Wildland fires are expected to become more frequent and severe in many ecosystems, potentially posing a threat to many sensitive species. We evaluated the effects of a large, stand-replacement wildfire on three species of pond-breeding amphibians by estimating changes in occupancy of breeding sites during the three years before and after the fire burned 42 of 83 previously surveyed wetlands. Annual occupancy and colonization for each species was estimated using recently developed models that incorporate detection probabilities to provide unbiased parameter estimates. We did not find negative effects of the fire on the occupancy or colonization rates of the long-toed salamander (Ambystoma macrodactylum). Instead, its occupancy was higher across the study area after the fire, possibly in response to a large snowpack that may have facilitated colonization of unoccupied wetlands. Naïve data (uncorrected for detection probability) for the Columbia spotted frog (Rana luteiventris) initially led to the conclusion of increased occupancy and colonization in wetlands that burned. After accounting for temporal and spatial variation in detection probabilities, however, it was evident that these parameters were relatively stable in both areas before and after the fire. We found a similar discrepancy between naïve and estimated occupancy of A. macrodactylum that resulted from different detection probabilities in burned and control wetlands. The boreal toad (Bufo boreas) was not found breeding in the area prior to the fire but colonized several wetlands the year after they burned. Occupancy by B. boreas then declined during years 2 and 3 following the fire. Our study suggests that the amphibian populations we studied are resistant to wildfire and that B. boreas may experience short-term benefits from wildfire. Our data also illustrate how naïve presence–non-detection data can provide misleading results.
The study of coastal groundwater has recently surfaced as an active interdisciplinary area of research, driven foremost by its importance as a poorly quantified pathway for subsurface material transport into coastal ecosystems. Key issue in coastal groundwater research include a complete geochemical characterization of the groundwater(s); quantification of the kinetics of subsurface transport, including rock-water interactions; determination of groundwater ages; tracing of groundwater discharge into coastal waters using radiochemical fingerprints; and an assessment of the potential ecological impact of such subsurface flow to a reviving water body. For such applications, the isotopic systemics of select naturally occurring radionucludes in the U/Th series has proven to be particularly useful. These radionuclides (e.g., U, Th, Ram and Rn) are ubiquitous in all groundwaters ad are represented by several isotopes with widely different half-lives and chemistries (Figure 1). As a result, varied biogeochemical processes occurring over a broad range of time scales can be studied.
\nIn source rock, most U/Th series isotopes in secular equilibrium; that is, the rate of decay of a daughter isotope is equal to that of it radiogenic parent, and so will have equal activities (in this context, the specific activity is simply a measure of the amount of radioactivity per unit amount). In contrast, these nuclides exhibit strong fractionations within the surrounding groundwaters because of their respective physiochemical differences. Disequilibria in U/Th series radionuclides can thus be used to identify distinct water masses, quantify release rates from source rocks, assess groundwater migration rates, and assess groundwater discharge rates in coastal waters., Large isotopic variations also have the potential for providing precise fingerprints for groundwaters from specific aquifers and have been explored as a means for calculating groundwater ages and estuarine water mass transit times.
\nThe highly fractionated nature of U/Th series nuclides in groundwater is illustrated by the range in some measured activities. highest activities are typically observed for 222Rn, reflecting the inert nature of this noble gas. Groundwater 222Rn (t1/2=3.8) activities are thus controlled only by rapid in situ decay (Table 1) and production within host rocks, without the added complications of reversible removal via absorption or precipitation. Uranium, which is soluble as U(VI) in oxidizing waters, is present in intermediate activities in groundwaters that are moderated by redox-initiated removal onto aquifer rocks. The alkaline earth Ra and, to a greater extent, the less soluble actinide Th are readily removed from groundwater by water -- rock interactions and so are strongly depleted. Both of these elements have very short-lived as well as longer-lived isotopes, and so isotopes compositions reflect processes over a range of time scales.
\nMany studies have evaluated and behavior of select radionuclides in groundwater and surface water systems. Recent advances in high-=precision mass spectrometry have opted new possibilities for more subtle interpretations in select long-lived U/Th series isotopes, such as U, Ra, Pa, and Th. However, these techniques have yet to be fully developed, ahns as a consequence, such data remain largely scarce and underutilized. Although many different approaches have been developed to study radionucluide behavior in groundwater, all are based on principles of radioactive production and decay and knowledge of source terms from weathering and recoil processes, as well as removal terms from the interaction with aquifer host rock surface by sorption and precipitation.
\nThis review is structured to present first a brief description of the background, driving forces, scales, and ecological significance of submarine groundwater discharge. Following this, a description of the geochemistry and behavior of select radionuclides in groundwater will be presented, and their application to tracing submarine groundwater discharge will be discussed.
","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Chemical Reviews","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","publisher":"American Chemical Society","doi":"10.1021/cr0503761","issn":"00092665","usgsCitation":"Swarzenski, P., 2007, U/Th series radionuclides as coastal groundwater tracers: Chemical Reviews, v. 107, no. 2, p. 663-674, https://doi.org/10.1021/cr0503761.","productDescription":"12 p.","startPage":"663","endPage":"674","numberOfPages":"12","costCenters":[{"id":186,"text":"Coastal and Marine Geology Program","active":true,"usgs":true}],"links":[{"id":213233,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1021/cr0503761"},{"id":240838,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"107","issue":"2","noUsgsAuthors":false,"publicationDate":"2007-01-20","publicationStatus":"PW","scienceBaseUri":"505bbb36e4b08c986b328580","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":438542,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}} ,{"id":70032770,"text":"70032770 - 2007 - Long-term limnological research and monitoring at Crater Lake, Oregon","interactions":[],"lastModifiedDate":"2017-11-15T13:23:06","indexId":"70032770","displayToPublicDate":"2007-01-01T00:00:00","publicationYear":"2007","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1919,"text":"Hydrobiologia","onlineIssn":"1573-5117","printIssn":"0018-8158","active":true,"publicationSubtype":{"id":10}},"title":"Long-term limnological research and monitoring at Crater Lake, Oregon","docAbstract":"Crater Lake is located in the caldera of Mount Mazama in Crater Lake National Park, Oregon. The lake has a surface area of about 53 km2at an elevation of 1882 m and a maximum depth of 594 m. Limited studies of this ultraoligotrophic lake conducted between 1896 and 1981, lead to a 10-year limnological study to evaluate any potential degradation of water quality. No long-term variations in water quality were observed that could be attributed to anthropogenic activity. Building on the success of this study, a permanent limnological program has been established with a long-term monitoring program to insure a reliable data base for use in the future. Of equal importance, this program serves as a research platform to develop and communicate to the public a better understanding of the coupled biological, physical, and geochemical processes in the lake and its surrounding environment. This special volume represents our current state of knowledge of the status of this pristine ecosystem including its special optical properties, algal nutrient limitations, pelagic bacteria, and models of the inter-relationships of thermal properties, nutrients, phytoplankton, deep-water mixing, and water budgets. ?? 2007 Springer Science+Business Media B.V.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Hydrobiologia","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1007/s10750-006-0342-6","issn":"00188158","usgsCitation":"Larson, G., Collier, R., and Buktenica, M., 2007, Long-term limnological research and monitoring at Crater Lake, Oregon: Hydrobiologia, v. 574, no. 1, p. 1-11, https://doi.org/10.1007/s10750-006-0342-6.","startPage":"1","endPage":"11","numberOfPages":"11","costCenters":[{"id":290,"text":"Forest and Rangeland Ecosystem Science Center","active":false,"usgs":true}],"links":[{"id":241604,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":213929,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1007/s10750-006-0342-6"}],"volume":"574","issue":"1","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a4998e4b0c8380cd68750","contributors":{"authors":[{"text":"Larson, G.L.","contributorId":103021,"corporation":false,"usgs":true,"family":"Larson","given":"G.L.","email":"","affiliations":[],"preferred":false,"id":437834,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Collier, R.","contributorId":36370,"corporation":false,"usgs":true,"family":"Collier","given":"R.","email":"","affiliations":[],"preferred":false,"id":437832,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Buktenica, M.","contributorId":76148,"corporation":false,"usgs":true,"family":"Buktenica","given":"M.","affiliations":[],"preferred":false,"id":437833,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70030058,"text":"70030058 - 2007 - Meter-scale morphology of the north polar region of mars","interactions":[],"lastModifiedDate":"2018-11-27T11:39:08","indexId":"70030058","displayToPublicDate":"2007-01-01T00:00:00","publicationYear":"2007","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":3338,"text":"Science","active":true,"publicationSubtype":{"id":10}},"title":"Meter-scale morphology of the north polar region of mars","docAbstract":"Mars' north pole is covered by a dome of layered ice deposits. Detailed (∼30 centimeters per pixel) images of this region were obtained with the High-Resolution Imaging Science Experiment on board the Mars Reconnaissance Orbiter (MRO). Planum Boreum basal unit scarps reveal cross-bedding and show evidence for recent mass wasting, flow, and debris accumulation. The north polar layers themselves are as thin as 10 centimeters but appear to be covered by a dusty veneer in places, which may obscure thinner layers. Repetition of particular layer types implies that quasi-periodic climate changes influenced the stratigraphic sequence in the polar layered deposits, informing models for recent climate variations on Mars.
