,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}}
,{"id":70186547,"text":"70186547 - 1999 - Comparison of aerial survey procedures for estimating polar bear density: Results of pilot studies in northern Alaska","interactions":[{"subject":{"id":70186547,"text":"70186547 - 1999 - Comparison of aerial survey procedures for estimating polar bear density: Results of pilot studies in northern Alaska","indexId":"70186547","publicationYear":"1999","noYear":false,"title":"Comparison of aerial survey procedures for estimating polar bear density: Results of pilot studies in northern Alaska"},"predicate":"IS_PART_OF","object":{"id":70180186,"text":"70180186 - 1999 - Marine mammal survey and assessment methods","indexId":"70180186","publicationYear":"1999","noYear":false,"title":"Marine mammal survey and assessment methods"},"id":1}],"isPartOf":{"id":70180186,"text":"70180186 - 1999 - Marine mammal survey and assessment methods","indexId":"70180186","publicationYear":"1999","noYear":false,"title":"Marine mammal survey and assessment methods"},"lastModifiedDate":"2017-04-06T16:04:24","indexId":"70186547","displayToPublicDate":"1999-01-01T00:00:00","publicationYear":"1999","noYear":false,"publicationType":{"id":24,"text":"Conference Paper"},"publicationSubtype":{"id":19,"text":"Conference Paper"},"title":"Comparison of aerial survey procedures for estimating polar bear density: Results of pilot studies in northern Alaska","docAbstract":"<p><span>The U.S. Marine Mammal Protection Act (MMPA) and International Agreement on the Conservation of Polar Bears mandate that boundaries and sizes of polar bear (</span><i><span>Ursus maritimus</span></i><span>) populations be known so they can be managed at optimum sustainable levels. However, data to estimate polar bear numbers for the Chukchi/Bering Sea and Beaufort Sea populations in Alaska are limited. We evaluated aerial line transect methodology for assessing the size of these Alaskan polar bear populations during pilot studies in spring 1987 and summer 1994. In April and May 1987 we flew 12.239 km of transect lines in the northern Bering, Chukchi, and western Beaufort seas. In June 1994 we flew 6.244 km of transect lines in a primary survey unit using a helicopter, and 5,701 km of transect lines in a secondary survey unit using a fixed-wing aircraft in the Beaufort Sea. We examined visibility bias in aerial transect surveys, double counts by independent observers, single-season mark-resight methods, the suitability of using polar bear sign to stratify the study area, and adaptive sampling methods. Fifteen polar bear groups were observed during the 1987 study. Probability of detecting bears decreased with increasing perpendicular distance from the transect line, and probability of detecting polar bear groups likely increased with increasing group size. We estimated population density in high density areas to be 446 km<sup>2</sup>/bear. In 1994, 15 polar bear groups were observed by independent front and rear seat observers on transect lines in the primary survey unit. Density estimates ranged from 284 km<sup>2</sup>/bear to 197 km<sup>2</sup>/bear depending on the model selected. Low polar bear numbers scattered over large areas of polar ice in 1987 indicated that spring is a poor time to conduct aerial surveys. Based on the 1994 survey we determined that ship-based helicopter or land-based fixed-wing aerial surveys conducted at the ice-edge in late summer-early fall may produce robust density estimates for polar bear populations in the Chukchi/Bering and Beaufort seas.