No abstract available.
","largerWorkType":{"id":4,"text":"Book"},"largerWorkTitle":"Society of Wetland Scientists International Conference","largerWorkSubtype":{"id":12,"text":"Conference publication"},"conferenceTitle":"Society of Wetland Scientists International Conference","conferenceDate":"June 2007","conferenceLocation":"Sacramento, CA","language":"English","publisher":"Society of Wetland Scientists","usgsCitation":"Miles, A., Spring, S., Ricca, M., Takekawa, J., Athearn, N., and Schoellhamer, D., 2007, Spatial and temporal structure of macroinvertebrate assemblages, San Francisco Bay salt ponds, in Society of Wetland Scientists International Conference, Sacramento, CA, June 2007, p. 51-51.","productDescription":"1 p.","startPage":"51","endPage":"51","onlineOnly":"N","additionalOnlineFiles":"N","costCenters":[{"id":552,"text":"San Francisco Bay-Delta","active":false,"usgs":true},{"id":5079,"text":"Pacific Regional Director's Office","active":true,"usgs":true}],"links":[{"id":326141,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"57a5b8dae4b0ebae89b78a45","contributors":{"authors":[{"text":"Miles, A.K. 0000-0002-3108-808X","orcid":"https://orcid.org/0000-0002-3108-808X","contributorId":85902,"corporation":false,"usgs":true,"family":"Miles","given":"A.K.","affiliations":[],"preferred":false,"id":644822,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Spring, S.E.","contributorId":35258,"corporation":false,"usgs":true,"family":"Spring","given":"S.E.","email":"","affiliations":[],"preferred":false,"id":644823,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Ricca, M.A.","contributorId":103609,"corporation":false,"usgs":true,"family":"Ricca","given":"M.A.","affiliations":[],"preferred":false,"id":644824,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Takekawa, J.T.","contributorId":173477,"corporation":false,"usgs":false,"family":"Takekawa","given":"J.T.","email":"","affiliations":[],"preferred":false,"id":644825,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Athearn, N.D.","contributorId":86958,"corporation":false,"usgs":true,"family":"Athearn","given":"N.D.","affiliations":[],"preferred":false,"id":644826,"contributorType":{"id":1,"text":"Authors"},"rank":5},{"text":"Schoellhamer, D. H. 0000-0001-9488-7340","orcid":"https://orcid.org/0000-0001-9488-7340","contributorId":85624,"corporation":false,"usgs":true,"family":"Schoellhamer","given":"D. H.","affiliations":[],"preferred":false,"id":644827,"contributorType":{"id":1,"text":"Authors"},"rank":6}]}} ,{"id":70031683,"text":"70031683 - 2007 - Does amplitude scaling of ground motion records result in biased nonlinear structural drift responses?","interactions":[],"lastModifiedDate":"2012-03-12T17:21:12","indexId":"70031683","displayToPublicDate":"2007-01-01T00:00:00","publicationYear":"2007","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1434,"text":"Earthquake Engineering and Structural Dynamics","active":true,"publicationSubtype":{"id":10}},"title":"Does amplitude scaling of ground motion records result in biased nonlinear structural drift responses?","docAbstract":"Limitations of the existing earthquake ground motion database lead to scaling of records to obtain seismograms consistent with a ground motion target for structural design and evaluation. In the engineering seismology community, acceptable limits for 'legitimate' scaling vary from one (no scaling allowed) to 10 or more. The concerns expressed by detractors of scaling are mostly based on the knowledge of, for example, differences in ground motion characteristics for different earthquake magnitude-distance (Mw-Rclose) scenarios, and much less on their effects on structures. At the other end of the spectrum, proponents have demonstrated that scaling is not only legitimate but also useful for assessing structural response statistics for Mw-Rclose scenarios. Their studies, however, have not investigated more recent purposes of scaling and have not always drawn conclusions for a wide spectrum of structural vibration periods and strengths. This article investigates whether scaling of records randomly selected from an Mw-Rclose bin (or range) to a target fundamental-mode spectral acceleration (Sa) level introduces bias in the expected nonlinear structural drift response of both single-degree-of-freedom oscillators and one multi-degree-of-freedom building. The bias is quantified relative to unscaled records from the target Mw-Rclose bin that are 'naturally' at the target Sa level. We consider scaling of records from the target Mw-Rclose bin and from other Mw-Rclose bins. The results demonstrate that scaling can indeed introduce a bias that, for the most part, ca be explained by differences between the elastic response spectra of the scaled versus unscaled records. Copyright ?? 2007 John Wiley & Sons, Ltd.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Earthquake Engineering and Structural Dynamics","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1002/eqe.695","issn":"00988847","usgsCitation":"Luco, N., and Bazzurro, P., 2007, Does amplitude scaling of ground motion records result in biased nonlinear structural drift responses?: Earthquake Engineering and Structural Dynamics, v. 36, no. 13, p. 1813-1835, https://doi.org/10.1002/eqe.695.","startPage":"1813","endPage":"1835","numberOfPages":"23","costCenters":[],"links":[{"id":212335,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1002/eqe.695"},{"id":239803,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"36","issue":"13","noUsgsAuthors":false,"publicationDate":"2007-06-22","publicationStatus":"PW","scienceBaseUri":"505a038ae4b0c8380cd50512","contributors":{"authors":[{"text":"Luco, N.","contributorId":34240,"corporation":false,"usgs":true,"family":"Luco","given":"N.","email":"","affiliations":[],"preferred":false,"id":432674,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Bazzurro, P.","contributorId":90537,"corporation":false,"usgs":true,"family":"Bazzurro","given":"P.","email":"","affiliations":[],"preferred":false,"id":432675,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70031181,"text":"70031181 - 2007 - Tree and stand transpiration in a Midwestern bur oak savanna after elm encroachment and restoration thinning","interactions":[],"lastModifiedDate":"2012-03-12T17:21:17","indexId":"70031181","displayToPublicDate":"2007-01-01T00:00:00","publicationYear":"2007","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1687,"text":"Forest Ecology and Management","active":true,"publicationSubtype":{"id":10}},"title":"Tree and stand transpiration in a Midwestern bur oak savanna after elm encroachment and restoration thinning","docAbstract":"Oak savannas, once common in the Midwest, are now isolated remnants within agricultural landscapes. Savanna remnants are frequently encroached by invasive trees to become woodlands. Thinning and prescribed burning can restore savanna structure, but the ecohydrological effects of managing these remnants are poorly understood. In this study, we measured sap flow (Js) to quantify transpiration in an Iowa bur oak (Quercus macrocarpa) savanna woodland encroached by elms (Ulmus americana), and in an adjacent restored savanna after thinning to remove elms, during summer 2004. Savanna oaks had greater mean daily Js (35.9 L dm-2 day-1) than woodland oaks (20.7 L dm-2 day-1) and elms (12.4 L dm-2 day-1). The response of Js to vapor pressure deficit (D) was unexpectedly weak, although oaks in both stands showed negative correlation between daily Js and D for D > 0.4 kPa. An earlier daily peak in Js in the elm trees showed a possible advantage for water uptake. As anticipated, the woodland's stand transpiration was greater (1.23 mm day-1) than the savanna's (0.35 mm day-1), yet the savanna achieved 30% of the woodland's transpiration with only 11% of its sapwood area. The difference in transpiration influenced water table depths, which were 2 m in the savanna and 6.5 m in the woodland. Regionally, row-crop agriculture has increased groundwater recharge and raised water tables, providing surplus water that perhaps facilitated elm encroachment. This has implications for restoration of savanna remnants. If achieving a savanna ecohydrology is an aim of restoration, then restoration strategies may require buffers, or targeting of large or hydrologically isolated remnants. ?? 