Vertical profiles of the chlorofluorocarbons CFC‐11, CFC‐12, and CFC‐113 penetrating aerobic and anaerobic parts of a shallow sandy aquifer show that the CFC gases are degraded in the <1 m thick transition zone from aerobic to anaerobic groundwater in a pyritic sand aquifer at Rabis Creek, Denmark. Two‐dimensional solute transport simulations with either zero‐order or first‐order degradation in the anaerobic zone corroborate this interpretation. The transport model was previously calibrated against detailed tritium profiles in the same wells. First‐order degradation is found to best match the observed CFC profiles yielding an approximate half‐life of a few months for CFC‐11. Degradation is not as clearly recognized for CFC‐12 and CFC‐113, but it may occur with rates corresponding to a half‐life of a few years or more. Data indicate a geochemical control of the CFC concentration gradient at the redox front and that denitrification and denitrifiers are not of major importance for the observed CFC degradation. The responsible mechanism behind the observed degradation is not known but we suggest that reductive dehalogenation by surface‐bound Fe(II) on pyrite possibly enhanced by the presence of Fe(III)‐bearing weathering products (green rust) may be a plausible mechanism. The observed data and the performed simulations confirm the potential application of the CFC gases as age‐dating tools in the aerobic part of the investigated aquifer, but also that CFC data must be analyzed carefully before it is used as a dating tool in reducing aquifers because degradation may have occurred. The use of multiple or alternative tracers should be considered in anaerobic environments.
","language":"English","publisher":"American Geophysical Union","doi":"10.1029/2006WR005854","usgsCitation":"Hinsby, K., Højberg, A., Engesgaard, P., Jensen, K., Larsen, F., Plummer, N., and Busenberg, E., 2007, Transport and degradation of chlorofluorocarbons (CFCs) in the pyritic Rabis Creek aquifer, Denmark: Water Resources Research, v. 43, no. 10, Article W10423; 15 p., https://doi.org/10.1029/2006WR005854.","productDescription":"Article W10423; 15 p.","costCenters":[{"id":436,"text":"National Research Program - Eastern Branch","active":true,"usgs":true}],"links":[{"id":487015,"rank":1,"type":{"id":40,"text":"Open Access Publisher Index Page"},"url":"https://doi.org/10.1029/2006wr005854","text":"Publisher Index Page"},{"id":239857,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"country":"Denmark","otherGeospatial":"Rabis Creek aquifer","volume":"43","issue":"10","noUsgsAuthors":false,"publicationDate":"2007-10-20","publicationStatus":"PW","scienceBaseUri":"505bb73ae4b08c986b32711e","contributors":{"authors":[{"text":"Hinsby, K.","contributorId":15013,"corporation":false,"usgs":true,"family":"Hinsby","given":"K.","affiliations":[],"preferred":false,"id":431520,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Højberg, Anker L.","contributorId":187776,"corporation":false,"usgs":false,"family":"Højberg","given":"Anker L.","affiliations":[],"preferred":false,"id":431518,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Engesgaard, P.","contributorId":12695,"corporation":false,"usgs":true,"family":"Engesgaard","given":"P.","affiliations":[],"preferred":false,"id":431519,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Jensen, K.H.","contributorId":75710,"corporation":false,"usgs":true,"family":"Jensen","given":"K.H.","email":"","affiliations":[],"preferred":false,"id":431522,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Larsen, F.","contributorId":104288,"corporation":false,"usgs":true,"family":"Larsen","given":"F.","affiliations":[],"preferred":false,"id":431524,"contributorType":{"id":1,"text":"Authors"},"rank":5},{"text":"Plummer, Niel 0000-0002-4020-1013 nplummer@usgs.gov","orcid":"https://orcid.org/0000-0002-4020-1013","contributorId":190100,"corporation":false,"usgs":true,"family":"Plummer","given":"Niel","email":"nplummer@usgs.gov","affiliations":[{"id":436,"text":"National Research Program - Eastern Branch","active":true,"usgs":true}],"preferred":true,"id":431523,"contributorType":{"id":1,"text":"Authors"},"rank":6},{"text":"Busenberg, Eurybiades ebusenbe@usgs.gov","contributorId":2271,"corporation":false,"usgs":true,"family":"Busenberg","given":"Eurybiades","email":"ebusenbe@usgs.gov","affiliations":[{"id":436,"text":"National Research Program - Eastern Branch","active":true,"usgs":true}],"preferred":true,"id":431521,"contributorType":{"id":1,"text":"Authors"},"rank":7}]}} ,{"id":70031439,"text":"70031439 - 2007 - Geochemical and geophysical examination of submarine groundwater discharge and associated nutrient loading estimates into Lynch Cove, Hood Canal, WA","interactions":[],"lastModifiedDate":"2017-03-03T13:53:19","indexId":"70031439","displayToPublicDate":"2007-01-01T00:00:00","publicationYear":"2007","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1565,"text":"Environmental Science & Technology","onlineIssn":"1520-5851","printIssn":"0013-936X","active":true,"publicationSubtype":{"id":10}},"title":"Geochemical and geophysical examination of submarine groundwater discharge and associated nutrient loading estimates into Lynch Cove, Hood Canal, WA","docAbstract":"Geochemical tracer data (i.e., 222Rn and four naturally occurring Ra isotopes), electromagnetic (EM) seepage meter results, and high-resolution, stationary electrical resistivity images were used to examine the bi-directional (i.e., submarine groundwater discharge and recharge) exchange of a coastal aquifer with seawater. Our study site for these experiments was Lynch Cove, the terminus of Hood Canal, WA, where fjord-like conditions dramatically limit water column circulation that can lead to recurring summer-time hypoxic events. In such a system a precise nutrient budget may be particularly sensitive to groundwater-derived nutrient loading. Shore-perpendicular time-series subsurface resistivity profiles show clear, decimeter-scale tidal modulation of the coastal aquifer in response to large, regional hydraulic gradients, hydrologically transmissive glacial terrain, and large (4-5 m) tidal amplitudes. A 5-day 222Rn time-series shows a strong inverse covariance between 222Rn activities (0.5−29 dpm L-1) and water level fluctuations, and provides compelling evidence for tidally modulated exchange of groundwater across the sediment/water interface. Mean Rn-derived submarine groundwater discharge (SGD) rates of 85 ± 84 cm d-1 agree closely in the timing and magnitude with EM seepage meter results that showed discharge during low tide and recharge during high tide events. To evaluate the importance of fresh versus saline SGD, Rn-derived SGD rates (as a proxy of total SGD) were compared to excess 226Ra-derived SGD rates (as a proxy for the saline contribution of SGD). The calculated SGD rates, which include a significant (>80%) component of recycled seawater, are used to estimate associated nutrient (NH4+, Si, PO43-, NO3 + NO2, TDN) loads to Lynch Cove. The dissolved inorganic nitrogen (DIN = NH4 + NO2 + NO3) SGD loading estimate of 5.9 × 104 mol d-1 is 1−2 orders of magnitude larger than similar estimates derived from atmospheric deposition and surface water runoff, respectively.