","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Science","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","publisher":"American Association for the Advancement of Science (AAAS)","doi":"10.1126/science.1143544","issn":"00368075","usgsCitation":"Herkenhoff, K.E., Byrne, S., Russell, P., Fishbaugh, K., and McEwen, A.S., 2007, Meter-scale morphology of the north polar region of mars: Science, v. 317, no. 5845, p. 1711-1715, https://doi.org/10.1126/science.1143544.","productDescription":"5 p.","startPage":"1711","endPage":"1715","numberOfPages":"5","costCenters":[{"id":131,"text":"Astrogeology Science Center","active":true,"usgs":true}],"links":[{"id":240596,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"otherGeospatial":"Mars","volume":"317","issue":"5845","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a551fe4b0c8380cd6d129","contributors":{"authors":[{"text":"Herkenhoff, Kenneth E. 0000-0002-3153-6663 kherkenhoff@usgs.gov","orcid":"https://orcid.org/0000-0002-3153-6663","contributorId":2275,"corporation":false,"usgs":true,"family":"Herkenhoff","given":"Kenneth","email":"kherkenhoff@usgs.gov","middleInitial":"E.","affiliations":[{"id":131,"text":"Astrogeology Science Center","active":true,"usgs":true}],"preferred":true,"id":425533,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Byrne, S.","contributorId":105083,"corporation":false,"usgs":true,"family":"Byrne","given":"S.","email":"","affiliations":[],"preferred":false,"id":425536,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Russell, P.S.","contributorId":100987,"corporation":false,"usgs":true,"family":"Russell","given":"P.S.","email":"","affiliations":[],"preferred":false,"id":425534,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Fishbaugh, K.E.","contributorId":102692,"corporation":false,"usgs":true,"family":"Fishbaugh","given":"K.E.","email":"","affiliations":[],"preferred":false,"id":425535,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"McEwen, A. S.","contributorId":11317,"corporation":false,"usgs":true,"family":"McEwen","given":"A.","email":"","middleInitial":"S.","affiliations":[],"preferred":false,"id":425532,"contributorType":{"id":1,"text":"Authors"},"rank":5}]}} ,{"id":70033112,"text":"70033112 - 2007 - Evaluating nephrotoxicity of high-molecular-weight organic compounds in drinking water from lignite aquifers","interactions":[],"lastModifiedDate":"2013-03-15T20:30:44","indexId":"70033112","displayToPublicDate":"2007-01-01T00:00:00","publicationYear":"2007","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2481,"text":"Journal of Toxicology and Environmental Health, Part A","active":true,"publicationSubtype":{"id":10}},"title":"Evaluating nephrotoxicity of high-molecular-weight organic compounds in drinking water from lignite aquifers","docAbstract":"High-molecular-weight organic compounds such as humic acids and/or fulvic acids that are naturally mobilized from lignite beds into untreated drinking-water supplies were suggested as one possible cause of Balkan endemic nephropathy (BEN) and cancer of the renal pelvis. A lab investigation was undertaken in order to assess the nephrotoxic potential of such organic compounds using an in vitro tissue culture model. Because of the infeasibility of exposing kidney tissue to low concentrations of organics for years in the lab, tangential flow ultrafiltration was employed to hyperconcentrate samples suitable for discerning effects in the short time frames necessitated by tissue culture systems. Effects on HK-2 kidney cells were measured using two different cell proliferation assays (MTT and alamarBlue). Results demonstrated that exposure of kidney tissue to high-molecular-weight organics produced excess cell death or proliferation depending on concentration and duration of exposure. Copyright ?? Taylor & Francis Group, LLC.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Journal of Toxicology and Environmental Health, Part A","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1080/15287390701551274","issn":"15287394","usgsCitation":"Bunnell, J., Tatu, C., Lerch, H., Orem, W., and Pavlovic, N., 2007, Evaluating nephrotoxicity of high-molecular-weight organic compounds in drinking water from lignite aquifers: Journal of Toxicology and Environmental Health, Part A, v. 70, no. 24, p. 2089-2091, https://doi.org/10.1080/15287390701551274.","startPage":"2089","endPage":"2091","numberOfPages":"3","costCenters":[],"links":[{"id":213528,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1080/15287390701551274"},{"id":241158,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"70","issue":"24","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a0beae4b0c8380cd5293c","contributors":{"authors":[{"text":"Bunnell, J.E.","contributorId":63512,"corporation":false,"usgs":true,"family":"Bunnell","given":"J.E.","email":"","affiliations":[],"preferred":false,"id":439426,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Tatu, C. A.","contributorId":89942,"corporation":false,"usgs":false,"family":"Tatu","given":"C. A.","affiliations":[],"preferred":false,"id":439427,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Lerch, H.E.","contributorId":100371,"corporation":false,"usgs":true,"family":"Lerch","given":"H.E.","email":"","affiliations":[],"preferred":false,"id":439429,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Orem, W. H. 0000-0003-4990-0539","orcid":"https://orcid.org/0000-0003-4990-0539","contributorId":93084,"corporation":false,"usgs":true,"family":"Orem","given":"W. H.","affiliations":[],"preferred":false,"id":439428,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Pavlovic, N.","contributorId":13912,"corporation":false,"usgs":true,"family":"Pavlovic","given":"N.","email":"","affiliations":[],"preferred":false,"id":439425,"contributorType":{"id":1,"text":"Authors"},"rank":5}]}} ,{"id":70030952,"text":"70030952 - 2007 - Attenuation of ground-motion spectral amplitudes in southeastern Australia","interactions":[],"lastModifiedDate":"2012-03-12T17:21:04","indexId":"70030952","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":"Attenuation of ground-motion spectral amplitudes in southeastern Australia","docAbstract":"A dataset comprising some 1200 weak- and strong-motion records from 84 earthquakes is compiled to develop a regional ground-motion model for southeastern Australia (SEA). Events were recorded from 1993 to 2004 and range in size from moment magnitude 2.0 ??? M ??? 4.7. The decay of vertical-component Fourier spectral amplitudes is modeled by trilinear geometrical spreading. The decay of low-frequency spectral amplitudes can be approximated by the coefficient of R-1.3 (where R is hypocentral distance) within 90 km of the seismic source. From approximately 90 to 160 km, we observe a transition zone in which the seismic coda are affected by postcritical reflections from midcrustal and Moho discontinuities. In this hypocentral distance range, geometrical spreading is approximately R+0.1. Beyond 160 km, low-frequency seismic energy attenuates rapidly with source-receiver distance, having a geometrical spreading coefficient of R-1.6. The associated regional seismic-quality factor can be expressed by the polynomial: log Q(f) = 3.66 - 1.44 log f + 0.768 (log f)2 + 0.058 (log f)3 for frequencies 0.78 ??? f ??? 19.9 Hz. Fourier spectral amplitudes, corrected for geometrical spreading and anelastic attenuation, are regressed with M to obtain quadratic source scaling coefficients. Modeled vertical-component displacement spectra fit the observed data well. Amplitude residuals are, on average, relatively small and do not vary with hypocentral distance. Predicted source spectra (i.e., at R = 1 km) are consistent with eastern North American (ENA) Models at low frequencies (f less than approximately 2 Hz) indicating that moment magnitudes calculated for SEA earthquakes are consistent with moment magnitude scales used in ENA over the observed magnitude range. The models presented represent the first spectral ground-motion prediction equations develooed for the southeastern Australian region. This work provides a useful framework for the development of regional ground-motion relations for earthquake hazard and risk assessment in SEA.