</span></p>","largerWorkType":{"id":4,"text":"Book"},"largerWorkTitle":"Marine mammal survey and assessment methods","largerWorkSubtype":{"id":12,"text":"Conference publication"},"conferenceTitle":"Symposium on surveys, status & trends of marine mammal populations","conferenceDate":"25-27 February, 1998","conferenceLocation":"Seattle, WA","language":"English","publisher":"A.A. Balkema","publisherLocation":"Rotterdam, Netherlands","isbn":"9789058090430","usgsCitation":"McDonald, L.L., and Garner, G.W., 1999, Comparison of aerial survey procedures for estimating polar bear density: Results of pilot studies in northern Alaska, <i>in</i> Marine mammal survey and assessment methods, Seattle, WA, 25-27 February, 1998, p. 37-52.","productDescription":"16 p.","startPage":"37","endPage":"52","costCenters":[{"id":114,"text":"Alaska Science Center","active":true,"usgs":true}],"links":[{"id":339215,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":339214,"rank":1,"type":{"id":15,"text":"Index Page"},"url":"https://www.crcpress.com/Marine-Mammal-Survey-and-Assessment-Methods/Laake-Robertson-Amstrup/p/book/9789058090430"}],"noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"58e60275e4b09da6799ac697","contributors":{"editors":[{"text":"Garner, Gerald W.","contributorId":149918,"corporation":false,"usgs":false,"family":"Garner","given":"Gerald","email":"","middleInitial":"W.","affiliations":[{"id":13117,"text":"Institute of Arctic Biology, University of Alaska Fairbanks","active":true,"usgs":false}],"preferred":false,"id":688730,"contributorType":{"id":2,"text":"Editors"},"rank":1},{"text":"Amstrup, Steven C.","contributorId":67034,"corporation":false,"usgs":false,"family":"Amstrup","given":"Steven","email":"","middleInitial":"C.","affiliations":[{"id":13182,"text":"Polar Bears International","active":true,"usgs":false}],"preferred":false,"id":688731,"contributorType":{"id":2,"text":"Editors"},"rank":2},{"text":"Laake, Jeffrey L.","contributorId":83851,"corporation":false,"usgs":false,"family":"Laake","given":"Jeffrey","email":"","middleInitial":"L.","affiliations":[{"id":6578,"text":"National Marine Fisheries Service, Seattle, WA 98112, USA","active":true,"usgs":false}],"preferred":false,"id":688732,"contributorType":{"id":2,"text":"Editors"},"rank":3},{"text":"Manly, Bryan F.J.","contributorId":41770,"corporation":false,"usgs":true,"family":"Manly","given":"Bryan","email":"","middleInitial":"F.J.","affiliations":[],"preferred":false,"id":688734,"contributorType":{"id":2,"text":"Editors"},"rank":4},{"text":"McDonald, Lyman L.","contributorId":14939,"corporation":false,"usgs":true,"family":"McDonald","given":"Lyman","email":"","middleInitial":"L.","affiliations":[],"preferred":false,"id":688733,"contributorType":{"id":2,"text":"Editors"},"rank":5},{"text":"Robertson, Donna G.","contributorId":29965,"corporation":false,"usgs":true,"family":"Robertson","given":"Donna","email":"","middleInitial":"G.","affiliations":[],"preferred":false,"id":688735,"contributorType":{"id":2,"text":"Editors"},"rank":6}],"authors":[{"text":"McDonald, Lyman L.","contributorId":14939,"corporation":false,"usgs":true,"family":"McDonald","given":"Lyman","email":"","middleInitial":"L.","affiliations":[],"preferred":false,"id":688728,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Garner, Gerald W.","contributorId":149918,"corporation":false,"usgs":false,"family":"Garner","given":"Gerald","email":"","middleInitial":"W.","affiliations":[{"id":13117,"text":"Institute of Arctic Biology, University of Alaska Fairbanks","active":true,"usgs":false}],"preferred":false,"id":688729,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}}
,{"id":70021411,"text":"70021411 - 1999 - The relative importance of light and nutrient limitation of phytoplankton growth: A simple index of coastal ecosystem sensitivity to nutrient enrichment","interactions":[],"lastModifiedDate":"2018-12-19T08:40:31","indexId":"70021411","displayToPublicDate":"1999-01-01T00:00:00","publicationYear":"1999","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":863,"text":"Aquatic Ecology","active":true,"publicationSubtype":{"id":10}},"title":"The relative importance of light and nutrient limitation of phytoplankton growth: A simple index of coastal ecosystem sensitivity to nutrient enrichment","docAbstract":"<p>Anthropogenic nutrient enrichment of the coastal zone is now a well-established fact. However, there is still uncertainty about the mechanisms through which nutrient enrichment can