2007.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Forest Ecology and Management","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1016/j.foreco.2007.04.043","issn":"03781127","usgsCitation":"Asbjornsen, H., Tomer, M., Gomez-Cardenas, M., Brudvig, L., Greenan, C., and Schilling, K., 2007, Tree and stand transpiration in a Midwestern bur oak savanna after elm encroachment and restoration thinning: Forest Ecology and Management, v. 247, no. 1-3, p. 209-219, https://doi.org/10.1016/j.foreco.2007.04.043.","startPage":"209","endPage":"219","numberOfPages":"11","costCenters":[],"links":[{"id":211492,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/j.foreco.2007.04.043"},{"id":238788,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"247","issue":"1-3","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505bb79ae4b08c986b32738a","contributors":{"authors":[{"text":"Asbjornsen, H.","contributorId":86968,"corporation":false,"usgs":true,"family":"Asbjornsen","given":"H.","affiliations":[],"preferred":false,"id":430400,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Tomer, M.D.","contributorId":77359,"corporation":false,"usgs":true,"family":"Tomer","given":"M.D.","email":"","affiliations":[],"preferred":false,"id":430398,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Gomez-Cardenas, M.","contributorId":82919,"corporation":false,"usgs":true,"family":"Gomez-Cardenas","given":"M.","email":"","affiliations":[],"preferred":false,"id":430399,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Brudvig, L.A.","contributorId":28065,"corporation":false,"usgs":true,"family":"Brudvig","given":"L.A.","affiliations":[],"preferred":false,"id":430396,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Greenan, C.M.","contributorId":31198,"corporation":false,"usgs":true,"family":"Greenan","given":"C.M.","email":"","affiliations":[],"preferred":false,"id":430397,"contributorType":{"id":1,"text":"Authors"},"rank":5},{"text":"Schilling, K.","contributorId":101423,"corporation":false,"usgs":true,"family":"Schilling","given":"K.","affiliations":[],"preferred":false,"id":430401,"contributorType":{"id":1,"text":"Authors"},"rank":6}]}} ,{"id":70031184,"text":"70031184 - 2007 - Lithology-derived structure classification from the joint interpretation of magnetotelluric and seismic models","interactions":[],"lastModifiedDate":"2012-03-12T17:21:17","indexId":"70031184","displayToPublicDate":"2007-01-01T00:00:00","publicationYear":"2007","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1803,"text":"Geophysical Journal International","active":true,"publicationSubtype":{"id":10}},"title":"Lithology-derived structure classification from the joint interpretation of magnetotelluric and seismic models","docAbstract":"Magnetotelluric and seismic methods provide complementary information about the resistivity and velocity structure of the subsurface on similar scales and resolutions. No global relation, however, exists between these parameters, and correlations are often valid for only a limited target area. Independently derived inverse models from these methods can be combined using a classification approach to map geologic structure. The method employed is based solely on the statistical correlation of physical properties in a joint parameter space and is independent of theoretical or empirical relations linking electrical and seismic parameters. Regions of high correlation (classes) between resistivity and velocity can in turn be mapped back and re-examined in depth section. The spatial distribution of these classes, and the boundaries between them, provide structural information not evident in the individual models. This method is applied to a 10 km long profile crossing the Dead Sea Transform in Jordan. Several prominent classes are identified with specific lithologies in accordance with local geology. An abrupt change in lithology across the fault, together with vertical uplift of the basement suggest the fault is sub-vertical within the upper crust. ?? 2007 The Authors Journal compilation ?? 2007 RAS.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Geophysical Journal International","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1111/j.1365-246X.2007.03440.x","issn":"0956540X","usgsCitation":"Bedrosian, P.A., Maercklin, N., Weckmann, U., Bartov, Y., Ryberg, T., and Ritter, O., 2007, Lithology-derived structure classification from the joint interpretation of magnetotelluric and seismic models: Geophysical Journal International, v. 170, no. 2, p. 737-748, https://doi.org/10.1111/j.1365-246X.2007.03440.x.","startPage":"737","endPage":"748","numberOfPages":"12","costCenters":[],"links":[{"id":487681,"rank":10000,"type":{"id":40,"text":"Open Access Publisher Index Page"},"url":"https://doi.org/10.1111/j.1365-246x.2007.03440.x","text":"Publisher Index Page"},{"id":238819,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":211519,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1111/j.1365-246X.2007.03440.x"}],"volume":"170","issue":"2","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a4892e4b0c8380cd67f65","contributors":{"authors":[{"text":"Bedrosian, P. A.","contributorId":100109,"corporation":false,"usgs":true,"family":"Bedrosian","given":"P.","email":"","middleInitial":"A.","affiliations":[],"preferred":false,"id":430412,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Maercklin, N.","contributorId":81302,"corporation":false,"usgs":true,"family":"Maercklin","given":"N.","email":"","affiliations":[],"preferred":false,"id":430410,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Weckmann, U.","contributorId":14186,"corporation":false,"usgs":true,"family":"Weckmann","given":"U.","email":"","affiliations":[],"preferred":false,"id":430407,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Bartov, Y.","contributorId":65230,"corporation":false,"usgs":true,"family":"Bartov","given":"Y.","email":"","affiliations":[],"preferred":false,"id":430409,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Ryberg, T.","contributorId":91643,"corporation":false,"usgs":true,"family":"Ryberg","given":"T.","email":"","affiliations":[],"preferred":false,"id":430411,"contributorType":{"id":1,"text":"Authors"},"rank":5},{"text":"Ritter, O.","contributorId":33515,"corporation":false,"usgs":true,"family":"Ritter","given":"O.","email":"","affiliations":[],"preferred":false,"id":430408,"contributorType":{"id":1,"text":"Authors"},"rank":6}]}} ,{"id":70031185,"text":"70031185 - 2007 - Comparison of earthquake source spectra and attenuation in eastern North America and southeastern Australia","interactions":[],"lastModifiedDate":"2012-03-12T17:21:17","indexId":"70031185","displayToPublicDate":"2007-01-01T00:00:00","publicationYear":"2007","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":"Comparison of earthquake source spectra and attenuation in eastern North America and southeastern Australia","docAbstract":"The paucity of ground-motion data in stable continental regions (SCRs) remains a key limitation when developing relations that seek to predict effects of strong ground shaking from large damaging earthquakes. It is desirable to combine data from more than one SCR to increase database size, but this raises questions as to whether the source and attenuation properties of the SCRs are equivalent. We compare recently compiled spectral-amplitude databases from small to moderate events (moment magnitudes, 2.0 ??? M ??? 5.0) in both southeastern Australia and eastern North America (ENA). Both are SCRs but are widely separated, spatially and in tectonic history. We statistically compare ground motions by plotting mean and standard deviations of spectral amplitudes for data grouped in magnitude and distance bins. These comparisons show that the source and attenuation properties of the two regions are very similar, in particular, at shorter hypocentral distances R (i.e., R < 70 km). At larger distances, regional attenuation differences are observed that may be attributed to differences in crustal structure. We conclude that it is valid to combine the Australian and ENA ground-motion datasets in the development of ground-motion prediction equations, with some limitations in frequency and distance ranges. These ground-motion relations may serve as generic functions for SCRs around the world.