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Bulletin of the Seismological Society of America","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1785/0120060172","issn":"00371106","usgsCitation":"Allen, T., Cummins, P., Dhu, T., and Schneider, J., 2007, Attenuation of ground-motion spectral amplitudes in southeastern Australia: Bulletin of the Seismological Society of America, v. 97, no. 4, p. 1279-1292, https://doi.org/10.1785/0120060172.","startPage":"1279","endPage":"1292","numberOfPages":"14","costCenters":[],"links":[{"id":239001,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":211667,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1785/0120060172"}],"volume":"97","issue":"4","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"5059eed1e4b0c8380cd49fb4","contributors":{"authors":[{"text":"Allen, T.I.","contributorId":6659,"corporation":false,"usgs":true,"family":"Allen","given":"T.I.","email":"","affiliations":[],"preferred":false,"id":429361,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Cummins, P.R.","contributorId":69360,"corporation":false,"usgs":true,"family":"Cummins","given":"P.R.","email":"","affiliations":[],"preferred":false,"id":429363,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Dhu, T.","contributorId":80076,"corporation":false,"usgs":true,"family":"Dhu","given":"T.","affiliations":[],"preferred":false,"id":429364,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Schneider, J.F.","contributorId":16200,"corporation":false,"usgs":true,"family":"Schneider","given":"J.F.","email":"","affiliations":[],"preferred":false,"id":429362,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}} ,{"id":70031599,"text":"70031599 - 2007 - Evaluation of the applicability of the dual‐domain mass transfer model in porous media containing connected high‐conductivity channels","interactions":[],"lastModifiedDate":"2018-04-03T12:25:24","indexId":"70031599","displayToPublicDate":"2007-01-01T00:00:00","publicationYear":"2007","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":3722,"text":"Water Resources Research","onlineIssn":"1944-7973","printIssn":"0043-1397","active":true,"publicationSubtype":{"id":10}},"title":"Evaluation of the applicability of the dual‐domain mass transfer model in porous media containing connected high‐conductivity channels","docAbstract":"This paper evaluates the dual‐domain mass transfer (DDMT) model to represent transport processes when small‐scale high‐conductivity (K) preferential flow paths (PFPs) are present in a homogenous porous media matrix. The effects of PFPs upon solute transport were examined through detailed numerical experiments involving different realizations of PFP networks, PFP/matrix conductivity contrasts varying from 10:1 to 200:1, different magnitudes of effective conductivities, and a range of molecular diffusion coefficients. Results suggest that the DDMT model can reproduce both the near‐source peak and the downstream low‐concentration spreading observed in the embedded dendritic network when there are large conductivity contrasts between high‐K PFPs and the low‐K matrix. The accuracy of the DDMT model is also affected by the geometry of PFP networks and by the relative significance of the diffusion process in the network‐matrix system.
","language":"English","publisher":"American Geophysical Union","doi":"10.1029/2007WR005965","usgsCitation":"Liu, G., Zheng, C., and Gorelick, S.M., 2007, Evaluation of the applicability of the dual‐domain mass transfer model in porous media containing connected high‐conductivity channels: Water Resources Research, v. 43, no. 12, Article W12407; 12 p., https://doi.org/10.1029/2007WR005965.","productDescription":"Article W12407; 12 p.","costCenters":[],"links":[{"id":477206,"rank":1,"type":{"id":40,"text":"Open Access Publisher Index Page"},"url":"https://doi.org/10.1029/2007wr005965","text":"Publisher Index Page"},{"id":240147,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"43","issue":"12","noUsgsAuthors":false,"publicationDate":"2007-12-20","publicationStatus":"PW","scienceBaseUri":"505a0cdce4b0c8380cd52d12","contributors":{"authors":[{"text":"Liu, Gaisheng","contributorId":15158,"corporation":false,"usgs":true,"family":"Liu","given":"Gaisheng","email":"","affiliations":[],"preferred":false,"id":432270,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Zheng, Chunmiao","contributorId":49233,"corporation":false,"usgs":true,"family":"Zheng","given":"Chunmiao","affiliations":[],"preferred":false,"id":432272,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Gorelick, Steven M.","contributorId":69295,"corporation":false,"usgs":true,"family":"Gorelick","given":"Steven","email":"","middleInitial":"M.","affiliations":[],"preferred":false,"id":432271,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70030100,"text":"70030100 - 2007 - Improved wetland remote sensing in Yellowstone National Park using classification trees to combine TM imagery and ancillary environmental data","interactions":[],"lastModifiedDate":"2018-02-21T11:28:14","indexId":"70030100","displayToPublicDate":"2007-01-01T00:00:00","publicationYear":"2007","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":3254,"text":"Remote Sensing of Environment","printIssn":"0034-4257","active":true,"publicationSubtype":{"id":10}},"title":"Improved wetland remote sensing in Yellowstone National Park using classification trees to combine TM imagery and ancillary environmental data","docAbstract":"The U.S. Fish and Wildlife Service uses the term palustrine wetland to describe vegetated wetlands traditionally identified as marsh, bog, fen, swamp, or wet meadow. Landsat TM imagery was combined with image texture and ancillary environmental data to model probabilities of palustrine wetland occurrence in Yellowstone National Park using classification trees. Model training and test locations were identified from National Wetlands Inventory maps, and classification trees were built for seven years spanning a range of annual precipitation. At a coarse level, palustrine wetland was separated from upland. At a finer level, five palustrine wetland types were discriminated: aquatic bed (PAB), emergent (PEM), forested (PFO), scrub–shrub (PSS), and unconsolidated shore (PUS). TM-derived variables alone were relatively accurate at separating wetland from upland, but model error rates dropped incrementally as image texture, DEM-derived terrain variables, and other ancillary GIS layers were added. For classification trees making use of all available predictors, average overall test error rates were 7.8% for palustrine wetland/upland models and 17.0% for palustrine wetland type models, with consistent accuracies across years. However, models were prone to wetland over-prediction. While the predominant PEM class was classified with omission and commission error rates less than 14%, we had difficulty identifying the PAB and PSS classes. Ancillary vegetation information greatly improved PSS classification and moderately improved PFO discrimination. Association with geothermal areas distinguished PUS wetlands. Wetland over-prediction was exacerbated by class imbalance in likely combination with spatial and spectral limitations of the TM sensor. Wetland probability surfaces may be more informative than hard classification, and appear to respond to climate-driven wetland variability. The developed method is portable, relatively easy to implement, and should be applicable in other settings and over larger extents.
