Fish harvested from the Pacific Ocean are a major contributor to human methylmercury (MeHg) exposure. Limited oceanic mercury (Hg) data, particularly MeHg, has confounded our understanding of linkages between sources, methylation sites, and concentrations in marine food webs. Here we present methylated (MeHg and dimethylmercury (Me2Hg)) and total Hg concentrations from 16 hydrographic stations in the eastern North Pacific Ocean. We use these data in combination with information from previous cruises and coupled atmospheric‐oceanic modeling results to better understand controls on Hg concentrations, distribution, and bioavailability. Total Hg concentrations (average 1.14 ± 0.38 pM) are elevated relative to previous cruises. Modeling results agree with observed increases and suggest that at present atmospheric Hg deposition rates, basin‐wide Hg concentrations will double relative to circa 1995 by 2050. Methylated Hg accounts for up to 29% of the total Hg in subsurface waters (average 260 ± 114 fM). We observed lower ambient methylated Hg concentrations in the euphotic zone and older, deeper water masses, which likely result from decay of MeHg and Me2Hg when net production is not occurring. We found a significant, positive linear relationship between methylated Hg concentrations and rates of organic carbon remineralization (r2 = 0.66, p < 0.001). These results provide evidence for the importance of particulate organic carbon (POC) transport and remineralization on the production and distribution of methylated Hg species in marine waters. Specifically, settling POC provides a source of inorganic Hg(II) to microbially active subsurface waters and can also provide a substrate for microbial activity facilitating water column methylation.
","language":"English","publisher":"AGU","doi":"10.1029/2008GB003425","issn":"08866236","usgsCitation":"Sunderland, E., Krabbenhoft, D., Moreau, J., Strode, S., and Landing, W., 2009, Mercury sources, distribution, and bioavailability in the North Pacific Ocean: Insights from data and models: Global Biogeochemical Cycles, v. 23, no. 2, https://doi.org/10.1029/2008GB003425.","costCenters":[{"id":589,"text":"Toxic Substances Hydrology Program","active":true,"usgs":true}],"links":[{"id":476220,"rank":10000,"type":{"id":40,"text":"Open Access Publisher Index Page"},"url":"https://doi.org/10.1029/2008gb003425","text":"Publisher Index Page"},{"id":244560,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":216675,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1029/2008GB003425"}],"volume":"23","issue":"2","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a542de4b0c8380cd6ced7","contributors":{"authors":[{"text":"Sunderland, E.M.","contributorId":45546,"corporation":false,"usgs":true,"family":"Sunderland","given":"E.M.","email":"","affiliations":[],"preferred":false,"id":445335,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"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":445338,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Moreau, J.W.","contributorId":64457,"corporation":false,"usgs":true,"family":"Moreau","given":"J.W.","affiliations":[],"preferred":false,"id":445336,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Strode, S.A.","contributorId":73439,"corporation":false,"usgs":true,"family":"Strode","given":"S.A.","email":"","affiliations":[],"preferred":false,"id":445337,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Landing, W.M.","contributorId":99303,"corporation":false,"usgs":true,"family":"Landing","given":"W.M.","email":"","affiliations":[],"preferred":false,"id":445339,"contributorType":{"id":1,"text":"Authors"},"rank":5}]}} ,{"id":70034293,"text":"70034293 - 2009 - Comparing approaches for simulating the reactive transport of U(VI) in ground water","interactions":[],"lastModifiedDate":"2018-10-05T10:16:12","indexId":"70034293","displayToPublicDate":"2009-01-01T00:00:00","publicationYear":"2009","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2745,"text":"Mine Water and the Environment","active":true,"publicationSubtype":{"id":10}},"title":"Comparing approaches for simulating the reactive transport of U(VI) in ground water","docAbstract":"The reactive transport of U(VI) in a well-characterized shallow alluvial aquifer at a former U(VI) mill located near Naturita, CO, was predicted for comparative purposes using a surface complexation model (SCM) and a constant K d approach to simulate U(VI) adsorption. The ground water at the site had U(VI) concentrations that ranged from 0.01 to 20 µM, alkalinities that ranged from 2.5 to 18 meq/L, and a nearly constant pH of 7.1. The SCM used to simulate U(VI) adsorption was previously determined independently using laboratory batch adsorption experiments. Simulations obtained using the SCM approach were compared with simulations that used a constant K d approach to simulate adsorption using previously determined site-specific K d values. In both cases, the ground water flow and transport models used a conceptual model that was previously calibrated to a chloride plume present at the site. Simulations with the SCM approach demonstrated that the retardation factor varied temporally and spatially because of the differential transport of alkalinity and dissolved U(VI) and the nonlinearity of the U(VI) adsorption. The SCM model also simulated a prolonged slow decline in U(VI) concentration, which was not simulated using a constant K d model. Simulations using the SCM approach and the constant K d approach were similar after 20 years of transport but diverged significantly after 60 years. The simulations demonstrate the need for site-specific geochemical information on U(VI) adsorption to produce credible simulations of future transport.