","language":"English","publisher":"American Chemical Society","doi":"10.1021/es070881a","issn":"0013936X","usgsCitation":"Swarzenski, P., Simonds, F., Paulson, A., Kruse, S., and Reich, C., 2007, Geochemical and geophysical examination of submarine groundwater discharge and associated nutrient loading estimates into Lynch Cove, Hood Canal, WA: Environmental Science & Technology, v. 41, no. 20, p. 7022-7029, https://doi.org/10.1021/es070881a.","productDescription":"8 p.","startPage":"7022","endPage":"7029","onlineOnly":"N","additionalOnlineFiles":"N","costCenters":[{"id":186,"text":"Coastal and Marine Geology Program","active":true,"usgs":true},{"id":622,"text":"Washington Water Science Center","active":true,"usgs":true}],"links":[{"id":239757,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"country":"United States","state":"Washington","otherGeospatial":"Hood Canal, Lynch Cove","volume":"41","issue":"20","noUsgsAuthors":false,"publicationDate":"2007-09-19","publicationStatus":"PW","scienceBaseUri":"505a15d0e4b0c8380cd54f58","contributors":{"authors":[{"text":"Swarzenski, P.W. 0000-0003-0116-0578","orcid":"https://orcid.org/0000-0003-0116-0578","contributorId":29487,"corporation":false,"usgs":true,"family":"Swarzenski","given":"P.W.","affiliations":[],"preferred":false,"id":431505,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Simonds, F. W.","contributorId":54616,"corporation":false,"usgs":true,"family":"Simonds","given":"F. W.","affiliations":[],"preferred":false,"id":431508,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Paulson, A.J. apaulson@usgs.gov","contributorId":89617,"corporation":false,"usgs":true,"family":"Paulson","given":"A.J.","email":"apaulson@usgs.gov","affiliations":[],"preferred":false,"id":431509,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Kruse, S.","contributorId":33103,"corporation":false,"usgs":true,"family":"Kruse","given":"S.","email":"","affiliations":[],"preferred":false,"id":431506,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Reich, C.","contributorId":41787,"corporation":false,"usgs":true,"family":"Reich","given":"C.","email":"","affiliations":[],"preferred":false,"id":431507,"contributorType":{"id":1,"text":"Authors"},"rank":5}]}} ,{"id":70031436,"text":"70031436 - 2007 - Effects of earlier sea ice breakup on survival and population size of polar bears in western Hudson Bay","interactions":[],"lastModifiedDate":"2012-03-12T17:21:11","indexId":"70031436","displayToPublicDate":"2007-01-01T00:00:00","publicationYear":"2007","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":"Effects of earlier sea ice breakup on survival and population size of polar bears in western Hudson Bay","docAbstract":"Some of the most pronounced ecological responses to climatic warming are expected to occur in polar marine regions, where temperature increases have been the greatest and sea ice provides a sensitive mechanism by which climatic conditions affect sympagic (i.e., with ice) species. Population-level effects of climatic change, however, remain difficult to quantify. We used a flexible extension of Cormack-Jolly-Seber capture-recapture models to estimate population size and survival for polar bears (Ursus maritimus), one of the most ice-dependent of Arctic marine mammals. We analyzed data for polar bears captured from 1984 to 2004 along the western coast of Hudson Bay and in the community of Churchill, Manitoba, Canada. The Western Hudson Bay polar bear population declined from 1,194 (95% CI = 1,020-1,368) in 1987 to 935 (95% CI = 794-1,076) in 2004. Total apparent survival of prime-adult polar bears (5-19 yr) was stable for females (0.93; 95% CI = 0.91-0.94) and males (0.90; 95% CI = 0.88-0.91). Survival of juvenile, subadult, and senescent-adult polar bears was correlated with spring sea ice breakup date, which was variable among years and occurred approximately 3 weeks earlier in 2004 than in 1984. We propose that this correlation provides evidence for a causal association between earlier sea ice breakup (due to climatic warming) and decreased polar bear survival. It may also explain why Churchill, like other communities along the western coast of Hudson Bay, has experienced an increase in human-polar bear interactions in recent years. Earlier sea ice breakup may have resulted in a larger number of nutritionally stressed polar bears, which are encroaching on human habitations in search of supplemental food. Because western Hudson Bay is near the southern limit of the species' range, our findings may foreshadow the demographic responses and management challenges that more northerly polar bear populations will experience if climatic warming in the Arctic continues as projected.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Journal of Wildlife Management","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.2193/2006-180","issn":"0022541X","usgsCitation":"Regehr, E., Lunn, N., Amstrup, S.C., and Stirling, I., 2007, Effects of earlier sea ice breakup on survival and population size of polar bears in western Hudson Bay: Journal of Wildlife Management, v. 71, no. 8, p. 2673-2683, https://doi.org/10.2193/2006-180.","startPage":"2673","endPage":"2683","numberOfPages":"11","costCenters":[],"links":[{"id":212262,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.2193/2006-180"},{"id":239724,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"71","issue":"8","noUsgsAuthors":false,"publicationDate":"2010-12-13","publicationStatus":"PW","scienceBaseUri":"505a06d8e4b0c8380cd5143f","contributors":{"authors":[{"text":"Regehr, E.V.","contributorId":90937,"corporation":false,"usgs":true,"family":"Regehr","given":"E.V.","affiliations":[],"preferred":false,"id":431493,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Lunn, N.J.","contributorId":42920,"corporation":false,"usgs":true,"family":"Lunn","given":"N.J.","email":"","affiliations":[],"preferred":false,"id":431491,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"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":431492,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Stirling, I.","contributorId":103615,"corporation":false,"usgs":false,"family":"Stirling","given":"I.","email":"","affiliations":[],"preferred":false,"id":431494,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}} ,{"id":70031432,"text":"70031432 - 2007 - Linking resources with demography to understand resource limitation for bears","interactions":[],"lastModifiedDate":"2012-03-12T17:21:11","indexId":"70031432","displayToPublicDate":"2007-01-01T00:00:00","publicationYear":"2007","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2163,"text":"Journal of Applied Ecology","active":true,"publicationSubtype":{"id":10}},"title":"Linking resources with demography to understand resource limitation for bears","docAbstract":"1. Identifying the resources that limit growth of animal populations is essential for effective conservation; however, resource limitation is difficult to quantify. Recent advances in geographical information systems (GIS) and resource modelling can be combined with demographic modelling to yield insights into resource limitation. 2. Using long-term data on a population of black bears Ursus americanus, we evaluated competing hypotheses about whether availability of hard mast (acorns and nuts) or soft mast (fleshy fruits) limited bears in the southern Appalachians, USA, during 1981-2002. The effects of clearcutting on habitat quality were also evaluated. Annual survival, recruitment and population growth rate were estimated using capture-recapture data from 101 females. The availability of hard mast, soft mast and clearcuts was estimated with a GIS, as each changed through time as a result of harvest and succession, and then availabilities were incorporated as covariates for each demographic parameter. 3. The model with the additive availability of hard mast and soft mast across the landscape predicted survival and population growth rate. Availability of young clearcuts predicted recruitment, but not population growth or survival. 4. Availability of hard mast stands across the landscape and availability of soft mast across the landscape were more important than hard mast production and availability of soft mast in young clearcuts, respectively. 5. Synthesis and applications. Our results indicate that older stands, which support high levels of hard mast and moderate levels of soft mast, should be maintained to sustain population growth of bears in the southern Appalachians. Simultaneously, the acreage of intermediate aged stands (10-25 years), which support very low levels of both hard mast and soft mast, should be minimized. The approach used in this study has broad application for wildlife management and conservation. State and federal wildlife agencies often possess long-term data on both resource availability and capture-recapture for wild populations. Combined, these two data types can be used to estimate survival, recruitment, population growth, elasticities of vital rates and the effects of resource availability on demographic parameters. Hence data that are traditionally used to understand population trends can be used to evaluate how and why demography changes over time. ?? 2007 The Authors.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Journal of Applied Ecology","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1111/j.1365-2664.2007.01317.x","issn":"00218901","usgsCitation":"Reynolds-Hogland, M.J., Pacifici, L., and Mitchell, M., 2007, Linking resources with demography to understand resource limitation for bears: Journal of Applied Ecology, v. 44, no. 6, p. 1166-1175, https://doi.org/10.1111/j.1365-2664.2007.01317.x.","startPage":"1166","endPage":"1175","numberOfPages":"10","costCenters":[],"links":[{"id":477178,"rank":10000,"type":{"id":40,"text":"Open Access Publisher Index Page"},"url":"https://doi.org/10.1111/j.1365-2664.2007.01317.x","text":"Publisher Index Page"},{"id":212204,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1111/j.1365-2664.2007.01317.x"},{"id":239655,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"44","issue":"6","noUsgsAuthors":false,"publicationDate":"2007-05-09","publicationStatus":"PW","scienceBaseUri":"505a47d9e4b0c8380cd67a16","contributors":{"authors":[{"text":"Reynolds-Hogland, M. J.","contributorId":57647,"corporation":false,"usgs":true,"family":"Reynolds-Hogland","given":"M.","email":"","middleInitial":"J.","affiliations":[],"preferred":false,"id":431470,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Pacifici, L.B.","contributorId":93278,"corporation":false,"usgs":true,"family":"Pacifici","given":"L.B.","email":"","affiliations":[],"preferred":false,"id":431471,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Mitchell, M.S.","contributorId":26724,"corporation":false,"usgs":true,"family":"Mitchell","given":"M.S.","email":"","affiliations":[],"preferred":false,"id":431469,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70031418,"text":"70031418 - 2007 - Study of a prehistoric landslide using seismic reflection methods integrated with geological data in the Wasatch Mountains, Utah, USA","interactions":[],"lastModifiedDate":"2012-03-12T17:21:13","indexId":"70031418","displayToPublicDate":"2007-01-01T00:00:00","publicationYear":"2007","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1517,"text":"Engineering