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Bulletin of the Seismological Society of America","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1785/0120060206","issn":"00371106","usgsCitation":"Allen, T., and Atkinson, G.M., 2007, Comparison of earthquake source spectra and attenuation in eastern North America and southeastern Australia: Bulletin of the Seismological Society of America, v. 97, no. 4, p. 1350-1354, https://doi.org/10.1785/0120060206.","startPage":"1350","endPage":"1354","numberOfPages":"5","costCenters":[],"links":[{"id":211546,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1785/0120060206"},{"id":238848,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"97","issue":"4","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"5059f85de4b0c8380cd4d05d","contributors":{"authors":[{"text":"Allen, T.I.","contributorId":6659,"corporation":false,"usgs":true,"family":"Allen","given":"T.I.","email":"","affiliations":[],"preferred":false,"id":430413,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Atkinson, G. M.","contributorId":69283,"corporation":false,"usgs":true,"family":"Atkinson","given":"G.","email":"","middleInitial":"M.","affiliations":[],"preferred":false,"id":430414,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70031186,"text":"70031186 - 2007 - Mineralogic constraints on sulfur-rich soils from Pancam spectra at Gusev crater, Mars","interactions":[],"lastModifiedDate":"2012-03-12T17:21:17","indexId":"70031186","displayToPublicDate":"2007-01-01T00:00:00","publicationYear":"2007","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":"Mineralogic constraints on sulfur-rich soils from Pancam spectra at Gusev crater, Mars","docAbstract":"The Mars Exploration Rover (MER) Spirit excavated sulfur-rich soils exhibiting high albedo and relatively white to yellow colors at three main locations on and south of Husband Hill in Gusev crater, Mars. The multispectral visible/near-infrared properties of these disturbed soils revealed by the Pancam stereo color camera vary appreciably over small spatial scales, but exhibit spectral features suggestive of ferric sulfates. Spectral mixture models constrain the mineralogy of these soils to include ferric sulfates in various states of hydration, such as ferricopiapite [Fe2/32+Fe43+ (SO4)6(OH)2??20(H2O)], hydronium jarosite [(H3O)Fe33+ (SO4)2(OH)6], fibroferrite [Fe3+(SO4)(OH)??5(H2O)], rhomboclase [HFe3+(SO4)2??4 (H2O)], and paracoquimbite [Fe23+ (SO4)3.9(H2O)]. Copyright 2007 by the American Geophysical Union.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Geophysical Research Letters","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1029/2007GL029894","issn":"00948276","usgsCitation":"Johnson, J.R., Bell, J., Cloutis, E., Staid, M., Farrand, W.H., McCoy, T., Rice, M., Wang, A., and Yen, A., 2007, Mineralogic constraints on sulfur-rich soils from Pancam spectra at Gusev crater, Mars: Geophysical Research Letters, v. 34, no. 13, https://doi.org/10.1029/2007GL029894.","costCenters":[],"links":[{"id":477204,"rank":10000,"type":{"id":40,"text":"Open Access Publisher Index Page"},"url":"https://doi.org/10.1029/2007gl029894","text":"Publisher Index Page"},{"id":211547,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1029/2007GL029894"},{"id":238849,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"34","issue":"13","noUsgsAuthors":false,"publicationDate":"2007-07-06","publicationStatus":"PW","scienceBaseUri":"505a5a8ae4b0c8380cd6ef53","contributors":{"authors":[{"text":"Johnson, J. R.","contributorId":69278,"corporation":false,"usgs":true,"family":"Johnson","given":"J.","email":"","middleInitial":"R.","affiliations":[],"preferred":false,"id":430421,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Bell, J.F.","contributorId":36663,"corporation":false,"usgs":true,"family":"Bell","given":"J.F.","affiliations":[],"preferred":false,"id":430416,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Cloutis, E.","contributorId":90184,"corporation":false,"usgs":true,"family":"Cloutis","given":"E.","email":"","affiliations":[],"preferred":false,"id":430423,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Staid, M.","contributorId":68561,"corporation":false,"usgs":true,"family":"Staid","given":"M.","email":"","affiliations":[],"preferred":false,"id":430420,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Farrand, W. H.","contributorId":64372,"corporation":false,"usgs":true,"family":"Farrand","given":"W.","email":"","middleInitial":"H.","affiliations":[],"preferred":false,"id":430419,"contributorType":{"id":1,"text":"Authors"},"rank":5},{"text":"McCoy, T.","contributorId":56776,"corporation":false,"usgs":true,"family":"McCoy","given":"T.","email":"","affiliations":[],"preferred":false,"id":430418,"contributorType":{"id":1,"text":"Authors"},"rank":6},{"text":"Rice, M.","contributorId":32283,"corporation":false,"usgs":true,"family":"Rice","given":"M.","affiliations":[],"preferred":false,"id":430415,"contributorType":{"id":1,"text":"Authors"},"rank":7},{"text":"Wang, A.","contributorId":46735,"corporation":false,"usgs":true,"family":"Wang","given":"A.","email":"","affiliations":[],"preferred":false,"id":430417,"contributorType":{"id":1,"text":"Authors"},"rank":8},{"text":"Yen, A.","contributorId":76054,"corporation":false,"usgs":true,"family":"Yen","given":"A.","affiliations":[],"preferred":false,"id":430422,"contributorType":{"id":1,"text":"Authors"},"rank":9}]}} ,{"id":70031671,"text":"70031671 - 2007 - Cross-shelf transport of pink shrimp larvae: Interactions of tidal currents, larval vertical migrations and internal tides","interactions":[],"lastModifiedDate":"2016-03-30T13:29:29","indexId":"70031671","displayToPublicDate":"2007-01-01T00:00:00","publicationYear":"2007","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2663,"text":"Marine Ecology Progress Series","active":true,"publicationSubtype":{"id":10}},"title":"Cross-shelf transport of pink shrimp larvae: Interactions of tidal currents, larval vertical migrations and internal tides","docAbstract":"Transport and behavior of pink shrimp Farfantepenaeus duorarum larvae were investigated on the southwestern Florida (SWF) shelf of the Gulf of Mexico between the Dry Tortugas spawning grounds and Florida Bay nursery grounds. Stratified plankton samples and hydrographic data were collected at 2 h intervals at 3 stations located on a cross-shelf transect. At the Marquesas station, midway between Dry Tortugas and Florida Bay, internal tides were recognized by anomalously cool water, a shallow thermocline with strong density gradients, strong current shear, and a high concentration of pink shrimp larvae at the shallow thermocline. Low Richardson numbers occurred at the pycnocline depth, indicating vertical shear instability and possible turbulent transport from the lower to the upper layer where myses and postlarvae were concentrated. Analysis of vertically stratified plankton suggested that larvae perform vertical migrations and the specific behavior changes ontogenetically; protozoeae were found deeper than myses, and myses deeper than postlarvae. Relative concentrations of protozoea in the upper, middle and bottom layers were consistent with a diel vertical migration, whereas that of postlarvae and myses were consistent with the semidiurnal tides in phase with the flood tide. Postlarvae, the shallowest dwellers that migrate with a semidiurnal periodicity, experienced the largest net onshore flux and larval concentrations were highly correlated with the cross-shelf current. These results provide the first evidence of an onshore tidal transport (a type of selective tidal stream transport, STST), in decapod larvae migrating in continental shelf waters offshore, ca. 100 km from the coast and at a depth of 20 m, while approaching the coastal nursery grounds. Longer time series would be necessary to establish whether internal tides play any role in the larval onshore transport of this species and determine if the STST is the dominant onshore transport mechanism.