","language":"English","publisher":"Springer","doi":"10.1007/s10230-009-0064-x","issn":"10259112","usgsCitation":"Curtis, G., Kohler, M., and Davis, J., 2009, Comparing approaches for simulating the reactive transport of U(VI) in ground water: Mine Water and the Environment, v. 28, no. 2, p. 84-93, https://doi.org/10.1007/s10230-009-0064-x.","productDescription":"10 p.","startPage":"84","endPage":"93","costCenters":[{"id":589,"text":"Toxic Substances Hydrology Program","active":true,"usgs":true}],"links":[{"id":216793,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1007/s10230-009-0064-x"},{"id":244685,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"28","issue":"2","noUsgsAuthors":false,"publicationDate":"2009-02-20","publicationStatus":"PW","scienceBaseUri":"5059f831e4b0c8380cd4cf2a","contributors":{"authors":[{"text":"Curtis, G.P.","contributorId":65619,"corporation":false,"usgs":true,"family":"Curtis","given":"G.P.","email":"","affiliations":[],"preferred":false,"id":445117,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Kohler, M.","contributorId":32694,"corporation":false,"usgs":true,"family":"Kohler","given":"M.","affiliations":[],"preferred":false,"id":445116,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Davis, J.A.","contributorId":71694,"corporation":false,"usgs":true,"family":"Davis","given":"J.A.","email":"","affiliations":[],"preferred":false,"id":445118,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70034266,"text":"70034266 - 2009 - Assigning land use to supply wells for the statistical characterization of regional groundwater quality: Correlating urban land use and VOC occurrence","interactions":[],"lastModifiedDate":"2018-09-19T08:47:04","indexId":"70034266","displayToPublicDate":"2009-01-01T00:00:00","publicationYear":"2009","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":"Assigning land use to supply wells for the statistical characterization of regional groundwater quality: Correlating urban land use and VOC occurrence","docAbstract":"Many national and regional groundwater studies have correlated land use \"near\" a well, often using a 500 m radius circle, with water quality. However, the use of a 500 m circle may seem counterintuitive given that contributing areas are expected to extend up-gradient from wells, and not be circular in shape. The objective of this study was to evaluate if a 500 m circle is adequate for assigning land use to a well for the statistical correlation between urban land use and the occurrence of volatile organic compounds (VOCs). Land use and VOC data came from 277 supply wells in four study areas in California. Land use was computed using ten different-sized circles and wedges (250 m to 10 km in radius), and three different-sized \"searchlights\" (1-2 km in length). We define these shapes as contributing area surrogates (CASs), recognizing that a simple shape is at best a surrogate for the actual contributing area. The presence or absence of correlation between land use and the occurrence of VOCs was evaluated using Kendall's tau (??). Values of ?? were within 10% of one another for wedges and circles ranging in size from 500 m to 2 km, with correlations remaining statistically significant (p < 0.05) for all CAS sizes and shapes, suggesting that a 500 m circular CAS is adequate for assigning land use to a well. Additional evaluation indicated that urban land use is autocorrelated at distances ranging from 8 to 36 km. Thus, urban land use in a 500 m CAS is likely to be predictive of urban land use in the actual contributing area.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Journal of Hydrology","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1016/j.jhydrol.2009.02.056","issn":"00221694","usgsCitation":"Johnson, T., and Belitz, K., 2009, Assigning land use to supply wells for the statistical characterization of regional groundwater quality: Correlating urban land use and VOC occurrence: Journal of Hydrology, v. 370, no. 1-4, p. 100-108, https://doi.org/10.1016/j.jhydrol.2009.02.056.","startPage":"100","endPage":"108","numberOfPages":"9","costCenters":[{"id":154,"text":"California Water Science Center","active":true,"usgs":true}],"links":[{"id":244780,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":216882,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/j.jhydrol.2009.02.056"}],"volume":"370","issue":"1-4","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"5059ee8be4b0c8380cd49dea","contributors":{"authors":[{"text":"Johnson, T.D.","contributorId":32744,"corporation":false,"usgs":true,"family":"Johnson","given":"T.D.","email":"","affiliations":[],"preferred":false,"id":444986,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Belitz, K. 0000-0003-4481-2345","orcid":"https://orcid.org/0000-0003-4481-2345","contributorId":10164,"corporation":false,"usgs":true,"family":"Belitz","given":"K.","affiliations":[],"preferred":false,"id":444985,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70034180,"text":"70034180 - 2009 - Estimating transition probabilities among everglades wetland communities using multistate models","interactions":[],"lastModifiedDate":"2012-03-12T17:21:46","indexId":"70034180","displayToPublicDate":"2009-01-01T00:00:00","publicationYear":"2009","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":"Estimating transition probabilities among everglades wetland communities using multistate models","docAbstract":"In this study we were able to provide the first estimates of transition probabilities of wet prairie and slough vegetative communities in Water Conservation Area 3A (WCA3A) of the Florida Everglades and to identify the hydrologic variables that determine these transitions. These estimates can be used in management models aimed at restoring proportions of wet prairie and slough habitats to historical levels in the Everglades. To determine what was driving the transitions between wet prairie and slough communities we evaluated three hypotheses: seasonality, impoundment, and wet and dry year cycles using likelihood-based multistate models to determine the main driver of wet prairie conversion in WCA3A. The most parsimonious model included the effect of wet and dry year cycles on vegetative community conversions. Several ecologists have noted wet prairie conversion in southern WCA3A but these are the first estimates of transition probabilities among these community types. In addition, to being useful for management of the Everglades we believe that our framework can be used to address management questions in other ecosystems. ?? 2009 The Society of Wetland Scientists.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Wetlands","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1672/09-014S.1","issn":"02775212","usgsCitation":"Hotaling, A., Martin, J., and Kitchens, W., 2009, Estimating transition probabilities among everglades wetland communities using multistate models: Wetlands, v. 29, no. 4, p. 1224-1233, https://doi.org/10.1672/09-014S.1.","startPage":"1224","endPage":"1233","numberOfPages":"10","costCenters":[],"links":[{"id":216606,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1672/09-014S.1"},{"id":244486,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"29","issue":"4","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a0b68e4b0c8380cd526e9","contributors":{"authors":[{"text":"Hotaling, A.S.","contributorId":102297,"corporation":false,"usgs":true,"family":"Hotaling","given":"A.S.","email":"","affiliations":[],"preferred":false,"id":444471,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Martin, J.","contributorId":18871,"corporation":false,"usgs":true,"family":"Martin","given":"J.","affiliations":[],"preferred":false,"id":444469,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Kitchens, W.M.","contributorId":87647,"corporation":false,"usgs":true,"family":"Kitchens","given":"W.M.","affiliations":[],"preferred":false,"id":444470,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70033999,"text":"70033999 - 2009 - Water balance dynamics in the Nile Basin","interactions":[],"lastModifiedDate":"2017-04-05T11:19:47","indexId":"70033999","displayToPublicDate":"2009-01-01T00:00:00","publicationYear":"2009","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":"Water balance dynamics in the Nile Basin","docAbstract":"Understanding the temporal and spatial dynamics of key water balance components of the Nile River will provide important information for the management of its water resources. This study used satellite-derived rainfall and other key weather variables derived from the Global Data Assimilation System to estimate and map the distribution of rainfall, actual evapotranspiration (ETa), and runoff. Daily water balance components were modelled in a grid-cell environment at 0·1 degree (∼10 km) spatial resolution for 7 years from 2001 through 2007. Annual maps of the key water balance components and derived variables such as runoff and ETa as a percent of rainfall were produced. Generally, the spatial patterns of rainfall and ETa indicate high values in the upstream watersheds (Uganda, southern Sudan, and southwestern Ethiopia) and low values in the downstream watersheds. However, runoff as a percent of rainfall is much higher in the Ethiopian highlands around the Blue Nile subwatershed. The analysis also showed the possible impact of land degradation in the Ethiopian highlands in reducing ETa magnitudes despite the availability of sufficient rainfall. Although the model estimates require field validation for the different subwatersheds, the runoff volume estimate for the Blue Nile subwatershed is within 7·0% of a figure reported from an earlier study. Further research is required for a thorough validation of the results and their integration with ecohydrologic models for better management of water and land resources in the various Nile Basin ecosystems.
