{"pageNumber":"238","pageRowStart":"5925","pageSize":"25","recordCount":16506,"records":[{"id":70031724,"text":"70031724 - 2008 - A comparison of winter mercury accumulation at forested and no-canopy sites measured with different snow sampling techniques","interactions":[],"lastModifiedDate":"2018-10-22T09:16:55","indexId":"70031724","displayToPublicDate":"2008-01-01T00:00:00","publicationYear":"2008","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 comparison of winter mercury accumulation at forested and no-canopy sites measured with different snow sampling techniques","docAbstract":"<div id=\"abstracts\" class=\"Abstracts\"><div id=\"aep-abstract-id13\" class=\"abstract author\" lang=\"en\"><div id=\"aep-abstract-sec-id14\"><p>Atmospheric mercury (Hg) is delivered to ecosystems via rain, snow, cloud/fog, and dry deposition. The importance of snow, especially snow that has passed through the forest canopy (throughfall), in delivering Hg to terrestrial ecosystems has received little attention in the literature. The snowpack is a dynamic system that links atmospheric deposition and ecosystem cycling through deposition and emission of deposited Hg. To examine the magnitude of Hg delivery via snowfall, and to illuminate processes affecting Hg flux to catchments during winter (cold season), Hg in snow in no-canopy areas and under forest canopies measured with four collection methods were compared: (1) Hg in wet precipitation as measured by the Mercury Deposition Network (MDN) for the site in Acadia National Park, Maine, USA, (2) event throughfall (collected after snowfall cessation for accumulations of &gt;8&nbsp;cm), (3) season-long throughfall collected using the same apparatus for event sampling but deployed for the entire cold season, and (4) snowpack sampling. Estimates (mean&nbsp;±&nbsp;SE) of Hg deposition using these methods during the 91-day cold season in 2004–2005 at conifer sites showed that season-long throughfall Hg flux (1.80&nbsp;μg/m<sup>2</sup>)&nbsp;&lt;&nbsp;snowpack Hg (2.38&nbsp;±&nbsp;0.68&nbsp;μg/m<sup>2</sup>) &lt; event throughfall flux (5.63&nbsp;±&nbsp;0.38&nbsp;μg/m<sup>2</sup>). Mercury deposition at the MDN site (0.91&nbsp;μg/m<sup>2</sup>) was similar to that measured at other no-canopy sites in the area using the other methods, but was 3.4 times less than was measured under conifer canopies using the event sampling regime. This indicates that snow accumulated under the forest canopy received Hg from the overstory or exhibited less re-emission of Hg deposited in snow relative to open areas. The soil surface of field-scale plots were sprayed with a natural rain water sample that contained an Hg tracer (<sup>202</sup>Hg) just prior to the first snowfall to explore whether some snowpack Hg might be explained from soil emissions. The appearance of the<span>&nbsp;</span><sup>202</sup>Hg tracer in the snowpack (0–64% of the total Hg mass in the snowpack) suggests that movement of Hg from the soil into the snowpack is possible. However, as with any tracer study the<span>&nbsp;</span><sup>202</sup>Hg tracer may not precisely represent the reactivity and mobility of natural Hg in soils.</p></div></div></div>","language":"English","publisher":"Elsevier","doi":"10.1016/j.apgeochem.2007.12.009","issn":"08832927","usgsCitation":"Nelson, S., Johnson, K., Weathers, K., Loftin, C., Fernandez, I., Kahl, J.S., and Krabbenhoft, D., 2008, A comparison of winter mercury accumulation at forested and no-canopy sites measured with different snow sampling techniques: Applied Geochemistry, v. 23, no. 3, p. 384-398, https://doi.org/10.1016/j.apgeochem.2007.12.009.","productDescription":"15 p.","startPage":"384","endPage":"398","costCenters":[{"id":589,"text":"Toxic Substances Hydrology Program","active":true,"usgs":true}],"links":[{"id":239943,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":212453,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/j.apgeochem.2007.12.009"}],"volume":"23","issue":"3","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"5059e37ce4b0c8380cd46072","contributors":{"authors":[{"text":"Nelson, S.J.","contributorId":45901,"corporation":false,"usgs":true,"family":"Nelson","given":"S.J.","email":"","affiliations":[],"preferred":false,"id":432866,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Johnson, K.B.","contributorId":31208,"corporation":false,"usgs":true,"family":"Johnson","given":"K.B.","email":"","affiliations":[],"preferred":false,"id":432864,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Weathers, K.C.","contributorId":41378,"corporation":false,"usgs":true,"family":"Weathers","given":"K.C.","email":"","affiliations":[],"preferred":false,"id":432865,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Loftin, C.S.","contributorId":92771,"corporation":false,"usgs":true,"family":"Loftin","given":"C.S.","email":"","affiliations":[],"preferred":false,"id":432870,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Fernandez, I.J.","contributorId":61221,"corporation":false,"usgs":true,"family":"Fernandez","given":"I.J.","email":"","affiliations":[],"preferred":false,"id":432867,"contributorType":{"id":1,"text":"Authors"},"rank":5},{"text":"Kahl, J. S.","contributorId":77885,"corporation":false,"usgs":false,"family":"Kahl","given":"J.","email":"","middleInitial":"S.","affiliations":[],"preferred":false,"id":432868,"contributorType":{"id":1,"text":"Authors"},"rank":6},{"text":"Krabbenhoft, D. P. 0000-0003-1964-5020","orcid":"https://orcid.org/0000-0003-1964-5020","contributorId":90765,"corporation":false,"usgs":true,"family":"Krabbenhoft","given":"D. P.","affiliations":[],"preferred":false,"id":432869,"contributorType":{"id":1,"text":"Authors"},"rank":7}]}}
,{"id":70032980,"text":"70032980 - 2008 - A fully distributed implementation of mean annual streamflow regional regression equations","interactions":[],"lastModifiedDate":"2017-04-03T12:49:45","indexId":"70032980","displayToPublicDate":"2008-01-01T00:00:00","publicationYear":"2008","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2529,"text":"Journal of the American Water Resources Association","active":true,"publicationSubtype":{"id":10}},"title":"A fully distributed implementation of mean annual streamflow regional regression equations","docAbstract":"<p><span>Estimates of mean annual streamflow are needed for a variety of hydrologic assessments. Away from gage locations, regional regression equations that are a function of upstream area, precipitation, and temperature are commonly used. Geographic information systems technology has facilitated their use for projects, but traditional approaches using the polygon overlay operator have been too inefficient for national scale applications. As an alternative, the Elevation Derivatives for National Applications (EDNA) database was used as a framework for a fully distributed implementation of mean annual streamflow regional regression equations. The raster “flow accumulation” operator was used to efficiently achieve spatially continuous parameterization of the equations for every 30&nbsp;m grid cell of the conterminous United States (U.S.). Results were confirmed by comparing with measured flows at stations of the Hydro-Climatic Data Network, and their applications value demonstrated in the development of a national geospatial hydropower assessment. Interactive tools at the EDNA website make possible the fast and efficient query of mean annual streamflow for any location in the conterminous U.S., providing a valuable complement to other national initiatives (StreamStats and the National Hydrography Dataset Plus).</span></p>","language":"English","publisher":"Wiley","doi":"10.1111/j.1752-1688.2008.00258.x","issn":"10934","usgsCitation":"Verdin, K., and Worstell, B., 2008, A fully distributed implementation of mean annual streamflow regional regression equations: Journal of the American Water Resources Association, v. 44, no. 6, p. 1537-1547, https://doi.org/10.1111/j.1752-1688.2008.00258.x.","productDescription":"11 p.","startPage":"1537","endPage":"1547","numberOfPages":"11","costCenters":[{"id":222,"text":"Earth Resources Observation and Science (EROS) Center","active":true,"usgs":true}],"links":[{"id":240708,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":213116,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1111/j.1752-1688.2008.00258.x"}],"volume":"44","issue":"6","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"5059e3e4e4b0c8380cd462aa","contributors":{"authors":[{"text":"Verdin, K.L.","contributorId":66438,"corporation":false,"usgs":true,"family":"Verdin","given":"K.L.","email":"","affiliations":[],"preferred":false,"id":438816,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Worstell, B. 0000-0001-8927-3336","orcid":"https://orcid.org/0000-0001-8927-3336","contributorId":92059,"corporation":false,"usgs":true,"family":"Worstell","given":"B.","affiliations":[],"preferred":false,"id":438817,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}}
,{"id":70031723,"text":"70031723 - 2008 - Evapotranspiration rates and crop coefficients for a restored marsh in the Sacramento-San Joaquin Delta, California, USA","interactions":[],"lastModifiedDate":"2018-05-25T13:07:55","indexId":"70031723","displayToPublicDate":"2008-01-01T00:00:00","publicationYear":"2008","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1924,"text":"Hydrological Processes","active":true,"publicationSubtype":{"id":10}},"title":"Evapotranspiration rates and crop coefficients for a restored marsh in the Sacramento-San Joaquin Delta, California, USA","docAbstract":"<p><span>The surface renewal method was used to estimate evapotranspiration (ET) for a restored marsh on Twitchell Island in the Sacramento–San Joaquin Delta, California, USA. ET estimates for the marsh, together with reference ET measurements from a nearby climate station, were used to determine crop coefficients over a 3‐year period during the growing season. The mean ET rate for the study period was 6 mm day</span><sup>−1</sup><span>, which is high compared with other marshes with similar vegetation. High ET rates at the marsh may be due to the windy, semi‐arid Mediterranean climate of the region, and the permanently flooded nature of the marsh, which results in very low surface resistance of the vegetation. Crop coefficient (</span><i>K</i><sub>c</sub><span>) values for the marsh ranged from 0·73 to 1·18. The mean<span>&nbsp;</span></span><i>K</i><sub>c</sub><span><span>&nbsp;</span>value over the entire study period was 0·95. The daily<span>&nbsp;</span></span><i>K</i><sub>c</sub><span><span>&nbsp;</span>values for any given month varied from year to year, and the standard deviation of daily<span>&nbsp;</span></span><i>K</i><sub>c</sub><span><span>&nbsp;</span>values varied between months. Although several climate variables were undoubtedly responsible for this variation, our analysis revealed that wind direction and the temperature of standing water in the wetland were of particular importance in determining ET rates and<span>&nbsp;</span></span><i>K</i><sub>c</sub><span><span>&nbsp;</span>values.<span>&nbsp;</span></span></p>","language":"English","publisher":"Wiley","doi":"10.1002/hyp.6650","issn":"08856087","usgsCitation":"Drexler, J., Anderson, F.E., and Snyder, R.L., 2008, Evapotranspiration rates and crop coefficients for a restored marsh in the Sacramento-San Joaquin Delta, California, USA: Hydrological Processes, v. 22, no. 6, p. 725-735, https://doi.org/10.1002/hyp.6650.","productDescription":"11 p.","startPage":"725","endPage":"735","numberOfPages":"11","costCenters":[{"id":154,"text":"California Water Science Center","active":true,"usgs":true}],"links":[{"id":239909,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":212422,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1002/hyp.6650"}],"volume":"22","issue":"6","noUsgsAuthors":false,"publicationDate":"2007-05-23","publicationStatus":"PW","scienceBaseUri":"505a0d20e4b0c8380cd52e21","contributors":{"authors":[{"text":"Drexler, Judith Z. 0000-0002-0127-3866 jdrexler@usgs.gov","orcid":"https://orcid.org/0000-0002-0127-3866","contributorId":1659,"corporation":false,"usgs":true,"family":"Drexler","given":"Judith Z.","email":"jdrexler@usgs.gov","affiliations":[{"id":154,"text":"California Water Science Center","active":true,"usgs":true}],"preferred":false,"id":432861,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Anderson, Frank E. 0000-0002-1418-4678 fanders@usgs.gov","orcid":"https://orcid.org/0000-0002-1418-4678","contributorId":2605,"corporation":false,"usgs":true,"family":"Anderson","given":"Frank","email":"fanders@usgs.gov","middleInitial":"E.","affiliations":[{"id":154,"text":"California Water Science Center","active":true,"usgs":true}],"preferred":true,"id":432863,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Snyder, Richard L.","contributorId":167497,"corporation":false,"usgs":false,"family":"Snyder","given":"Richard","email":"","middleInitial":"L.","affiliations":[{"id":24726,"text":"Department of Land, Air and Water Resources","active":true,"usgs":false}],"preferred":false,"id":432862,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}}