","language":"English","publisher":"Elsevier","doi":"10.1016/j.rse.2006.10.019","issn":"00344257","usgsCitation":"Wright, C., and Gallant, A.L., 2007, Improved wetland remote sensing in Yellowstone National Park using classification trees to combine TM imagery and ancillary environmental data: Remote Sensing of Environment, v. 107, no. 4, p. 582-605, https://doi.org/10.1016/j.rse.2006.10.019.","productDescription":"24 p.","startPage":"582","endPage":"605","numberOfPages":"24","costCenters":[{"id":222,"text":"Earth Resources Observation and Science (EROS) Center","active":true,"usgs":true}],"links":[{"id":240226,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":212700,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/j.rse.2006.10.019"}],"volume":"107","issue":"4","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a3968e4b0c8380cd618f2","contributors":{"authors":[{"text":"Wright, C.","contributorId":69589,"corporation":false,"usgs":true,"family":"Wright","given":"C.","affiliations":[],"preferred":false,"id":425715,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Gallant, Alisa L. 0000-0002-3029-6637 gallant@usgs.gov","orcid":"https://orcid.org/0000-0002-3029-6637","contributorId":2940,"corporation":false,"usgs":true,"family":"Gallant","given":"Alisa","email":"gallant@usgs.gov","middleInitial":"L.","affiliations":[{"id":223,"text":"Earth Resources Observation and Science (EROS) Center (Geography)","active":false,"usgs":true},{"id":222,"text":"Earth Resources Observation and Science (EROS) Center","active":true,"usgs":true}],"preferred":true,"id":425716,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70030105,"text":"70030105 - 2007 - Species richness and soil properties in Pinus ponderosa forests: A structural equation modeling analysis","interactions":[],"lastModifiedDate":"2012-03-12T17:21:05","indexId":"70030105","displayToPublicDate":"2007-01-01T00:00:00","publicationYear":"2007","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2490,"text":"Journal of Vegetation Science","active":true,"publicationSubtype":{"id":10}},"title":"Species richness and soil properties in Pinus ponderosa forests: A structural equation modeling analysis","docAbstract":"Question: How are the effects of mineral soil properties on understory plant species richness propagated through a network of processes involving the forest overstory, soil organic matter, soil nitrogen, and understory plant abundance? Location: North-central Arizona, USA. Methods: We sampled 75 0.05-ha plots across a broad soil gradient in a Pinus ponderosa (ponderosa pine) forest ecosystem. We evaluated multivariate models of plant species richness using structural equation modeling. Results: Richness was highest at intermediate levels of understory plant cover, suggesting that both colonization success and competitive exclusion can limit richness in this system. We did not detect a reciprocal positive effect of richness on plant cover. Richness was strongly related to soil nitrogen in the model, with evidence for both a direct negative effect and an indirect non-linear relationship mediated through understory plant cover. Soil organic matter appeared to have a positive influence on understory richness that was independent of soil nitrogen. Richness was lowest where the forest overstory was densest, which can be explained through indirect effects on soil organic matter, soil nitrogen and understory cover. Finally, model results suggest a variety of direct and indirect processes whereby mineral soil properties can influence richness. Conclusions: Understory plant species richness and plant cover in P. ponderosa forests appear to be significantly influenced by soil organic matter and nitrogen, which are, in turn, related to overstory density and composition and mineral soil properties. Thus, soil properties can impose direct and indirect constraints on local species diversity in ponderosa pine forests. ?? IAVS; Opulus Press.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Journal of Vegetation Science","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1658/1100-9233(2007)18[231:SRASPI]2.0.CO;2","issn":"11009233","usgsCitation":"Laughlin, D., Abella, S., Covington, W., and Grace, J., 2007, Species richness and soil properties in Pinus ponderosa forests: A structural equation modeling analysis: Journal of Vegetation Science, v. 18, no. 2, p. 231-242, https://doi.org/10.1658/1100-9233(2007)18[231:SRASPI]2.0.CO;2.","startPage":"231","endPage":"242","numberOfPages":"12","costCenters":[],"links":[{"id":240298,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":212762,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1658/1100-9233(2007)18[231:SRASPI]2.0.CO;2"}],"volume":"18","issue":"2","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505b950fe4b08c986b31ad13","contributors":{"authors":[{"text":"Laughlin, D.C.","contributorId":42407,"corporation":false,"usgs":true,"family":"Laughlin","given":"D.C.","email":"","affiliations":[],"preferred":false,"id":425729,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Abella, S.R.","contributorId":47982,"corporation":false,"usgs":true,"family":"Abella","given":"S.R.","affiliations":[],"preferred":false,"id":425730,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Covington, W.W.","contributorId":22151,"corporation":false,"usgs":true,"family":"Covington","given":"W.W.","email":"","affiliations":[],"preferred":false,"id":425727,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Grace, J.B. 0000-0001-6374-4726","orcid":"https://orcid.org/0000-0001-6374-4726","contributorId":38938,"corporation":false,"usgs":true,"family":"Grace","given":"J.B.","affiliations":[],"preferred":false,"id":425728,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}} ,{"id":70030000,"text":"70030000 - 2007 - Detection, attribution, and sensitivity of trends toward earlier streamflow in the Sierra Nevada","interactions":[],"lastModifiedDate":"2016-07-27T12:22:06","indexId":"70030000","displayToPublicDate":"2007-01-01T00:00:00","publicationYear":"2007","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2316,"text":"Journal of Geophysical Research D: Atmospheres","active":true,"publicationSubtype":{"id":10}},"title":"Detection, attribution, and sensitivity of trends toward earlier streamflow in the Sierra Nevada","docAbstract":"Observed changes in the timing of snowmelt dominated streamflow in the western United States are often linked to anthropogenic or other external causes. We assess whether observed streamflow timing changes can be statistically attributed to external forcing, or whether they still lie within the bounds of natural (internal) variability for four large Sierra Nevada (CA) basins, at inflow points to major reservoirs. Streamflow timing is measured by \"center timing\" (CT), the day when half the annual flow has passed a given point. We use a physically based hydrology model driven by meteorological input from a global climate model to quantify the natural variability in CT trends. Estimated 50-year trends in CT due to natural climate variability often exceed estimated actual CT trends from 1950 to 1999. Thus, although observed trends in CT to date may be statistically significant, they cannot yet be statistically attributed to external influences on climate. We estimate that projected CT changes at the four major reservoir inflows will, with 90% confidence, exceed those from natural variability within 1-4 decades or 4-8 decades, depending on rates of future greenhouse gas emissions. To identify areas most likely to exhibit CT changes in response to rising temperatures, we calculate changes in CT under temperature increases from 1 to 5??. We find that areas with average winter temperatures between -2??C and -4??C are most likely to respond with significant CT shifts. Correspondingly, elevations from 2000 to 2800 in are most sensitive to temperature increases, with CT changes exceeding 45 days (earlier) relative to 1961-1990. Copyright 2007 by the American Geophysical Union.