","language":"English","publisher":"Wiley","doi":"10.1002/hyp.7364","issn":"08856087","usgsCitation":"Senay, G.B., Asante, K., and Artan, G.A., 2009, Water balance dynamics in the Nile Basin: Hydrological Processes, v. 23, no. 26, p. 3675-3681, https://doi.org/10.1002/hyp.7364.","productDescription":"7 p.","startPage":"3675","endPage":"3681","numberOfPages":"7","costCenters":[{"id":222,"text":"Earth Resources Observation and Science (EROS) Center","active":true,"usgs":true}],"links":[{"id":244730,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":216834,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1002/hyp.7364"}],"volume":"23","issue":"26","noUsgsAuthors":false,"publicationDate":"2009-08-26","publicationStatus":"PW","scienceBaseUri":"505bc7c2e4b08c986b32c5f2","contributors":{"authors":[{"text":"Senay, Gabriel B. 0000-0002-8810-8539 senay@usgs.gov","orcid":"https://orcid.org/0000-0002-8810-8539","contributorId":3114,"corporation":false,"usgs":true,"family":"Senay","given":"Gabriel","email":"senay@usgs.gov","middleInitial":"B.","affiliations":[{"id":223,"text":"Earth Resources Observation and Science (EROS) Center (Geography)","active":false,"usgs":true}],"preferred":true,"id":443581,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Asante, Kwabena 0000-0001-5408-1852","orcid":"https://orcid.org/0000-0001-5408-1852","contributorId":65948,"corporation":false,"usgs":true,"family":"Asante","given":"Kwabena","affiliations":[],"preferred":false,"id":443583,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Artan, Guleid A. 0000-0001-8409-6182 gartan@usgs.gov","orcid":"https://orcid.org/0000-0001-8409-6182","contributorId":2938,"corporation":false,"usgs":true,"family":"Artan","given":"Guleid","email":"gartan@usgs.gov","middleInitial":"A.","affiliations":[{"id":223,"text":"Earth Resources Observation and Science (EROS) Center (Geography)","active":false,"usgs":true}],"preferred":true,"id":443582,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70033958,"text":"70033958 - 2009 - Isotopic composition of low-latitude paleoprecipitation during the Early Cretaceous","interactions":[],"lastModifiedDate":"2012-03-12T17:21:33","indexId":"70033958","displayToPublicDate":"2009-01-01T00:00:00","publicationYear":"2009","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1786,"text":"Geological Society of America Bulletin","active":true,"publicationSubtype":{"id":10}},"title":"Isotopic composition of low-latitude paleoprecipitation during the Early Cretaceous","docAbstract":"The response of the hydrologic cycle in global greenhouse conditions is important to our understanding of future climate change and to the calibration of global climate models. Past greenhouse conditions, such as those of the Cretaceous, can be used to provide empirical data with which to evaluate climate models. Recent empirical studies have utilized pedogenic carbonates to estimate the isotopic composition of meteoric waters and calculate precipitation rates for the AptianAlbian. These studies were limited to data from mid(35??N) to high (75??N) paleolatitudes, and thus future improvements in accuracy will require more estimates of meteoric water compositions from numerous localities around the globe. This study provides data for tropical latitudes (18.5??N paleolatitude) from the Tlayua Formation, Puebla, Mexico. In addition, the study confirms a shallow nearshore depositional environment for the Tlayua Formation. Petrographic observations of fenestral fabrics, gypsum crystal molds, stromatolitic structures, and pedogenic matrix birefringence fabric support the interpretation that the strata represent deposition in a tidal flat environment. Carbonate isotopic data from limestones of the Tlayua Formation provide evidence of early meteoric diagenesis in the form of meteoric calcite lines. These trends in ??18O versus ??13C were used to calculate the mean ??18O value of meteoric water, which is estimated at -5.46 ?? 0.56??? (Vienna Standard Mean Ocean Water [VSMOW]). Positive linear covariant trends in oxygen and carbon isotopic values from some horizons were used to estimate evaporative losses of vadose groundwater from tropical exposure surfaces during the Albian, and the resulting values range from 8% to 12%. However, the presence of evaporative mineral molds indicates more extensive evaporation. The added tropical data improve latitudinal coverage of paleoprecipitation ??18O estimates. The data presented here imply that earlier isotope mass balance models most likely underestimated tropical to subtropical precipitation and evaporation fluxes. The limited latitudinal constraints for earlier isotope mass balance modeling of the Albian hydrologic cycle of the Northern Hemisphere Americas resulted in extrapolated low-latitude precipitation ??18O values that were much heavier (up to 3???) than the values observed in this study. The lighter values identified in this study indicate a more pronounced rainout effect for tropical regions and quite possibly a more vigorous evaporation effect. These and additional low-latitude data are required to better constrain changes in the hydrologic cycle during the Cretaceous greenhouse period, and to reduce the uncertainties resulting from limited geographic coverage of proxy data. ?? 2009 Geological Society of America.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Geological Society of America Bulletin","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1130/B26453.1","issn":"00167606","usgsCitation":"Suarez, M., Gonzalez, L.A., Ludvigson, G.A., Vega, F., and Alvarado-Ortega, J., 2009, Isotopic composition of low-latitude paleoprecipitation during the Early Cretaceous: Geological Society of America Bulletin, v. 121, no. 11-12, p. 1584-1595, https://doi.org/10.1130/B26453.1.","startPage":"1584","endPage":"1595","numberOfPages":"12","costCenters":[],"links":[{"id":214243,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1130/B26453.1"},{"id":241943,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"121","issue":"11-12","noUsgsAuthors":false,"publicationDate":"2009-08-28","publicationStatus":"PW","scienceBaseUri":"505a3fa3e4b0c8380cd646a4","contributors":{"authors":[{"text":"Suarez, M.B.","contributorId":18589,"corporation":false,"usgs":true,"family":"Suarez","given":"M.B.","email":"","affiliations":[],"preferred":false,"id":443397,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Gonzalez, Luis A.","contributorId":20922,"corporation":false,"usgs":true,"family":"Gonzalez","given":"Luis","email":"","middleInitial":"A.","affiliations":[],"preferred":false,"id":443398,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Ludvigson, Greg A.","contributorId":80803,"corporation":false,"usgs":true,"family":"Ludvigson","given":"Greg","email":"","middleInitial":"A.","affiliations":[],"preferred":false,"id":443399,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Vega, F.J.","contributorId":97337,"corporation":false,"usgs":true,"family":"Vega","given":"F.J.","email":"","affiliations":[],"preferred":false,"id":443401,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Alvarado-Ortega, J.","contributorId":84574,"corporation":false,"usgs":true,"family":"Alvarado-Ortega","given":"J.","email":"","affiliations":[],"preferred":false,"id":443400,"contributorType":{"id":1,"text":"Authors"},"rank":5}]}} ,{"id":70033924,"text":"70033924 - 2009 - Isomer-specific determination of 4-nonylphenols using comprehensive two-dimensional gas chromatography/time-of-flight mass spectrometry","interactions":[],"lastModifiedDate":"2018-10-12T10:26:17","indexId":"70033924","displayToPublicDate":"2009-01-01T00:00:00","publicationYear":"2009","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":"Isomer-specific determination of 4-nonylphenols using comprehensive two-dimensional gas chromatography/time-of-flight mass spectrometry","docAbstract":"Technical nonylphenol (tNP), used for industrial production of nonylphenol polyethoxylate surfactants, is a complex mixture of C3−10-phenols. The major components, 4-nonylphenols, are weak endocrine disruptors whose estrogenicities vary according to the structure of the branched nonyl group. Thus, accurate risk assessment requires isomer-specific determination of 4-NPs. Comprehensive two-dimensional gas chromatography/time-of-flight mass spectrometry (GC × GC/ToFMS) was used to characterize tNP samples obtained from seven commercial suppliers. Under optimal chromatographic conditions, 153−204 alkylphenol peaks, 59−66 of which were identified as 4-NPs, were detected. The 4-NPs comprised ∼86−94% of tNP, with 2-NPs and decylphenols making up ∼2−9% and ∼2−5%, respectively. The tNP products were analyzed for eight synthetic 4-NP isomers, and results were compared with published data based on GC/MS analysis. Significant differences were found among the products and between two samples from a single supplier. The enhanced resolution of GC × GC coupled with fast mass spectral data acquisition by ToFMS facilitated identification of all major 4-NP isomers and a number of previously unrecognized components. Analysis of tNP altered by the bacterium, Sphingobium xenophagum Bayram, revealed several persistent 4-NPs whose structures and estrogenicities are presently unknown. The potential of this technology for isomer-specific determination of 4-NP isomers in environmental matrices is demonstrated using samples of wastewater-contaminated groundwater and municipal wastewater.
Aeolian processes are of particular importance in dryland ecosystems where ground cover is inherently sparse because of limited precipitation. Dryland ecosystems include grassland, shrubland, savanna, woodland, and forest, and can be viewed collectively as a continuum of woody plant cover spanning from grasslands with no woody plant cover up to forests with nearly complete woody plant cover. Along this continuum, the spacing and shape of woody plants determine the spatial density of roughness elements, which directly affects aeolian sediment transport. Despite the extensiveness of dryland ecosystems, studies of aeolian sediment transport have generally focused on agricultural fields, deserts, or highly disturbed sites where rates of transport are likely to be greatest. Until recently, few measurements have been made of aeolian sediment transport over multiple wind events and across a variety of types of dryland ecosystems. To evaluate potential trends in aeolian sediment transport as a function of woody plant cover, estimates of aeolian sediment transport from recently published studies, in concert with rates from four additional locations (two grassland and two woodland sites), are reported here. The synthesis of these reports leads to the development of a new conceptual framework for aeolian sediment transport in dryland ecosystems along the grassland–forest continuum.
The findings suggest that: (1) for relatively undisturbed ecosystems, shrublands have inherently greater aeolian sediment transport because of wake interference flow associated with intermediate levels of density and spacing of woody plants; and (2) for disturbed ecosystems, the upper bound for aeolian sediment transport decreases as a function of increasing amounts of woody plant cover because of the effects of the height and density of the canopy on airflow patterns and ground cover associated with woody plant cover. Consequently, aeolian sediment transport following disturbance spans the largest range of rates in grasslands and associated systems with no woody plants (e.g., agricultural fields), an intermediate range in shrublands, and a relatively small range in woodlands and forests. These trends are consistent with previous observations relating large rates of wind erosion to intermediate values for spatial density of roughness elements. The framework for aeolian sediment transport, which is also relevant to dust fluxes, wind erosion, and related aeolian processes, is applicable to a diverse suite of environmental challenges, including land degradation and desertification, dust storms, contaminant transport, and alterations of the hydrological cycle.
Recent national concerns regarding the environmental occurrence of emerging contaminants (ECs) have catalyzed a series of recent studies. Many ECs are released into the environment through discharges from wastewater treatment plants (WWTPs) and other sources. In 2005, the U.S. Geological Survey and the City of Longmont initiated an investigation of selected ECs in a 13.8‐km reach of St. Vrain Creek, Colorado. Seven sites were sampled for ECs following a Lagrangian design; sites were located upstream, downstream, and in the outfall of the Longmont WWTP, and at the mouths of two tributaries, Left Hand Creek and Boulder Creek (which is influenced by multiple WWTP outfalls). Samples for 61 ECs in 16 chemical use categories were analyzed and 36 were detected in one or more samples. Of these, 16 have known or suspected endocrine‐disrupting potential. At and downstream from the WWTP outfall, detergent metabolites, fire retardants, and steroids were detected at the highest concentrations, which commonly exceeded 1 μg/l in 2005 and 2 μg/l in 2006. Most individual ECs were measured at concentrations less than 2 μg/l. The results indicate that outfalls from WWTPs are the largest but may not be the sole source of ECs in St. Vrain Creek. In 2005, high discharge was associated with fewer EC detections, lower total EC concentrations, and smaller EC loads in St. Vrain Creek and its tributaries as compared with 2006. EC behavior differed by individual compound, and some differences between sites could be attributed to analytical variability or to other factors such as physical or chemical characteristics or distance from contributing sources. Loads of some ECs, such as diethoxynonylphenol, accumulated or attenuated depending on location, discharge, and distance downstream from the WWTP, whereas others, such as bisphenol A, were largely conservative. The extent to which ECs in St. Vrain Creek affect native fish species and macroinvertebrate communities is unknown, but recent studies have shown that fish respond to very low concentrations of ECs, and further study on the fate and transport of these contaminants in the aquatic environment is warranted.