,{"id":70030447,"text":"70030447 - 2008 - Hydrochemical characterization of groundwater in the Akyem area, Ghana","interactions":[],"lastModifiedDate":"2012-03-12T17:21:04","indexId":"70030447","displayToPublicDate":"2008-01-01T00:00:00","publicationYear":"2008","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2257,"text":"Journal of Environmental Hydrology","active":true,"publicationSubtype":{"id":10}},"title":"Hydrochemical characterization of groundwater in the Akyem area, Ghana","docAbstract":"The Akyem area is a small farming community located in southeastern Ghana. Groundwater samples from wells in the area were analyzed for concentrations of the major ions, silica, electrical conductivity and pH. The objective was to determine the main controls on the hydrochemistry of ground-water. Mass balance modeling was used together with multivariate R-mode hierarchical cluster analysis to determine the significant sources of variation in the hydrochemistry. Two water types exist in this area. The first is influenced most by the weathering of silicate minerals from the underlying geology, and is thus rich in silica, sodium, calcium, bicarbonate, and magnesium ions. The second is water that has been influenced by the effects of fertilizers and other anthropogenic activities in the area. Mineral speciation and silicate mineral stability diagrams suggest that montmorillonite, probably derived from the incongruent dissolution of feldspars and micas, is the most stable silicate phase in the groundwaters. The apparent incongruent weathering of silicate minerals in the groundwater system has led to the enrichment of sodium, calcium, magnesium and bicarbonate ions as well as silica, leading to the supersaturation of calcite, aragonite, dolomite and quartz. Stability in the montmorillonite field suggests restricted flow conditions and a long groundwater residence time, leading to greater exposure of the rock to weathering. Cation exchange processes appear to play minor roles in the hydrochemistry of groundwater.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Journal of Environmental Hydrology","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","issn":"10583","usgsCitation":"Banoeng-Yakubo, B., Yidana, S., Anku, Y., Akabzaa, T., and Asiedu, D., 2008, Hydrochemical characterization of groundwater in the Akyem area, Ghana: Journal of Environmental Hydrology, v. 16, p. 1-12.","startPage":"1","endPage":"12","numberOfPages":"12","costCenters":[],"links":[{"id":239172,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"16","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a332ce4b0c8380cd5edbf","contributors":{"authors":[{"text":"Banoeng-Yakubo, B.","contributorId":75332,"corporation":false,"usgs":true,"family":"Banoeng-Yakubo","given":"B.","email":"","affiliations":[],"preferred":false,"id":427190,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Yidana, S.M.","contributorId":59554,"corporation":false,"usgs":true,"family":"Yidana","given":"S.M.","email":"","affiliations":[],"preferred":false,"id":427189,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Anku, Y.","contributorId":96083,"corporation":false,"usgs":true,"family":"Anku","given":"Y.","affiliations":[],"preferred":false,"id":427192,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Akabzaa, T.","contributorId":39580,"corporation":false,"usgs":true,"family":"Akabzaa","given":"T.","email":"","affiliations":[],"preferred":false,"id":427188,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Asiedu, D.","contributorId":76131,"corporation":false,"usgs":true,"family":"Asiedu","given":"D.","affiliations":[],"preferred":false,"id":427191,"contributorType":{"id":1,"text":"Authors"},"rank":5}]}}
,{"id":70032970,"text":"70032970 - 2008 - Mass balance and isotope effects during nitrogen transport through septic tank systems with packed-bed (sand) filters","interactions":[],"lastModifiedDate":"2018-10-22T09:21:53","indexId":"70032970","displayToPublicDate":"2008-01-01T00:00:00","publicationYear":"2008","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":3352,"text":"Science of the Total Environment","active":true,"publicationSubtype":{"id":10}},"title":"Mass balance and isotope effects during nitrogen transport through septic tank systems with packed-bed (sand) filters","docAbstract":"<div id=\"abstracts\" class=\"Abstracts\"><div id=\"aep-abstract-id8\" class=\"abstract author\"><div id=\"aep-abstract-sec-id9\"><p><span>Septic tank&nbsp;systems are an important source of NO</span><sub>3</sub><sup>−</sup><span>&nbsp;to many&nbsp;aquifers, yet characterization of N mass balance and isotope systematics following septic tank&nbsp;effluent&nbsp;discharge into unsaturated sediments has received limited attention. In this study, samples of septic tank effluent before and after transport through single-pass packed-bed filters (sand filters) were evaluated to elucidate mass balance and&nbsp;isotope effects&nbsp;associated with septic tank effluent discharge to unsaturated sediments. Chemical and isotopic data from five newly installed pairs and ten established pairs of septic tanks and packed-bed filters serving single homes in Oregon indicate that aqueous solute concentrations are affected by variations in recharge (precipitation, evapotranspiration), NH</span><sub>4</sub><sup>+</sup><span>&nbsp;sorption&nbsp;(primarily in immature systems),&nbsp;nitrification, and gaseous N loss via NH</span><sub>3</sub><span>&nbsp;volatilization&nbsp;and(or) N</span><sub>2</sub><span>&nbsp;</span>or N<sub>2</sub>O release during nitrification/denitrification. Substantial NH<sub>4</sub><sup>+</sup><span>&nbsp;</span>sorption capacity was also observed in laboratory columns with synthetic effluent. Septic tank effluent<span>&nbsp;</span><i>δ</i><sup>15</sup>N–NH<sub>4</sub><sup>+</sup><span>&nbsp;</span>values were almost constant and averaged +&nbsp;4.9‰&nbsp;±&nbsp;0.4‰ (1<span>&nbsp;</span><i>σ</i>). In contrast,<span>&nbsp;</span><i>δ</i><sup>15</sup>N values of NO<sub>3</sub><sup>−</sup>leaving mature packed-bed filters were variable (+&nbsp;0.8 to +&nbsp;14.4‰) and averaged +&nbsp;7.2‰&nbsp;±&nbsp;2.6‰. Net N loss in the two networks of packed-bed filters was indicated by average 10–30% decreases in Cl<sup>−</sup>-normalized N concentrations and 2–3‰ increases in<span>&nbsp;</span><i>δ</i><sup>15</sup><span>N, consistent with&nbsp;fractionation&nbsp;accompanying gaseous N losses and corroborating established links between septic tank effluent and NO</span><sub>3</sub><sup>−</sup><span>&nbsp;</span>in a local, shallow aquifer. Values of<span>&nbsp;</span><i>δ</i><sup>18</sup>O–NO<sub>3</sub><sup>−</sup><span>&nbsp;</span>leaving mature packed-bed filters ranged from −&nbsp;10.2 to −&nbsp;2.3‰ (mean −&nbsp;6.4‰&nbsp;±&nbsp;1.8‰), and were intermediate between a 2/3 H<sub>2</sub>O–O&nbsp;+&nbsp;1/3 O<sub>2</sub>–O conceptualization and a 100% H<sub>2</sub>O–O conceptualization of<span>&nbsp;</span><i>δ</i><sup>18</sup>O–NO<sub>3</sub><sup>−</sup><span>&nbsp;</span>generation during nitrification.</p></div></div></div>","language":"English","publisher":"Elsevier","doi":"10.1016/j.scitotenv.2008.08.036","issn":"00489","usgsCitation":"Hinkle, S., Böhlke, J., and Fisher, L., 2008, Mass balance and isotope effects during nitrogen transport through septic tank systems with packed-bed (sand) filters: Science of the Total Environment, v. 407, no. 1, p. 324-332, https://doi.org/10.1016/j.scitotenv.2008.08.036.","productDescription":"9 p.","startPage":"324","endPage":"332","costCenters":[{"id":589,"text":"Toxic Substances Hydrology Program","active":true,"usgs":true}],"links":[{"id":213451,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/j.scitotenv.2008.08.036"},{"id":241077,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"407","issue":"1","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a5245e4b0c8380cd6c2b2","contributors":{"authors":[{"text":"Hinkle, S.R.","contributorId":74778,"corporation":false,"usgs":true,"family":"Hinkle","given":"S.R.","email":"","affiliations":[],"preferred":false,"id":438753,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Böhlke, J.K. 0000-0001-5693-6455","orcid":"https://orcid.org/0000-0001-5693-6455","contributorId":96696,"corporation":false,"usgs":true,"family":"Böhlke","given":"J.K.","affiliations":[],"preferred":false,"id":438754,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Fisher, L.H.","contributorId":34725,"corporation":false,"usgs":true,"family":"Fisher","given":"L.H.","email":"","affiliations":[],"preferred":false,"id":438752,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}}
,{"id":70030582,"text":"70030582 - 2008 - Dry down impacts on apple snail (Pomacea paludosa) demography: Implications for wetland water management","interactions":[],"lastModifiedDate":"2012-03-12T17:21:04","indexId":"70030582","displayToPublicDate":"2008-01-01T00:00:00","publicationYear":"2008","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":3750,"text":"Wetlands","onlineIssn":"1943-6246","printIssn":"0277-5212","active":true,"publicationSubtype":{"id":10}},"title":"Dry down impacts on apple snail (Pomacea paludosa) demography: Implications for wetland water management","docAbstract":"Florida apple snails (Pomacea paludosa Say) are prey for several wetland-dependent predators, most notably for the endangered Florida snail kite (Rostrhamus sociabilis Vieillot). Management concerns for kites have been raised regarding the impacts of wetland dry downs on snails, but little data exists to validate these concerns. We simulated drying events in experimental tanks, where we observed that snail survival patterns, regardless of hydrology, were driven by a post-reproductive die off. In contrast to earlier reports of little to no dry down tolerance, we found that 70% of pre-reproductive adult-sized snails survived a 12-week dry down. Smaller size classes of snails exhibited significantly lower survival rates (< 50% after eight weeks dry). Field surveys showed that 77% of egg production occurs in April-June. Our hydrologic analyses of six peninsular Florida wetlands showed that most dry downs overlapped a portion of the peak snail breeding season, and 70% of dry downs were ??? 12 weeks in duration. Dry down timing can affect recruitment by truncating annual egg production and stranding juveniles. Dry down survival rates and seasonal patterns of egg cluster production helped define a range of hydrologic conditions that support robust apple snail populations, and illustrate why multiple characteristics of dry down events should be considered in developing target hydrologic regimes for wetland fauna. ?? 2008, The Society of Wetland Scientists.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Wetlands","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1672/07-115.1","issn":"02775","usgsCitation":"Darby, P., Bennetts, R., and Percival, H., 2008, Dry down impacts on apple snail (Pomacea paludosa) demography: Implications for wetland water management: Wetlands, v. 28, no. 1, p. 204-214, https://doi.org/10.1672/07-115.1.","startPage":"204","endPage":"214","numberOfPages":"11","costCenters":[],"links":[{"id":211728,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1672/07-115.1"},{"id":239073,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"28","issue":"1","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a0402e4b0c8380cd5073b","contributors":{"authors":[{"text":"Darby, P.C.","contributorId":101044,"corporation":false,"usgs":true,"family":"Darby","given":"P.C.","email":"","affiliations":[],"preferred":false,"id":427738,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Bennetts, R.E.","contributorId":103214,"corporation":false,"usgs":true,"family":"Bennetts","given":"R.E.","affiliations":[],"preferred":false,"id":427739,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Percival, H.F.","contributorId":31716,"corporation":false,"usgs":true,"family":"Percival","given":"H.F.","email":"","affiliations":[],"preferred":false,"id":427737,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}}