Geology","active":true,"publicationSubtype":{"id":10}},"title":"Study of a prehistoric landslide using seismic reflection methods integrated with geological data in the Wasatch Mountains, Utah, USA","docAbstract":"An integration of geological and geophysical techniques characterizes the internal and basal structure of a landslide along the western margin of the Wasatch Mountains in northern Utah, USA. The study area is within a region of planned and continuing residential development. The Little Valley Landslide is a prehistoric landslide as old as 13??ka B.P. Drilling and trenching at the site indicate that the landslide consists of chaotic and disturbed weathered volcanic material derived from Tertiary age volcanic rocks that comprise a great portion of the Wasatch Range. Five short high-resolution common mid-point seismic reflection profiles over selected portions of the site examine the feasibility of using seismic reflection to study prehistoric landslides in the Wasatch Mountain region. Due to the expected complexity of the near-surface geology, we have pursued an experimental approach in the data processing, examining the effects of muting first arrivals, frequency filtering, model-based static corrections, and seismic migration. The results provide a framework for understanding the overall configuration of the landslide, its basal (failure) surface, and the structure immediately underlying this surface. A glide surface or de??collement is interpreted to underlie the landslide suggesting a large mass movement. The interpretation of a glide surface is based on the onset of coherent reflectivity, calibrated by information from a borehole located along one of the seismic profiles. The glide surface is deepest in the center portion of the landslide and shallows up slope, suggesting a trough-like feature. This study shows that seismic reflection techniques can be successfully used in complex alpine landslide regions to (1) provide a framework in which to link geological data and (2) reduce the need for an extensive trenching and drilling program. ?? 2007 Elsevier B.V. All rights reserved.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Engineering Geology","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1016/j.enggeo.2007.08.006","issn":"00137952","usgsCitation":"Tingey, B., McBride, J., Thompson, T., Stephenson, W.J., South, J., and Bushman, M., 2007, Study of a prehistoric landslide using seismic reflection methods integrated with geological data in the Wasatch Mountains, Utah, USA: Engineering Geology, v. 95, no. 1-2, p. 1-29, https://doi.org/10.1016/j.enggeo.2007.08.006.","startPage":"1","endPage":"29","numberOfPages":"29","costCenters":[],"links":[{"id":212529,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/j.enggeo.2007.08.006"},{"id":240026,"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":"505b9cd1e4b08c986b31d4d1","contributors":{"authors":[{"text":"Tingey, B.E.","contributorId":73397,"corporation":false,"usgs":true,"family":"Tingey","given":"B.E.","email":"","affiliations":[],"preferred":false,"id":431423,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"McBride, J.H.","contributorId":99712,"corporation":false,"usgs":true,"family":"McBride","given":"J.H.","email":"","affiliations":[],"preferred":false,"id":431427,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Thompson, T.J.","contributorId":86969,"corporation":false,"usgs":true,"family":"Thompson","given":"T.J.","email":"","affiliations":[],"preferred":false,"id":431425,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Stephenson, W. J.","contributorId":87982,"corporation":false,"usgs":true,"family":"Stephenson","given":"W.","email":"","middleInitial":"J.","affiliations":[],"preferred":false,"id":431426,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"South, J.V.","contributorId":72188,"corporation":false,"usgs":true,"family":"South","given":"J.V.","email":"","affiliations":[],"preferred":false,"id":431422,"contributorType":{"id":1,"text":"Authors"},"rank":5},{"text":"Bushman, M.","contributorId":75335,"corporation":false,"usgs":true,"family":"Bushman","given":"M.","email":"","affiliations":[],"preferred":false,"id":431424,"contributorType":{"id":1,"text":"Authors"},"rank":6}]}} ,{"id":70031415,"text":"70031415 - 2007 - Amphibian populations in the terrestrial environment: Is there evidence of declines of terrestrial forest amphibians in northwestern California?","interactions":[],"lastModifiedDate":"2012-03-12T17:21:14","indexId":"70031415","displayToPublicDate":"2007-01-01T00:00:00","publicationYear":"2007","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2334,"text":"Journal of Herpetology","active":true,"publicationSubtype":{"id":10}},"title":"Amphibian populations in the terrestrial environment: Is there evidence of declines of terrestrial forest amphibians in northwestern California?","docAbstract":"Amphibian declines have been documented worldwide; however the vast majority are species associated with aquatic habitats. Information on the status and trends of terrestrial amphibians is almost entirely lacking. Here we use data collected across a 12-yr period (sampling from 1984-86 and from 1993-95) to address the question of whether evidence exists for declines among terrestrial amphibians in northwestern California forests. The majority of amphibians, both species and relative numbers, in these forests are direct-developing salamanders of the family Plethodontidae. We examined amphibian richness and evenness, and the relative abundances of the four most common species of plethodontid salamanders. We examined evidence of differences between years in two ecological provinces (coastal and interior) and across young, mature, and late seral forests and with reference to a moisture gradient from xeric to hydric within late seral forests. We found evidence of declines in species richness across years on late seral mesic stands and in the coastal ecological province, but these differences appeared to be caused by differences in the detection of rarer species, rather than evidence of an overall pattern. We also found differences among specific years in numbers of individuals of the most abundant species, Ensatina eschscholtzii, but these differences also failed to reflect a consistent pattern of declines between the two decadal sample periods. Results showing differences in richness, evenness, and relative abundances along both the seral and moisture continua were consistent with previous research. Overall, we found no compelling evidence of a downward trend in terrestrial plethodontid salamanders. We believe that continued monitoring of terrestrial salamander populations is important to understanding mechanisms of population declines in amphibian species. Copyright 2007 Society for the Study of Amphibians and Reptiles.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Journal of Herpetology","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1670/0022-1511(2007)41[469:APITTE]2.0.CO;2","issn":"00221511","usgsCitation":"Welsh, H., Fellers, G.M., and Lind, A., 2007, Amphibian populations in the terrestrial environment: Is there evidence of declines of terrestrial forest amphibians in northwestern California?: Journal of Herpetology, v. 41, no. 3, p. 469-482, https://doi.org/10.1670/0022-1511(2007)41[469:APITTE]2.0.CO;2.","startPage":"469","endPage":"482","numberOfPages":"14","costCenters":[],"links":[{"id":212468,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1670/0022-1511(2007)41[469:APITTE]2.0.CO;2"},{"id":239958,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"41","issue":"3","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"5059e9c5e4b0c8380cd48442","contributors":{"authors":[{"text":"Welsh, H.H. Jr.","contributorId":95986,"corporation":false,"usgs":true,"family":"Welsh","given":"H.H.","suffix":"Jr.","email":"","affiliations":[],"preferred":false,"id":431409,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Fellers, G. M.","contributorId":82653,"corporation":false,"usgs":true,"family":"Fellers","given":"G.","email":"","middleInitial":"M.","affiliations":[],"preferred":false,"id":431408,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Lind, A.J.","contributorId":46763,"corporation":false,"usgs":true,"family":"Lind","given":"A.J.","email":"","affiliations":[],"preferred":false,"id":431407,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70031413,"text":"70031413 - 2007 - Implementing regional sediment management to sustain navigation at an energetic tidal inlet","interactions":[],"lastModifiedDate":"2023-07-25T12:09:38.182377","indexId":"70031413","displayToPublicDate":"2007-01-01T00:00:00","publicationYear":"2007","noYear":false,"publicationType":{"id":24,"text":"Conference Paper"},"publicationSubtype":{"id":19,"text":"Conference Paper"},"title":"Implementing regional sediment management to sustain navigation at an energetic tidal inlet","docAbstract":"Regional Sediment Management (RSM) is a systems-based approach for managing multiple projects involving sediment. RSM fosters balance between infrastructure and natural system processes, resulting in reduced project costs and achievement of greater benefits. This paper introduces the RSM concept and describes how RSM is being implemented at the Mouth of the Columbia River to sustain the inlet's 100-year old navigation infrastructure and adjacent shore lands. Implementing RSM at this energetic inlet involves feeding the inlet's morphology using dredged material, and letting nature do the work of dispersing the placed dredged material to supplement the inlet's sediment budget, without compromising the reliability of the navigation channel. The paper discusses the types of data that are being collected and analyzed to understand the environmental forcing affecting the inlet's morphology. The paper also addresses how dredged material disposal is being conducted to implement RSM.","largerWorkType":{"id":4,"text":"Book"},"largerWorkTitle":"Coastal Sediments '07 - Proceedings of 6th International Symposium on Coastal Engineering and Science of Coastal Sediment Processes","largerWorkSubtype":{"id":12,"text":"Conference publication"},"conferenceTitle":"6th International Symposium on Coastal Engineering and Science of Coastal Sediment Processes","conferenceDate":"May 13-17, 2007","conferenceLocation":"New Orleans, LA","language":"English","publisher":"ASCE","doi":"10.1061/40926(239)139","usgsCitation":"Moritz, H., Gelfenbaum, G., Kaminsky, G.M., Ruggiero, P., Oltman-shay, J., and Mckillip, D., 2007, Implementing regional sediment management to sustain navigation at an energetic tidal inlet, in Coastal Sediments '07 - Proceedings of 6th International Symposium on Coastal Engineering and Science of Coastal Sediment Processes, New Orleans, LA, May 13-17, 