","language":"English","publisher":"American Water Resources Association","doi":"10.1111/j.1752-1688.2008.00290.x","issn":"10934","usgsCitation":"Brown, J., Battaglin, W., and Zuellig, R., 2009, Lagrangian sampling for emerging contaminants through an urban stream corridor in Colorado: Journal of the American Water Resources Association, v. 45, no. 1, p. 68-82, https://doi.org/10.1111/j.1752-1688.2008.00290.x.","productDescription":"15 p.","startPage":"68","endPage":"82","costCenters":[{"id":191,"text":"Colorado Water Science Center","active":true,"usgs":true},{"id":589,"text":"Toxic Substances Hydrology Program","active":true,"usgs":true}],"links":[{"id":476364,"rank":10000,"type":{"id":40,"text":"Open Access Publisher Index Page"},"url":"https://doi.org/10.1111/j.1752-1688.2008.00290.x","text":"Publisher Index Page"},{"id":241219,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":213581,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1111/j.1752-1688.2008.00290.x"}],"volume":"45","issue":"1","noUsgsAuthors":false,"publicationDate":"2009-01-27","publicationStatus":"PW","scienceBaseUri":"505a4135e4b0c8380cd653af","contributors":{"authors":[{"text":"Brown, J.B.","contributorId":91307,"corporation":false,"usgs":true,"family":"Brown","given":"J.B.","email":"","affiliations":[],"preferred":false,"id":438968,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Battaglin, W.A.","contributorId":16376,"corporation":false,"usgs":true,"family":"Battaglin","given":"W.A.","email":"","affiliations":[],"preferred":false,"id":438966,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Zuellig, R.E.","contributorId":37045,"corporation":false,"usgs":true,"family":"Zuellig","given":"R.E.","affiliations":[],"preferred":false,"id":438967,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70032978,"text":"70032978 - 2009 - Wastewater effluent, combined sewer overflows, and other sources of organic compounds to Lake Champlain","interactions":[],"lastModifiedDate":"2018-10-12T08:31:01","indexId":"70032978","displayToPublicDate":"2009-01-01T00:00:00","publicationYear":"2009","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":"Wastewater effluent, combined sewer overflows, and other sources of organic compounds to Lake Champlain","docAbstract":"Abstract: Some sources of organic wastewater compounds (OWCs) to streams, lakes, and estuaries, including wastewater‐treatment‐plant effluent, have been well documented, but other sources, particularly wet‐weather discharges from combined‐sewer‐overflow (CSO) and urban runoff, may also be major sources of OWCs. Samples of wastewater‐treatment‐plant (WWTP) effluent, CSO effluent, urban streams, large rivers, a reference (undeveloped) stream, and Lake Champlain were collected from March to August 2006. The highest concentrations of many OWCs associated with wastewater were in WWTP‐effluent samples, but high concentrations of some OWCs in samples of CSO effluent and storm runoff from urban streams subject to leaky sewer pipes or CSOs were also detected. Total concentrations and numbers of compounds detected differed substantially among sampling sites. The highest total OWC concentrations (10‐100 μg/l) were in samples of WWTP and CSO effluent. Total OWC concentrations in samples from urban streams ranged from 0.1 to 10 μg/l, and urban stream‐stormflow samples had higher concentrations than baseflow samples because of contributions of OWCs from CSOs and leaking sewer pipes. The relations between OWC concentrations in WWTP‐effluent and those in CSO effluent and urban streams varied with the degree to which the compound is removed through normal wastewater treatment. Concentrations of compounds that are highly removed during normal wastewater treatment [including caffeine, Tris(2‐butoxyethyl)phosphate, and cholesterol] were generally similar to or higher in CSO effluent than in WWTP effluent (and ranged from around 1 to over 10 μg/l) because CSO effluent is untreated, and were higher in urban‐stream stormflow samples than in baseflow samples as a result of CSO discharge and leakage from near‐surface sources during storms. Concentrations of compounds that are poorly removed during treatment, by contrast, are higher in WWTP effluent than in CSO, due to dilution. Results indicate that CSO effluent and urban stormwaters can be a significant major source of OWCs entering large water bodies such as Burlington Bay.
Highway runoff has the potential to negatively impact receiving systems including stormwater retention ponds where highway particulate matter can accumulate following runoff events. Tire wear particles, which contain about 1% Zn by mass, make up approximately one-third of the vehicle derived particulates in highway runoff and therefore may serve as a stressor to organisms utilizing retention ponds as habitat. In this study, we focused on the potential contribution of tire debris to Zn accumulation by Rana sylvaticalarvae and possible lethal or sublethal impacts resulting from exposure to weathered tire debris during development. Eggs and larvae were exposed to aged sediments (containing either ZnCl2 or tire particulate matter, both providing nominal concentrations of 1000 mg Zn kg−1) through metamorphosis. Water column Zn was elevated in both the ZnCl2 and tire treatments relative to the control treatment, indicating that aging allowed Zn leaching from tire debris to occur. Tissue Zn was also elevated for the ZnCl2and tire treatments indicating that Zn in the treatments was available for uptake by the amphibians. Exposure to both ZnCl2 and tire treatments increased the time for larvae to complete metamorphosis in comparison with controls. We also observed that the longer the organisms took to complete metamorphosis, the smaller their mass at metamorphosis. Our results indicate that Zn leached from aged tire debris is bioavailable to developing R. sylvaticalarvae and that exposure to tire debris amended sediments can result in measurable physiological outcomes to wood frogs that may influence population dynamics.