,{"id":70032911,"text":"70032911 - 2008 - Occurrence and turnover of nitric oxide in a nitrogen-impacted sand and gravel aquifer","interactions":[],"lastModifiedDate":"2018-10-22T09:02:45","indexId":"70032911","displayToPublicDate":"2008-01-01T00:00:00","publicationYear":"2008","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":"Occurrence and turnover of nitric oxide in a nitrogen-impacted sand and gravel aquifer","docAbstract":"<div class=\"hlFld-Abstract\"><div id=\"abstractBox\"><p class=\"articleBody_abstractText\">Little is known about nitric oxide (NO) production or consumption in the subsurface, an environment which may be conducive to NO accumulation. A study conducted in a nitrogen-contaminated aquifer on Cape Cod, Massachusetts assessed the occurrence and turnover of NO within a contaminant plume in which nitrification and denitrification were known to occur. NO (up to 8.6 nM) was detected in restricted vertical zones located within a nitrate (NO<sub>3</sub><sup>−</sup>) gradient and characterized by low dissolved oxygen (&lt;10 μM). NO concentrations correlated best with nitrite (NO<sub>2</sub><sup>−</sup>) (up to 35 μM), but nitrous oxide (N<sub>2</sub>O) (up to 1 μM) also was present. Single-well injection tests were used to determine NO production and consumption in situ within these zones. First-order rate constants for NO consumption were similar (0.05−0.08 h<sup>−1</sup>) at high and low (260 and 10 nM) NO concentrations, suggesting a turnover time at in situ concentrations of 10−20 h. Tracer tests with<span>&nbsp;</span><sup>15</sup>N[NO] demonstrated that oxidation to<span>&nbsp;</span><sup>15</sup>N[NO<sub>2</sub><sup>−</sup>] occurred only during the initial stages, but after 4 h reduction to<span>&nbsp;</span><sup>15</sup>N[N<sub>2</sub>O] was the primary reaction product. Added NO<sub>2</sub><sup>−</sup><span>&nbsp;</span>(31 μM) or NO<sub>3</sub><sup>−</sup><span>&nbsp;</span>(53 μM) resulted in a linear NO accumulation at 2.4 and 1.0 nM h<sup>−1</sup><span>&nbsp;</span>for the first 6 h of in situ tests. These results suggest that NO was primarily produced by denitrification within this aquifer.</p></div></div><div class=\"hlFld-Fulltext\"><br data-mce-bogus=\"1\"></div>","language":"English","publisher":"ACS","doi":"10.1021/es801290v","issn":"00139","usgsCitation":"Smith, R.L., and Yoshinari, T., 2008, Occurrence and turnover of nitric oxide in a nitrogen-impacted sand and gravel aquifer: Environmental Science & Technology, v. 42, no. 22, p. 8245-8251, https://doi.org/10.1021/es801290v.","productDescription":"7 p.","startPage":"8245","endPage":"8251","costCenters":[{"id":589,"text":"Toxic Substances Hydrology Program","active":true,"usgs":true}],"links":[{"id":241178,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":213545,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1021/es801290v"}],"volume":"42","issue":"22","noUsgsAuthors":false,"publicationDate":"2008-10-22","publicationStatus":"PW","scienceBaseUri":"505a6b86e4b0c8380cd74752","contributors":{"authors":[{"text":"Smith, R. L.","contributorId":93904,"corporation":false,"usgs":true,"family":"Smith","given":"R.","email":"","middleInitial":"L.","affiliations":[{"id":595,"text":"U.S. Geological Survey","active":false,"usgs":true}],"preferred":false,"id":438477,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Yoshinari, T.","contributorId":56391,"corporation":false,"usgs":true,"family":"Yoshinari","given":"T.","affiliations":[],"preferred":false,"id":438476,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}}
,{"id":70030329,"text":"70030329 - 2008 - The effects of land use on fluvial sediment chemistry for the conterminous U.S. - Results from the first cycle of the NAWQA Program: Trace and major elements, phosphorus, carbon, and sulfur","interactions":[],"lastModifiedDate":"2012-03-12T17:21:11","indexId":"70030329","displayToPublicDate":"2008-01-01T00:00:00","publicationYear":"2008","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":3352,"text":"Science of the Total Environment","active":true,"publicationSubtype":{"id":10}},"title":"The effects of land use on fluvial sediment chemistry for the conterminous U.S. - Results from the first cycle of the NAWQA Program: Trace and major elements, phosphorus, carbon, and sulfur","docAbstract":"In 1991, the U.S. Geological Survey (USGS) began the first cycle of its National Water Quality Assessment (NAWQA) Program. The Program encompassed 51 river basins that collectively accounted for more than 70% of the total water use (excluding power generation), and 50% of the drinking water supply in the U.S. The basins represented a variety of hydrologic settings, rock types (geology), land-use categories, and population densities. One aspect of the first cycle included bed sediment sampling; sites were chosen to represent baseline and important land-use categories (e.g., agriculture, urban) in each basin. In total, over 1200 bed sediment samples were collected. All samples were size-limited (< 63????m) to facilitate spatial and/or temporal comparisons, and subsequently analyzed for a variety of chemical constituents including major (e.g., Fe, Al,) and trace elements (e.g., Cu, Zn, Cd), nutrients (e.g., P), and carbon. The analyses yielded total (??? 95% of the concentrations present), rather than total-recoverable chemical data. Land-use percentages, upstream underlying geology, and population density were determined for each site and evaluated to asses their relative influence on sediment chemistry. Baseline concentrations for the entire U.S. also were generated from a subset of all the samples, and are based on material collected from low population (??? 27??p km- 2) density, low percent urban (??? 5%), agricultural or undeveloped areas. The NAWQA baseline values are similar to those found in other national and global datasets. Further, it appears that upstream/underlying rock type has only a limited effect (mostly major elements) on sediment chemistry. The only land-use category that appears to substantially affect sediment chemistry is percent urban, and this result is mirrored by population density; in fact, the latter appears more consistent than the former.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Science of the Total Environment","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1016/j.scitotenv.2008.04.027","issn":"00489","usgsCitation":"Horowitz, A.J., and Stephens, V., 2008, The effects of land use on fluvial sediment chemistry for the conterminous U.S. - Results from the first cycle of the NAWQA Program: Trace and major elements, phosphorus, carbon, and sulfur: Science of the Total Environment, v. 400, no. 1-3, p. 290-314, https://doi.org/10.1016/j.scitotenv.2008.04.027.","startPage":"290","endPage":"314","numberOfPages":"25","costCenters":[],"links":[{"id":212062,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/j.scitotenv.2008.04.027"},{"id":239477,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"400","issue":"1-3","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505bab89e4b08c986b322eda","contributors":{"authors":[{"text":"Horowitz, A. J.","contributorId":102066,"corporation":false,"usgs":true,"family":"Horowitz","given":"A.","email":"","middleInitial":"J.","affiliations":[],"preferred":false,"id":426718,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Stephens, V. C.","contributorId":46569,"corporation":false,"usgs":true,"family":"Stephens","given":"V. C.","affiliations":[],"preferred":false,"id":426717,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}}
,{"id":70032365,"text":"70032365 - 2008 - Detection and attribution of temperature changes in the mountainous Western United States","interactions":[],"lastModifiedDate":"2012-03-12T17:21:24","indexId":"70032365","displayToPublicDate":"2008-01-01T00:00:00","publicationYear":"2008","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2216,"text":"Journal of Climate","active":true,"publicationSubtype":{"id":10}},"title":"Detection and attribution of temperature changes in the mountainous Western United States","docAbstract":"Large changes in the hydrology of the western United States have been observed since the mid-twentieth century. These include a reduction in the amount of precipitation arriving as snow, a decline in snowpack at low and midelevations, and a shift toward earlier arrival of both snowmelt and the centroid (center of mass) of streamflows. To project future water supply reliability, it is crucial to obtain a better understanding of the underlying cause or causes for these changes. A regional warming is often posited as the cause of these changes without formal testing of different competitive explanations for the warming. In this study, a rigorous detection and attribution analysis is performed to determine the causes of the late winter/early spring changes in hydrologically relevant temperature variables over mountain ranges of the western United States. Natural internal climate variability, as estimated from two long control climate model simulations, is insufficient to explain the rapid increase in daily minimum and maximum temperatures, the sharp decline in frost days, and the rise in degree-days above 0??C (a simple proxy for temperature driven snowmelt). These observed changes are also inconsistent with the model-predicted responses to variability in solar irradiance and volcanic activity. The observations are consistent with climite simulations that include the combined effects of anthropogenic greenhouse gases and aerosols. It is found that, for each temperature variable considered, an anthropogenic signal is identifiable in observational fields. The results are robust to uncertainties in model-estimated fingerprints and natural variability noise, to the choice of statistical down-scaling method, and to various processing options in the detection and attribution method. ?? 2008 American Meteorological Society.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Journal of Climate","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1175/2008JCLI2397.1","issn":"08948","usgsCitation":"Bonfils, C., Santer, B., Pierce, D., Hidalgo, H., Bala, G., Das, T., Barnett, T., Cayan, D., Doutriaux, C., Wood, A., Mirin, A., and Nozawa, T., 2008, Detection and attribution of temperature changes in the mountainous Western United States: Journal of Climate, v. 21, no. 23, p. 6404-6424, https://doi.org/10.1175/2008JCLI2397.1.","startPage":"6404","endPage":"6424","numberOfPages":"21","costCenters":[],"links":[{"id":487695,"rank":10000,"type":{"id":40,"text":"Open Access Publisher Index Page"},"url":"https://doi.org/10.1175/2008jcli2397.1","text":"Publisher Index Page"},{"id":213963,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1175/2008JCLI2397.1"},{"id":241641,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"21","issue":"23","noUsgsAuthors":false,"publicationDate":"2008-12-01","publicationStatus":"PW","scienceBaseUri":"5059ff66e4b0c8380cd4f17c","contributors":{"authors":[{"text":"Bonfils, Celine","contributorId":51542,"corporation":false,"usgs":true,"family":"Bonfils","given":"Celine","email":"","affiliations":[],"preferred":false,"id":435800,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Santer, B.D.","contributorId":95702,"corporation":false,"usgs":true,"family":"Santer","given":"B.D.","email":"","affiliations":[],"preferred":false,"id":435805,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Pierce, D.W.","contributorId":23342,"corporation":false,"usgs":true,"family":"Pierce","given":"D.W.","email":"","affiliations":[],"preferred":false,"id":435796,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Hidalgo, H.G.","contributorId":81229,"corporation":false,"usgs":true,"family":"Hidalgo","given":"H.G.","email":"","affiliations":[],"preferred":false,"id":435802,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Bala, G.","contributorId":86983,"corporation":false,"usgs":true,"family":"Bala","given":"G.","email":"","affiliations":[],"preferred":false,"id":435804,"contributorType":{"id":1,"text":"Authors"},"rank":5},{"text":"Das, T.","contributorId":99383,"corporation":false,"usgs":true,"family":"Das","given":"T.","email":"","affiliations":[],"preferred":false,"id":435806,"contributorType":{"id":1,"text":"Authors"},"rank":6},{"text":"Barnett, T.P.","contributorId":54763,"corporation":false,"usgs":true,"family":"Barnett","given":"T.P.","email":"","affiliations":[],"preferred":false,"id":435801,"contributorType":{"id":1,"text":"Authors"},"rank":7},{"text":"Cayan, D.R.","contributorId":25961,"corporation":false,"usgs":false,"family":"Cayan","given":"D.R.","email":"","affiliations":[{"id":16196,"text":"Scripps Institution of Oceanography, La Jolla, CA","active":true,"usgs":false}],"preferred":false,"id":435797,"contributorType":{"id":1,"text":"Authors"},"rank":8},{"text":"Doutriaux, C.","contributorId":50364,"corporation":false,"usgs":true,"family":"Doutriaux","given":"C.","email":"","affiliations":[],"preferred":false,"id":435799,"contributorType":{"id":1,"text":"Authors"},"rank":9},{"text":"Wood, A.W.","contributorId":43542,"corporation":false,"usgs":true,"family":"Wood","given":"A.W.","email":"","affiliations":[],"preferred":false,"id":435798,"contributorType":{"id":1,"text":"Authors"},"rank":10},{"text":"Mirin, A.","contributorId":104294,"corporation":false,"usgs":true,"family":"Mirin","given":"A.","affiliations":[],"preferred":false,"id":435807,"contributorType":{"id":1,"text":"Authors"},"rank":11},{"text":"Nozawa, T.","contributorId":83345,"corporation":false,"usgs":true,"family":"Nozawa","given":"T.","email":"","affiliations":[],"preferred":false,"id":435803,"contributorType":{"id":1,"text":"Authors"},"rank":12}]}}