","language":"English","publisher":"Inter-Research","publisherLocation":"Oldendorf/Luhe, Germany","doi":"10.3354/meps06916","issn":"01718630","usgsCitation":"Criales, M.M., Browder, J.A., Mooers, C., Robblee, M., Cardenas, H., and Jackson, T.L., 2007, Cross-shelf transport of pink shrimp larvae: Interactions of tidal currents, larval vertical migrations and internal tides: Marine Ecology Progress Series, v. 345, p. 167-184, https://doi.org/10.3354/meps06916.","productDescription":"18 p.","startPage":"167","endPage":"184","numberOfPages":"18","onlineOnly":"N","additionalOnlineFiles":"N","costCenters":[],"links":[{"id":477140,"rank":10000,"type":{"id":40,"text":"Open Access Publisher Index Page"},"url":"https://doi.org/10.3354/meps06916","text":"Publisher Index Page"},{"id":239637,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":212187,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.3354/meps06916"}],"country":"United States","state":"Florida","otherGeospatial":"Dry Tortugas, Florida Bay","geographicExtents":"{\n \"type\": \"FeatureCollection\",\n \"features\": [\n {\n \"type\": \"Feature\",\n \"properties\": {},\n \"geometry\": {\n \"type\": \"Polygon\",\n \"coordinates\": [\n [\n [\n -79.91455078125,\n 25.94816628853973\n ],\n [\n -79.9200439453125,\n 25.54244147012483\n ],\n [\n -80.2166748046875,\n 25.04081549894912\n ],\n [\n -80.8648681640625,\n 24.56211235799689\n ],\n [\n -81.5789794921875,\n 24.412140070651528\n ],\n [\n -82.6336669921875,\n 24.382124181118236\n ],\n [\n -83.07861328125,\n 24.45215015618098\n ],\n [\n -83.1060791015625,\n 24.696934226366672\n ],\n [\n -82.5787353515625,\n 24.806681353851964\n ],\n [\n -81.3262939453125,\n 24.926294766395593\n ],\n [\n -80.760498046875,\n 25.224820176765036\n ],\n [\n -80.4364013671875,\n 25.606855993715016\n ],\n [\n -80.343017578125,\n 25.849336891707605\n ],\n [\n -80.2056884765625,\n 25.93828707492375\n ],\n [\n -80.04638671875,\n 25.96792222903405\n ],\n [\n -79.91455078125,\n 25.94816628853973\n ]\n ]\n ]\n }\n }\n ]\n}","volume":"345","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"5059fcc5e4b0c8380cd4e41a","contributors":{"authors":[{"text":"Criales, Maria M.","contributorId":69330,"corporation":false,"usgs":false,"family":"Criales","given":"Maria","email":"","middleInitial":"M.","affiliations":[{"id":12565,"text":"Rosenstiel School of Atomospheric Science, University of Miami","active":true,"usgs":false}],"preferred":false,"id":432605,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Browder, Joan A.","contributorId":7439,"corporation":false,"usgs":true,"family":"Browder","given":"Joan","email":"","middleInitial":"A.","affiliations":[],"preferred":false,"id":432601,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Mooers, C.N.K.","contributorId":13762,"corporation":false,"usgs":true,"family":"Mooers","given":"C.N.K.","email":"","affiliations":[],"preferred":false,"id":432603,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Robblee, M. B.","contributorId":23879,"corporation":false,"usgs":true,"family":"Robblee","given":"M. B.","affiliations":[],"preferred":false,"id":432604,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Cardenas, H.","contributorId":11411,"corporation":false,"usgs":true,"family":"Cardenas","given":"H.","email":"","affiliations":[],"preferred":false,"id":432602,"contributorType":{"id":1,"text":"Authors"},"rank":5},{"text":"Jackson, Thomas L.","contributorId":93667,"corporation":false,"usgs":true,"family":"Jackson","given":"Thomas","email":"","middleInitial":"L.","affiliations":[],"preferred":false,"id":432606,"contributorType":{"id":1,"text":"Authors"},"rank":6}]}} ,{"id":70031188,"text":"70031188 - 2007 - Three-dimensional flow in the Florida platform: Theoretical analysis of Kohout convection at its type locality","interactions":[],"lastModifiedDate":"2018-10-17T08:25:36","indexId":"70031188","displayToPublicDate":"2007-01-01T00:00:00","publicationYear":"2007","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1796,"text":"Geology","active":true,"publicationSubtype":{"id":10}},"title":"Three-dimensional flow in the Florida platform: Theoretical analysis of Kohout convection at its type locality","docAbstract":"Kohout convection is the name given to the circulation of saline groundwater deep within carbonate platforms, first proposed by F.A. Kohout in the 1960s for south Florida. It is now seen as an Mg pump for dolomitization by seawater. As proposed by Kohout, cold seawater is drawn into the Florida platform from the deep Straits of Florida as part of a geothermally driven circulation in which the seawater then rises in the interior of the platform to mix and exit with the discharging meteoric water of the Floridan aquifer system. Simulation of the asymmetrically emergent Florida platform with the new three-dimensional (3-D), finite-element groundwater flow and transport model SUTRA-MS, which couples salinity- and temperature-dependent density variations, allows analysis of how much of the cyclic flow is due to geothermal heating (free convection) as opposed to mixing with meteoric water discharging to the shoreline (forced convection). Simulation of the system with and without geothermal heating reveals that the inflow of seawater from the Straits of Florida would be similar without the heat flow, but the distribution would differ significantly. The addition of heat flow reduces the asymmetry of the circulation: it decreases seawater inflows on the Atlantic side by 8% and on the Guff of Mexico side by half. The study illustrates the complex interplay of freshwater-saltwater mixing, geothermal heat flow, and projected dolomitization in complicated 3-D settings with asymmetric boundary conditions and realistic horizontal and vertical variations in hydraulic properties.
","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Geology","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1130/G23374A.1","issn":"00917613","usgsCitation":"Hughes, J., Vacher, H.L., and Sanford, W.E., 2007, Three-dimensional flow in the Florida platform: Theoretical analysis of Kohout convection at its type locality: Geology, v. 35, no. 7, p. 663-666, https://doi.org/10.1130/G23374A.1.","productDescription":"4 p.","startPage":"663","endPage":"666","costCenters":[{"id":589,"text":"Toxic Substances Hydrology Program","active":true,"usgs":true}],"links":[{"id":238821,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":211521,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1130/G23374A.1"}],"country":"United States","state":"Florida","volume":"35","issue":"7","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505bb327e4b08c986b325bf4","contributors":{"authors":[{"text":"Hughes, J.D.","contributorId":25539,"corporation":false,"usgs":true,"family":"Hughes","given":"J.D.","email":"","affiliations":[],"preferred":false,"id":430430,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Vacher, H. Leonard","contributorId":90529,"corporation":false,"usgs":false,"family":"Vacher","given":"H.","email":"","middleInitial":"Leonard","affiliations":[],"preferred":false,"id":430431,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Sanford, Ward E. 0000-0002-6624-0280 wsanford@usgs.gov","orcid":"https://orcid.org/0000-0002-6624-0280","contributorId":2268,"corporation":false,"usgs":true,"family":"Sanford","given":"Ward","email":"wsanford@usgs.gov","middleInitial":"E.","affiliations":[{"id":436,"text":"National Research Program - Eastern Branch","active":true,"usgs":true},{"id":37778,"text":"WMA - Integrated Modeling and Prediction Division","active":true,"usgs":true}],"preferred":true,"id":430432,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70031669,"text":"70031669 - 2007 - CO2 storage capacity estimation: Methodology and gaps","interactions":[],"lastModifiedDate":"2012-03-12T17:21:05","indexId":"70031669","displayToPublicDate":"2007-01-01T00:00:00","publicationYear":"2007","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2049,"text":"International Journal of Greenhouse Gas Control","active":true,"publicationSubtype":{"id":10}},"title":"CO2 storage capacity estimation: Methodology and gaps","docAbstract":"Implementation of CO2 capture and geological storage (CCGS) technology at the scale needed to achieve a significant and meaningful reduction in CO2 emissions requires knowledge of the available CO2 storage capacity. CO2 storage capacity assessments may be conducted at various scales-in decreasing order of size and increasing order of resolution: country, basin, regional, local and site-specific. Estimation of the