","language":"English","publisher":"Wiley","doi":"10.1016/j.chemosphere.2008.09.056","issn":"00456","usgsCitation":"Camponelli, K., Casey, R., Snodgrass, J., Lev, S., and Landa, E.R., 2009, Impacts of weathered tire debris on the development of Rana sylvatica larvae: Chemosphere, v. 74, no. 5, p. 717-722, https://doi.org/10.1016/j.chemosphere.2008.09.056.","productDescription":"6 p.","startPage":"717","endPage":"722","costCenters":[{"id":589,"text":"Toxic Substances Hydrology Program","active":true,"usgs":true}],"links":[{"id":241148,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":213518,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/j.chemosphere.2008.09.056"}],"volume":"74","issue":"5","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a3902e4b0c8380cd61785","contributors":{"authors":[{"text":"Camponelli, K.M.","contributorId":81699,"corporation":false,"usgs":true,"family":"Camponelli","given":"K.M.","affiliations":[],"preferred":false,"id":438794,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Casey, R.E.","contributorId":68543,"corporation":false,"usgs":true,"family":"Casey","given":"R.E.","email":"","affiliations":[],"preferred":false,"id":438793,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Snodgrass, J.W.","contributorId":39102,"corporation":false,"usgs":true,"family":"Snodgrass","given":"J.W.","email":"","affiliations":[],"preferred":false,"id":438792,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Lev, S.M.","contributorId":10230,"corporation":false,"usgs":true,"family":"Lev","given":"S.M.","email":"","affiliations":[],"preferred":false,"id":438791,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Landa, E. R.","contributorId":100002,"corporation":false,"usgs":true,"family":"Landa","given":"E.","email":"","middleInitial":"R.","affiliations":[],"preferred":false,"id":438795,"contributorType":{"id":1,"text":"Authors"},"rank":5}]}} ,{"id":70032946,"text":"70032946 - 2009 - Structural characterization of terrestrial microbial Mn oxides from Pinal Creek, AZ","interactions":[],"lastModifiedDate":"2018-10-15T08:24:55","indexId":"70032946","displayToPublicDate":"2009-01-01T00:00:00","publicationYear":"2009","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":"Structural characterization of terrestrial microbial Mn oxides from Pinal Creek, AZ","docAbstract":"The microbial catalysis of Mn(II) oxidation is believed to be a dominant source of abundant sorption- and redox-active Mn oxides in marine, freshwater, and subsurface aquatic environments. In spite of their importance, environmental oxides of known biogenic origin have generally not been characterized in detail from a structural perspective. Hyporheic zone Mn oxide grain coatings at Pinal Creek, Arizona, a metals-contaminated stream, have been identified as being dominantly microbial in origin and are well studied from bulk chemistry and contaminant hydrology perspectives. This site thus presents an excellent opportunity to study the structures of terrestrial microbial Mn oxides in detail. XRD and EXAFS measurements performed in this study indicate that the hydrated Pinal Creek Mn oxide grain coatings are layer-type Mn oxides with dominantly hexagonal or pseudo-hexagonal layer symmetry. XRD and TEM measurements suggest the oxides to be nanoparticulate plates with average dimensions on the order of 11 nm thick × 35 nm diameter, but with individual particles exhibiting thickness as small as a single layer and sheets as wide as 500 nm. The hydrated oxides exhibit a 10-Å basal-plane spacing and turbostratic disorder. EXAFS analyses suggest the oxides contain layer Mn(IV) site vacancy defects, and layer Mn(III) is inferred to be present, as deduced from Jahn–Teller distortion of the local structure. The physical geometry and structural details of the coatings suggest formation within microbial biofilms. The biogenic Mn oxides are stable with respect to transformation into thermodynamically more stable phases over a time scale of at least 5 months. The nanoparticulate layered structural motif, also observed in pure culture laboratory studies, appears to be characteristic of biogenic Mn oxides and may explain the common occurrence of this mineral habit in soils and sediments.
Geologically based methodologies to assess the possible volumes of subsurface CO2 storage must apply clear and uniform definitions of resource and reserve concepts to each assessment unit (AU). Application of the current state of knowledge of geologic, hydrologic, geochemical, and geophysical parameters (contingencies) that control storage volume and injectivity allows definition of the contingent resource (CR) of storage. The parameters known with the greatest certainty are based on observations on known traps (KTs) within the AU that produced oil, gas, and water. The aggregate volume of KTs within an AU defines the most conservation volume of contingent resource. Application of the concept of reserve growth to CR volume provides a logical path for subsequent reevaluation of the total resource as knowledge of CO2 storage processes increases during implementation of storage projects. Increased knowledge of storage performance over time will probably allow the volume of the contingent resource of storage to grow over time, although negative growth is possible.
","language":"English","publisher":"Elsevier","doi":"10.1016/j.egypro.2009.02.036","usgsCitation":"Burruss, R., 2009, CO2 storage resources, reserves, and reserve growth: Toward a methodology for integrated assessment of the storage capacity of oil and gas reservoirs and saline formations: Energy Procedia, v. 1, no. 1, p. 2679-2683, https://doi.org/10.1016/j.egypro.2009.02.036.","productDescription":"5 p.","startPage":"2679","endPage":"2683","ipdsId":"IP-009941","costCenters":[{"id":241,"text":"Eastern Energy Resources Science Center","active":true,"usgs":true}],"links":[{"id":476308,"rank":0,"type":{"id":40,"text":"Open Access Publisher Index Page"},"url":"https://doi.org/10.1016/j.egypro.2009.02.036","text":"Publisher Index Page"},{"id":348700,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"1","issue":"1","publishingServiceCenter":{"id":9,"text":"Reston PSC"},"noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"5a610cfee4b06e28e9c2576f","contributors":{"authors":[{"text":"Burruss, Robert 0000-0001-6827-804X burruss@usgs.gov","orcid":"https://orcid.org/0000-0001-6827-804X","contributorId":146833,"corporation":false,"usgs":true,"family":"Burruss","given":"Robert","email":"burruss@usgs.gov","affiliations":[{"id":241,"text":"Eastern Energy Resources Science Center","active":true,"usgs":true}],"preferred":true,"id":716977,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}} ,{"id":70032875,"text":"70032875 - 2009 - Essentials of iron, chromium, and calcium isotope analysis of natural materials by thermal ionization mass spectrometry","interactions":[],"lastModifiedDate":"2012-03-12T17:21:23","indexId":"70032875","displayToPublicDate":"2009-01-01T00:00:00","publicationYear":"2009","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1213,"text":"Chemical