,{"id":70032849,"text":"70032849 - 2008 - Geochemical investigation of weathering processes in a forested headwater catchment: Mass-balance weathering fluxes","interactions":[],"lastModifiedDate":"2012-03-12T17:21:33","indexId":"70032849","displayToPublicDate":"2008-01-01T00:00:00","publicationYear":"2008","noYear":false,"publicationType":{"id":24,"text":"Conference Paper"},"publicationSubtype":{"id":19,"text":"Conference Paper"},"title":"Geochemical investigation of weathering processes in a forested headwater catchment: Mass-balance weathering fluxes","docAbstract":"Geochemical research on natural weathering has often been directed towards explanations of the chemical composition of surface water and ground water resulting from subsurface water-rock interactions. These interactions are often defined as the incongruent dissolution of primary silicates, such as feldspar, producing secondary weathering products, such as clay minerals and oxyhydroxides, and solute fluxes (Meunier and Velde, 1979). The chemical composition of the clay-mineral product is often ignored. However, in earlier investigations, the saprolitic weathering profile at the South Fork Brokenback Run (SFBR) watershed, Shenandoah National Park, Virginia, was characterized extensively in terms of its mineralogical and chemical composition (Piccoli, 1987; Pochatila et al., 2006; Jones et al., 2007) and its basic hydrology. O'Brien et al. (1997) attempted to determine the contribution of primary mineral weathering to observed stream chemistry at SFBR. Mass-balance model results, however, could provide only a rough estimate of the weathering reactions because idealized mineral compositions were utilized in the calculations. Making use of detailed information on the mineral occurrence in the regolith, the objective of the present study was to evaluate the effects of compositional variation on mineral-solute mass-balance modelling and to generate plausible quantitative weathering reactions that support both the chemical evolution of the surface water and ground water in the catchment, as well as the mineralogical evolution of the weathering profile. ?? 2008 The Mineralogical Society.","largerWorkTitle":"Mineralogical Magazine","language":"English","doi":"10.1180/minmag.2008.072.1.65","issn":"00264","usgsCitation":"Jones, B., and Herman, J., 2008, Geochemical investigation of weathering processes in a forested headwater catchment: Mass-balance weathering fluxes, <i>in</i> Mineralogical Magazine, v. 72, no. 1, p. 65-69, https://doi.org/10.1180/minmag.2008.072.1.65.","startPage":"65","endPage":"69","numberOfPages":"5","costCenters":[],"links":[{"id":214057,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1180/minmag.2008.072.1.65"},{"id":241744,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"72","issue":"1","noUsgsAuthors":false,"publicationDate":"2018-07-05","publicationStatus":"PW","scienceBaseUri":"505a1646e4b0c8380cd55103","contributors":{"authors":[{"text":"Jones, B.F.","contributorId":52156,"corporation":false,"usgs":true,"family":"Jones","given":"B.F.","email":"","affiliations":[],"preferred":false,"id":438220,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Herman, J.S.","contributorId":73345,"corporation":false,"usgs":true,"family":"Herman","given":"J.S.","email":"","affiliations":[],"preferred":false,"id":438221,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}}
,{"id":70031887,"text":"70031887 - 2008 - In situ estimation of the effective chemical diffusion coefficient of a rock matrix in a fractured aquifer","interactions":[],"lastModifiedDate":"2020-07-17T19:26:25.312435","indexId":"70031887","displayToPublicDate":"2008-01-01T00:00:00","publicationYear":"2008","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1923,"text":"Hydrogeology Journal","active":true,"publicationSubtype":{"id":10}},"title":"In situ estimation of the effective chemical diffusion coefficient of a rock matrix in a fractured aquifer","docAbstract":"<p class=\"Para\"><span>An in situ method of estimating the effective diffusion coefficient for a chemical constituent that diffuses into the primary porosity of a rock is developed by abruptly changing the concentration of the dissolved constituent in a borehole in contact with the rock matrix and monitoring the time-varying concentration. The experiment was conducted in a borehole completed in mudstone on the campus of the University of the Free State in Bloemfontein, South Africa. Numerous tracer tests were conducted at this site, which left a residual concentration of sodium chloride in boreholes that diffused into the rock matrix over a period of years. Fresh water was introduced into a borehole in contact with the mudstone, and the time-varying increase of chloride was observed by monitoring the electrical conductivity (EC) at various depths in the borehole. Estimates of the effective diffusion coefficient were obtained by interpreting measurements of EC over 34&nbsp;d. The effective diffusion coefficient at a depth of 36&nbsp;m was approximately 7.8×10</span><sup>−6</sup><span>&nbsp;m</span><sup>2</sup><span>/d, but was sensitive to the assumed matrix porosity. The formation factor and mass flux for the mudstone were also estimated from the experiment.</span></p>","language":"English","publisher":"Springer","doi":"10.1007/s10040-007-0255-0","issn":"14312174","usgsCitation":"Gebrekristos, R., Shapiro, A., and Usher, B., 2008, In situ estimation of the effective chemical diffusion coefficient of a rock matrix in a fractured aquifer: Hydrogeology Journal, v. 16, no. 4, p. 629-639, https://doi.org/10.1007/s10040-007-0255-0.","productDescription":"11 p.","startPage":"629","endPage":"639","costCenters":[{"id":589,"text":"Toxic Substances Hydrology Program","active":true,"usgs":true}],"links":[{"id":242521,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"country":"South Africa","city":"Bloemfontein","geographicExtents":"{\n  \"type\": \"FeatureCollection\",\n  \"features\": [\n    {\n      \"type\": \"Feature\",\n      \"properties\": {},\n      \"geometry\": {\n        \"type\": \"Polygon\",\n        \"coordinates\": [\n          [\n            [\n              26.03759765625,\n              -29.288794393648296\n            ],\n            [\n              26.42486572265625,\n              -29.288794393648296\n            ],\n            [\n              26.42486572265625,\n              -28.969700808694157\n            ],\n            [\n              26.03759765625,\n              -28.969700808694157\n            ],\n            [\n              26.03759765625,\n              -29.288794393648296\n            ]\n          ]\n        ]\n      }\n    }\n  ]\n}","volume":"16","issue":"4","noUsgsAuthors":false,"publicationDate":"2008-01-15","publicationStatus":"PW","scienceBaseUri":"505a399fe4b0c8380cd619a7","contributors":{"authors":[{"text":"Gebrekristos, R.A.","contributorId":25830,"corporation":false,"usgs":true,"family":"Gebrekristos","given":"R.A.","email":"","affiliations":[],"preferred":false,"id":433593,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Shapiro, A.M. 0000-0002-6425-9607","orcid":"https://orcid.org/0000-0002-6425-9607","contributorId":88384,"corporation":false,"usgs":true,"family":"Shapiro","given":"A.M.","affiliations":[],"preferred":true,"id":433595,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Usher, B.H.","contributorId":81763,"corporation":false,"usgs":true,"family":"Usher","given":"B.H.","email":"","affiliations":[],"preferred":false,"id":433594,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}}
,{"id":70032844,"text":"70032844 - 2008 - Water-quality monitoring and process understanding in support of environmental policy and management","interactions":[],"lastModifiedDate":"2012-03-12T17:21:23","indexId":"70032844","displayToPublicDate":"2008-01-01T00:00:00","publicationYear":"2008","noYear":false,"publicationType":{"id":24,"text":"Conference Paper"},"publicationSubtype":{"id":19,"text":"Conference Paper"},"title":"Water-quality monitoring and process understanding in support of environmental policy and management","docAbstract":"The quantity and quality of freshwater at any point on the landscape reflect the combined effects of many processes operating along hydrological pathways within a drainage basin/watershed/catchment. Primary drivers for the availability of water are landscape changes and patterns, and the processes affecting the timing, magnitude, and intensity of precipitation, including global climate change. The degradation of air, land, and water in one part of a drainage basin can have negative effects on users downstream; the time and space scales of the effects are determined by the residence time along the various hydrological pathways. Hydrology affects transport, deposition, and recycling of inorganic materials and sediment. These components affect biota and associated ecosystem processes, which rely on sustainable flows throughout a drainage basin. Human activities on all spatial scales affect both water quantity and quality, and some human activities can have a disproportionate effect on an entire drainage basin. Aquatic systems have been continuously modified by agriculture, through land-use change, irrigation and navigation, disposal of urban, mining, and industrial wastes, and engineering modifications to the environment. Interdisciplinary integrated basin studies within the last several decades have provided a more comprehensive understanding of the linkages among air, land, and water resources. This understanding, coupled with environmental monitoring, has evolved a more multidisciplinary integrated approach to resource management, particularly within drainage basins.","largerWorkTitle":"IAHS-AISH Publication","conferenceTitle":"River Basins - From Hydrological Science to Water Management","conferenceLocation":"Paris","language":"English","issn":"01447","isbn":"9781901502695","usgsCitation":"Peters, N., 2008, Water-quality monitoring and process understanding in support of environmental policy and management, <i>in</i> IAHS-AISH Publication, no. 323, Paris, p. 93-109.","startPage":"93","endPage":"109","numberOfPages":"17","costCenters":[],"links":[{"id":241672,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"issue":"323","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505bce33e4b08c986b32e29e","contributors":{"authors":[{"text":"Peters, N.E.","contributorId":33332,"corporation":false,"usgs":true,"family":"Peters","given":"N.E.","email":"","affiliations":[],"preferred":false,"id":438203,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}}
,{"id":70035374,"text":"70035374 - 2008 - Late Quaternary MIS 6-8 shoreline features of pluvial Owens Lake, Owens Valley, eastern California","interactions":[],"lastModifiedDate":"2012-03-12T17:21:54","indexId":"70035374","displayToPublicDate":"2008-01-01T00:00:00","publicationYear":"2008","noYear":false,"publicationType":{"id":24,"text":"Conference Paper"},"publicationSubtype":{"id":19,"text":"Conference Paper"},"title":"Late Quaternary MIS 6-8 shoreline features of pluvial Owens Lake, Owens Valley, eastern California","docAbstract":"The chronologic history of pluvial Owens Lake along the eastern Sierra Nevada in Owens Valley, California, has previously been reported for the interval of time from ca. 25 calibrated ka to the present. However, the age, distribution, and paleoclimatic context of higher-elevation shoreline features have not been formally documented. We describe the location and characteristics of wave-formed erosional and depositional features, as well as fluvial strath terraces that grade into an older shoreline of pluvial Owens Lake. These pluvial-lacustrine features are described between the Olancha area to the south and Poverty Hills area to the north, and they appear to be vertically deformed -20 ?? 4 m across the active oblique-dextral Owens Valley fault zone. They occur at elevations from 1176 to 1182 m along the lower flanks of the Inyo Mountains and Coso Range east of the fault zone to as high as -1204 m west of the fault zone. This relict shoreline, referred to as the 1180 m shoreline, lies -20-40 m higher than the previously documented Last Glacial Maximum shoreline at -1160 m, which occupied the valley during marine isotope stage 2 (MIS 2). Crosscutting relations of wave-formed platforms, notches, and sandy beach deposits, as well as strath terraces on lava flows of the Big Pine volcanic field, bracket the age of the 1180 m shoreline to the time interval between ca. 340 ?? 60 ka and ca. 130 ?? 50 ka. This interval includes marine oxygen isotope stages 8-6 (MIS 8-6), corresponding to 260-240 ka and 185-130 ka, respectively. An additional age estimate for this shoreline is provided by a cosmogenic <sup>36</sup>Cl model age of ca. 160 ?? 32 ka on reefal tufa at ???1170 m elevation from the southeastern margin of the valley. This <sup>36</sup>Cl model age corroborates the constraining ages based on dated lava flows and refines the lake age to the MIS 6 interval. Documentation of this larger pluvial Owens Lake offers insight to the hydrologic balance along the east side of the southern Sierra Nevada and will assist with future regional paleoclimatic models within the western Basin and Range. ?? 2008 The Geo logical Society of America.","largerWorkTitle":"Special Paper of the Geological Society of America","language":"English","doi":"10.1130/2008.2439(08)","issn":"00721077","usgsCitation":"Jayko, A.S., and Bacon, S., 2008, Late Quaternary MIS 6-8 shoreline features of pluvial Owens Lake, Owens Valley, eastern California, <i>in</i> Special Paper of the Geological Society of America, no. 439, p. 185-206, https://doi.org/10.1130/2008.2439(08).","startPage":"185","endPage":"206","numberOfPages":"22","costCenters":[],"links":[{"id":243139,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":215344,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1130/2008.2439(08)"}],"issue":"439","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a4522e4b0c8380cd67073","contributors":{"authors":[{"text":"Jayko, A. S. 0000-0002-7378-0330","orcid":"https://orcid.org/0000-0002-7378-0330","contributorId":18011,"corporation":false,"usgs":true,"family":"Jayko","given":"A.","email":"","middleInitial":"S.","affiliations":[],"preferred":false,"id":450374,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Bacon, S.N.","contributorId":41636,"corporation":false,"usgs":true,"family":"Bacon","given":"S.N.","email":"","affiliations":[],"preferred":false,"id":450375,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}}