disrupt biological communities and ecosystem processes in the coastal zone. For example, while some estuaries exhibit classic symptoms of acute eutrophication, including enhanced production of algal biomass, other nutrient-rich estuaries maintain low algal biomass and primary production. This implies that large differences exist among coastal ecosystems in the rates and patterns of nutrient assimilation and cycling. Part of this variability comes from differences among ecosystems in the other resource that can limit algal growth and production - the light energy required for photosynthesis. Complete understanding of the eutrophication process requires consideration of the interacting effects of light and nutrients, including the role of light availability as a regulator of the expression of eutrophication. A simple index of the relative strength of light and nutrient limitation of algal growth can be derived from models that describe growth rate as a function of these resources. This index can then be used as one diagnostic to classify the sensitivity of coastal ecosystems to the harmful effects of eutrophication. Here I illustrate the application of this diagnostic with light and nutrient measurements made in three California estuaries and two Dutch estuaries.</p>","language":"English","publisher":"Kluwer Academic Publishers","doi":"10.1023/A:1009952125558","issn":"13862588","usgsCitation":"Cloern, J., 1999, The relative importance of light and nutrient limitation of phytoplankton growth: A simple index of coastal ecosystem sensitivity to nutrient enrichment: Aquatic Ecology, v. 33, no. 1, p. 3-16, https://doi.org/10.1023/A:1009952125558.","productDescription":"14 p. ","startPage":"3","endPage":"16","onlineOnly":"N","additionalOnlineFiles":"N","costCenters":[{"id":552,"text":"San Francisco Bay-Delta","active":false,"usgs":true},{"id":589,"text":"Toxic Substances Hydrology Program","active":true,"usgs":true},{"id":5079,"text":"Pacific Regional Director's Office","active":true,"usgs":true}],"links":[{"id":230074,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":206514,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1023/A:1009952125558"}],"volume":"33","issue":"1","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505baf2ce4b08c986b3245da","contributors":{"authors":[{"text":"Cloern, J. E.","contributorId":59453,"corporation":false,"usgs":true,"family":"Cloern","given":"J. E.","affiliations":[],"preferred":false,"id":389785,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}}
,{"id":1008025,"text":"1008025 - 1999 - Studies of reproductive output of the desert tortoise at Joshua Tree National Park, the Mojave National Preserve, and comparative sites","interactions":[],"lastModifiedDate":"2016-09-30T13:32:52","indexId":"1008025","displayToPublicDate":"1999-01-01T00:00:00","publicationYear":"1999","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":3014,"text":"Park Science","active":true,"publicationSubtype":{"id":10}},"title":"Studies of reproductive output of the desert tortoise at Joshua Tree National Park, the Mojave National Preserve, and comparative sites","docAbstract":"<p>The stability of any population is a function of how many young are produced and how many survive to reproduce. Populations with low reproductive output and high mortality will decline until such time as deaths and births are at least balanced. Monitoring populations of sensitive species is particularly important to ensure that conditions do not favor decline or extinction. </p><p>Turtles, including tortoises, are characterized by life history traits that make them slow to adapt to rapid changes in mortality and habitat alteration. Long life spans (in excess of 50 years), late maturity, and widely variable nest success are traits that allowed turtles to outlive the dinosaurs, but they are poorly adapted for life in the rapidly changing modern world. Increased mortality of young and adults can seriously tip the delicate balance required for turtles to survive.