2007, https://doi.org/10.1061/40926(239)139.","costCenters":[],"links":[{"id":239924,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"noUsgsAuthors":false,"publicationDate":"2012-04-26","publicationStatus":"PW","scienceBaseUri":"505a3914e4b0c8380cd617c1","contributors":{"authors":[{"text":"Moritz, H.R.","contributorId":42040,"corporation":false,"usgs":true,"family":"Moritz","given":"H.R.","email":"","affiliations":[],"preferred":false,"id":431400,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Gelfenbaum, G.R.","contributorId":88766,"corporation":false,"usgs":true,"family":"Gelfenbaum","given":"G.R.","email":"","affiliations":[],"preferred":false,"id":431403,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Kaminsky, G. M.","contributorId":50586,"corporation":false,"usgs":true,"family":"Kaminsky","given":"G.","email":"","middleInitial":"M.","affiliations":[],"preferred":false,"id":431401,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Ruggiero, P.","contributorId":25995,"corporation":false,"usgs":true,"family":"Ruggiero","given":"P.","affiliations":[],"preferred":false,"id":431399,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Oltman-shay, J.","contributorId":101877,"corporation":false,"usgs":true,"family":"Oltman-shay","given":"J.","email":"","affiliations":[],"preferred":false,"id":431404,"contributorType":{"id":1,"text":"Authors"},"rank":5},{"text":"Mckillip, D.J.","contributorId":88559,"corporation":false,"usgs":true,"family":"Mckillip","given":"D.J.","email":"","affiliations":[],"preferred":false,"id":431402,"contributorType":{"id":1,"text":"Authors"},"rank":6}]}} ,{"id":70030743,"text":"70030743 - 2007 - A simulation-based approach for estimating premining water quality: Red Mountain Creek, Colorado","interactions":[],"lastModifiedDate":"2018-10-17T11:22:55","indexId":"70030743","displayToPublicDate":"2007-01-01T00:00:00","publicationYear":"2007","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":835,"text":"Applied Geochemistry","active":true,"publicationSubtype":{"id":10}},"title":"A simulation-based approach for estimating premining water quality: Red Mountain Creek, Colorado","docAbstract":"Regulatory agencies are often charged with the task of setting site-specific numeric water quality standards for impaired streams. This task is particularly difficult for streams draining highly mineralized watersheds with past mining activity. Baseline water quality data obtained prior to mining are often non-existent and application of generic water quality standards developed for unmineralized watersheds is suspect given the geology of most watersheds affected by mining. Various approaches have been used to estimate premining conditions, but none of the existing approaches rigorously consider the physical and geochemical processes that ultimately determine instream water quality. An approach based on simulation modeling is therefore proposed herein. The approach utilizes synoptic data that provide spatially-detailed profiles of concentration, streamflow, and constituent load along the study reach. This field data set is used to calibrate a reactive stream transport model that considers the suite of physical and geochemical processes that affect constituent concentrations during instream transport. A key input to the model is the quality and quantity of waters entering the study reach. This input is based on chemical analyses available from synoptic sampling and observed increases in streamflow along the study reach. Given the calibrated model, additional simulations are conducted to estimate premining conditions. In these simulations, the chemistry of mining-affected sources is replaced with the chemistry of waters that are thought to be unaffected by mining (proximal, premining analogues). The resultant simulations provide estimates of premining water quality that reflect both the reduced loads that were present prior to mining and the processes that affect these loads as they are transported downstream. This simulation-based approach is demonstrated using data from Red Mountain Creek, Colorado, a small stream draining a heavily-mined watershed. Model application to the premining problem for Red Mountain Creek is based on limited field reconnaissance and chemical analyses; additional field work and analyses may be needed to develop definitive, quantitative estimates of premining water quality.","language":"English","publisher":"Elsevier","doi":"10.1016/j.apgeochem.2007.03.054","issn":"08832927","usgsCitation":"Runkel, R.L., Kimball, B.A., Walton-Day, K., and Verplanck, P.L., 2007, A simulation-based approach for estimating premining water quality: Red Mountain Creek, Colorado: Applied Geochemistry, v. 22, no. 9, p. 1899-1918, https://doi.org/10.1016/j.apgeochem.2007.03.054.","productDescription":"20 p.","startPage":"1899","endPage":"1918","numberOfPages":"20","costCenters":[{"id":191,"text":"Colorado Water Science Center","active":true,"usgs":true},{"id":589,"text":"Toxic Substances Hydrology Program","active":true,"usgs":true}],"links":[{"id":238855,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":211552,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/j.apgeochem.2007.03.054"}],"country":"United States","state":"Colorado","otherGeospatial":"Red Mountain Creek","volume":"22","issue":"9","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"5059e598e4b0c8380cd46e66","contributors":{"authors":[{"text":"Runkel, Robert L. 0000-0003-3220-481X runkel@usgs.gov","orcid":"https://orcid.org/0000-0003-3220-481X","contributorId":685,"corporation":false,"usgs":true,"family":"Runkel","given":"Robert","email":"runkel@usgs.gov","middleInitial":"L.","affiliations":[{"id":191,"text":"Colorado Water Science Center","active":true,"usgs":true}],"preferred":true,"id":428487,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Kimball, Briant A","contributorId":118888,"corporation":false,"usgs":true,"family":"Kimball","given":"Briant","email":"","middleInitial":"A","affiliations":[],"preferred":false,"id":428486,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Walton-Day, Katherine 0000-0002-9146-6193 kwaltond@usgs.gov","orcid":"https://orcid.org/0000-0002-9146-6193","contributorId":1245,"corporation":false,"usgs":true,"family":"Walton-Day","given":"Katherine","email":"kwaltond@usgs.gov","affiliations":[{"id":191,"text":"Colorado Water Science Center","active":true,"usgs":true}],"preferred":false,"id":428485,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Verplanck, Philip L. 0000-0002-3653-6419 plv@usgs.gov","orcid":"https://orcid.org/0000-0002-3653-6419","contributorId":728,"corporation":false,"usgs":true,"family":"Verplanck","given":"Philip","email":"plv@usgs.gov","middleInitial":"L.","affiliations":[{"id":171,"text":"Central Mineral and Environmental Resources Science Center","active":true,"usgs":true}],"preferred":true,"id":428488,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}} ,{"id":70031408,"text":"70031408 - 2007 - In situ time-series measurements of subseafloor sediment properties","interactions":[],"lastModifiedDate":"2023-07-21T12:03:17.038477","indexId":"70031408","displayToPublicDate":"2007-01-01T00:00:00","publicationYear":"2007","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1941,"text":"IEEE Journal of Oceanic Engineering","active":true,"publicationSubtype":{"id":10}},"title":"In situ time-series measurements of subseafloor sediment properties","docAbstract":"Numerous models are in widespread use for the estimation of soil water retention from more easily measured textural data. Improved models are needed for better prediction and wider applicability. We developed a basic framework from which new and existing models can be derived to facilitate improvements. Starting from the assumption that every particle has a characteristic dimension R associated uniquely with a matric pressure ψ and that the form of the ψ–R relation is the defining characteristic of each model, this framework leads to particular models by specification of geometric relationships between pores and particles. Typical assumptions are that particles are spheres, pores are cylinders with volume equal to the associated particle volume times the void ratio, and that the capillary inverse proportionality between radius and matric pressure is valid. Examples include fixed-pore-shape and fixed-pore-length models. We also developed alternative versions of the model of Arya and Paris that eliminate its interval-size dependence and other problems. The alternative models are calculable by direct application of algebraic formulas rather than manipulation of data tables and intermediate results, and they easily combine with other models (e.g., incorporating structural effects) that are formulated on a continuous basis. Additionally, we developed a family of models based on the same pore geometry as the widely used unsaturated hydraulic conductivity model of Mualem. Predictions of measurements for different suitable media show that some of the models provide consistently good results and can be chosen based on ease of calculations and other factors.
","language":"English","publisher":"Soil Science Society of America","doi":"10.2136/vzj2007.0019","issn":"15391663","usgsCitation":"Nimmo, J.R., Herkelrath, W.N., and Laguna, L., 2007, Physically based estimation of soil water retention from textural data: General framework, new models, and streamlined existing models: Vadose Zone Journal, v. 6, no. 4, p. 766-773, https://doi.org/10.2136/vzj2007.0019.","productDescription":"8 p.","startPage":"766","endPage":"773","numberOfPages":"8","costCenters":[{"id":589,"text":"Toxic Substances Hydrology Program","active":true,"usgs":true}],"links":[{"id":498910,"rank":2,"type":{"id":40,"text":"Open Access Publisher Index Page"},"url":"https://doi.org/10.2136/vzj2007.0019","text":"Publisher Index Page"},{"id":239755,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"6","issue":"4","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a7af0e4b0c8380cd7918e","contributors":{"authors":[{"text":"Nimmo, John R. 0000-0001-8191-1727 jrnimmo@usgs.gov","orcid":"https://orcid.org/0000-0001-8191-1727","contributorId":757,"corporation":false,"usgs":true,"family":"Nimmo","given":"John","email":"jrnimmo@usgs.gov","middleInitial":"R.","affiliations":[{"id":438,"text":"National Research Program - Western Branch","active":true,"usgs":true},{"id":37277,"text":"WMA - Earth System Processes Division","active":true,"usgs":true}],"preferred":true,"id":431354,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Herkelrath, William N. 0000-0002-6149-5524 wnherkel@usgs.gov","orcid":"https://orcid.org/0000-0002-6149-5524","contributorId":2612,"corporation":false,"usgs":true,"family":"Herkelrath","given":"William","email":"wnherkel@usgs.gov","middleInitial":"N.","affiliations":[{"id":438,"text":"National Research Program - Western Branch","active":true,"usgs":true}],"preferred":true,"id":431355,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Laguna, Luna","contributorId":12694,"corporation":false,"usgs":true,"family":"Laguna","given":"Luna","email":"","affiliations":[],"preferred":false,"id":431353,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70031390,"text":"70031390 - 2007 - Summer microhabitat use of fluvial bull trout in Eastern Oregon streams","interactions":[],"lastModifiedDate":"2012-03-12T17:21:08","indexId":"70031390","displayToPublicDate":"2007-01-01T00:00:00","publicationYear":"2007","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2886,"text":"North American Journal of Fisheries Management","active":true,"publicationSubtype":{"id":10}},"title":"Summer microhabitat use of fluvial bull trout in Eastern Oregon streams","docAbstract":"The management and recovery of populations of bull trout Salvelinus confluentus requires a comprehensive understanding of habitat use across