,{"id":70035244,"text":"70035244 - 2008 - Multistage late Cenozoic evolution of the Amargosa River drainage, southwestern Nevada and eastern California Society of America. All rights reserved","interactions":[],"lastModifiedDate":"2012-03-12T17:21:53","indexId":"70035244","displayToPublicDate":"2008-01-01T00:00:00","publicationYear":"2008","noYear":false,"publicationType":{"id":24,"text":"Conference Paper"},"publicationSubtype":{"id":19,"text":"Conference Paper"},"title":"Multistage late Cenozoic evolution of the Amargosa River drainage, southwestern Nevada and eastern California Society of America. All rights reserved","docAbstract":"Stratigraphic and geomorphic analyses reveal that the regional drainage basin of the modern Amargosa River formed via multistage linkage of formerly isolated basins in a diachronous series of integration events between late Miocene and latest Pleistocene-Holocene time. The 275-km-long Amargosa River system drains generally southward across a large (15,540 km&lt;sup&gt; <sup>2&lt;/sup&gt;</sup>) watershed in southwestern Nevada and eastern California to its terminus in central Death Valley. This drainage basin is divided into four major subbasins along the main channel and several minor subbasins on tributaries; these subbasins contain features, including central valley lowlands surrounded by highlands that form external divides or internal paleodivides, which suggest relict individual physiographic-hydrologic basins. From north to south, the main subbasins along the main channel are: (1) an upper headwaters subbasin, which is deeply incised into mostly Tertiary sediments and volcanic rocks; (2) an unincised low-gradient section within the Amargosa Desert; (3) a mostly incised section centered on Tecopa Valley and tributary drainages; and (4) a west- to northwest-oriented mostly aggrading lower section along the axis of southern Death Valley. Adjoining subbasins are hydro-logically linked by interconnecting narrows or canyon reaches that are variably incised into formerly continuous paleodivides. The most important linkages along the main channel include: (1) the Beatty narrows, which developed across a Tertiary bedrock paleodivide between the upper and Amargosa Desert subbasins during a latest Miocene-early Pliocene to middle Pleistocene interval (ca. 4-0.5 Ma); (2) the Eagle Mountain narrows, which cut into a mostly alluvial paleodivide between the Amar-gosa Desert and Tecopa subbasins in middle to late Pleistocene (ca. 150-100 ka) time; and (3) the Amargosa Canyon, which formed in late middle Pleistocene (ca. 200140 ka) time through a breached, actively uplifting paleodivide between the Tecopa and southern Death Valley subbasins. Collectively, the interconnecting reaches represent discrete integration events that incrementally produced the modern drainage basin starting near Beatty sometime after 4 Ma and ending in the Salt Creek tributary in the latest Pleistocene to Holocene (post-30 ka). Potential mechanisms for drainage integration across paleodivides include basin overtopping from sedimentary infilling above paleodivide elevations, paleolake spillover, groundwater sapping, and (or) headward erosion of dissecting channels in lower-altitude subbasins. These processes are complexly influenced by fluvial responses to factors such as climatic change, local base-level differences across divides, and (or) tectonic activity (the latter only recognized in Amargosa Canyon). ?? 2008 The Geological Society of America.","largerWorkTitle":"Special Paper of the Geological Society of America","language":"English","doi":"10.1130/2008.2439(03)","issn":"00721077","usgsCitation":"Menges, C., 2008, Multistage late Cenozoic evolution of the Amargosa River drainage, southwestern Nevada and eastern California Society of America. All rights reserved, <i>in</i> Special Paper of the Geological Society of America, no. 439, p. 39-90, https://doi.org/10.1130/2008.2439(03).","startPage":"39","endPage":"90","numberOfPages":"52","costCenters":[],"links":[{"id":215337,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1130/2008.2439(03)"},{"id":243132,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"issue":"439","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a60aae4b0c8380cd715f4","contributors":{"authors":[{"text":"Menges, C.M.","contributorId":71200,"corporation":false,"usgs":false,"family":"Menges","given":"C.M.","affiliations":[],"preferred":false,"id":449880,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}}
,{"id":70032756,"text":"70032756 - 2008 - Estimating groundwater recharge in Hebei Plain, China under varying land use practices using tritium and bromide tracers","interactions":[],"lastModifiedDate":"2012-03-12T17:21:23","indexId":"70032756","displayToPublicDate":"2008-01-01T00:00:00","publicationYear":"2008","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2342,"text":"Journal of Hydrology","active":true,"publicationSubtype":{"id":10}},"title":"Estimating groundwater recharge in Hebei Plain, China under varying land use practices using tritium and bromide tracers","docAbstract":"Tritium and bromide were used as applied tracers to determine groundwater recharge in Hebei Plain, North China, to evaluate the impacts of different soil types, land use, irrigation, and crop cultivation practice on recharge. Additional objectives were to evaluate temporal variability of recharge and the effect on results of the particular tracer used. Thirty-nine profiles at representative locations were chosen for investigation. Average recharge rates and recharge coefficient determined by tritium and bromide tracing for different sites were 0.00-1.05 mm/d and 0.0-42.5%, respectively. The results showed relative recharge rates for the following paired influences (items within each pair are listed with the influence producing greater recharge first): flood-irrigated cropland and non-irrigated non-cultivation land, flood irrigation (0.42-0.58 mm/d) and sprinkling irrigation (0.17-0.23 mm/d), no stalk mulch (0.56-0.80 mm/d) and stalk mulch (0.44-0.60 mm/d), vegetable (e.g. Chinese cabbage and garlic, 0.70 mm/d) and wheat-maize (0.38 mm/d), peanut (0.51 mm/d) and peach (0.43 mm/d). The results also showed greater recharge for the first year of tracer travel than for the second. Because total precipitation and irrigation were greater in the first year than in the second, this may reflect temporal variability of recharge. The method may not be applicable where the water table is shallow (less than 3 m). A comparison of the near-ideal tritium tracer with the more common but less ideal bromide showed that bromide moved approximately 23% faster than tritiated water, perhaps because of anion exclusion. ?? 2008 Elsevier B.V.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Journal of Hydrology","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1016/j.jhydrol.2008.04.011","issn":"00221694","usgsCitation":"Wang, B., Jin, M., Nimmo, J., Yang, L., and Wang, W., 2008, Estimating groundwater recharge in Hebei Plain, China under varying land use practices using tritium and bromide tracers: Journal of Hydrology, v. 356, no. 1-2, p. 209-222, https://doi.org/10.1016/j.jhydrol.2008.04.011.","startPage":"209","endPage":"222","numberOfPages":"14","costCenters":[],"links":[{"id":213737,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/j.jhydrol.2008.04.011"},{"id":241394,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"356","issue":"1-2","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a0b20e4b0c8380cd525ac","contributors":{"authors":[{"text":"Wang, B.","contributorId":29011,"corporation":false,"usgs":true,"family":"Wang","given":"B.","email":"","affiliations":[],"preferred":false,"id":437772,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Jin, M.","contributorId":44745,"corporation":false,"usgs":true,"family":"Jin","given":"M.","email":"","affiliations":[],"preferred":false,"id":437773,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Nimmo, J. R. 0000-0001-8191-1727","orcid":"https://orcid.org/0000-0001-8191-1727","contributorId":58304,"corporation":false,"usgs":true,"family":"Nimmo","given":"J. R.","affiliations":[],"preferred":false,"id":437774,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Yang, L.","contributorId":6200,"corporation":false,"usgs":true,"family":"Yang","given":"L.","affiliations":[],"preferred":false,"id":437771,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Wang, W.","contributorId":76003,"corporation":false,"usgs":true,"family":"Wang","given":"W.","affiliations":[],"preferred":false,"id":437775,"contributorType":{"id":1,"text":"Authors"},"rank":5}]}}
,{"id":70032363,"text":"70032363 - 2008 - Effects of residence time on summer nitrate uptake in Mississippi River flow-regulated backwaters","interactions":[],"lastModifiedDate":"2012-03-12T17:21:24","indexId":"70032363","displayToPublicDate":"2008-01-01T00:00:00","publicationYear":"2008","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":3301,"text":"River Research and Applications","active":true,"publicationSubtype":{"id":10}},"title":"Effects of residence time on summer nitrate uptake in Mississippi River flow-regulated backwaters","docAbstract":"Nitrate uptake may be improved in regulated floodplain rivers by increasing hydrological connectivity to backwaters. We examined summer nitrate uptake in a series of morphologically similar backwaters on the Upper Mississippi River receiving flow-regulated nitrate loads via gated culverts. Flows into individual backwaters were held constant over a summer period but varied in the summers of 2003 and 2004 to provide a range of hydraulic loads and residence times (??). The objectives were to determine optimum loading and ?? for maximum summer uptake. Higher flow adjustment led to increased loading but lower ?? and contact time for uptake. For highest flows, ?? was less than 1 day resulting in lower uptake rates (Unet, < 300 mg m-2 day-1), low uptake efficiency (U% < 20%) and a long uptake length (Snet > 4000 m). For low flows, ?? was greater than 5 days and U% approached 100%, but Unet was 200 mg m-2 day-1. Snet was < half the length of the backwaters under these conditions indicating that most of the load was assimilated in the upper reaches, leading to limited delivery to lower portions. Unet was maximal (384-629 mg m-2 day-1) for intermediate flows and ?? ranging between 1 and 1.5 days. Longer Snet (2000-4000 m) and lower U% (20-40%) reflected limitation of uptake in upper reaches by contact time, leading to transport to lower reaches for additional uptake. Uptake by ???10 000 ha of reconnected backwaters along the Upper Mississippi River (13% of the total backwater surface area) at a Unet of ???630 mg m-2 day-1 would be the equivalent of ???40% of the summer nitrate load (155 mg day-1) discharged from Lock and Dam 4. These results indicate that backwater nitrate uptake can play an important role in reducing nitrate loading to the Gulf of Mexico. Copyright ?? 2008 John Wiley & Sons, Ltd.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"River Research and Applications","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1002/rra.1150","issn":"15351","usgsCitation":"James, W., Richardson, W.B., and Soballe, D., 2008, Effects of residence time on summer nitrate uptake in Mississippi River flow-regulated backwaters: River Research and Applications, v. 24, no. 9, p. 1206-1217, https://doi.org/10.1002/rra.1150.","startPage":"1206","endPage":"1217","numberOfPages":"12","costCenters":[],"links":[{"id":241612,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":213937,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1002/rra.1150"}],"volume":"24","issue":"9","noUsgsAuthors":false,"publicationDate":"2008-04-29","publicationStatus":"PW","scienceBaseUri":"505a07b1e4b0c8380cd517aa","contributors":{"authors":[{"text":"James, W.F.","contributorId":58602,"corporation":false,"usgs":true,"family":"James","given":"W.F.","email":"","affiliations":[],"preferred":false,"id":435790,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Richardson, W. B.","contributorId":16363,"corporation":false,"usgs":true,"family":"Richardson","given":"W.","email":"","middleInitial":"B.","affiliations":[],"preferred":false,"id":435789,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Soballe, D.M.","contributorId":87654,"corporation":false,"usgs":true,"family":"Soballe","given":"D.M.","affiliations":[],"preferred":false,"id":435791,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}}