</p>","language":"English","usgsCitation":"Lovich, J., Medica, P., Avery, H., Meyer, K., Bowser, G., and Brown, A., 1999, Studies of reproductive output of the desert tortoise at Joshua Tree National Park, the Mojave National Preserve, and comparative sites: Park Science, v. 19, no. 1, p. 22-24.","productDescription":"3 p.","startPage":"22","endPage":"24","numberOfPages":"3","costCenters":[{"id":651,"text":"Western Ecological Research Center","active":true,"usgs":true}],"links":[{"id":329219,"rank":2,"type":{"id":15,"text":"Index Page"},"url":"https://dmg.gov/documents/STDY_Rprdctve_Output_DT_at_JTNP_MNP_Lovich_et_al_090199.pdf","linkFileType":{"id":1,"text":"pdf"}},{"id":131079,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"19","issue":"1","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b05e4b07f02db699fe2","contributors":{"authors":[{"text":"Lovich, J.E.","contributorId":102411,"corporation":false,"usgs":true,"family":"Lovich","given":"J.E.","email":"","affiliations":[],"preferred":false,"id":316575,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Medica, P.","contributorId":36491,"corporation":false,"usgs":true,"family":"Medica","given":"P.","email":"","affiliations":[],"preferred":false,"id":316573,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Avery, H.","contributorId":59758,"corporation":false,"usgs":true,"family":"Avery","given":"H.","email":"","affiliations":[],"preferred":false,"id":316574,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Meyer, K.","contributorId":28204,"corporation":false,"usgs":true,"family":"Meyer","given":"K.","email":"","affiliations":[],"preferred":false,"id":316571,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Bowser, G.","contributorId":33670,"corporation":false,"usgs":true,"family":"Bowser","given":"G.","email":"","affiliations":[],"preferred":false,"id":316572,"contributorType":{"id":1,"text":"Authors"},"rank":5},{"text":"Brown, A.","contributorId":27825,"corporation":false,"usgs":true,"family":"Brown","given":"A.","affiliations":[],"preferred":false,"id":316570,"contributorType":{"id":1,"text":"Authors"},"rank":6}]}}
,{"id":70211141,"text":"70211141 - 1999 - Geochronologic and isotope studies of calcite and silica constraining Quaternary unsaturated- and saturated zone hydrologic flux at Yucca Mountain, Nevada, USA","interactions":[],"lastModifiedDate":"2020-07-15T16:18:23.981101","indexId":"70211141","displayToPublicDate":"1998-12-31T11:10:07","publicationYear":"1999","noYear":false,"publicationType":{"id":24,"text":"Conference Paper"},"publicationSubtype":{"id":19,"text":"Conference Paper"},"title":"Geochronologic and isotope studies of calcite and silica constraining Quaternary unsaturated- and saturated zone hydrologic flux at Yucca Mountain, Nevada, USA","docAbstract":"<p><span>Both unsaturated- and saturated-zone aqueous solutions are capable of precipitating secondary mineral deposits that document the history and origins of past water flux. Calcite and opal occur as thin coatings on open fractures and cavity floors within the thick unsaturated zone at Yucca Mountain. Outermost surfaces of calcite have&nbsp;</span><sup>14</sup><span>C ages of between 44,000 and 16,000 radiocarbon years; however, the same surfaces have&nbsp;</span><sup>230</sup><span>Th/U ages from 28 ka to more than 500 ka. This discordance, along with negative covariance between conventionally calculated&nbsp;</span><sup>230</sup><span>Th/U ages and initial&nbsp;</span><sup>234</sup><span>U/</span><sup>238</sup><span>U is best explained by very slow rates of mineral growth where discrete depositional layers are too fine to separate and measure individually. Therefore, isotopic analyses and resulting ages represent mixtures between the deepest and shallowest layers incorporated within a given sub-sample.