","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Journal of Geophysical Research D: Atmospheres","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1029/2006JD008088","issn":"01480227","usgsCitation":"Maurer, E., Stewart, I., Bonfils, C., Duffy, P.B., and Cayan, D., 2007, Detection, attribution, and sensitivity of trends toward earlier streamflow in the Sierra Nevada: Journal of Geophysical Research D: Atmospheres, v. 112, no. 11, https://doi.org/10.1029/2006JD008088.","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":477109,"rank":10000,"type":{"id":40,"text":"Open Access Publisher Index Page"},"url":"https://doi.org/10.1029/2006jd008088","text":"Publisher Index Page"},{"id":240219,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":212694,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1029/2006JD008088"}],"volume":"112","issue":"11","noUsgsAuthors":false,"publicationDate":"2007-06-13","publicationStatus":"PW","scienceBaseUri":"5059ff7de4b0c8380cd4f210","contributors":{"authors":[{"text":"Maurer, E.P.","contributorId":30338,"corporation":false,"usgs":true,"family":"Maurer","given":"E.P.","email":"","affiliations":[],"preferred":false,"id":425234,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Stewart, I.T.","contributorId":80062,"corporation":false,"usgs":true,"family":"Stewart","given":"I.T.","email":"","affiliations":[],"preferred":false,"id":425238,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Bonfils, Celine","contributorId":51542,"corporation":false,"usgs":true,"family":"Bonfils","given":"Celine","email":"","affiliations":[],"preferred":false,"id":425236,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Duffy, P. B.","contributorId":77742,"corporation":false,"usgs":false,"family":"Duffy","given":"P.","email":"","middleInitial":"B.","affiliations":[],"preferred":false,"id":425237,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Cayan, D.","contributorId":49563,"corporation":false,"usgs":true,"family":"Cayan","given":"D.","email":"","affiliations":[],"preferred":false,"id":425235,"contributorType":{"id":1,"text":"Authors"},"rank":5}]}} ,{"id":70030061,"text":"70030061 - 2007 - A multiple-approach radiometric age estimate for the Rotoiti and Earthquake Flat eruptions, New Zealand, with implications for the MIS 4/3 boundary","interactions":[],"lastModifiedDate":"2023-08-02T11:10:15.786658","indexId":"70030061","displayToPublicDate":"2007-01-01T00:00:00","publicationYear":"2007","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":3219,"text":"Quaternary Science Reviews","active":true,"publicationSubtype":{"id":10}},"title":"A multiple-approach radiometric age estimate for the Rotoiti and Earthquake Flat eruptions, New Zealand, with implications for the MIS 4/3 boundary","docAbstract":"Pyroclastic fall deposits of the paired Rotoiti and Earthquake Flat eruptions from the Taupo Volcanic Zone (New Zealand) combine to form a widespread isochronous horizon over much of northern New Zealand and the southwest Pacific. This horizon is important for correlating climatic and environmental changes during the Last Glacial period, but has been the subject of numerous disparate age estimates between 35.1±2.8 and 71±6 ka (all errors are 1 s.d.), obtained by a variety of techniques. A potassium–argon (K–Ar) age of 64±4 ka was previously determined on bracketing lavas at Mayor Island volcano, offshore from the Taupo Volcanic Zone. We present a new, more-precise 40Ar/39Ar age determination on a lava flow on Mayor Island, that shortly post-dates the Rotoiti/Earthquake Flat fall deposits, of 58.5±1.1 ka. This value, coupled with existing ages from underlying lavas, yield a new estimate for the age of the combined eruptions of 61.0±1.4 ka, which is consistent with U–Th disequilibrium model-age data for zircons from the Rotoiti deposits. Direct 40Ar/39Ar age determinations of plagioclase and biotite from the Rotoiti and Earthquake Flat eruption products yield variable values between 49.6±2.8 and 125.3±10.0 ka, with the scatter attributed to low radiogenic Ar yields, and/or alteration, and/or inheritance of xenocrystic material with inherited Ar. Rotoiti/Earthquake Flat fall deposits occur in New Zealand in association with palynological indicators of mild climate, attributed to Marine Isotope Stage (MIS) 3 and thus used to suggest an age that is post-59 ka. The natures of the criteria used to define the MIS 4/3 boundary in the Northern and Southern hemispheres, however, imply that the new 61 ka age for the Rotoiti/Earthquake Flat eruption deposits will provide the inverse, namely, a more accurate isochronous marker for correlating diverse changes across the MIS 4/3 boundary in the southwest Pacific.
[1] Using a digital video-based Argus Beach Monitoring System (ABMS) on the north shore of Kachemak Bay in south central Alaska, we document the timing and magnitude of alongshore migration of intertidal sand bed forms over a cobble substrate during a 22-month observation period. Two separate sediment packages (sand bodies) of 1–2 m amplitude and ∼200 m wavelength, consisting of well-sorted sand, were observed to travel along shore at annually averaged rates of 278 m/yr (0.76 m/d) and 250 m/yr (0.68 m/d), respectively. Strong seasonality in migration rates was shown by the contrast of rapid winter and slow summer transport. Though set in a megatidal environment, data indicate that sand body migration is driven by eastward propagating wind waves as opposed to net westward directed tidal currents. Greatest weekly averaged rates of movement, exceeding 6 m/d, coincided with wave heights exceeding 2 m suggesting a correlation of wave height and sand body migration. Because Kachemak Bay is partially enclosed, waves responsible for sediment entrainment and transport are locally generated by winds that blow across lower Cook Inlet from the southwest, the direction of greatest fetch. Our estimates of sand body migration translate to a littoral transport rate between 4,400–6,300 m3/yr. Assuming an enclosed littoral cell, minimal riverine sediment contributions, and a sea cliff sedimentary fraction of 0.05, we estimate long-term local sea cliff retreat rates of 9–14 cm/yr. Applying a numerical model of wave energy dissipation to the temporally variable beach morphology suggests that sand bodies are responsible for enhancing wave energy dissipation by ∼13% offering protection from sea cliff retreat.
The Saginaw Bay walleye population (Sander vitreus) has not fully recovered from a collapse that began in the 1940s and has been dependent on stocking with only limited natural reproduction. Beginning in 2003, and through at least 2005, reproductive success of walleye surged to unprecedented levels. The increase was concurrent with ecological changes in Lake Huron and we sought to quantitatively model which factors most influenced this new dynamic. We developed Ricker stock-recruitment models for both wild and stock fish and evaluated them with second-order Akaike's information criterion to find the best model. Independent variables included adult alewife (Alosa pseudoharengus) abundance, spring water temperatures, chlorophyll a levels and total phosphorus levels. In all, 14 models were evaluated for production of wild age-0 walleyes and eight models for stocked age-0 walleyes. For wild walleyes, adult alewife abundance was the dominant factor, accounting for 58% of the variability in age-0 abundance. Production of wild age-0 fish increased when adult alewives were scarce. The only other plausible factor was spring water temperature. Predictably, alewife abundance was not important to stocked fish; instead temperature and adult walleye abundance were more significant variables. The surge in reproductive success for walleyes during 2003–2005 was most likely due to large declines in adult alewives in Lake Huron. While relatively strong year classes (age-1 and up) have been produced as a result of increased age-0 production during 2003–2005, the overall magnitude has not been as great as the initial age-0 abundance originally suggested. It appears that over-winter mortality is higher than in the past and may stem from higher predation or slower growth (lower condition for enduring winter thermal stress). From this it appears that low alewife abundance does not assure strong walleye year classes in Saginaw Bay but may be a prerequisite for them.