,{"id":70032238,"text":"70032238 - 2008 - Multi-residue method for the analysis of 85 current-use and legacy pesticides in bed and suspended sediments","interactions":[],"lastModifiedDate":"2018-10-22T07:52:00","indexId":"70032238","displayToPublicDate":"2008-01-01T00:00:00","publicationYear":"2008","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2214,"text":"Journal of Chromatography A","active":true,"publicationSubtype":{"id":10}},"title":"Multi-residue method for the analysis of 85 current-use and legacy pesticides in bed and suspended sediments","docAbstract":"A multi-residue method was developed for the simultaneous determination of 85 current-use and legacy organochlorine pesticides in a single sediment sample. After microwave-assisted extraction, clean-up of samples was optimized using gel permeation chromatography and either stacked carbon and alumina solid-phase extraction cartridges or a deactivated Florisil column. Analytes were determined by gas chromatography with ion-trap mass spectrometry and electron capture detection. Method detection limits ranged from 0.6 to 8.9 ??g/kg dry weight. Bed and suspended sediments from a variety of locations were analyzed to validate the method and 29 pesticides, including at least 1 from every class, were detected.","language":"English","publisher":"Elsevier","doi":"10.1016/j.chroma.2008.09.023","issn":"00219","usgsCitation":"Smalling, K., and Kuivila, K., 2008, Multi-residue method for the analysis of 85 current-use and legacy pesticides in bed and suspended sediments: Journal of Chromatography A, v. 1210, no. 1, p. 8-18, https://doi.org/10.1016/j.chroma.2008.09.023.","productDescription":"11 p.","startPage":"8","endPage":"18","costCenters":[{"id":154,"text":"California Water Science Center","active":true,"usgs":true},{"id":589,"text":"Toxic Substances Hydrology Program","active":true,"usgs":true}],"links":[{"id":242775,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":215011,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/j.chroma.2008.09.023"}],"volume":"1210","issue":"1","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a5fbee4b0c8380cd710ef","contributors":{"authors":[{"text":"Smalling, K.L.","contributorId":66068,"corporation":false,"usgs":true,"family":"Smalling","given":"K.L.","email":"","affiliations":[],"preferred":false,"id":435186,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Kuivila, K.M.","contributorId":34529,"corporation":false,"usgs":true,"family":"Kuivila","given":"K.M.","email":"","affiliations":[],"preferred":false,"id":435185,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}}
,{"id":70032207,"text":"70032207 - 2008 - Wetlands as principal zones of methylmercury production in southern Louisiana and the Gulf of Mexico region","interactions":[],"lastModifiedDate":"2018-10-17T08:14:29","indexId":"70032207","displayToPublicDate":"2008-01-01T00:00:00","publicationYear":"2008","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1555,"text":"Environmental Pollution","active":true,"publicationSubtype":{"id":10}},"title":"Wetlands as principal zones of methylmercury production in southern Louisiana and the Gulf of Mexico region","docAbstract":"<p>It is widely recognized that wetlands, especially those rich in organic matter and receiving appreciable atmospheric mercury (Hg) inputs, are important sites of methylmercury (MeHg) production. Extensive wetlands in the southeastern United States have many ecosystem attributes ideal for promoting high MeHg production rates; however, relatively few mercury cycling studies have been conducted in these environments. We conducted a landscape scale study examining Hg cycling in coastal Louisiana (USA) including four field trips conducted between August 2003 and May 2005. Sites were chosen to represent different ecosystem types, including: a large shallow eutrophic estuarine lake (Lake Pontchartrain), three rivers draining into the lake, a cypress-tupelo dominated freshwater swamp, and six emergent marshes ranging from a freshwater marsh dominated by<span>&nbsp;</span><i>Panicum hemitomon</i><span>&nbsp;</span>to a<span>&nbsp;</span><i>Spartina alterniflora</i><span>&nbsp;</span>dominated salt marsh close to the Gulf of Mexico. We measured MeHg and total Hg (THg) concentrations, and ancillary chemical characteristics, in whole and filtered surface water, and filtered porewater.</p><p>Overall, MeHg concentrations were greatest in surface water of freshwater wetlands and lowest in the profundal (non-vegetated) regions of the lake and river mainstems. Concentrations of THg and MeHg in filtered surface water were positively correlated with the highly reactive, aromatic (hydrophobic organic acid) fraction of dissolved organic carbon (DOC). These results suggest that DOC plays an important role in promoting the mobility, transport and bioavailability of inorganic Hg in these environments. Further, elevated porewater concentrations in marine and brackish wetlands suggest coastal wetlands along the Gulf Coast are key sites for MeHg production and may be a principal source of MeHg to foodwebs in the Gulf of Mexico.</p><p>Examining the relationships among MeHg, THg, and DOC across these multiple landscape types is a first step in evaluating possible links between key zones for Hg(II)-methylation and the bioaccumulation of mercury in the biota inhabiting the Gulf of Mexico region</p>","language":"English","publisher":"Elsevier","doi":"10.1016/j.envpol.2007.12.017","issn":"02697491","usgsCitation":"Hall, B., Aiken, G., Krabbenhoft, D., Marvin-DiPasquale, M., and Swarzenski, C., 2008, Wetlands as principal zones of methylmercury production in southern Louisiana and the Gulf of Mexico region: Environmental Pollution, v. 154, no. 1, p. 124-134, https://doi.org/10.1016/j.envpol.2007.12.017.","productDescription":"11 p.","startPage":"124","endPage":"134","costCenters":[{"id":589,"text":"Toxic Substances Hydrology Program","active":true,"usgs":true}],"links":[{"id":242802,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":215035,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/j.envpol.2007.12.017"}],"volume":"154","issue":"1","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505bd028e4b08c986b32ecd6","contributors":{"authors":[{"text":"Hall, B.D.","contributorId":42408,"corporation":false,"usgs":true,"family":"Hall","given":"B.D.","email":"","affiliations":[],"preferred":false,"id":435035,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Aiken, G. R. 0000-0001-8454-0984","orcid":"https://orcid.org/0000-0001-8454-0984","contributorId":14452,"corporation":false,"usgs":true,"family":"Aiken","given":"G. R.","affiliations":[],"preferred":false,"id":435033,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Krabbenhoft, D. P. 0000-0003-1964-5020","orcid":"https://orcid.org/0000-0003-1964-5020","contributorId":90765,"corporation":false,"usgs":true,"family":"Krabbenhoft","given":"D. P.","affiliations":[],"preferred":false,"id":435037,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Marvin-DiPasquale, M.","contributorId":28367,"corporation":false,"usgs":true,"family":"Marvin-DiPasquale","given":"M.","affiliations":[],"preferred":false,"id":435034,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Swarzenski, C.M.","contributorId":74856,"corporation":false,"usgs":true,"family":"Swarzenski","given":"C.M.","email":"","affiliations":[],"preferred":false,"id":435036,"contributorType":{"id":1,"text":"Authors"},"rank":5}]}}
,{"id":70035594,"text":"70035594 - 2008 - Reconstructing late Pliocene to middle Pleistocene Death Valley lakes and river systems as a test of pupfish (Cyprinodontidae) dispersal hypotheses","interactions":[],"lastModifiedDate":"2012-03-12T17:21:51","indexId":"70035594","displayToPublicDate":"2008-01-01T00:00:00","publicationYear":"2008","noYear":false,"publicationType":{"id":24,"text":"Conference Paper"},"publicationSubtype":{"id":19,"text":"Conference Paper"},"title":"Reconstructing late Pliocene to middle Pleistocene Death Valley lakes and river systems as a test of pupfish (Cyprinodontidae) dispersal hypotheses","docAbstract":"During glacial (pluvial) climatic periods, Death Valley is hypothesized to have episodically been the terminus for the Amargosa, Owens, and Mojave Rivers. Geological and biological studies have tended to support this hypothesis and a hydrological link that included the Colorado River, allowing dispersal of pupfish throughout southeastern California and western Nevada. Recent mitochondrial deoxyribonucleic acid (mtDNA) studies show a common pupfish (Cyprinodontidae) ancestry in this region with divergence beginning 3-2 Ma. We present tephrochronologic and paleomagnetic data in the context of testing the paleohydrologic connections with respect to the common collection point of the Amargosa, Owens, and Mojave Rivers in Death during successive time periods: (1) the late Pliocene to early Pleistocene (3-2 Ma), (2) early to middle Pleistocene (1.2-0.5 Ma), and (3) middle to late Pleistocene (<0.70.03 Ma; paleolakes Manly and Mojave). Using the 3.35 Ma Zabriskie Wash tuff and 3.28 Ma Nomlaki Tuff Member of the Tuscan and Tehama Formations, which are prominent marker beds in the region, we conclude that at 3-2 Ma, a narrow lake occupied the ancient Furnace Creek Basin and that Death Valley was not hydrologically connected with the Amargosa or Mojave Rivers. A paucity of data for Panamint Valley does not allow us to evaluate an Owens River connection to Death Valley ca. 3-2 Ma. Studies by others have shown that Death Valley was not hydrologically linked to the Amargosa, Owens, or Mojave Rivers from 1.2 to 0.5 Ma. We found no evidence that Lake Manly flooded back up the Mojave River to pluvial Lake Mojave between 0.18 and 0.12 Ma, although surface water flowed from the Amargosa and Owens Rivers to Death Valley at this time. There is also no evidence for a connection of the Owens, Amargosa, or Mojave Rivers to the Colorado River in the last 3-2 m.y. Therefore, the hypothesis that pupfish dispersed or were isolated in basins throughout southeastern California and western Nevada by such a connection is not supported. Beyond the biologically predicted time frame, however, sparse and disputed data suggest that a fluvial system connected Panamint (Owens River), Death, and Amargosa Valleys, which could account for the dispersal and isolation before 3 Ma. ?? 2008 The Geological Society of America.","largerWorkTitle":"Special Paper of the Geological Society of America","language":"English","doi":"10.1130/2008.2439(01)","issn":"00721077","usgsCitation":"Knott, J., Machette, M.N., Klinger, R., Sarna-Wojcicki, A., Liddicoat, J.C., Tinsley, J.C., David, B., and Ebbs, V., 2008, Reconstructing late Pliocene to middle Pleistocene Death Valley lakes and river systems as a test of pupfish (Cyprinodontidae) dispersal hypotheses, <i>in</i> Special Paper of the Geological Society of America, no. 439, p. 1-26, https://doi.org/10.1130/2008.2439(01).","startPage":"1","endPage":"26","numberOfPages":"26","costCenters":[],"links":[{"id":216128,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1130/2008.2439(01)"},{"id":243975,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"issue":"439","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"50e4a250e4b0e8fec6cdb56f","contributors":{"authors":[{"text":"Knott, J.R.","contributorId":26847,"corporation":false,"usgs":true,"family":"Knott","given":"J.R.","affiliations":[],"preferred":false,"id":451374,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Machette, M. N.","contributorId":19561,"corporation":false,"usgs":true,"family":"Machette","given":"M.","email":"","middleInitial":"N.","affiliations":[],"preferred":false,"id":451373,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Klinger, R.E.","contributorId":13807,"corporation":false,"usgs":true,"family":"Klinger","given":"R.E.","email":"","affiliations":[],"preferred":false,"id":451371,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Sarna-Wojcicki, A.M. 0000-0002-0244-9149","orcid":"https://orcid.org/0000-0002-0244-9149","contributorId":104022,"corporation":false,"usgs":true,"family":"Sarna-Wojcicki","given":"A.M.","affiliations":[],"preferred":false,"id":451378,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Liddicoat, J. C.","contributorId":76781,"corporation":false,"usgs":false,"family":"Liddicoat","given":"J.","email":"","middleInitial":"C.","affiliations":[],"preferred":false,"id":451377,"contributorType":{"id":1,"text":"Authors"},"rank":5},{"text":"Tinsley, J. C. III","contributorId":39777,"corporation":false,"usgs":true,"family":"Tinsley","given":"J.","suffix":"III","email":"","middleInitial":"C.","affiliations":[],"preferred":false,"id":451375,"contributorType":{"id":1,"text":"Authors"},"rank":6},{"text":"David, B.T.","contributorId":54428,"corporation":false,"usgs":true,"family":"David","given":"B.T.","email":"","affiliations":[],"preferred":false,"id":451376,"contributorType":{"id":1,"text":"Authors"},"rank":7},{"text":"Ebbs, V.M.","contributorId":15859,"corporation":false,"usgs":true,"family":"Ebbs","given":"V.M.","email":"","affiliations":[],"preferred":false,"id":451372,"contributorType":{"id":1,"text":"Authors"},"rank":8}]}}