</span></p>","largerWorkType":{"id":4,"text":"Book"},"largerWorkTitle":"Use of hydrogeochemical information in testing groundwater flow models: Technical summary and proceedings of a workshop","largerWorkSubtype":{"id":12,"text":"Conference publication"},"conferenceTitle":"Use of hydrogeochemical information in testing groundwater flow models: Workshop","conferenceDate":"September 1-3, 1997","conferenceLocation":"Borgholm, Sweden","language":"English","publisher":"Nuclear Energy Agency","usgsCitation":"Paces, J.B., Peterman, Z.E., Neymark, L., Whelan, J.F., and Marshall, B.D., 1999, Geochronologic and isotope studies of calcite and silica constraining Quaternary unsaturated- and saturated zone hydrologic flux at Yucca Mountain, Nevada, USA, <i>in</i> Use of hydrogeochemical information in testing groundwater flow models: Technical summary and proceedings of a workshop, Borgholm, Sweden, September 1-3, 1997, p. 329-336.","productDescription":"8 p.","startPage":"329","endPage":"336","costCenters":[{"id":35995,"text":"Geology, Geophysics, and Geochemistry Science Center","active":true,"usgs":true}],"links":[{"id":376409,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"country":"United States","state":"Nevada","otherGeospatial":"Yucca Mountain","geographicExtents":"{\n  \"type\": \"FeatureCollection\",\n  \"features\": [\n    {\n      \"type\": \"Feature\",\n      \"properties\": {},\n      \"geometry\": {\n        \"type\": \"Polygon\",\n        \"coordinates\": [\n          [\n            [\n              -116.48254394531249,\n              36.91352904330221\n            ],\n            [\n              -116.43602371215822,\n              36.91352904330221\n            ],\n            [\n              -116.43602371215822,\n              36.95757376878687\n            ],\n            [\n              -116.48254394531249,\n              36.95757376878687\n            ],\n            [\n              -116.48254394531249,\n              36.91352904330221\n            ]\n          ]\n        ]\n      }\n    }\n  ]\n}","noUsgsAuthors":false,"publicationStatus":"PW","contributors":{"authors":[{"text":"Paces, James B. 0000-0002-9809-8493 jbpaces@usgs.gov","orcid":"https://orcid.org/0000-0002-9809-8493","contributorId":2514,"corporation":false,"usgs":true,"family":"Paces","given":"James","email":"jbpaces@usgs.gov","middleInitial":"B.","affiliations":[{"id":318,"text":"Geosciences and Environmental Change Science Center","active":true,"usgs":true}],"preferred":true,"id":792924,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Peterman, Zell E. 0000-0002-5694-8082 peterman@usgs.gov","orcid":"https://orcid.org/0000-0002-5694-8082","contributorId":167699,"corporation":false,"usgs":true,"family":"Peterman","given":"Zell","email":"peterman@usgs.gov","middleInitial":"E.","affiliations":[{"id":164,"text":"Central Energy Resources Science Center","active":true,"usgs":true}],"preferred":true,"id":792925,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Neymark, Leonid A. 0000-0003-4190-0278 lneymark@usgs.gov","orcid":"https://orcid.org/0000-0003-4190-0278","contributorId":140338,"corporation":false,"usgs":true,"family":"Neymark","given":"Leonid A.","email":"lneymark@usgs.gov","affiliations":[{"id":171,"text":"Central Mineral and Environmental Resources Science Center","active":true,"usgs":true},{"id":318,"text":"Geosciences and Environmental Change Science Center","active":true,"usgs":true}],"preferred":true,"id":792926,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Whelan, Joseph F.","contributorId":29792,"corporation":false,"usgs":true,"family":"Whelan","given":"Joseph","email":"","middleInitial":"F.","affiliations":[],"preferred":false,"id":792927,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Marshall, Brian D. 0000-0002-8093-0093 bdmarsha@usgs.gov","orcid":"https://orcid.org/0000-0002-8093-0093","contributorId":520,"corporation":false,"usgs":true,"family":"Marshall","given":"Brian","email":"bdmarsha@usgs.gov","middleInitial":"D.","affiliations":[{"id":35995,"text":"Geology, Geophysics, and Geochemistry Science Center","active":true,"usgs":true}],"preferred":true,"id":792928,"contributorType":{"id":1,"text":"Authors"},"rank":5}]}}
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