different systems, life stages, and life history forms. To address these needs, we collected microhabitat use and availability data in three fluvial populations of bull trout in eastern Oregon. We evaluated diel differences in microhabitat use, the consistency of microhabitat use across systems and size-classes based on preference, and our ability to predict bull trout microhabitat use. Diel comparisons suggested bull trout continue to use deeper microhabitats with cover but shift into significantly slower habitats during nighttime periods; however, we observed no discrete differences in substrate use patterns across diel periods. Across life stages, we found that both juvenile and adult bull trout used slow-velocity microhabitats with cover, but the use of specific types varied. Both logistic regression and habitat preference analyses suggested that adult bull trout used deeper habitats than juveniles. Habitat preference analyses suggested that bull trout habitat use was consistent across all three systems, as chi-square tests rejected the null hypotheses that microhabitats were used in proportion to those available (P < 0.0001). Validation analyses indicated that the logistic regression models (juvenile and adult) were effective at predicting bull trout absence across all tests (specificity values = 100%); however, our ability to accurately predict bull trout absence was limited (sensitivity values = 0% across all tests). Our results highlight the limitations of the models used to predict microhabitat use for fish species like bull trout, which occur at naturally low densities. However, our results also demonstrate that bull trout microhabitat use patterns are generally consistent across systems, a pattern that parallels observations at both similar and larger scales and across life history forms. Thus, our results, in combination with previous bull trout habitat studies, provide managers with benchmarks for restoration in highly degraded systems.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"North American Journal of Fisheries Management","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1577/M06-154.1","issn":"02755947","usgsCitation":"Al-Chokhachy, R., and Budy, P., 2007, Summer microhabitat use of fluvial bull trout in Eastern Oregon streams: North American Journal of Fisheries Management, v. 27, no. 4, p. 1068-1081, https://doi.org/10.1577/M06-154.1.","startPage":"1068","endPage":"1081","numberOfPages":"14","costCenters":[],"links":[{"id":212618,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1577/M06-154.1"},{"id":240132,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"27","issue":"4","noUsgsAuthors":false,"publicationDate":"2007-11-01","publicationStatus":"PW","scienceBaseUri":"505b9f3ee4b08c986b31e430","contributors":{"authors":[{"text":"Al-Chokhachy, R.","contributorId":42431,"corporation":false,"usgs":true,"family":"Al-Chokhachy","given":"R.","affiliations":[],"preferred":false,"id":431300,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Budy, P.","contributorId":68091,"corporation":false,"usgs":true,"family":"Budy","given":"P.","affiliations":[],"preferred":false,"id":431301,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70031384,"text":"70031384 - 2007 - Investigation of magnesium isotope fractionation during basalt differentiation: Implications for a chondritic composition of the terrestrial mantle","interactions":[],"lastModifiedDate":"2019-03-25T11:12:04","indexId":"70031384","displayToPublicDate":"2007-01-01T00:00:00","publicationYear":"2007","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1427,"text":"Earth and Planetary Science Letters","active":true,"publicationSubtype":{"id":10}},"title":"Investigation of magnesium isotope fractionation during basalt differentiation: Implications for a chondritic composition of the terrestrial mantle","docAbstract":"To investigate whether magnesium isotopes are fractionated during basalt differentiation, we have performed high-precision Mg isotopic analyses by multi-collector inductively coupled plasma mass spectrometry (MC-ICP-MS) on a set of well-characterized samples from Kilauea Iki lava lake, Hawaii, USA. Samples from the Kilauea Iki lava lake, produced by closed-system crystal-melt fractionation, range from olivine-rich cumulates to highly differentiated basalts with MgO content ranging from 2.37 to 26.87 wt.%. Our results demonstrate that although these basalts have diverse chemical compositions, mineralogies, crystallization temperatures and degrees of differentiation, their Mg isotopic compositions display no measurable variation within the limits of our external precision (average δ26Mg = − 0.36 ± 0.10 and δ25Mg = − 0.20 ± 0.07; uncertainties are 2SD). This indicates that Mg isotopic fractionation during crystal-melt fractionation at temperatures of ≥ 1055 °C is undetectable at the level of precision of the current investigation. Calculations based on our data suggest that at near-magmatic temperatures the maximum fractionation in the 26Mg/24Mg ratio between olivine and melt is 0.07‰. Two additional oceanic basalts, two continental basalts (BCR-1 and BCR-2), and two primitive carbonaceous chondrites (Allende and Murchison) analyzed in this study have Mg isotopic compositions similar to the Kilauea Iki lava lake samples. In contrast to a recent report [U. Wiechert, A.N. Halliday, Non-chondritic magnesium and the origins of the inner terrestrial planets, Earth and Planetary Science Letters 256 (2007) 360–371], the results presented here suggest that the Bulk Silicate Earth has a chondritic Mg isotopic composition.
We treat both the number of earthquakes and the deformation following a mainshock as the superposition of a steady background accumulation and the postearthquake process. The preseismic displacement and seismicity rates ru and rE are used as estimates of the background rates. Let t be the time after the mainshock, u(t) + u0 the postseismic displacement less the background accumulation rut, and ΔN(t) the observed cumulative number of postseismic earthquakes less the background accumulation rEt. For the first 160 days (duration limited by the occurrence of another nearby earthquake) following the Chengkung (M 6.5, 10 December 2003, eastern Taiwan) and the first 560 days following the Parkfield (M 6.0, 28 September 2004, central California) earthquakes u(t) + u0 is a linear function of ΔN(t). The aftershock accumulation ΔN(t) for both earthquakes is described by the modified Omori Law dΔN/dt ∝ (1 + t/τ)−p with p = 0.96 and τ = 0.03 days. Although the Chengkung earthquake involved sinistral, reverse slip on a moderately dipping fault and the Parkfield earthquake right-lateral slip on a near-vertical fault, the earthquakes share an unusual feature: both occurred on faults exhibiting interseismic fault creep at the surface. The source of the observed postseismic deformation appears to be afterslip on the coseismic rupture. The linear relation between u(t) + u0 and N(t) suggests that this afterslip also generates the aftershocks. The linear relation between u(t) + u0 and ΔN(t) obtains after neither the 1999 M 7.1 Hector Mine (southern California) nor the 1999 M 7.6 Chi-Chi (central Taiwan) earthquakes, neither of which occurred on fault segments exhibiting fault creep.
This paper presents small-scale push–pull tests designed to evaluate the kinetic controls on
The 2004 Parkfield, California, earthquake is used to investigate stability and uncertainty aspects of the finite-fault slip inversion problem with different a priori model assumptions. We utilize records from 54 strong ground motion stations and 13 continuous, 1-Hz sampled, geodetic instruments. Two inversion procedures are compared: a linear least-squares subfault-based methodology and a nonlinear global search algorithm. These two methods encompass a wide range of the different approaches that have been used to solve the finite-fault slip inversion problem. For the Parkfield earthquake and the inversion of velocity or displacement waveforms, near-surface related site response (top 100 m, frequencies above 1 Hz) is shown to not significantly affect the solution. Results are also insensitive to selection of slip rate functions with similar duration and to subfault size if proper stabilizing constraints are used. The linear and nonlinear formulations yield consistent results when the same limitations in model parameters are in place and the same inversion norm is used. However, the solution is sensitive to the choice of inversion norm, the bounds on model parameters, such as rake and rupture velocity, and the size of the model fault plane. The geodetic data set for Parkfield gives a slip distribution different from that of the strong-motion data, which may be due to the spatial limitation of the geodetic stations and the bandlimited nature of the strong-motion data. Cross validation and the bootstrap method are used to set limits on the upper bound for rupture velocity and to derive mean slip models and standard deviations in model parameters. This analysis shows that slip on the northwestern half of the Parkfield rupture plane from the inversion of strong-motion data is model dependent and has a greater uncertainty than slip near the hypocenter.
","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Bulletin of the Seismological Society of America","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","publisher":"Seismological Society of America","publisherLocation":"Stanford","doi":"10.1785/0120070080","issn":"00371106","usgsCitation":"Hartzell, S., Liu, P., Mendoza, C., Ji, C., and Larson, K., 2007, Stability and uncertainty of finite-fault slip inversions: Application to the 2004 Parkfield, California, earthquake: Bulletin of the Seismological Society of America, v. 97, no. 6, p. 1911-1934, https://doi.org/10.1785/0120070080.","productDescription":"24 p.","startPage":"1911","endPage":"1934","numberOfPages":"24","onlineOnly":"N","additionalOnlineFiles":"N","costCenters":[],"links":[{"id":240060,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":212559,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1785/0120070080"}],"country":"United States","state":"California","city":"Parkfield","geographicExtents":"{\n \"type\": \"FeatureCollection\",\n \"features\": [\n {\n \"type\": \"Feature\",\n \"properties\": {},\n \"geometry\": {\n \"type\": \"Polygon\",\n \"coordinates\": [\n [\n [\n -120.750732421875,\n 35.84230806912384\n ],\n [\n -120.69854736328125,\n 35.725332497303015\n ],\n [\n -120.64773559570311,\n 35.66399091134812\n ],\n [\n -120.36758422851561,\n 35.649485098277204\n ],\n [\n -120.16708374023438,\n 35.715298012125295\n ],\n [\n -120.16708374023438,\n 35.84564769832635\n ],\n [\n -120.24948120117188,\n 35.97800618085568\n ],\n [\n -120.33462524414061,\n 36.061311571582486\n ],\n [\n -120.49667358398438,\n 36.12900165569652\n ],\n [\n -120.65322875976562,\n 36.12456474813333\n ],\n [\n -120.79055786132812,\n 36.07907198829112\n ],\n [\n -120.80291748046874,\n 35.94910642813857\n ],\n [\n -120.750732421875,\n 35.84230806912384\n ]\n ]\n ]\n }\n }\n ]\n}","volume":"97","issue":"6","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505b964be4b08c986b31b40c","contributors":{"authors":[{"text":"Hartzell, S.","contributorId":12603,"corporation":false,"usgs":true,"family":"Hartzell","given":"S.","email":"","affiliations":[],"preferred":false,"id":431167,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Liu, P.","contributorId":98443,"corporation":false,"usgs":true,"family":"Liu","given":"P.","email":"","affiliations":[],"preferred":false,"id":431171,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Mendoza, C.","contributorId":82059,"corporation":false,"usgs":true,"family":"Mendoza","given":"C.","email":"","affiliations":[],"preferred":false,"id":431169,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Ji, C.","contributorId":31093,"corporation":false,"usgs":true,"family":"Ji","given":"C.","email":"","affiliations":[],"preferred":false,"id":431168,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Larson, K.M.","contributorId":84949,"corporation":false,"usgs":true,"family":"Larson","given":"K.M.","email":"","affiliations":[],"preferred":false,"id":431170,"contributorType":{"id":1,"text":"Authors"},"rank":5}]}} ,{"id":70031346,"text":"70031346 - 2007 - Lethal and sublethal effects of ammonia to juvenile Lampsilis mussels (Unionidae) in sediment and water-only exposures","interactions":[],"lastModifiedDate":"2012-03-12T17:21:13","indexId":"70031346","displayToPublicDate":"2007-01-01T00:00:00","publicationYear":"2007","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1571,"text":"Environmental Toxicology and Chemistry","active":true,"publicationSubtype":{"id":10}},"title":"Lethal and sublethal effects of ammonia to juvenile Lampsilis mussels (Unionidae) in sediment and water-only exposures","docAbstract":"We compared the sensitivity of two juvenile unionid mussels (Lampsilis cardium and Lampsilis higginsii) to ammonia in 96-h water-only and sediment tests by use of mortality and growth measurements. Twenty mussels were placed in chambers buried 2.5 cm into reference sediments to approximate pore-water exposure (sediment tests) or elevated above the bottom of the experimental units (water-only tests). In the sediment tests, a pH gradient existed between the overlying water (mean 8.0), sediment-water interface (mean 7.7), and 2.5 cm depth (mean 7.4). We assumed that mussels were exposed to ammonia in pore water and report effect concentrations in pore water, but if they were exposed to the higher pH water, more of the ammonia would be in the toxic un-ionized (NH 3) form. The only differences in toxicity and growth between mussel species occurred in some of the water-only tests. In sediment tests, median lethal concentrations (LC50s) ranged from 124 to 125 ??g NH3-N/L. In water-only tests, LC50s ranged from 157 to 372 ??g NH3-N/L. In sediment tests, median effective concentrations (EC50s based on growth) ranged from 30 to 32 ??g NH3-N/L. Juvenile mussels in the water-only tests grew poorly and did not exhibit a dose-response relation. These data demonstrate that growth is a sensitive and valuable endpoint for studies on ammonia toxicity with juvenile freshwater mussels and that growth should be measured via sediment tests. ?? 2007 SETAC.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Environmental Toxicology and Chemistry","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1897/06-245R.1","issn":"07307268","usgsCitation":"Newton, T., and Bartsch, M., 2007, Lethal and sublethal effects of ammonia to juvenile Lampsilis mussels (Unionidae) in sediment and water-only exposures: Environmental Toxicology and Chemistry, v. 26, no. 10, p. 2057-2065, https://doi.org/10.1897/06-245R.1.","startPage":"2057","endPage":"2065","numberOfPages":"9","costCenters":[],"links":[{"id":212463,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1897/06-245R.1"},{"id":239953,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"26","issue":"10","noUsgsAuthors":false,"publicationDate":"2007-10-01","publicationStatus":"PW","scienceBaseUri":"505a4661e4b0c8380cd67627","contributors":{"authors":[{"text":"Newton, T.J.","contributorId":104428,"corporation":false,"usgs":true,"family":"Newton","given":"T.J.","email":"","affiliations":[],"preferred":false,"id":431149,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Bartsch, M.R.","contributorId":42908,"corporation":false,"usgs":true,"family":"Bartsch","given":"M.R.","email":"","affiliations":[],"preferred":false,"id":431148,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70031338,"text":"70031338 - 2007 - Monitoring and modeling ice-rock avalanches from ice-capped volcanoes: A case study of frequent large avalanches on Iliamna Volcano, Alaska","interactions":[],"lastModifiedDate":"2012-03-12T17:21:14","indexId":"70031338","displayToPublicDate":"2007-01-01T00:00:00","publicationYear":"2007","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2499,"text":"Journal of Volcanology and Geothermal Research","active":true,"publicationSubtype":{"id":10}},"title":"Monitoring and modeling ice-rock avalanches from ice-capped volcanoes: A case study of frequent large avalanches on Iliamna Volcano, Alaska","docAbstract":"Iliamna is an andesitic stratovolcano of the Aleutian arc with regular gas and steam emissions and mantled by several large glaciers. Iliamna Volcano exhibits an unusual combination of frequent and large ice-rock avalanches in the order of 1 ?? 106??m3 to 3 ?? 107??m3 with recent return periods of 2-4??years. We have reconstructed an avalanche event record for the past 45??years that indicates Iliamna avalanches occur at higher frequency at a given magnitude than other mass failures in volcanic and alpine environments. Iliamna Volcano is thus an ideal site to study such mass failures and its relation to volcanic activity. In this study, we present different methods that fit into a concept of (1) long-term monitoring, (2) early warning, and (3) event documentation and analysis of ice-rock avalanches on ice-capped active volcanoes. Long-term monitoring methods include seismic signal analysis, and space-and airborne observations. Landsat and ASTER satellite data was used to study the extent of hydrothermally altered rocks and surface thermal anomalies at the summit region of Iliamna. Subpixel heat source calculation for the summit regions where avalanches initiate yielded temperatures of 307 to 613??K assuming heat source areas of 1000 to 25??m2, respectively, indicating strong convective heat flux processes. Such heat flow causes ice melting conditions and is thus likely to reduce the strength at the base of the glacier. We furthermore demonstrate typical seismic records of Iliamna avalanches with rarely observed precursory signals up to two hours prior to failure, and show how such signals could be used for a multi-stage avalanche warning system in the future. For event analysis and documentation, space- and airborne observations and seismic records in combination with SRTM and ASTER derived terrain data allowed us to reconstruct avalanche dynamics and to identify remarkably similar failure and propagation mechanisms of Iliamna avalanches for the past 45??years. Simple avalanche flow modeling was able to reasonably replicate Iliamna avalanches and can thus be applied for hazard assessments. Hazards at Iliamna Volcano are low due to its remote location; however, we emphasize the transfer potential of the methods presented here to other ice-capped volcanoes with much higher hazards such as those in the Cascades or the Andes. ?? 2007 Elsevier B.V. All rights reserved.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Journal of Volcanology and Geothermal Research","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1016/j.jvolgeores.2007.08.009","issn":"03770273","usgsCitation":"Huggel, C., Caplan-Auerbach, J., Waythomas, C.F., and Wessels, R., 2007, Monitoring and modeling ice-rock avalanches from ice-capped volcanoes: A case study of frequent large avalanches on Iliamna Volcano, Alaska: Journal of Volcanology and Geothermal Research, v. 168, no. 1-4, p. 114-136, https://doi.org/10.1016/j.jvolgeores.2007.08.009.","startPage":"114","endPage":"136","numberOfPages":"23","costCenters":[],"links":[{"id":239784,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":212318,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/j.jvolgeores.2007.08.009"}],"volume":"168","issue":"1-4","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a5d89e4b0c8380cd70439","contributors":{"authors":[{"text":"Huggel, C.","contributorId":89347,"corporation":false,"usgs":true,"family":"Huggel","given":"C.","email":"","affiliations":[],"preferred":false,"id":431108,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Caplan-Auerbach, J.","contributorId":7057,"corporation":false,"usgs":true,"family":"Caplan-Auerbach","given":"J.","email":"","affiliations":[],"preferred":false,"id":431106,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Waythomas, C. F.","contributorId":10065,"corporation":false,"usgs":true,"family":"Waythomas","given":"C.","email":"","middleInitial":"F.","affiliations":[],"preferred":false,"id":431107,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Wessels, R.L.","contributorId":108281,"corporation":false,"usgs":true,"family":"Wessels","given":"R.L.","affiliations":[],"preferred":false,"id":431109,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}} ,{"id":70031336,"text":"70031336 - 2007 - Homogeneity of the geochemical reference material BRP-1 (paraná basin basalt) and assessment of minimum mass","interactions":[],"lastModifiedDate":"2015-04-06T09:43:33","indexId":"70031336","displayToPublicDate":"2007-01-01T00:00:00","publicationYear":"2007","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1822,"text":"Geostandards and Geoanalytical Research","active":true,"publicationSubtype":{"id":10}},"title":"Homogeneity of the geochemical reference material BRP-1 (paraná basin basalt) and assessment of minimum mass","docAbstract":"Reference materials (RM) are required for quantitative analyses and their successful use is associated with the degree of homogeneity, and the traceability and confidence limits of the values established by characterisation. During the production of a RM, the chemical characterisation can only commence after it has been demonstrated that the material has the required level of homogeneity. Here we describe the preparation of BRP-1, a proposed geochemical reference material, and the results of the tests to evaluate its degree of homogeneity between and within bottles. BRP-1 is the first of two geochemical RM being produced by Brazilian institutions in collaboration with the United States Geological Survey (USGS) and the International Association of Geoanalysts (IAG). Two test portions of twenty bottles of BRP-1 were analysed by wavelength dispersive-XRF spectrometry and major, minor and eighteen trace elements were determined. The results show that for most of the investigated elements, the units of BRP-1 were homogeneous at conditions approximately three times more rigorous than those strived for by the test of “sufficient homogeneity”. Furthermore, the within bottle homogeneity of BRP-1 was evaluated using small beam (1 mm2) synchrotron radiation XRF spectrometry and, for comparison, the USGS reference materials BCR-2 and GSP-2 were also evaluated. From our data, it has been possible to assign representative minimum masses for some major constituents (1 mg) and for some trace elements (1-13 mg), except Zr in GSP-2, for which test portions of 74 mg are recommended.