","language":"English","publisher":"International Association for Great Lakes Research","doi":"10.3394/0380-1330(2007)33[118:EAECST]2.0.CO;2","issn":"03801330","usgsCitation":"Fielder, D., Schaeffer, J., and Thomas, M., 2007, Environmental and ecological conditions surrounding the production of large year classes of walleye (Sander vitreus) in Saginaw Bay, Lake Huron: Journal of Great Lakes Research, v. 33, no. Supplement 1, p. 118-132, https://doi.org/10.3394/0380-1330(2007)33[118:EAECST]2.0.CO;2.","productDescription":"15 p.","startPage":"118","endPage":"132","onlineOnly":"N","additionalOnlineFiles":"N","costCenters":[{"id":324,"text":"Great Lakes Science Center","active":true,"usgs":true}],"links":[{"id":240404,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":212850,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.3394/0380-1330(2007)33[118:EAECST]2.0.CO;2"}],"volume":"33","issue":"Supplement 1","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a099be4b0c8380cd51fb4","contributors":{"authors":[{"text":"Fielder, D.G.","contributorId":22152,"corporation":false,"usgs":true,"family":"Fielder","given":"D.G.","email":"","affiliations":[],"preferred":false,"id":425740,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Schaeffer, J.S.","contributorId":42688,"corporation":false,"usgs":true,"family":"Schaeffer","given":"J.S.","email":"","affiliations":[],"preferred":false,"id":425741,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Thomas, M.V.","contributorId":66908,"corporation":false,"usgs":true,"family":"Thomas","given":"M.V.","email":"","affiliations":[],"preferred":false,"id":425742,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70030050,"text":"70030050 - 2007 - Glacier changes in southeast Alaska and northwest British Columbia and contribution to sea level rise","interactions":[],"lastModifiedDate":"2012-03-12T17:21:09","indexId":"70030050","displayToPublicDate":"2007-01-01T00:00:00","publicationYear":"2007","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2318,"text":"Journal of Geophysical Research F: Earth Surface","active":true,"publicationSubtype":{"id":10}},"title":"Glacier changes in southeast Alaska and northwest British Columbia and contribution to sea level rise","docAbstract":"The digital elevation model (DEM) from the 2000 Shuttle Radar Topography Mission (SRTM) was differenced from a composite DEM based on air photos dating from 1948 to 1987 to detennine glacier volume changes in southeast Alaska and adjoining Canada. SRTM accuracy was assessed at ??5 in through comparison with airborne laser altimetry and control locations measured with GPS. Glacier surface elevations lowered over 95% of the 14,580 km2 glacier-covered area analyzed, with some glaciers thinning as much as 640 in. A combination of factors have contributed to this wastage, including calving retreats of tidewater and lacustrine glaciers and climate change. Many glaciers in this region are particularly sensitive to climate change, as they have large areas at low elevations. However, several tidewater glaciers that had historically undergone calving retreats are now expanding and appear to be in the advancing stage of the tidewater glacier cycle. The net average rate of ice loss is estimated at 16.7 ?? 4.4 km3/yr, equivalent to a global sea level rise contribution of 0.04 ?? 0.01 mm/yr. Copyright 2007 by the American Geophysical Union.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Journal of Geophysical Research F: Earth Surface","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1029/2006JF000586","issn":"01480227","usgsCitation":"Larsen, C., Motyka, R., Arendt, A., Echelmeyer, K., and Geissler, P., 2007, Glacier changes in southeast Alaska and northwest British Columbia and contribution to sea level rise: Journal of Geophysical Research F: Earth Surface, v. 112, no. 1, https://doi.org/10.1029/2006JF000586.","costCenters":[],"links":[{"id":477126,"rank":10000,"type":{"id":40,"text":"Open Access Publisher Index Page"},"url":"https://doi.org/10.1029/2006jf000586","text":"Publisher Index Page"},{"id":240467,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":212902,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1029/2006JF000586"}],"volume":"112","issue":"1","noUsgsAuthors":false,"publicationDate":"2007-02-24","publicationStatus":"PW","scienceBaseUri":"505a2914e4b0c8380cd5a66a","contributors":{"authors":[{"text":"Larsen, C.F.","contributorId":96091,"corporation":false,"usgs":true,"family":"Larsen","given":"C.F.","email":"","affiliations":[],"preferred":false,"id":425468,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Motyka, R.J.","contributorId":49594,"corporation":false,"usgs":true,"family":"Motyka","given":"R.J.","email":"","affiliations":[],"preferred":false,"id":425466,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Arendt, A.A.","contributorId":99379,"corporation":false,"usgs":false,"family":"Arendt","given":"A.A.","email":"","affiliations":[{"id":12920,"text":"Applied Physics Laboratory, University of Washington","active":true,"usgs":false}],"preferred":false,"id":425469,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Echelmeyer, K.A.","contributorId":11781,"corporation":false,"usgs":true,"family":"Echelmeyer","given":"K.A.","email":"","affiliations":[],"preferred":false,"id":425465,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Geissler, P.E.","contributorId":67636,"corporation":false,"usgs":true,"family":"Geissler","given":"P.E.","email":"","affiliations":[],"preferred":false,"id":425467,"contributorType":{"id":1,"text":"Authors"},"rank":5}]}} ,{"id":70030048,"text":"70030048 - 2007 - Unconventional shale-gas systems: The Mississippian Barnett Shale of north-central Texas as one model for thermogenic shale-gas assessment","interactions":[],"lastModifiedDate":"2012-03-12T17:21:09","indexId":"70030048","displayToPublicDate":"2007-01-01T00:00:00","publicationYear":"2007","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":701,"text":"American Association of Petroleum Geologists Bulletin","active":true,"publicationSubtype":{"id":10}},"title":"Unconventional shale-gas systems: The Mississippian Barnett Shale of north-central Texas as one model for thermogenic shale-gas assessment","docAbstract":"Shale-gas resource plays can be distinguished by gas type and system characteristics. The Newark East gas field, located in the Fort Worth Basin, Texas, is defined by thermogenic gas production from low-porosity and low-permeability Barnett Shale. The Barnett Shale gas system, a self-contained source-reservoir system, has generated large amounts of gas in the key productive areas because of various characteristics and processes, including (1) excellent original organic richness and generation potential; (2) primary and secondary cracking of kerogen and retained oil, respectively; (3) retention of oil for cracking to gas by adsorption; (4) porosity resulting from organic matter decomposition; and (5) brittle mineralogical composition. The calculated total gas in place (GIP) based on estimated ultimate recovery that is based on production profiles and operator estimates is about 204 bcf/section (5.78 ?? 109 m3/1.73 ?? 104 m3). We estimate that the Barnett Shale has a total generation potential of about 609 bbl of oil equivalent/ac-ft or the equivalent of 3657 mcf/ac-ft (84.0 m3/m3). Assuming a thickness of 350 ft (107 m) and only sufficient hydrogen for partial cracking of retained oil to gas, a total generation potential of 820 bcf/section is estimated. Of this potential, approximately 60% was expelled, and the balance was retained for secondary cracking of oil to gas, if sufficient thermal maturity was reached. Gas storage capacity of the Barnett Shale at typical reservoir pressure, volume, and temperature conditions and 6% porosity shows a maximum storage capacity of 540 mcf/ac-ft or 159 scf/ton. Copyright ?? 2007. The American Association of Petroleum Geologists. All rights reserved.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"American Association of Petroleum Geologists Bulletin","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1306/12190606068","issn":"01491423","usgsCitation":"Jarvie, D., Hill, R., Ruble, T., and Pollastro, R.M., 2007, Unconventional shale-gas systems: The Mississippian Barnett Shale of north-central Texas as one model for thermogenic shale-gas assessment: American Association of Petroleum Geologists Bulletin, v. 91, no. 4, p. 475-499, https://doi.org/10.1306/12190606068.","startPage":"475","endPage":"499","numberOfPages":"25","costCenters":[],"links":[{"id":212875,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1306/12190606068"},{"id":240434,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"91","issue":"4","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505bbc2ee4b08c986b328aae","contributors":{"authors":[{"text":"Jarvie, D.M.","contributorId":69768,"corporation":false,"usgs":true,"family":"Jarvie","given":"D.M.","email":"","affiliations":[],"preferred":false,"id":425459,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Hill, R.J.","contributorId":92850,"corporation":false,"usgs":true,"family":"Hill","given":"R.J.","email":"","affiliations":[],"preferred":false,"id":425460,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Ruble, T.E.","contributorId":30402,"corporation":false,"usgs":true,"family":"Ruble","given":"T.E.","email":"","affiliations":[],"preferred":false,"id":425458,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Pollastro, R. M.","contributorId":6809,"corporation":false,"usgs":true,"family":"Pollastro","given":"R.","email":"","middleInitial":"M.","affiliations":[],"preferred":false,"id":425457,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}} ,{"id":70030110,"text":"70030110 - 2007 - Suspended sediment transport in an ephemeral stream following wildfire","interactions":[],"lastModifiedDate":"2023-08-03T11:40:18.33254","indexId":"70030110","displayToPublicDate":"2007-01-01T00:00:00","publicationYear":"2007","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2318,"text":"Journal of Geophysical Research F: Earth Surface","active":true,"publicationSubtype":{"id":10}},"title":"Suspended sediment transport in an ephemeral stream following wildfire","docAbstract":"We examine the impacts of a stand-clearing wildfire on the characteristics and magnitude of suspended sediment transport in ephemeral streams draining the burn area. We report the results of a monitoring program that includes 2 years of data prior to the Cerro Grande fire in New Mexico, and 3 years of postfire data. Suspended sediment concentration (SSC) increased by about 2 orders of magnitude following the fire, and the proportion of silt and clay increased from 50% to 80%. For a given flow event, SSC is highest at the flood bore and decreases monotonically with time, a pattern evident in every flood sampled both before and after the fire. We propose that the accumulation of flow and wash load at the flow front is an inherent characteristic of ephemeral stream flows, due to amplified momentum losses at the flood bore. We present a new model for computing suspended sediment transport in ephemeral streams (in the presence or absence of wildfire) by relating SSC to the time following the arrival of the flood bore, rather than to instantaneous discharge. Using this model and a rainfall history, we estimate that in the 3 years following the fire, floods transported in suspension a mass equivalent to about 3 mm of landscape lowering across the burn area, 20% of this following a single rainstorm. We test the model by computing fine sediment delivery to a small reservoir in an adjacent watershed, where we have a detailed record of postfire sedimentation based on repeat surveys. Systematic discrepancies between modeled and measured sedimentation rates in the reservoir suggest rapid reductions in suspended sediment delivery in the first several years after the fire.