Geology","active":true,"publicationSubtype":{"id":10}},"title":"Essentials of iron, chromium, and calcium isotope analysis of natural materials by thermal ionization mass spectrometry","docAbstract":"The use of isotopes to understand the behavior of metals in geological, hydrological, and biological systems has rapidly expanded in recent years. One of the mass spectrometric techniques used to analyze metal isotopes is thermal ionization mass spectrometry, or TIMS. While TIMS has been a useful analytical technique for the measurement of isotopic composition for decades and TIMS instruments are widely distributed, there are significant difficulties associated with using TIMS to analyze isotopes of the lighter alkaline earth elements and transition metals. Overcoming these difficulties to produce relatively long-lived and stable ion beams from microgram-sized samples is a non-trivial task. We focus here on TIMS analysis of three geologically and environmentally important elements (Fe, Cr, and Ca) and present an in-depth look at several key aspects that we feel have the greatest potential to trouble new users. Our discussion includes accessible descriptions of different analytical approaches and issues, including filament loading procedures, collector cup configurations, peak shapes and interferences, and the use of isotopic double spikes and related error estimation. Building on previous work, we present quantitative simulations, applied specifically in this study to Fe and Ca, that explore the effects of (1) time-variable evaporation of isotopically homogeneous spots from a filament and (2) interferences on the isotope ratios derived from a double spike subtraction routine. We discuss how and to what extent interferences at spike masses, as well as at other measured masses, affect the double spike-subtracted isotope ratio of interest (44Ca/40Ca in the case presented, though a similar analysis can be used to evaluate 56Fe/54Fe and 53Cr/52Cr). The conclusions of these simulations are neither intuitive nor immediately obvious, making this examination useful for those who are developing new methodologies. While all simulations are carried out in the context of a specific isotope system, it should be noted that the same methods can be used to evaluate any isotope system of interest. ?? 2008 Elsevier B.V.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Chemical Geology","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1016/j.chemgeo.2008.06.018","issn":"00092","usgsCitation":"Fantle, M., and Bullen, T., 2009, Essentials of iron, chromium, and calcium isotope analysis of natural materials by thermal ionization mass spectrometry: Chemical Geology, v. 258, no. 1-2, p. 50-64, https://doi.org/10.1016/j.chemgeo.2008.06.018.","startPage":"50","endPage":"64","numberOfPages":"15","costCenters":[],"links":[{"id":213961,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/j.chemgeo.2008.06.018"},{"id":241638,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"258","issue":"1-2","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a0a60e4b0c8380cd52320","contributors":{"authors":[{"text":"Fantle, M.S.","contributorId":84170,"corporation":false,"usgs":true,"family":"Fantle","given":"M.S.","email":"","affiliations":[],"preferred":false,"id":438328,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Bullen, T.D.","contributorId":79911,"corporation":false,"usgs":true,"family":"Bullen","given":"T.D.","email":"","affiliations":[],"preferred":false,"id":438327,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70032874,"text":"70032874 - 2009 - Hydraulic anisotropy characterization of pneumatic-fractured sediments using azimuthal self potential gradient","interactions":[],"lastModifiedDate":"2012-03-12T17:21:24","indexId":"70032874","displayToPublicDate":"2009-01-01T00:00:00","publicationYear":"2009","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2233,"text":"Journal of Contaminant Hydrology","active":true,"publicationSubtype":{"id":10}},"title":"Hydraulic anisotropy characterization of pneumatic-fractured sediments using azimuthal self potential gradient","docAbstract":"The pneumatic fracturing technique is used to enhance the permeability and porosity of tight unconsolidated soils (e.g. clays), thereby improving the effectiveness of remediation treatments. Azimuthal self potential gradient (ASPG) surveys were performed on a compacted, unconsolidated clay block in order to evaluate their potential to delineate contaminant migration pathways in a mechanically-induced fracture network. Azimuthal resistivity (ARS) measurements were also made for comparative purposes. Following similar procedures to those used in the field, compressed kaolinite sediments were pneumatically fractured and the resulting fracture geometry characterized from strike analysis of visible fractures combined with strike data from optical borehole televiewer (BHTV) imaging. We subsequently injected a simulated treatment (electrolyte/dye) into the fractures. Both ASPG and ARS data exhibit anisotropic geoelectric signatures resulting from the fracturing. Self potentials observed during injection of electrolyte are consistent with electrokinetic theory and previous laboratory results on a fracture block model. Visual (polar plot) analysis and linear regression of cross plots show ASPG lobes are correlated with azimuths of high fracture strike density, evidence that the ASPG anisotropy is a proxy measure of hydraulic anisotropy created by the pneumatic fracturing. However, ARS data are uncorrelated with fracture strike maxima and resistivity anisotropy is probably dominated by enhanced surface conduction along azimuths of weak 'starter paths' formed from pulverization of the clay and increases in interfacial surface area. We find the magnitude of electrokinetic SP scales with the applied N2 gas pressure gradient (??PN2) for any particular hydraulically-active fracture set and that the positive lobe of the ASPG anomaly indicates the flow direction within the fracture network. These findings demonstrate the use of ASPG in characterizing the effectiveness of (1) pneumatic fracturing and (2) defining likely flow directions of remedial treatments in unconsolidated sediments and rock. ?? 2008 Elsevier B.V. All rights reserved.