CO2 storage capacity in depleted oil and gas reservoirs is straightforward and is based on recoverable reserves, reservoir properties and in situ CO2 characteristics. In the case of CO2-EOR, the CO2 storage capacity can be roughly evaluated on the basis of worldwide field experience or more accurately through numerical simulations. Determination of the theoretical CO2 storage capacity in coal beds is based on coal thickness and CO2 adsorption isotherms, and recovery and completion factors. Evaluation of the CO2 storage capacity in deep saline aquifers is very complex because four trapping mechanisms that act at different rates are involved and, at times, all mechanisms may be operating simultaneously. The level of detail and resolution required in the data make reliable and accurate estimation of CO2 storage capacity in deep saline aquifers practical only at the local and site-specific scales. This paper follows a previous one on issues and development of standards for CO2 storage capacity estimation, and provides a clear set of definitions and methodologies for the assessment of CO2 storage capacity in geological media. Notwithstanding the defined methodologies suggested for estimating CO2 storage capacity, major challenges lie ahead because of lack of data, particularly for coal beds and deep saline aquifers, lack of knowledge about the coefficients that reduce storage capacity from theoretical to effective and to practical, and lack of knowledge about the interplay between various trapping mechanisms at work in deep saline aquifers. ?? 2007 Elsevier Ltd. All rights reserved.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"International Journal of Greenhouse Gas Control","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1016/S1750-5836(07)00086-2","issn":"17505836","usgsCitation":"Bachu, S., Bonijoly, D., Bradshaw, J., Burruss, R., Holloway, S., Christensen, N., and Mathiassen, O., 2007, CO2 storage capacity estimation: Methodology and gaps: International Journal of Greenhouse Gas Control, v. 1, no. 4, p. 430-443, https://doi.org/10.1016/S1750-5836(07)00086-2.","startPage":"430","endPage":"443","numberOfPages":"14","costCenters":[],"links":[{"id":477261,"rank":10000,"type":{"id":41,"text":"Open Access External Repository Page"},"url":"http://nora.nerc.ac.uk/id/eprint/4475/1/Abstract.pdf","text":"External Repository"},{"id":240151,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":212635,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/S1750-5836(07)00086-2"}],"volume":"1","issue":"4","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"5059f2d5e4b0c8380cd4b3f7","contributors":{"authors":[{"text":"Bachu, S.","contributorId":35124,"corporation":false,"usgs":true,"family":"Bachu","given":"S.","email":"","affiliations":[],"preferred":false,"id":432592,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Bonijoly, D.","contributorId":51985,"corporation":false,"usgs":true,"family":"Bonijoly","given":"D.","email":"","affiliations":[],"preferred":false,"id":432593,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Bradshaw, J.","contributorId":75758,"corporation":false,"usgs":true,"family":"Bradshaw","given":"J.","email":"","affiliations":[],"preferred":false,"id":432595,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Burruss, R.","contributorId":18178,"corporation":false,"usgs":true,"family":"Burruss","given":"R.","affiliations":[],"preferred":false,"id":432590,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Holloway, S.","contributorId":22150,"corporation":false,"usgs":true,"family":"Holloway","given":"S.","email":"","affiliations":[],"preferred":false,"id":432591,"contributorType":{"id":1,"text":"Authors"},"rank":5},{"text":"Christensen, N.P.","contributorId":70193,"corporation":false,"usgs":true,"family":"Christensen","given":"N.P.","email":"","affiliations":[],"preferred":false,"id":432594,"contributorType":{"id":1,"text":"Authors"},"rank":6},{"text":"Mathiassen, O.M.","contributorId":95275,"corporation":false,"usgs":true,"family":"Mathiassen","given":"O.M.","email":"","affiliations":[],"preferred":false,"id":432596,"contributorType":{"id":1,"text":"Authors"},"rank":7}]}} ,{"id":70031668,"text":"70031668 - 2007 - Flood regionalization: A hybrid geographic and predictor-variable region-of-influence regression method","interactions":[],"lastModifiedDate":"2012-03-12T17:21:05","indexId":"70031668","displayToPublicDate":"2007-01-01T00:00:00","publicationYear":"2007","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2341,"text":"Journal of Hydrologic Engineering","active":true,"publicationSubtype":{"id":10}},"title":"Flood regionalization: A hybrid geographic and predictor-variable region-of-influence regression method","docAbstract":"To facilitate estimation of streamflow characteristics at an ungauged site, hydrologists often define a region of influence containing gauged sites hydrologically similar to the estimation site. This region can be defined either in geographic space or in the space of the variables that are used to predict streamflow (predictor variables). These approaches are complementary, and a combination of the two may be superior to either. Here we propose a hybrid region-of-influence (HRoI) regression method that combines the two approaches. The new method was applied with streamflow records from 1,091 gauges in the southeastern United States to estimate the 50-year peak flow (Q50). The HRoI approach yielded lower root-mean-square estimation errors and produced fewer extreme errors than either the predictor-variable or geographic region-of-influence approaches. It is concluded, for Q50 in the study region, that similarity with respect to the basin characteristics considered (area, slope, and annual precipitation) is important, but incomplete, and that the consideration of geographic proximity of stations provides a useful surrogate for characteristics that are not included in the analysis. ?? 2007 ASCE.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Journal of Hydrologic Engineering","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1061/(ASCE)1084-0699(2007)12:6(585)","issn":"10840699","usgsCitation":"Eng, K., Milly, P., and Tasker, G.D., 2007, Flood regionalization: A hybrid geographic and predictor-variable region-of-influence regression method: Journal of Hydrologic Engineering, v. 12, no. 6, p. 585-591, https://doi.org/10.1061/(ASCE)1084-0699(2007)12:6(585).","startPage":"585","endPage":"591","numberOfPages":"7","costCenters":[],"links":[{"id":212608,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1061/(ASCE)1084-0699(2007)12:6(585)"},{"id":240116,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"12","issue":"6","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a1150e4b0c8380cd53f5f","contributors":{"authors":[{"text":"Eng, K.","contributorId":51063,"corporation":false,"usgs":true,"family":"Eng","given":"K.","email":"","affiliations":[],"preferred":false,"id":432587,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Milly, P. C. D.","contributorId":100489,"corporation":false,"usgs":true,"family":"Milly","given":"P. C. D.","affiliations":[],"preferred":false,"id":432589,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Tasker, Gary D.","contributorId":83097,"corporation":false,"usgs":true,"family":"Tasker","given":"Gary","email":"","middleInitial":"D.","affiliations":[],"preferred":false,"id":432588,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70031667,"text":"70031667 - 2007 - Energy feedbacks of northern high-latitude ecosystems to the climate system due to reduced snow cover during 20th century warming","interactions":[],"lastModifiedDate":"2012-03-12T17:21:05","indexId":"70031667","displayToPublicDate":"2007-01-01T00:00:00","publicationYear":"2007","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1837,"text":"Global Change Biology","active":true,"publicationSubtype":{"id":10}},"title":"Energy feedbacks of northern high-latitude ecosystems to the climate system due to reduced snow cover during 20th century warming","docAbstract":"The warming associated with changes in snow cover in northern high-latitude terrestrial regions represents an important energy feedback to the climate system. Here, we simulate snow cover-climate feedbacks (i.e. changes in snow cover on atmospheric heating) across the Pan-arctic over two distinct warming periods during the 20th century, 1910-1940 and 1970-2000. We offer evidence that increases in snow cover-climate feedbacks during 1970-2000 were nearly three times larger than during 1910-1940 because the recent snow-cover change occurred in spring, when radiation load is highest, rather than in autumn. Based on linear regression analysis, we also detected a greater sensitivity of snow cover-climate feedbacks to temperature trends during the more recent time period. Pan-arctic vegetation types differed substantially in snow cover-climate feedbacks. Those with a high seasonal contrast in albedo, such as tundra, showed much larger changes in atmospheric heating than did those with a low seasonal contrast in albedo, such as forests, even if the changes in snow-cover duration were similar across the vegetation types. These changes in energy exchange warrant careful consideration in studies of climate change, particularly with respect to associated shifts in vegetation between forests, grasslands, and tundra. ?? 