In contrast with the extreme variability expected for water and contaminant fluxes in the unsaturated zone, evidence from 64 field tests of preferential flow indicates that the maximum transport speed Vmax, adjusted for episodicity of infiltration, deviates little from a geometric mean of 13 m/d. A model based on constant‐speed travel during infiltration pulses of actual or estimated duration can predict Vmax with approximate order‐of‐magnitude accuracy, irrespective of medium or travel distance, thereby facilitating such problems as the prediction of worst‐case contaminant traveltimes. The lesser variability suggests that preferential flow is subject to rate‐limiting mechanisms analogous to those that impose a terminal velocity on objects in free fall and to rate‐compensating mechanisms analogous to Le Chatlier's principle. A critical feature allowing such mechanisms to dominate may be the presence of interfacial boundaries confined by neither solid material nor capillary forces.
","language":"English","publisher":"American Geophysical Union","doi":"10.1029/2006WR005372","usgsCitation":"Nimmo, J.R., 2007, Simple predictions of maximum transport rate in unsaturated soil and rock: Water Resources Research, v. 43, no. 5, W05426; 11 p., https://doi.org/10.1029/2006WR005372.","productDescription":"W05426; 11 p.","costCenters":[{"id":589,"text":"Toxic Substances Hydrology Program","active":true,"usgs":true}],"links":[{"id":477005,"rank":1,"type":{"id":40,"text":"Open Access Publisher Index Page"},"url":"https://doi.org/10.1029/2006wr005372","text":"Publisher Index Page"},{"id":240293,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"43","issue":"5","noUsgsAuthors":false,"publicationDate":"2007-05-22","publicationStatus":"PW","scienceBaseUri":"505b8f6ee4b08c986b318f17","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":425421,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}} ,{"id":70030038,"text":"70030038 - 2007 - Development of the California Current during the past 12,000 yr based on diatoms and silicoflagellates","interactions":[],"lastModifiedDate":"2022-12-05T17:49:12.10361","indexId":"70030038","displayToPublicDate":"2007-01-01T00:00:00","publicationYear":"2007","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2996,"text":"Palaeogeography, Palaeoclimatology, Palaeoecology","printIssn":"0031-0182","active":true,"publicationSubtype":{"id":10}},"title":"Development of the California Current during the past 12,000 yr based on diatoms and silicoflagellates","docAbstract":"Detailed diatom and silicoflagellates records in three cores from the offshore region of southern Oregon to central California reveal the evolution of the northern part of the California Current during the past 12,000 yr. The early Holocene, prior to ∼ 9 ka, was characterized by relatively warm sea surface temperatures (SST), owing to enhanced northerly flow of the subtropical waters comparable to the modern Davidson Current. Progressive strengthening of the North Pacific High lead to intensification of the southward flow of the California Current at ∼ 8 ka, resulting in increased coastal upwelling and relatively cooler SST which persisted until ∼ 5 ka. Reduced southward flow of the California Current between ∼ 4.8 ka and 3.6 ka may have been responsible for a period of decreased upwelling. Modern seasonal oceanographic cycles, as evidenced by increased spring–early summer coastal upwelling and warming of early fall SST evolved between 3.5 and 3.2 ka. Widespread occurrence of paleoceanographic and paleoclimatic change between ∼ 3.5–3.0 ka along the eastern margins of the North Pacific was likely a response to increasing ENSO variability in the tropical Pacific.
","language":"English","publisher":"Elsevier","doi":"10.1016/j.palaeo.2006.12.009","usgsCitation":"Barron, J.A., and Bukry, D., 2007, Development of the California Current during the past 12,000 yr based on diatoms and silicoflagellates: Palaeogeography, Palaeoclimatology, Palaeoecology, v. 248, no. 3-4, p. 313-338, https://doi.org/10.1016/j.palaeo.2006.12.009.","productDescription":"26 p.","startPage":"313","endPage":"338","onlineOnly":"N","additionalOnlineFiles":"N","costCenters":[{"id":617,"text":"Volcano Science Center","active":true,"usgs":true}],"links":[{"id":240292,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"country":"United States","state":"California, Oregon","geographicExtents":"{\n \"type\": \"FeatureCollection\",\n \"features\": [\n {\n \"type\": \"Feature\",\n \"properties\": {},\n \"geometry\": {\n \"type\": \"Polygon\",\n \"coordinates\": [\n [\n [\n -123.134765625,\n 43.58039085560784\n ],\n [\n -124.5849609375,\n 43.70759350405294\n ],\n [\n -124.76074218749999,\n 42.293564192170095\n ],\n [\n -124.62890625,\n 41.50857729743935\n ],\n [\n -124.5849609375,\n 39.36827914916014\n ],\n [\n -122.51953124999999,\n 36.27970720524017\n ],\n [\n -121.46484375,\n 35.06597313798418\n ],\n [\n -120.05859375,\n 36.13787471840729\n ],\n [\n -121.640625,\n 37.43997405227057\n ],\n [\n -123.00292968749999,\n 40.51379915504413\n ],\n [\n -123.134765625,\n 43.58039085560784\n ]\n ]\n ]\n }\n }\n ]\n}","volume":"248","issue":"3-4","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a0068e4b0c8380cd4f751","contributors":{"authors":[{"text":"Barron, John A. 0000-0002-9309-1145 jbarron@usgs.gov","orcid":"https://orcid.org/0000-0002-9309-1145","contributorId":2222,"corporation":false,"usgs":true,"family":"Barron","given":"John","email":"jbarron@usgs.gov","middleInitial":"A.","affiliations":[{"id":617,"text":"Volcano Science Center","active":true,"usgs":true}],"preferred":true,"id":425420,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Bukry, David 0000-0003-4540-890X","orcid":"https://orcid.org/0000-0003-4540-890X","contributorId":30980,"corporation":false,"usgs":true,"family":"Bukry","given":"David","affiliations":[],"preferred":false,"id":425419,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70030033,"text":"70030033 - 2007 - Evidence for prosauropod dinosaur gastroliths in the Bull Run Formation (Upper Triassic, Norian) of Virginia","interactions":[],"lastModifiedDate":"2018-03-06T14:49:12","indexId":"70030033","displayToPublicDate":"2007-01-01T00:00:00","publicationYear":"2007","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1965,"text":"Ichnos: An International Journal for Plant and Animal Traces","onlineIssn":"1563-5236","printIssn":"1042-0940","active":true,"publicationSubtype":{"id":10}},"title":"Evidence for prosauropod dinosaur gastroliths in the Bull Run Formation (Upper Triassic, Norian) of Virginia","docAbstract":"Definitive criteria for distinguishing gastroliths from sedimentary clasts are lacking for many depositional settings, and many reported occurrences of gastroliths either cannot be verified or have been refuted. We discuss four occurrences of gastrolith-like stones (category 6 exoliths) not found within skeletal remains from the Upper Triassic Bull Run Formation of northern Virginia, USA. Despite their lack of obvious skeletal association, the most parsimonious explanation for several characteristics of these stones is their prolonged residence in the gastric mills of large animals. These characteristics include 1) typical gastrolith microscopic surface texture, 2) evidence of pervasive surface wear on many of these stones that has secondarily removed variable amounts of thick weathering rinds typically found on these stones, and 3) a width/length-ratio modal peak for these stones that is more strongly developed than in any population of fluvial or fanglomerate stones of any age found in this region. When taken together, these properties of the stones can be explained most parsimoniously by animal ingestion and gastric-mill abrasion. The size of these stones indicates the animals that swallowed them were large, and the best candidate is a prosauropod dinosaur, possibly an ancestor of the Early Jurassic gastrolith-producing prosauropod Massospondylus or Ammosaurus.