","language":"English","publisher":"Elsevier","doi":"10.1111/j.1751-908X.2007.00111.x","issn":"16394488","usgsCitation":"Cotta, A.J., Enzweiler, J., Wilson, S.A., Perez, C.A., Nardy, A.J., and Larizzatti, J.H., 2007, Homogeneity of the geochemical reference material BRP-1 (paraná basin basalt) and assessment of minimum mass: Geostandards and Geoanalytical Research, v. 31, no. 4, p. 379-393, https://doi.org/10.1111/j.1751-908X.2007.00111.x.","productDescription":"15 p.","startPage":"379","endPage":"393","onlineOnly":"N","additionalOnlineFiles":"N","costCenters":[],"links":[{"id":239751,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":212288,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1111/j.1751-908X.2007.00111.x"}],"country":"Brazil","state":"Sao Paulo","city":"Ribeirao Preto","geographicExtents":"{\n \"type\": \"FeatureCollection\",\n \"features\": [\n {\n \"type\": \"Feature\",\n \"properties\": {},\n \"geometry\": {\n \"type\": \"Polygon\",\n \"coordinates\": [\n [\n [\n -35.45013427734375,\n -8.553861881323053\n ],\n [\n -35.45013427734375,\n -8.43569632034908\n ],\n [\n -35.299072265625,\n -8.43569632034908\n ],\n [\n -35.299072265625,\n -8.553861881323053\n ],\n [\n -35.45013427734375,\n -8.553861881323053\n ]\n ]\n ]\n }\n }\n ]\n}","volume":"31","issue":"4","noUsgsAuthors":false,"publicationDate":"2007-11-23","publicationStatus":"PW","scienceBaseUri":"505a3213e4b0c8380cd5e4d7","contributors":{"authors":[{"text":"Cotta, Aloisio J. B.","contributorId":106715,"corporation":false,"usgs":true,"family":"Cotta","given":"Aloisio","email":"","middleInitial":"J. B.","affiliations":[],"preferred":false,"id":431100,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Enzweiler, Jacinta","contributorId":31579,"corporation":false,"usgs":true,"family":"Enzweiler","given":"Jacinta","email":"","affiliations":[],"preferred":false,"id":431097,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Wilson, Stephen A. 0000-0002-9468-0005 swilson@usgs.gov","orcid":"https://orcid.org/0000-0002-9468-0005","contributorId":1617,"corporation":false,"usgs":true,"family":"Wilson","given":"Stephen","email":"swilson@usgs.gov","middleInitial":"A.","affiliations":[],"preferred":true,"id":431096,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Perez, Carlos A.","contributorId":94099,"corporation":false,"usgs":true,"family":"Perez","given":"Carlos","email":"","middleInitial":"A.","affiliations":[],"preferred":false,"id":431098,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Nardy, Antonio J. R.","contributorId":98114,"corporation":false,"usgs":true,"family":"Nardy","given":"Antonio","email":"","middleInitial":"J. R.","affiliations":[],"preferred":false,"id":431099,"contributorType":{"id":1,"text":"Authors"},"rank":5},{"text":"Larizzatti, Joao H.","contributorId":12693,"corporation":false,"usgs":true,"family":"Larizzatti","given":"Joao","email":"","middleInitial":"H.","affiliations":[],"preferred":false,"id":431095,"contributorType":{"id":1,"text":"Authors"},"rank":6}]}} ,{"id":70031335,"text":"70031335 - 2007 - Home ranges and habitat use of sloth bears Melursus ursinus inornatus in Wasgomuwa National Park, Sri Lanka","interactions":[],"lastModifiedDate":"2012-03-12T17:21:14","indexId":"70031335","displayToPublicDate":"2007-01-01T00:00:00","publicationYear":"2007","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":3766,"text":"Wildlife Biology","active":true,"publicationSubtype":{"id":10}},"title":"Home ranges and habitat use of sloth bears Melursus ursinus inornatus in Wasgomuwa National Park, Sri Lanka","docAbstract":"We studied home ranges and habitat selection of 10 adult sloth bears Melursus ursinus inornatus at Wasgomuwa National Park, Sri Lanka during 2002-2003. Very little is known about the ecology and behaviour of M. u. inornatus, which is a subspecies found in Sri Lanka. Our study was undertaken to assess space and habitat requirements typical of a viable population of M. u. inornatus to facilitate future conservation efforts. We captured and radio-collared 10 adult sloth bears and used the telemetry data to assess home-range size and habitat use. Mean 95% fixed kernel home ranges were 2.2 km2 (SE = 0.61) and 3.8 km2 (SE = 1.01) for adult females and males, respectively. Although areas outside the national park were accessible to bears, home ranges were almost exclusively situated within the national park boundaries. Within the home ranges, high forests were used more and abandoned agricultural fields (chenas) were used less than expected based on availability. Our estimates of home-range size are among the smallest reported for any species of bear. Thus, despite its relatively small size, Wasgomuwa National Park may support a sizeable population of sloth bears. The restriction of human activity within protected areas may be necessary for long-term viability of sloth bear populations in Sri Lanka as is maintenance of forest or scrub cover in areas with existing sloth bear populations and along potential travel corridors. ?? Wildlife Biology 2007.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Wildlife Biology","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.2981/0909-6396(2007)13[272:HRAHUO]2.0.CO;2","issn":"09096396","usgsCitation":"Ratnayeke, S., Van Manen, F., and Padmalal, U., 2007, Home ranges and habitat use of sloth bears Melursus ursinus inornatus in Wasgomuwa National Park, Sri Lanka: Wildlife Biology, v. 13, no. 3, p. 272-284, https://doi.org/10.2981/0909-6396(2007)13[272:HRAHUO]2.0.CO;2.","startPage":"272","endPage":"284","numberOfPages":"13","costCenters":[],"links":[{"id":477182,"rank":10000,"type":{"id":40,"text":"Open Access Publisher Index Page"},"url":"https://doi.org/10.2981/0909-6396(2007)13[272:hrahuo]2.0.co;2","text":"Publisher Index Page"},{"id":239750,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":212287,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.2981/0909-6396(2007)13[272:HRAHUO]2.0.CO;2"}],"volume":"13","issue":"3","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a320be4b0c8380cd5e495","contributors":{"authors":[{"text":"Ratnayeke, S.","contributorId":33921,"corporation":false,"usgs":true,"family":"Ratnayeke","given":"S.","affiliations":[],"preferred":false,"id":431093,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Van Manen, F.T.","contributorId":45241,"corporation":false,"usgs":true,"family":"Van Manen","given":"F.T.","email":"","affiliations":[],"preferred":false,"id":431094,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Padmalal, U.K.G.K.","contributorId":9859,"corporation":false,"usgs":true,"family":"Padmalal","given":"U.K.G.K.","email":"","affiliations":[],"preferred":false,"id":431092,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70031334,"text":"70031334 - 2007 - Evaluation of a small beach nourishment project to enhance habitat suitability for horseshoe crabs","interactions":[],"lastModifiedDate":"2012-03-12T17:21:10","indexId":"70031334","displayToPublicDate":"2007-01-01T00:00:00","publicationYear":"2007","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1801,"text":"Geomorphology","active":true,"publicationSubtype":{"id":10}},"title":"Evaluation of a small beach nourishment project to enhance habitat suitability for horseshoe crabs","docAbstract":"This field study evaluates the effect of nourishing an estuarine beach with gravel to enhance spawning rates by horseshoe crabs. A total of 564??m3 of coarse sand and gravel were emplaced in two 90??m-long treatment segments at Bowers Beach, Delaware, USA from 9 to 11 April 2002. Field data were gathered between 6 April and 24 May 2002 to characterize the two fill segments and the un-nourished segments between them as well as two control segments at the adjacent Ted Harvey Beach. Sediment samples were taken from the foreshore surface and at depth before and after the nourishment. Bay water levels, wave heights, and beach ground water characteristics were monitored over a 12-hour tidal cycle at one of the nourished (15 May 2002) and the unnourished segment (16 May 2002) at Bowers Beach and at one of the control segments at Ted Harvey Beach (21 May 2002) using piezometers and pressure transducers inserted in wells. The beaches were cored to estimate the density of horseshoe crab eggs deposited during the spawning season. Horseshoe crab eggs were buried in pouches at 0.15 to 0.20??m depth for 30 to 40??days to evaluate their survival in developing into embryo or larval stage. Bulk sediment samples were taken to evaluate moisture characteristics near locations where egg pouches were buried. Density of spawning females at Bowers Beach was 1.04??m- 2 in 2001 and 1.20??m- 2 in 2002. These rates are lower than at Ted Harvey Beach but reveal an increase in spawning while Ted Harvey Beach underwent a considerable decrease (2.63??m- 2 to 1.35??m- 2). Sediments low on the foreshore remained nearly saturated throughout the tidal cycle at both beaches. The average hydraulic conductivity on the upper foreshore at the non-treatment section at Bowers Beach (0.19??cm s- 1) was less than at Ted Harvey Beach (0.27??cm s- 1), and the finer, better sorted sediments at depth at Bowers Beach resulted in a higher porosity, creating greater moisture retention potential. Egg development was greatest at mid foreshore at all sites. Eggs at the lower foreshore elevation remained viable, but did not develop to the embryo stage. Between-beach differences were limited to high elevations where higher mortality occurred at Ted Harvey Beach due to desiccation. Adding small amounts of gravel to a sand beach may change the appearance of the surface but may not appreciably increase mean grain size and sorting at depth or the hydraulic conductivity over the spawning season. The pebble fraction may be important for site selection, but finer sizes may be more important for egg survival because of moisture retention. ?? 2006 Elsevier B.V. All rights reserved.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Geomorphology","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1016/j.geomorph.2006.07.017","issn":"0169555X","usgsCitation":"Jackson, N., Smith, D., Tiyarattanachai, R., and Nordstrom, K., 2007, Evaluation of a small beach nourishment project to enhance habitat suitability for horseshoe crabs: Geomorphology, v. 89, no. 1-2 SPEC. ISS., p. 172-185, https://doi.org/10.1016/j.geomorph.2006.07.017.","startPage":"172","endPage":"185","numberOfPages":"14","costCenters":[],"links":[{"id":212258,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/j.geomorph.2006.07.017"},{"id":239719,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"89","issue":"1-2 SPEC. ISS.","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a0c39e4b0c8380cd52aa9","contributors":{"authors":[{"text":"Jackson, N.L.","contributorId":104189,"corporation":false,"usgs":true,"family":"Jackson","given":"N.L.","email":"","affiliations":[],"preferred":false,"id":431091,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Smith, D. R. 0000-0001-6074-9257","orcid":"https://orcid.org/0000-0001-6074-9257","contributorId":44108,"corporation":false,"usgs":true,"family":"Smith","given":"D. R.","affiliations":[{"id":365,"text":"Leetown Science Center","active":true,"usgs":true}],"preferred":false,"id":431089,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Tiyarattanachai, R.","contributorId":65285,"corporation":false,"usgs":true,"family":"Tiyarattanachai","given":"R.","email":"","affiliations":[],"preferred":false,"id":431090,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Nordstrom, K.F.","contributorId":17733,"corporation":false,"usgs":true,"family":"Nordstrom","given":"K.F.","email":"","affiliations":[],"preferred":false,"id":431088,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}} ,{"id":70031329,"text":"70031329 - 2007 - Distinguishing wild vs. stocked lake trout (Salvelinus namaycush) in Lake Ontario: Evidence from carbon and oxygen stable isotope values of otoliths","interactions":[],"lastModifiedDate":"2016-04-28T13:38:13","indexId":"70031329","displayToPublicDate":"2007-01-01T00:00:00","publicationYear":"2007","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2330,"text":"Journal of Great Lakes Research","active":true,"publicationSubtype":{"id":10}},"title":"Distinguishing wild vs. stocked lake trout (Salvelinus namaycush) in Lake Ontario: Evidence from carbon and oxygen stable isotope values of otoliths","docAbstract":"We investigated the potential for using carbon and oxygen isotope values of otolith carbonate as a method to distinguish naturally produced (wild) lake trout (Salvelinus namaycush) from hatchery-reared lake trout in Lake Ontario. We determined δ 13C(CaCO3) and δ 18O(CaCO3) values of otoliths from juvenile fish taken from two hatcheries, and of otoliths from wild yearlings. Clear differences in isotope values were observed between the three groups. Subsequently we examined otoliths from large marked and unmarked fish captured in the lake, determining isotope values for regions of the otolith corresponding to the first year of life. Marked (i.e., stocked) fish showed isotope ratios similar to one of the hatchery groups, whereas unmarked fish, (wild fish or stocked fish that lost the mark) showed isotope ratios similar either to one of the hatchery groups or to the wild group. We interpret these data to suggest that carbon and oxygen isotope values can be used to determine the origin of lake trout in Lake Ontario, if a catalogue of characteristic isotope values from all candidate years and hatcheries is compiled.