2007 Blackwell Publishing Ltd.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Global Change Biology","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1111/j.1365-2486.2007.01450.x","issn":"13541013","usgsCitation":"Euskirchen, E., McGuire, A., and Chapin, F., 2007, Energy feedbacks of northern high-latitude ecosystems to the climate system due to reduced snow cover during 20th century warming: Global Change Biology, v. 13, no. 11, p. 2425-2438, https://doi.org/10.1111/j.1365-2486.2007.01450.x.","startPage":"2425","endPage":"2438","numberOfPages":"14","costCenters":[],"links":[{"id":212607,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1111/j.1365-2486.2007.01450.x"},{"id":240115,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"13","issue":"11","noUsgsAuthors":false,"publicationDate":"2007-09-05","publicationStatus":"PW","scienceBaseUri":"505a0949e4b0c8380cd51e62","contributors":{"authors":[{"text":"Euskirchen, E.S.","contributorId":44737,"corporation":false,"usgs":true,"family":"Euskirchen","given":"E.S.","affiliations":[],"preferred":false,"id":432585,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"McGuire, A. D.","contributorId":16552,"corporation":false,"usgs":true,"family":"McGuire","given":"A. D.","affiliations":[],"preferred":false,"id":432584,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Chapin, F.S.","contributorId":48384,"corporation":false,"usgs":true,"family":"Chapin","given":"F.S.","affiliations":[],"preferred":false,"id":432586,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70031189,"text":"70031189 - 2007 - Late Quaternary distal tephra-fall deposits in lacustrine sediments, Kenai Peninsula, Alaska","interactions":[],"lastModifiedDate":"2019-02-25T15:18:35","indexId":"70031189","displayToPublicDate":"2007-01-01T00:00:00","publicationYear":"2007","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":3218,"text":"Quaternary Research","active":true,"publicationSubtype":{"id":10}},"title":"Late Quaternary distal tephra-fall deposits in lacustrine sediments, Kenai Peninsula, Alaska","docAbstract":"Tephra-fall deposits from Cook Inlet volcanoes were detected in sediment cores from Tustumena and Paradox Lakes, Kenai Peninsula, Alaska, using magnetic susceptibility and petrography. The ages of tephra layers were estimated using 21 14C ages on macrofossils. Tephras layers are typically fine, gray ash, 1–5 mm thick, and composed of varying proportions of glass shards, pumice, and glass-coated phenocrysts. Of the two lakes, Paradox Lake contained a higher frequency of tephra (0.8 tephra/100 yr; 109 over the 13,200-yr record). The unusually large number of tephra in this lake relative to others previously studied in the area is attributed to the lake's physiography, sedimentology, and limnology. The frequency of ash fall was not constant through the Holocene. In Paradox Lake, tephra layers are absent between ca. 800–2200, 3800–4800, and 9000–10,300 cal yr BP, despite continuously layered lacustrine sediment. In contrast, between 5000 and 9000 cal yr BP, an average of 1.7 tephra layers are present per 100 yr. The peak period of tephra fall (7000–9000 cal yr BP; 2.6 tephra/100 yr) in Paradox Lake is consistent with the increase in volcanism between 7000 and 9000 yr ago recorded in the Greenland ice cores.
","language":"English","publisher":"Cambridge University Press","doi":"10.1016/j.yqres.2007.03.006","issn":"00335894","usgsCitation":"de Fontaine, C., Kaufman, D.S., Scott, A.R., Werner, A., Waythomas, C.F., and Brown, T., 2007, Late Quaternary distal tephra-fall deposits in lacustrine sediments, Kenai Peninsula, Alaska: Quaternary Research, v. 68, no. 1, p. 64-78, https://doi.org/10.1016/j.yqres.2007.03.006.","productDescription":"15 p.","startPage":"64","endPage":"78","costCenters":[{"id":615,"text":"Volcano Hazards Program","active":true,"usgs":true}],"links":[{"id":238850,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":211548,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/j.yqres.2007.03.006"}],"volume":"68","issue":"1","noUsgsAuthors":false,"publicationDate":"2017-01-20","publicationStatus":"PW","scienceBaseUri":"505a4525e4b0c8380cd67089","contributors":{"authors":[{"text":"de Fontaine, C.S.","contributorId":43976,"corporation":false,"usgs":true,"family":"de Fontaine","given":"C.S.","affiliations":[],"preferred":false,"id":430438,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Kaufman, D. S.","contributorId":18006,"corporation":false,"usgs":false,"family":"Kaufman","given":"D.","email":"","middleInitial":"S.","affiliations":[],"preferred":false,"id":430436,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Scott, Anderson R.","contributorId":7909,"corporation":false,"usgs":true,"family":"Scott","given":"Anderson","email":"","middleInitial":"R.","affiliations":[],"preferred":false,"id":430433,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Werner, A.","contributorId":42030,"corporation":false,"usgs":true,"family":"Werner","given":"A.","email":"","affiliations":[],"preferred":false,"id":430437,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Waythomas, Christopher F. 0000-0002-3898-272X cwaythomas@usgs.gov","orcid":"https://orcid.org/0000-0002-3898-272X","contributorId":640,"corporation":false,"usgs":true,"family":"Waythomas","given":"Christopher","email":"cwaythomas@usgs.gov","middleInitial":"F.","affiliations":[{"id":617,"text":"Volcano Science Center","active":true,"usgs":true}],"preferred":true,"id":430434,"contributorType":{"id":1,"text":"Authors"},"rank":5},{"text":"Brown, T.A.","contributorId":12885,"corporation":false,"usgs":true,"family":"Brown","given":"T.A.","email":"","affiliations":[],"preferred":false,"id":430435,"contributorType":{"id":1,"text":"Authors"},"rank":6}]}} ,{"id":70031196,"text":"70031196 - 2007 - Effects of anthropogenic developments on common Raven nesting biology in the west Mojave Desert","interactions":[],"lastModifiedDate":"2023-07-26T11:48:12.549559","indexId":"70031196","displayToPublicDate":"2007-01-01T00:00:00","publicationYear":"2007","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":"Effects of anthropogenic developments on common Raven nesting biology in the west Mojave Desert","docAbstract":"Subsidized predators may affect prey abundance, distribution, and demography. Common Ravens (Corvus corax) are anthropogenically subsidized throughout their range and, in the Mojave Desert, have increased in number dramatically over the last 3-4 decades. Human-provided food resources are thought to be important drivers of raven population growth, but human developments add other features as well, such as nesting platforms. From 1996 to 2000, we examined the nesting ecology of ravens in the Mojave Desert, relative to anthropogenic development. Ravens nested disproportionately near point sources of food and water subsidies (such as towns, landfills, and ponds) but not near roads (sources of road-killed carrion), even though both sources of subsidy enhanced fledging success. Initiation of breeding activity was more likely when a nest from the previous year was present at the start of a breeding season but was not affected by access to food. The relative effect of environmental modifications on fledging success varied from year to year, but the effect of access to humanprovided resources was comparatively consistent, suggesting that humans provide consistently high-quality breeding habitat for ravens. Anthropogenic land cover types in the desert are expected to promote raven population growth and to allow ravens to occupy parts of the desert that otherwise would not support them. Predatory impacts of ravens in the Mojave Desert can therefore be considered indirect effects of anthropogenic development.