,{"id":70032742,"text":"70032742 - 2008 - The persistence of lead from past gasoline emissions and mining drainage in a large riparian system: Evidence from lead isotopes in the Sacramento River, California","interactions":[],"lastModifiedDate":"2018-10-17T08:27:14","indexId":"70032742","displayToPublicDate":"2008-01-01T00:00:00","publicationYear":"2008","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1759,"text":"Geochimica et Cosmochimica Acta","active":true,"publicationSubtype":{"id":10}},"title":"The persistence of lead from past gasoline emissions and mining drainage in a large riparian system: Evidence from lead isotopes in the Sacramento River, California","docAbstract":"<div id=\"abstracts\" class=\"Abstracts\"><div id=\"aep-abstract-id15\" class=\"abstract author\" lang=\"en\"><div id=\"aep-abstract-sec-id16\"><p>Lead concentrations and isotope ratios measured in river water colloids and streambed sediment samples along 426&nbsp;km of the Sacramento River, California reveal that the influence of lead from the historical mining of massive sulfide deposits in the West Shasta Cu-mining district (at the headwaters of the Sacramento River) is confined to a 60&nbsp;km stretch of river immediately downstream of that mining region, whereas inputs from past leaded gasoline emissions and historical hydraulic Au-mining in the Sierra Nevadan foothills are the dominant lead sources in the remaining 370&nbsp;km of the river. Binary mixing calculations suggest that more than 50% of the lead in the Sacramento River outside of the region of influence of the West Shasta Cu-mining district is derived from past depositions of leaded gasoline emissions. This predominance is the first direct documentation of the geographic extent of gasoline lead persistence throughout a large riparian system (&gt;160,000&nbsp;km<sup>2</sup>) and corroborates previous observations based on samples taken at the mouth of the Sacramento River. In addition, new analyses of sediment samples from the hydraulic gold mines of the Sierra Nevada foothills confirm the present-day fluxes into the Sacramento River of contaminant metals derived from historical hydraulic Au-mining that occurred during the latter half of the 19th and early part of the 20th centuries. These fluxes occur predominantly during periods of elevated river discharge associated with heavy winter precipitation in northern California. In the broadest context, the study demonstrates the potential for altered precipitation patterns resulting from climate change to affect the mobility and transport of soil-bound contaminants in the surface environment.</p></div></div></div>","language":"English","publisher":"Elsevier","doi":"10.1016/j.gca.2008.10.006","issn":"00167","usgsCitation":"Dunlap, C., Alpers, C.N., Bouse, R., Taylor, H.E., Unruh, D., and Flegal, A., 2008, The persistence of lead from past gasoline emissions and mining drainage in a large riparian system: Evidence from lead isotopes in the Sacramento River, California: Geochimica et Cosmochimica Acta, v. 72, no. 24, p. 5935-5948, https://doi.org/10.1016/j.gca.2008.10.006.","productDescription":"14 p.","startPage":"5935","endPage":"5948","costCenters":[{"id":154,"text":"California Water Science Center","active":true,"usgs":true},{"id":589,"text":"Toxic Substances Hydrology Program","active":true,"usgs":true}],"links":[{"id":241736,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":214049,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/j.gca.2008.10.006"}],"volume":"72","issue":"24","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505bae89e4b08c986b32417a","contributors":{"authors":[{"text":"Dunlap, C.E.","contributorId":49570,"corporation":false,"usgs":true,"family":"Dunlap","given":"C.E.","email":"","affiliations":[],"preferred":false,"id":437702,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Alpers, Charles N. 0000-0001-6945-7365 cnalpers@usgs.gov","orcid":"https://orcid.org/0000-0001-6945-7365","contributorId":411,"corporation":false,"usgs":true,"family":"Alpers","given":"Charles","email":"cnalpers@usgs.gov","middleInitial":"N.","affiliations":[{"id":154,"text":"California Water Science Center","active":true,"usgs":true}],"preferred":true,"id":437705,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Bouse, R.","contributorId":89956,"corporation":false,"usgs":true,"family":"Bouse","given":"R.","affiliations":[],"preferred":false,"id":437704,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Taylor, Howard E. hetaylor@usgs.gov","contributorId":1551,"corporation":false,"usgs":true,"family":"Taylor","given":"Howard","email":"hetaylor@usgs.gov","middleInitial":"E.","affiliations":[{"id":5044,"text":"National Research Program - Central Branch","active":true,"usgs":true}],"preferred":true,"id":437701,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Unruh, D.M.","contributorId":8498,"corporation":false,"usgs":true,"family":"Unruh","given":"D.M.","email":"","affiliations":[],"preferred":false,"id":437700,"contributorType":{"id":1,"text":"Authors"},"rank":5},{"text":"Flegal, A.R.","contributorId":64607,"corporation":false,"usgs":true,"family":"Flegal","given":"A.R.","email":"","affiliations":[],"preferred":false,"id":437703,"contributorType":{"id":1,"text":"Authors"},"rank":6}]}}
,{"id":70030512,"text":"70030512 - 2008 - Is there enough sand? Evaluating the fate of Grand Canyon sandbars","interactions":[],"lastModifiedDate":"2019-08-27T08:22:38","indexId":"70030512","displayToPublicDate":"2008-01-01T00:00:00","publicationYear":"2008","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1728,"text":"GSA Today","active":true,"publicationSubtype":{"id":10}},"title":"Is there enough sand? Evaluating the fate of Grand Canyon sandbars","docAbstract":"Large dams have the potential to dramatically alter the flow regime, geomorphology, and aquatic ecosystem of downstream river reaches. Development of flow release regimes in order to meet multiple objectives is a challenge facing dam operators, resource managers, and scientists. Herein, we review previous work and present new analyses related to the effects of Glen Canyon Dam on the downstream reach of the Colorado River in Marble and Grand Canyons. The dam traps the entire incoming sediment load in Lake Powell and modulates the hydrologic regime by, for example, eliminating spring snowmelt floods, resulting in changes in the geomorphology of the river downstream. The primary geomorphic impact has been the erosion of sandbars along the banks of the river. Recognition of this impact has led to many scientific studies and a variety of experimental operations of Glen Canyon Dam with the goal of rebuilding the eroding sandbars. These efforts have thus far been generally unsuccessful and the question remains as to whether or not the dam can be operated such that sandbars can be rebuilt and maintained over extended periods with the existing sediment supply. We attempt to answer this question by evaluating a dam operation that may be considered a \"best-case scenario\" for rebuilding and maintaining eroded sandbars. Our analysis suggests that this best-case scenario may indeed have viability for rebuilding sandbars, and that the initial rate at which sandbars could be rebuilt is comparable to the rate at which sandbars have been eroded since dam construction. The question remains open as to the viability of operations that deviate from the best-case scenario that we have defined.","language":"English","publisher":"GeoSociety","doi":"10.1130/GSATG12A.1","issn":"10525","usgsCitation":"Wright, S., Schmidt, J.C., Melis, T., Topping, D., and Rubin, D.M., 2008, Is there enough sand? Evaluating the fate of Grand Canyon sandbars: GSA Today, v. 18, no. 8, p. 4-10, https://doi.org/10.1130/GSATG12A.1.","productDescription":"7 p.","startPage":"4","endPage":"10","numberOfPages":"7","costCenters":[{"id":568,"text":"Southwest Biological Science Center","active":true,"usgs":true}],"links":[{"id":239071,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":211726,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1130/GSATG12A.1"}],"country":"United States","otherGeospatial":"Grand Canyon","geographicExtents":"{\n  \"type\": \"FeatureCollection\",\n  \"features\": [\n    {\n      \"type\": \"Feature\",\n      \"properties\": {},\n      \"geometry\": {\n        \"type\": \"Polygon\",\n        \"coordinates\": [\n          [\n            [\n              -114.554443359375,\n              35.576916524038616\n            ],\n            [\n              -111.214599609375,\n              35.576916524038616\n            ],\n            [\n              -111.214599609375,\n              37.112145754751516\n            ],\n            [\n              -114.554443359375,\n              37.112145754751516\n            ],\n            [\n              -114.554443359375,\n              35.576916524038616\n            ]\n          ]\n        ]\n      }\n    }\n  ]\n}","volume":"18","issue":"8","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a3f33e4b0c8380cd6433e","contributors":{"authors":[{"text":"Wright, S.A.","contributorId":90080,"corporation":false,"usgs":true,"family":"Wright","given":"S.A.","email":"","affiliations":[],"preferred":false,"id":427432,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Schmidt, J. C.","contributorId":60245,"corporation":false,"usgs":true,"family":"Schmidt","given":"J.","email":"","middleInitial":"C.","affiliations":[],"preferred":false,"id":427431,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Melis, Theodore S. 0000-0003-0473-3968 tmelis@usgs.gov","orcid":"https://orcid.org/0000-0003-0473-3968","contributorId":1829,"corporation":false,"usgs":true,"family":"Melis","given":"Theodore S.","email":"tmelis@usgs.gov","affiliations":[{"id":568,"text":"Southwest Biological Science Center","active":true,"usgs":true}],"preferred":true,"id":769228,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Topping, D.J. 0000-0002-2104-4577","orcid":"https://orcid.org/0000-0002-2104-4577","contributorId":53927,"corporation":false,"usgs":true,"family":"Topping","given":"D.J.","affiliations":[],"preferred":false,"id":427430,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Rubin, D. M.","contributorId":103689,"corporation":false,"usgs":true,"family":"Rubin","given":"D.","email":"","middleInitial":"M.","affiliations":[],"preferred":false,"id":427433,"contributorType":{"id":1,"text":"Authors"},"rank":5}]}}
,{"id":70031865,"text":"70031865 - 2008 - A satellite snow depth multi-year average derived from SSM/I for the high latitude regions","interactions":[],"lastModifiedDate":"2012-03-12T17:21:25","indexId":"70031865","displayToPublicDate":"2008-01-01T00:00:00","publicationYear":"2008","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":"A satellite snow depth multi-year average derived from SSM/I for the high latitude regions","docAbstract":"The hydrological cycle for high latitude regions is inherently linked with the seasonal snowpack. Thus, accurately monitoring the snow depth and the associated aerial coverage are critical issues for monitoring the global climate system. Passive microwave satellite measurements provide an optimal means to monitor the snowpack over the arctic region. While the temporal evolution of snow extent can be observed globally from microwave radiometers, the determination of the corresponding snow depth is more difficult. A dynamic algorithm that accounts for the dependence of the microwave scattering on the snow grain size has been developed to estimate snow depth from Special Sensor Microwave/Imager (SSM/I) brightness temperatures and was validated over the U.S. Great Plains and Western Siberia. The purpose of this study is to assess the dynamic algorithm performance over the entire high latitude (land) region by computing a snow depth multi-year field for the time period 1987-1995. This multi-year average is compared to the Global Soil Wetness Project-Phase2 (GSWP2) snow depth computed from several state-of-the-art land surface schemes and averaged over the same time period. The multi-year average obtained by the dynamic algorithm is in good agreement with the GSWP2 snow depth field (the correlation coefficient for January is 0.55). The static algorithm, which assumes a constant snow grain size in space and time does not correlate with the GSWP2 snow depth field (the correlation coefficient with GSWP2 data for January is - 0.03), but exhibits a very high anti-correlation with the NCEP average January air temperature field (correlation coefficient - 0.77), the deepest satellite snow pack being located in the coldest regions, where the snow grain size may be significantly larger than the average value used in the static algorithm. The dynamic algorithm performs better over Eurasia (with a correlation coefficient with GSWP2 snow depth equal to 0.65) than over North America (where the correlation coefficient decreases to 0.29). ?? 2007 Elsevier Inc. All rights reserved.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Remote Sensing of Environment","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1016/j.rse.2007.12.002","issn":"00344257","usgsCitation":"Biancamaria, S., Mognard, N.M., Boone, A., Grippa, M., and Josberger, E., 2008, A satellite snow depth multi-year average derived from SSM/I for the high latitude regions: Remote Sensing of Environment, v. 112, no. 5, p. 2557-2568, https://doi.org/10.1016/j.rse.2007.12.002.","startPage":"2557","endPage":"2568","numberOfPages":"12","costCenters":[],"links":[{"id":476714,"rank":10000,"type":{"id":41,"text":"Open Access External Repository Page"},"url":"https://hal.science/hal-00575478","text":"External Repository"},{"id":214955,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/j.rse.2007.12.002"},{"id":242717,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"112","issue":"5","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"5059e569e4b0c8380cd46d52","contributors":{"authors":[{"text":"Biancamaria, S.","contributorId":21338,"corporation":false,"usgs":true,"family":"Biancamaria","given":"S.","email":"","affiliations":[],"preferred":false,"id":433495,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Mognard, N. M.","contributorId":27612,"corporation":false,"usgs":false,"family":"Mognard","given":"N.","email":"","middleInitial":"M.","affiliations":[],"preferred":false,"id":433496,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Boone, A.","contributorId":38348,"corporation":false,"usgs":true,"family":"Boone","given":"A.","email":"","affiliations":[],"preferred":false,"id":433497,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Grippa, M.","contributorId":82098,"corporation":false,"usgs":true,"family":"Grippa","given":"M.","email":"","affiliations":[],"preferred":false,"id":433499,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Josberger, E.G.","contributorId":61161,"corporation":false,"usgs":true,"family":"Josberger","given":"E.G.","email":"","affiliations":[],"preferred":false,"id":433498,"contributorType":{"id":1,"text":"Authors"},"rank":5}]}}