","language":"English","publisher":"International Association for Great Lakes Research","doi":"10.3394/0380-1330(2007)33[912:DWVSLT]2.0.CO;2","issn":"03801330","usgsCitation":"Schaner, T., Patterson, W., Lantry, B., and O'Gorman, R., 2007, Distinguishing wild vs. stocked lake trout (Salvelinus namaycush) in Lake Ontario: Evidence from carbon and oxygen stable isotope values of otoliths: Journal of Great Lakes Research, v. 33, no. 4, p. 912-916, https://doi.org/10.3394/0380-1330(2007)33[912:DWVSLT]2.0.CO;2.","productDescription":"5 p.","startPage":"912","endPage":"916","onlineOnly":"N","additionalOnlineFiles":"N","costCenters":[{"id":324,"text":"Great Lakes Science Center","active":true,"usgs":true}],"links":[{"id":239648,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":212198,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.3394/0380-1330(2007)33[912:DWVSLT]2.0.CO;2"}],"volume":"33","issue":"4","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a0253e4b0c8380cd4ffe1","contributors":{"authors":[{"text":"Schaner, T.","contributorId":12821,"corporation":false,"usgs":true,"family":"Schaner","given":"T.","email":"","affiliations":[],"preferred":false,"id":431072,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Patterson, W.P.","contributorId":94858,"corporation":false,"usgs":true,"family":"Patterson","given":"W.P.","email":"","affiliations":[],"preferred":false,"id":431075,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Lantry, B.F.","contributorId":19105,"corporation":false,"usgs":true,"family":"Lantry","given":"B.F.","email":"","affiliations":[],"preferred":false,"id":431073,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"O'Gorman, R.","contributorId":48896,"corporation":false,"usgs":true,"family":"O'Gorman","given":"R.","affiliations":[],"preferred":false,"id":431074,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}} ,{"id":70031326,"text":"70031326 - 2007 - Faunal re-evaluation of Mid-Pliocene conditions in the western equatorial Pacific","interactions":[],"lastModifiedDate":"2013-02-27T15:25:54","indexId":"70031326","displayToPublicDate":"2007-01-01T00:00:00","publicationYear":"2007","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2735,"text":"Micropaleontology","active":true,"publicationSubtype":{"id":10}},"title":"Faunal re-evaluation of Mid-Pliocene conditions in the western equatorial Pacific","docAbstract":"Mid-Pliocene low-latitude Pacific faunal (planktic foraminifer) sea surface temperature (SST) estimates are normally based upon the Modern Analog Technique (MAT). In the Eastern equatorial Pacific (EEP), where upwelling of cool water predominates, MAT can be used to discern both cooling and warming in Neogene records. SST today is ???30??C in the western equatorial Pacific (WEP) warm pool, the upper limit of the modern calibration data, and past warming above that level is difficult to assess using faunal methods. Mid-Pliocene fossil samples from the WEP have been analyzed using several variations of MAT with different outcomes and associated levels of confidence. While SST above ???30??C in the WEP during the mid-Pliocene cannot be ruled out due to the limitations of the method, temperatures this warm seem unlikely. In addition to the mid-Pliocene, planktic foraminifer assemblages from the coretop, last glacial maximum, last interglacial and the penultimate glacial (Marine Isotope Stage 6) show striking similarity to each other which suggests little to no change in the region between times of global climate extremes. There is generally good agreement between the Mg/Ca paleothermometer and MAT derived faunal SST estimates. Both suggest stability of the WEP warm pool.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Micropaleontology","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","publisher":"GeoScienceWorld","doi":"10.2113/gsmicropal.53.6.447","issn":"00262803","usgsCitation":"Dowsett, H., 2007, Faunal re-evaluation of Mid-Pliocene conditions in the western equatorial Pacific: Micropaleontology, v. 53, no. 6, p. 447-456, https://doi.org/10.2113/gsmicropal.53.6.447.","startPage":"447","endPage":"456","numberOfPages":"10","costCenters":[],"links":[{"id":239615,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":268484,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.2113/gsmicropal.53.6.447"}],"volume":"53","issue":"6","noUsgsAuthors":false,"publicationDate":"2009-08-10","publicationStatus":"PW","scienceBaseUri":"505a0f2ce4b0c8380cd537e1","contributors":{"authors":[{"text":"Dowsett, H.","contributorId":44303,"corporation":false,"usgs":true,"family":"Dowsett","given":"H.","email":"","affiliations":[],"preferred":false,"id":431062,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}} ,{"id":70031325,"text":"70031325 - 2007 - Sexual selection in the squirrel treefrog Hyla squirella: the role of multimodal cue assessment in female choice","interactions":[],"lastModifiedDate":"2014-04-08T10:43:22","indexId":"70031325","displayToPublicDate":"2007-01-01T00:00:00","publicationYear":"2007","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":770,"text":"Animal Behaviour","active":true,"publicationSubtype":{"id":10}},"title":"Sexual selection in the squirrel treefrog Hyla squirella: the role of multimodal cue assessment in female choice","docAbstract":"Anuran amphibians have provided an excellent system for the study of animal communication and sexual selection. Studies of female mate choice in anurans, however, have focused almost exclusively on the role of auditory signals. In this study, we examined the effect of both auditory and visual cues on female choice in the squirrel treefrog. Our experiments used a two-choice protocol in which we varied male vocalization properties, visual cues, or both, to assess female preferences for the different cues. Females discriminated against high-frequency calls and expressed a strong preference for calls that contained more energy per unit time (faster call rate). Females expressed a preference for the visual stimulus of a model of a calling male when call properties at the two speakers were held the same. They also showed a significant attraction to a model possessing a relatively large lateral body stripe. These data indicate that visual cues do play a role in mate attraction in this nocturnal frog species. Furthermore, this study adds to a growing body of evidence that suggests that multimodal signals play an important role in sexual selection.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Animal Behaviour","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1016/j.anbehav.2007.03.010","issn":"00033472","usgsCitation":"Taylor, R.C., Buchanan, B.W., and Doherty, J.L., 2007, Sexual selection in the squirrel treefrog Hyla squirella: the role of multimodal cue assessment in female choice: Animal Behaviour, v. 74, no. 6, p. 1753-1763, https://doi.org/10.1016/j.anbehav.2007.03.010.","productDescription":"11 p.","startPage":"1753","endPage":"1763","numberOfPages":"11","costCenters":[{"id":455,"text":"National Wetlands Research Center","active":true,"usgs":true}],"links":[{"id":212645,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/j.anbehav.2007.03.010"},{"id":240164,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"74","issue":"6","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505b8dc1e4b08c986b318549","contributors":{"authors":[{"text":"Taylor, Ryan C.","contributorId":20550,"corporation":false,"usgs":true,"family":"Taylor","given":"Ryan","email":"","middleInitial":"C.","affiliations":[],"preferred":false,"id":431059,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Buchanan, Bryant W.","contributorId":30041,"corporation":false,"usgs":true,"family":"Buchanan","given":"Bryant","email":"","middleInitial":"W.","affiliations":[],"preferred":false,"id":431060,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Doherty, Jessie L.","contributorId":37960,"corporation":false,"usgs":true,"family":"Doherty","given":"Jessie","email":"","middleInitial":"L.","affiliations":[],"preferred":false,"id":431061,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ]}