Skeletal evidence for Upper Triassic prosauropods is lacking in the Newark Supergroup basins; footprints (Agrestipus hottoni and Eubrontes isp.) from the Bull Run Formation in the Culpeper basin previously ascribed to prosauropods are now known to be underprints (Brachychirotherium parvum) of an aetosaur and underprints (Kayentapus minor) of a ceratosaur. The absence of prosauropod skeletal remains or footprints in all but the uppermost (upper Rhaetian) Triassic rocks of the Newark Supergroup is puzzling because prosauropod remains are abundant elsewhere in the world in Upper Triassic (Carnian, Norian, and lower Rhaetian) continental strata. The apparent scarcity of prosauropods in Upper Triassic strata of the Newark Supergroup is interpreted as an artifact of ecological partitioning, created by the habitat range and dietary preferences of phytosaurs and by the preservational biases at that time within the lithofacies of the Newark Supergroup basins.
","language":"English","publisher":"Taylor & Francis","doi":"10.1080/10420940601050030","usgsCitation":"Weems, R.E., Culp, M.J., and Wings, O., 2007, Evidence for prosauropod dinosaur gastroliths in the Bull Run Formation (Upper Triassic, Norian) of Virginia: Ichnos: An International Journal for Plant and Animal Traces, v. 14, no. 3-4, p. 271-295, https://doi.org/10.1080/10420940601050030.","productDescription":"25 p.","startPage":"271","endPage":"295","costCenters":[],"links":[{"id":240221,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"country":"United States","state":"Virginia","volume":"14","issue":"3-4","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a0d50e4b0c8380cd52f3f","contributors":{"authors":[{"text":"Weems, Robert E. 0000-0002-1907-7804 rweems@usgs.gov","orcid":"https://orcid.org/0000-0002-1907-7804","contributorId":2663,"corporation":false,"usgs":true,"family":"Weems","given":"Robert","email":"rweems@usgs.gov","middleInitial":"E.","affiliations":[{"id":40020,"text":"Florence Bascom Geoscience Center","active":true,"usgs":true},{"id":243,"text":"Eastern Geology and Paleoclimate Science Center","active":true,"usgs":true}],"preferred":true,"id":425404,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Culp, Michelle J.","contributorId":80083,"corporation":false,"usgs":false,"family":"Culp","given":"Michelle","email":"","middleInitial":"J.","affiliations":[],"preferred":false,"id":425406,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Wings, Oliver","contributorId":49604,"corporation":false,"usgs":false,"family":"Wings","given":"Oliver","email":"","affiliations":[],"preferred":false,"id":425405,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70030111,"text":"70030111 - 2007 - Structure of the California Coast Ranges and San Andreas Fault at SAFOD from seismic waveform inversion and reflection imaging","interactions":[],"lastModifiedDate":"2023-08-04T11:15:47.64567","indexId":"70030111","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":"Structure of the California Coast Ranges and San Andreas Fault at SAFOD from seismic waveform inversion and reflection imaging","docAbstract":"[1] A seismic reflection and refraction survey across the San Andreas Fault (SAF) near Parkfield provides a detailed characterization of crustal structure across the location of the San Andreas Fault Observatory at Depth (SAFOD). Steep-dip prestack migration and frequency domain acoustic waveform tomography were applied to obtain highly resolved images of the upper 5 km of the crust for 15 km on either side of the SAF. The resulting velocity model constrains the top of the Salinian granite with great detail. Steep-dip reflection seismic images show several strong-amplitude vertical reflectors in the uppermost crust near SAFOD that define an ∼2-km-wide zone comprising the main SAF and two or more local faults. Another prominent subvertical reflector at 2–4 km depth ∼9 km to the northeast of the SAF marks the boundary between the Franciscan terrane and the Great Valley Sequence. A deep seismic section of low resolution shows several reflectors in the Salinian crust west of the SAF. Two horizontal reflectors around 10 km depth correlate with strains of seismicity observed along-strike of the SAF. They represent midcrustal shear zones partially decoupling the ductile lower crust from the brittle upper crust. The deepest reflections from ∼25 km depth are interpreted as crust-mantle boundary.
Advanced borehole-geophysical methods were used to assess the geohydrology of fractured crystalline bedrock in 31 of 64 boreholes on the southern part of Manhattan Island, NY in preparation of the construction of a new water tunnel. The study area is located in a highly urbanized part of New York City. The boreholes penetrated gneiss, schist, and other crystalline bedrock that has an overall southwest-to northwest-dipping foliation. Most of the fractures intersected are nearly horizontal or have moderate- to high-angle northwest or eastward dip azimuths. Heat-pulse flowmeter logs obtained under nonpumping (ambient) and pumping conditions, together with other geophysical logs, delineated transmissive fracture zones in each borehole. Water-level and flowmeter data suggest the fractured-rock ground-water-flow system is interconnected. The 60 MHz directional borehole-radar logs delineated the location and orientation of several radar reflectors that did not intersect the projection of the borehole. A total of 53 faults intersected by the boreholes have mean orientation populations of N12°W, 66°W and N11°W, 70°E. A total of 77 transmissive fractures delineated using the heat-pulse flowmeter have mean orientations of N11°E, 14°SE (majority) and N23°E, 57°NW (minority). The transmissivity of the bedrock boreholes ranged from 0.7 to 870 feet squared (ft2) per day (0.07 to 81 metres squared (m2) per day).
","language":"English","publisher":"Oxford Academic","doi":"10.1088/1742-2132/4/3/S02","issn":"17422132","usgsCitation":"Stumm, F., Chu, A., Joesten, P., and Lane, J., 2007, Geohydrologic assessment of fractured crystalline bedrock on the southern part of Manhattan, New York, through the use of advanced borehole geophysical methods: Journal of Geophysics and Engineering, v. 4, no. 3, p. 245-252, https://doi.org/10.1088/1742-2132/4/3/S02.","productDescription":"8 p.","startPage":"245","endPage":"252","numberOfPages":"8","costCenters":[{"id":493,"text":"Office of Ground Water","active":true,"usgs":true}],"links":[{"id":240627,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"country":"United States","state":"New York","city":"Manhattan","geographicExtents":"{\n \"type\": \"FeatureCollection\",\n \"features\": [\n {\n \"type\": \"Feature\",\n \"properties\": {},\n \"geometry\": {\n \"type\": \"Polygon\",\n \"coordinates\": [\n [\n [\n -74.02450561523438,\n 40.69938133866613\n ],\n [\n -73.93386840820312,\n 40.69938133866613\n ],\n [\n -73.93386840820312,\n 40.79977641109269\n ],\n [\n -74.02450561523438,\n 40.79977641109269\n ],\n [\n -74.02450561523438,\n 40.69938133866613\n ]\n ]\n ]\n }\n }\n ]\n}","volume":"4","issue":"3","noUsgsAuthors":false,"publicationDate":"2007-08-31","publicationStatus":"PW","scienceBaseUri":"505a17a0e4b0c8380cd55578","contributors":{"authors":[{"text":"Stumm, F.","contributorId":33928,"corporation":false,"usgs":true,"family":"Stumm","given":"F.","email":"","affiliations":[],"preferred":false,"id":425382,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Chu, A.","contributorId":81697,"corporation":false,"usgs":true,"family":"Chu","given":"A.","email":"","affiliations":[],"preferred":false,"id":425385,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Joesten, P. K.","contributorId":62818,"corporation":false,"usgs":true,"family":"Joesten","given":"P. K.","affiliations":[],"preferred":false,"id":425383,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Lane, J.W. Jr.","contributorId":66723,"corporation":false,"usgs":true,"family":"Lane","given":"J.W.","suffix":"Jr.","email":"","affiliations":[],"preferred":false,"id":425384,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}} ]}