","language":"English","publisher":"Ecological Society of America","doi":"10.1890/06-1114.1","issn":"10510761","usgsCitation":"Kristan, W., and Boarman, W., 2007, Effects of anthropogenic developments on common Raven nesting biology in the west Mojave Desert: Ecological Applications, v. 17, no. 6, p. 1703-1713, https://doi.org/10.1890/06-1114.1.","productDescription":"11 p.","startPage":"1703","endPage":"1713","numberOfPages":"11","costCenters":[],"links":[{"id":238883,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"country":"United States","state":"California","otherGeospatial":"Mojave Desert","geographicExtents":"{\n \"type\": \"FeatureCollection\",\n \"features\": [\n {\n \"type\": \"Feature\",\n \"properties\": {},\n \"geometry\": {\n \"coordinates\": [\n [\n [\n -116.71818395045116,\n 36.09370934263055\n ],\n [\n -116.71818395045116,\n 33.8807150099009\n ],\n [\n -114.17044893828503,\n 33.8807150099009\n ],\n [\n -114.17044893828503,\n 36.09370934263055\n ],\n [\n -116.71818395045116,\n 36.09370934263055\n ]\n ]\n ],\n \"type\": \"Polygon\"\n }\n }\n ]\n}","volume":"17","issue":"6","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a068de4b0c8380cd512da","contributors":{"authors":[{"text":"Kristan, W. B. III","contributorId":106444,"corporation":false,"usgs":true,"family":"Kristan","given":"W. B.","suffix":"III","affiliations":[],"preferred":false,"id":430472,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Boarman, W.I.","contributorId":73523,"corporation":false,"usgs":true,"family":"Boarman","given":"W.I.","email":"","affiliations":[],"preferred":false,"id":430471,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70031666,"text":"70031666 - 2007 - Response of bird species densities to habitat structure and fire history along a Midwestern open-forest gradient","interactions":[],"lastModifiedDate":"2016-04-28T13:44:57","indexId":"70031666","displayToPublicDate":"2007-01-01T00:00:00","publicationYear":"2007","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1318,"text":"Condor","active":true,"publicationSubtype":{"id":10}},"title":"Response of bird species densities to habitat structure and fire history along a Midwestern open-forest gradient","docAbstract":"Oak savannas were historically common but are currently rare in the Midwestern United States. We assessed possible associations of bird species with savannas and other threatened habitats in the region by relating fire frequency and vegetation characteristics to seasonal densities of 72 bird species distributed across an open-forest gradient in northwestern Indiana. About one-third of the species did not exhibit statistically significant relationships with any combination of seven vegetation characteristics that included vegetation cover in five vertical strata, dead tree density, and tree height. For 40% of the remaining species, models best predicting species density incorporated tree density. Therefore, management based solely on manipulating tree density may not be an adequate strategy for managing bird populations along this open-forest gradient. Few species exhibited sharp peaks in predicted density under habitat conditions expected in restored savannas, suggesting that few savanna specialists occur among Midwestern bird species. When fire frequency, measured over fifteen years, was added to vegetation characteristics as a predictor of species density, it was incorporated into models for about one-quarter of species, suggesting that fire may modify habitat characteristics in ways that are important for birds but not captured by the structural habitat variables measured. Among those species, similar numbers had peaks in predicted density at low, intermediate, or high fire frequency. For species suggested by previous studies to have a preference for oak savannas along the open-forest gradient, estimated density was maximized at an average fire return interval of about one fire every three years. ?? The Cooper Ornithological Society 2007.
","language":"English","publisher":"Cooper Ornithological Society","doi":"10.1650/0010-5422(2007)109[734:ROBSDT]2.0.CO;2","issn":"00105422","usgsCitation":"Grundel, R., and Pavlovic, N., 2007, Response of bird species densities to habitat structure and fire history along a Midwestern open-forest gradient: Condor, v. 109, no. 4, p. 734-749, https://doi.org/10.1650/0010-5422(2007)109[734:ROBSDT]2.0.CO;2.","productDescription":"16 p.","startPage":"734","endPage":"749","onlineOnly":"N","additionalOnlineFiles":"N","costCenters":[{"id":324,"text":"Great Lakes Science Center","active":true,"usgs":true}],"links":[{"id":476963,"rank":10000,"type":{"id":40,"text":"Open Access Publisher Index Page"},"url":"https://zenodo.org/record/1236383","text":"Publisher Index Page"},{"id":240079,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":212576,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1650/0010-5422(2007)109[734:ROBSDT]2.0.CO;2"}],"volume":"109","issue":"4","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505aaa37e4b0c8380cd861ed","contributors":{"authors":[{"text":"Grundel, R.","contributorId":37110,"corporation":false,"usgs":true,"family":"Grundel","given":"R.","affiliations":[],"preferred":false,"id":432582,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Pavlovic, N.B.","contributorId":105076,"corporation":false,"usgs":true,"family":"Pavlovic","given":"N.B.","email":"","affiliations":[],"preferred":false,"id":432583,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70031665,"text":"70031665 - 2007 - Population inertia and its sensitivity to changes in vital rates and population structure","interactions":[],"lastModifiedDate":"2017-12-07T08:45:44","indexId":"70031665","displayToPublicDate":"2007-01-01T00:00:00","publicationYear":"2007","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1465,"text":"Ecology","active":true,"publicationSubtype":{"id":10}},"title":"Population inertia and its sensitivity to changes in vital rates and population structure","docAbstract":"Because the (st)age structure of a population may rarely be stable, studies of transient population dynamics and population momentum are becoming ever more popular. Yet, studies of \"population momentum\" are restricted in the sense that they describe the inertia of population size resulting from a demographic transition to the stationary population growth rate. Although rarely mentioned, inertia in population size is a general phenomenon and can be produced by any demographic transition or perturbation. Because population size is of central importance in demography, conservation, and management, formulas relating the sensitivity of population inertia to changes in underlying vital rates and population structure could provide much-needed insight into the dynamics of populations with unstable (st)age structure. Here, we derive such formulas, which are readily computable, and provide examples of their potential use in studies of life history and applied arenas of population study. ?? 2007 by the Ecological Society of America.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Ecology","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1890/06-1801.1","issn":"00129658","usgsCitation":"Koons, D.N., Holmes, R.R., and Grand, J.B., 2007, Population inertia and its sensitivity to changes in vital rates and population structure: Ecology, v. 88, no. 11, p. 2857-2867, https://doi.org/10.1890/06-1801.1.","startPage":"2857","endPage":"2867","numberOfPages":"11","costCenters":[],"links":[{"id":240078,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":212575,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1890/06-1801.1"}],"volume":"88","issue":"11","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a7d7be4b0c8380cd79f8e","contributors":{"authors":[{"text":"Koons, David N.","contributorId":28137,"corporation":false,"usgs":false,"family":"Koons","given":"David","email":"","middleInitial":"N.","affiliations":[{"id":6621,"text":"Colorado State University","active":true,"usgs":false}],"preferred":false,"id":432581,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Holmes, Randall R.","contributorId":201221,"corporation":false,"usgs":false,"family":"Holmes","given":"Randall","email":"","middleInitial":"R.","affiliations":[{"id":13360,"text":"Auburn University","active":true,"usgs":false}],"preferred":false,"id":432580,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Grand, J. Barry 0000-0002-3576-4567 barry_grand@usgs.gov","orcid":"https://orcid.org/0000-0002-3576-4567","contributorId":579,"corporation":false,"usgs":true,"family":"Grand","given":"J.","email":"barry_grand@usgs.gov","middleInitial":"Barry","affiliations":[{"id":198,"text":"Coop Res Unit Atlanta","active":true,"usgs":true}],"preferred":true,"id":432579,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70031199,"text":"70031199 - 2007 - Organic petrology of Paleocene Marcelina Formation coals, Paso Diablo mine, western Venezuela: Tectonic controls on coal type","interactions":[],"lastModifiedDate":"2012-03-12T17:21:17","indexId":"70031199","displayToPublicDate":"2007-01-01T00:00:00","publicationYear":"2007","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":"Organic petrology of Paleocene Marcelina Formation coals, Paso Diablo mine, western Venezuela: Tectonic controls on coal type","docAbstract":"About 7??Mt of high volatile bituminous coal are produced annually from the four coal zones of the Upper Paleocene Marcelina Formation at the Paso Diablo open-pit mine of western Venezuela. As part of an ongoing coal quality study, we have characterized twenty-two coal channel samples from the mine using organic petrology techniques. Samples also were analyzed for