,{"id":70032200,"text":"70032200 - 2008 - Transport of elemental mercury in the unsaturated zone from a waste disposal site in an arid region","interactions":[],"lastModifiedDate":"2018-10-22T08:06:22","indexId":"70032200","displayToPublicDate":"2008-01-01T00:00:00","publicationYear":"2008","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":"Transport of elemental mercury in the unsaturated zone from a waste disposal site in an arid region","docAbstract":"<p><span>Mercury contained in buried landfill waste may be released via upward emission to the atmosphere or downward leaching to groundwater. Data from the US Geological Survey’s Amargosa Desert Research Site (ADRS) in arid southwestern Nevada reveal another potential pathway of Hg release: long-distance (10</span><sup>2</sup><span>&nbsp;</span><span>m) lateral migration of elemental Hg (Hg</span><sup>0</sup><span>) through the unsaturated zone. Gas collected from multiple depths from two instrumented boreholes that sample the entire 110-m unsaturated zone thickness and are located 100 and 160</span><span>&nbsp;</span><span>m away from the closest waste burial trench exhibit gaseous Hg concentrations of up to 33 and 11</span><span>&nbsp;</span><span>ng</span><span>&nbsp;</span><span>m</span><sup>−3</sup><span>, respectively. The vertical distribution of gaseous Hg in the borehole closest to the disposal site shows distinct subsurface peaks in concentration at depths of 1.5 and 24</span><span>&nbsp;</span><span>m that cannot be explained by radial diffusive transport through a heterogeneous layered unsaturated zone. The inability of current models to explain gaseous Hg distribution at the ADRS highlights the need to advance the understanding of gas-phase contaminant transport in unsaturated zones to attain a comprehensive model of landfill Hg release.</span></p>","language":"English","publisher":"Elsevier","doi":"10.1016/j.apgeochem.2007.12.014","usgsCitation":"Walvoord, M.A., Andraski, B.J., Krabbenhoft, D., and Striegl, R.G., 2008, Transport of elemental mercury in the unsaturated zone from a waste disposal site in an arid region: Applied Geochemistry, v. 23, no. 3, p. 572-583, https://doi.org/10.1016/j.apgeochem.2007.12.014.","productDescription":"12 p.","startPage":"572","endPage":"583","costCenters":[{"id":465,"text":"Nevada Water Science Center","active":true,"usgs":true},{"id":589,"text":"Toxic Substances Hydrology Program","active":true,"usgs":true}],"links":[{"id":242702,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"23","issue":"3","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505bb74fe4b08c986b3271af","contributors":{"authors":[{"text":"Walvoord, Michelle Ann 0000-0003-4269-8366 walvoord@usgs.gov","orcid":"https://orcid.org/0000-0003-4269-8366","contributorId":147211,"corporation":false,"usgs":true,"family":"Walvoord","given":"Michelle","email":"walvoord@usgs.gov","middleInitial":"Ann","affiliations":[{"id":5044,"text":"National Research Program - Central Branch","active":true,"usgs":true}],"preferred":true,"id":435009,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Andraski, Brian J. 0000-0002-2086-0417 andraski@usgs.gov","orcid":"https://orcid.org/0000-0002-2086-0417","contributorId":168800,"corporation":false,"usgs":true,"family":"Andraski","given":"Brian","email":"andraski@usgs.gov","middleInitial":"J.","affiliations":[{"id":438,"text":"National Research Program - Western Branch","active":true,"usgs":true},{"id":38175,"text":"Toxics Substances Hydrology Program","active":true,"usgs":true},{"id":465,"text":"Nevada Water Science Center","active":true,"usgs":true}],"preferred":false,"id":435007,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Krabbenhoft, D. P. 0000-0003-1964-5020","orcid":"https://orcid.org/0000-0003-1964-5020","contributorId":90765,"corporation":false,"usgs":true,"family":"Krabbenhoft","given":"D. P.","affiliations":[],"preferred":false,"id":435008,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Striegl, Robert G. 0000-0002-8251-4659 rstriegl@usgs.gov","orcid":"https://orcid.org/0000-0002-8251-4659","contributorId":1630,"corporation":false,"usgs":true,"family":"Striegl","given":"Robert","email":"rstriegl@usgs.gov","middleInitial":"G.","affiliations":[{"id":5044,"text":"National Research Program - Central Branch","active":true,"usgs":true},{"id":37277,"text":"WMA - Earth System Processes Division","active":true,"usgs":true},{"id":36183,"text":"Hydro-Ecological Interactions Branch","active":true,"usgs":true},{"id":200,"text":"Coop Res Unit Seattle","active":true,"usgs":true}],"preferred":false,"id":435006,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}}
,{"id":70035358,"text":"70035358 - 2008 - Do beavers promote the invasion of non-native Tamarix in the Grand Canyon riparian zone","interactions":[],"lastModifiedDate":"2012-03-12T17:21:53","indexId":"70035358","displayToPublicDate":"2008-01-01T00:00:00","publicationYear":"2008","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":3750,"text":"Wetlands","onlineIssn":"1943-6246","printIssn":"0277-5212","active":true,"publicationSubtype":{"id":10}},"title":"Do beavers promote the invasion of non-native Tamarix in the Grand Canyon riparian zone","docAbstract":"Beavers (Castor canadensis Kuhl) can influence the competitive dynamics of plant species through selective foraging, collection of materials for dam creation, and alteration of hydrologic conditions. In the Grand Canyon National Park, the native Salix gooddingii C.R.Ball (Goodding's willow) and Salix exigua Nutt. (coyote willow) are a staple food of beavers. Because Salix competes with the invasive Tamarix ramosissima Ledeb., land mangers are concerned that beavers may cause an increase in Tamarix through selective foraging of Salix. A spatial analysis was conducted to assess whether the presence of beavers correlates with the relative abundance of Salix and Tamarix. These methods were designed to detect a system-wide effect of selective beaver foraging in this large study area (367 linear km of riparian habitat). Beavers, Salix, and Tamarix co-occurred at the broadest scales because they occupied similar riparian habitat, particularly geomorphic reaches of low and moderate resistivity. Once the affinity of Salix for particular reach types was accounted for, the presence of Salix was independent of beaver distribution. However, there was a weak positive association between beaver presence and Salix cover. Salix was limited to geomorphic settings with greater sinuosity and distinct terraces, while Tamarix occurred in sinuous and straighter sections of river channel (cliffs, channel margins) where it dominated the woody species composition. After accounting for covariates representing river geomorphology, the proportion of riparian surfaces covered by Tamarix was significantly greater for sites where beavers were present. This indicates that either Tamarix and beavers co-occur in similar habitats, beavers prefer habitats that have high Tamarix cover, or beavers contribute to Tamarix dominance through selective use of its native woody competitors. The hypothesis that beaver herbivory contributes to Tamarix dominance should be considered further through more mechanistic studies of beaver foraging processes and long-term plant community response. ?? 2008 The Society of Wetland Scientists.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Wetlands","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1672/07-142.1","issn":"02775212","usgsCitation":"Mortenson, S., Weisberg, P., and Ralston, B., 2008, Do beavers promote the invasion of non-native Tamarix in the Grand Canyon riparian zone: Wetlands, v. 28, no. 3, p. 666-675, https://doi.org/10.1672/07-142.1.","startPage":"666","endPage":"675","numberOfPages":"10","costCenters":[],"links":[{"id":215553,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1672/07-142.1"},{"id":243365,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"28","issue":"3","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a035de4b0c8380cd5044f","contributors":{"authors":[{"text":"Mortenson, S.G.","contributorId":75351,"corporation":false,"usgs":true,"family":"Mortenson","given":"S.G.","email":"","affiliations":[],"preferred":false,"id":450315,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Weisberg, P.J.","contributorId":68555,"corporation":false,"usgs":true,"family":"Weisberg","given":"P.J.","email":"","affiliations":[],"preferred":false,"id":450314,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Ralston, B.E.","contributorId":61662,"corporation":false,"usgs":true,"family":"Ralston","given":"B.E.","email":"","affiliations":[],"preferred":false,"id":450313,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}}
,{"id":70032197,"text":"70032197 - 2008 - Developing conceptual hydrogeological model for Potsdam sandstones in southwestern Quebec, Canada","interactions":[],"lastModifiedDate":"2012-03-12T17:21:28","indexId":"70032197","displayToPublicDate":"2008-01-01T00:00:00","publicationYear":"2008","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1923,"text":"Hydrogeology Journal","active":true,"publicationSubtype":{"id":10}},"title":"Developing conceptual hydrogeological model for Potsdam sandstones in southwestern Quebec, Canada","docAbstract":"A hydrogeological study was conducted in Potsdam sandstones on the international border between Canada (Quebec) and the USA (New York). Two sandstone formations, arkose and conglomerate (base) and well-cemented quartz arenite (upper), underlie the study area and form the major regional aquifer unit. Glacial till, littoral sand and gravel, and marine silt and clay discontinuously overlie the aquifer. In both sandstone formations, sub-horizontal bedding planes are ubiquitous and display significant hydraulic conductivities that are orders of magnitude more permeable than the intact rock matrix. Aquifer tests demonstrate that the two formations have similar bulk hydrologic properties, with average hydraulic conductivities ranging from 2 ?? 10-5 to 4 ?? 10-5 m/s. However, due to their different lithologic and structural characteristics, these two sandstones impose rather different controls on groundwater flow patterns in the study area. Flow is sustained through two types of fracture networks: sub-horizontal, laterally extensive fractures in the basal sandstone, where hydraulic connectivity is very good horizontally but very poor vertically and each of the water-bearing bedding planes can be considered as a separate planar two-dimensional aquifer unit; and the more fractured and vertically jointed system found in the upper sandstone that promotes a more dispersed, three-dimensional movement of groundwater. ?? Springer-Verlag 2007.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Hydrogeology Journal","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1007/s10040-007-0267-9","issn":"14312174","usgsCitation":"Nastev, M., Morin, R., Godin, R., and Rouleau, A., 2008, Developing conceptual hydrogeological model for Potsdam sandstones in southwestern Quebec, Canada: Hydrogeology Journal, v. 16, no. 2, p. 373-388, https://doi.org/10.1007/s10040-007-0267-9.","startPage":"373","endPage":"388","numberOfPages":"16","costCenters":[],"links":[{"id":214884,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1007/s10040-007-0267-9"},{"id":242640,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"16","issue":"2","noUsgsAuthors":false,"publicationDate":"2008-01-10","publicationStatus":"PW","scienceBaseUri":"505a000ee4b0c8380cd4f572","contributors":{"authors":[{"text":"Nastev, Miroslav","contributorId":10621,"corporation":false,"usgs":true,"family":"Nastev","given":"Miroslav","email":"","affiliations":[],"preferred":false,"id":434994,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Morin, R.","contributorId":6210,"corporation":false,"usgs":true,"family":"Morin","given":"R.","affiliations":[],"preferred":false,"id":434993,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Godin, Rejean","contributorId":19780,"corporation":false,"usgs":true,"family":"Godin","given":"Rejean","email":"","affiliations":[],"preferred":false,"id":434995,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Rouleau, Alain","contributorId":84165,"corporation":false,"usgs":true,"family":"Rouleau","given":"Alain","email":"","affiliations":[],"preferred":false,"id":434996,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}}
]}