proximate-ultimate parameters, forms of sulfur, free swelling index, ash fusion temperatures, and calorific value. Six of the samples represent incremental benches across the 12-13??m thick No. 4 bed, the stratigraphically lowest mined coal, which is also mined at the 10??km distant Mina Norte open-pit. Organic content of the No. 4 bed indicates an upward increase of woody vegetation and/or greater preservation of organic material throughout the life of the original mire(s). An upward increase in telovitrinite and corresponding decrease in detrovitrinite and inertinite illustrate this trend. In contrast, stratigraphically higher coal groups generally exhibit a 'dulling upward' trend. The generally high inertinite content, and low ash yield and sulfur content, suggest that the Paso Diablo coals were deposited in rain-fed raised mires, protected from clastic input and subjected to frequent oxidation and/or moisture stress. However, the two thinnest coal beds (both 0.7??m thick) are each characterized by lower inertinite and higher telovitrinite content relative to the rest of Paso Diablo coal beds, indicative of less well-established raised mire environments prior to drowning. Foreland basin Paleocene coals of western Venezuela, including the Paso Diablo deposit and time-correlative coal deposits of the Ta??chira and Me??rida Andes, are characterized by high inertinite and consistently lower ash and sulfur relative to Eocene and younger coals of the area. We interpret these age-delimited coal quality characteristics to be due to water availability as a function of the tectonic control of subsidence rate. It is postulated that slower subsidence rates dominated during the Paleocene while greater foreland basin subsidence rates during the Eocene-Miocene resulted from the loading of nappe thrust sheets as part of the main construction phases of the Andean orogen. South-southeastward advance and emplacement of the Lara nappes during the oblique transpressive collision of the Caribbean and South American tectonic plates in the Paleocene was further removed from the sites of peat deposition, resulting in slower subsidence rates. Slower subsidence in the Paleocene may have favored the growth of raised mires, generating higher inertinite concentrations through more frequent moisture stress. Consistently low ash yield and sulfur content would be due to the protection from clastic input in raised mires, in addition to the leaching of mineral matter by rainfall and the development of acidic conditions preventing fixation of sulfur. In contrast, peat mires of Eocene-Miocene age encountered rapid subsidence due to the proximity of nappe emplacement, resulting in lower inertinite content, higher and more variable sulfur content, and higher ash yield.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"International Journal of Coal Geology","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1016/j.coal.2006.05.002","issn":"01665162","usgsCitation":"Hackley, P., and Martinez, M., 2007, Organic petrology of Paleocene Marcelina Formation coals, Paso Diablo mine, western Venezuela: Tectonic controls on coal type: International Journal of Coal Geology, v. 71, no. 4, p. 505-526, https://doi.org/10.1016/j.coal.2006.05.002.","startPage":"505","endPage":"526","numberOfPages":"22","costCenters":[],"links":[{"id":238884,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":211576,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/j.coal.2006.05.002"}],"volume":"71","issue":"4","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a6fd6e4b0c8380cd75cc4","contributors":{"authors":[{"text":"Hackley, P.C. 0000-0002-5957-2551","orcid":"https://orcid.org/0000-0002-5957-2551","contributorId":60756,"corporation":false,"usgs":true,"family":"Hackley","given":"P.C.","affiliations":[],"preferred":false,"id":430479,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Martinez, M.","contributorId":49910,"corporation":false,"usgs":true,"family":"Martinez","given":"M.","affiliations":[],"preferred":false,"id":430478,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70031200,"text":"70031200 - 2007 - Reducing energy-related CO2 emissions using accelerated weathering of limestone","interactions":[],"lastModifiedDate":"2016-12-07T13:02:01","indexId":"70031200","displayToPublicDate":"2007-01-01T00:00:00","publicationYear":"2007","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1505,"text":"Energy","active":true,"publicationSubtype":{"id":10}},"title":"Reducing energy-related CO2 emissions using accelerated weathering of limestone","docAbstract":"The use and impacts of accelerated weathering of limestone (AWL; reaction: CO2+H2O+CaCO3→Ca2++2(HCO3-) is explored as a CO2 capture and sequestration method. It is shown that significant limestone resources are relatively close to a majority of CO2-emitting power plants along the coastal US, a favored siting location for AWL. Waste fines, representing more than 20% of current US crushed limestone production (>109 tonnes/yr), could provide an inexpensive or free source of AWL carbonate. With limestone transportation then as the dominant cost variable, CO2 mitigation costs of $3-$4/tonne appear to be possible in certain locations. Perhaps 10–20% of US point–source CO2 emissions could be mitigated in this fashion. It is experimentally shown that CO2 sequestration rates of 10-6 to 10-5 moles/sec per m2 of limestone surface area are achievable, with reaction densities on the order of 10-2 tonnes CO2 m-3day-1, highly dependent on limestone particle size, solution turbulence and flow, and CO2 concentration. Modeling shows that AWL would allow carbon storage in the ocean with significantly reduced impacts to seawater pH relative to direct CO2 disposal into the atmosphere or sea. The addition of AWL-derived alkalinity to the ocean may itself be beneficial for marine biota.
","language":"English","publisher":"Elsevier","doi":"10.1016/j.energy.2006.10.011","issn":"03605442","usgsCitation":"Rau, G.H., Knauss, K.G., Langer, W.H., and Caldeira, K., 2007, Reducing energy-related CO2 emissions using accelerated weathering of limestone: Energy, v. 32, no. 8, p. 1471-1477, https://doi.org/10.1016/j.energy.2006.10.011.","productDescription":"7 p.","startPage":"1471","endPage":"1477","numberOfPages":"7","costCenters":[],"links":[{"id":238885,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"32","issue":"8","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"50e4a3cce4b0e8fec6cdb99f","contributors":{"authors":[{"text":"Rau, Greg H.","contributorId":78963,"corporation":false,"usgs":false,"family":"Rau","given":"Greg","email":"","middleInitial":"H.","affiliations":[{"id":6949,"text":"University of California, Santa Cruz","active":true,"usgs":false}],"preferred":false,"id":430481,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Knauss, Kevin G.","contributorId":177240,"corporation":false,"usgs":false,"family":"Knauss","given":"Kevin","email":"","middleInitial":"G.","affiliations":[{"id":13621,"text":"Lawrence Livermore National Laboratory","active":true,"usgs":false}],"preferred":false,"id":430483,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Langer, William H. blanger@usgs.gov","contributorId":1241,"corporation":false,"usgs":true,"family":"Langer","given":"William","email":"blanger@usgs.gov","middleInitial":"H.","affiliations":[{"id":387,"text":"Mineral Resources Program","active":true,"usgs":true}],"preferred":false,"id":430482,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Caldeira, Ken","contributorId":12287,"corporation":false,"usgs":true,"family":"Caldeira","given":"Ken","affiliations":[],"preferred":false,"id":430480,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}} ,{"id":70031201,"text":"70031201 - 2007 - Three-dimensional P wave velocity model for the San Francisco Bay region, California","interactions":[],"lastModifiedDate":"2023-08-01T11:41:35.989038","indexId":"70031201","displayToPublicDate":"2007-01-01T00:00:00","publicationYear":"2007","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":"Three-dimensional P wave velocity model for the San Francisco Bay region, California","docAbstract":"[1] A new three-dimensional P wave velocity model for the greater San Francisco Bay region has been derived using the double-difference seismic tomography method, using data from about 5,500 chemical explosions or air gun blasts and approximately 6,000 earthquakes. The model region covers 140 km NE-SW by 240 km NW-SE, extending from 20 km south of Monterey to Santa Rosa and reaching from the Pacific coast to the edge of the Great Valley. Our model provides the first regional view of a number of basement highs that are imaged in the uppermost few kilometers of the model, and images a number of velocity anomaly lows associated with known Mesozoic and Cenozoic basins in the study area. High velocity (Vp > 6.5 km/s) features at ∼15-km depth beneath part of the edge of the Great Valley and along the San Francisco peninsula are interpreted as ophiolite bodies. The relocated earthquakes provide a clear picture of the geometry of the major faults in the region, illuminating fault dips that are generally consistent with previous studies. Ninety-five percent of the earthquakes have depths between 2.3 and 15.2 km, and the corresponding seismic velocities at the hypocenters range from 4.8 km/s (presumably corresponding to Franciscan basement or Mesozoic sedimentary rocks of the Great Valley Sequence) to 6.8 km/s. The top of the seismogenic zone is thus largely controlled by basement depth, but the base of the seismogenic zone is not restricted to seismic velocities of ≤6.3 km/s in this region, as had been previously proposed.