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Journal of Contaminant Hydrology","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1016/j.jconhyd.2008.09.023","issn":"01697","usgsCitation":"Wishart, D., Slater, L., Schnell, D., and Herman, G., 2009, Hydraulic anisotropy characterization of pneumatic-fractured sediments using azimuthal self potential gradient: Journal of Contaminant Hydrology, v. 103, no. 3-4, p. 134-144, https://doi.org/10.1016/j.jconhyd.2008.09.023.","startPage":"134","endPage":"144","numberOfPages":"11","costCenters":[],"links":[{"id":241610,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":213935,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/j.jconhyd.2008.09.023"}],"volume":"103","issue":"3-4","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a32dbe4b0c8380cd5eb21","contributors":{"authors":[{"text":"Wishart, D.N.","contributorId":32359,"corporation":false,"usgs":true,"family":"Wishart","given":"D.N.","email":"","affiliations":[],"preferred":false,"id":438323,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Slater, L.D.","contributorId":63229,"corporation":false,"usgs":true,"family":"Slater","given":"L.D.","email":"","affiliations":[],"preferred":false,"id":438325,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Schnell, D.L.","contributorId":48770,"corporation":false,"usgs":true,"family":"Schnell","given":"D.L.","email":"","affiliations":[],"preferred":false,"id":438324,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Herman, G.C.","contributorId":102215,"corporation":false,"usgs":true,"family":"Herman","given":"G.C.","email":"","affiliations":[],"preferred":false,"id":438326,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}} ,{"id":70032278,"text":"70032278 - 2009 - Distinguishing iron-reducing from sulfate-reducing conditions","interactions":[],"lastModifiedDate":"2018-10-05T10:23:44","indexId":"70032278","displayToPublicDate":"2009-01-01T00:00:00","publicationYear":"2009","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1861,"text":"Ground Water","active":true,"publicationSubtype":{"id":10}},"title":"Distinguishing iron-reducing from sulfate-reducing conditions","docAbstract":"Ground water systems dominated by iron‐ or sulfate‐reducing conditions may be distinguished by observing concentrations of dissolved iron (Fe2+) and sulfide (sum of H2S, HS−, and S= species and denoted here as “H2S”). This approach is based on the observation that concentrations of Fe2+ and H2S in ground water systems tend to be inversely related according to a hyperbolic function. That is, when Fe2+ concentrations are high, H2S concentrations tend to be low and vice versa. This relation partly reflects the rapid reaction kinetics of Fe2+ with H2S to produce relatively insoluble ferrous sulfides (FeS). This relation also reflects competition for organic substrates between the iron‐ and the sulfate‐reducing microorganisms that catalyze the production of Fe2+ and H2S. These solubility and microbial constraints operate in tandem, resulting in the observed hyperbolic relation between Fe2+ and H2S concentrations. Concentrations of redox indicators, including dissolved hydrogen (H2) measured in a shallow aquifer in Hanahan, South Carolina, suggest that if the Fe2+/H2S mass ratio (units of mg/L) exceeded 10, the screened interval being tapped was consistently iron reducing (H2∼0.2 to 0.8 nM). Conversely, if the Fe2+/H2S ratio was less than 0.30, consistent sulfate‐reducing (H2∼1 to 5 nM) conditions were observed over time. Concomitantly high Fe2+ and H2S concentrations were associated with H2 concentrations that varied between 0.2 and 5.0 nM over time, suggesting mixing of water from adjacent iron‐ and sulfate‐reducing zones or concomitant iron and sulfate reduction under nonelectron donor–limited conditions. These observations suggest that Fe2+/H2S mass ratios may provide useful information concerning the occurrence and distribution of iron and sulfate reduction in ground water systems.
","language":"English","publisher":"NGWA","doi":"10.1111/j.1745-6584.2008.00536.x","issn":"00174","usgsCitation":"Chapelle, F.H., Bradley, P., Thomas, M., and McMahon, P., 2009, Distinguishing iron-reducing from sulfate-reducing conditions: Ground Water, v. 47, no. 2, p. 300-305, https://doi.org/10.1111/j.1745-6584.2008.00536.x.","productDescription":"6 p.","startPage":"300","endPage":"305","costCenters":[{"id":191,"text":"Colorado Water Science Center","active":true,"usgs":true},{"id":589,"text":"Toxic Substances Hydrology Program","active":true,"usgs":true}],"links":[{"id":242374,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":214632,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1111/j.1745-6584.2008.00536.x"}],"volume":"47","issue":"2","noUsgsAuthors":false,"publicationDate":"2009-02-23","publicationStatus":"PW","scienceBaseUri":"505a0250e4b0c8380cd4ffce","contributors":{"authors":[{"text":"Chapelle, F. H.","contributorId":101697,"corporation":false,"usgs":true,"family":"Chapelle","given":"F.","email":"","middleInitial":"H.","affiliations":[],"preferred":false,"id":435405,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Bradley, P. M. 0000-0001-7522-8606","orcid":"https://orcid.org/0000-0001-7522-8606","contributorId":29465,"corporation":false,"usgs":true,"family":"Bradley","given":"P. M.","affiliations":[],"preferred":false,"id":435403,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Thomas, M.A.","contributorId":66877,"corporation":false,"usgs":true,"family":"Thomas","given":"M.A.","email":"","affiliations":[],"preferred":false,"id":435404,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"McMahon, P.B. 0000-0001-7452-2379","orcid":"https://orcid.org/0000-0001-7452-2379","contributorId":10762,"corporation":false,"usgs":true,"family":"McMahon","given":"P.B.","affiliations":[],"preferred":false,"id":435402,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}} ,{"id":70032309,"text":"70032309 - 2009 - Copper isotope fractionation in acid mine drainage","interactions":[],"lastModifiedDate":"2018-11-02T08:53:19","indexId":"70032309","displayToPublicDate":"2009-01-01T00:00:00","publicationYear":"2009","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":"Copper isotope fractionation in acid mine drainage","docAbstract":"We measured the Cu isotopic composition of primary minerals and stream water affected by acid mine drainage in a mineralized watershed (Colorado, USA). The δ65Cu values (based on 65Cu/63Cu) of enargite (δ65Cu = −0.01 ± 0.10‰; 2σ) and chalcopyrite (δ65Cu = 0.16 ± 0.10‰) are within the range of reported values for terrestrial primary Cu sulfides (−1‰ < δ65Cu < 1‰). These mineral samples show lower δ65Cu values than stream waters (1.38‰ ⩽ δ65Cu ⩽ 1.69‰). The average isotopic fractionation (Δaq-min = δ65Cuaq − δ65Cumin, where the latter is measured on mineral samples from the field system), equals 1.43 ± 0.14‰ and 1.60 ± 0.14‰ for chalcopyrite and enargite, respectively. To interpret this field survey, we leached chalcopyrite and enargite in batch experiments and found that, as in the field, the leachate is enriched in 65Cu relative to chalcopyrite (1.37 ± 0.14‰) and enargite (0.98 ± 0.14‰) when microorganisms are absent. Leaching of minerals in the presence of Acidithiobacillus ferrooxidans results in smaller average fractionation in the opposite direction for chalcopyrite (
The objective of this study was to compare fecal indicator bacteria (FIB) (fecal coliforms, Escherichia coli [EC], and enterococci [ENT]) concentrations with a wide array of typical organic wastewater chemicals and selected bacterial genes as indicators of fecal pollution in water samples collected at or near 18 surface water drinking water intakes. Genes tested included esp (indicating human-pathogenic ENT) and nine genes associated with various animal sources of shiga-toxin–producing EC (STEC). Fecal pollution was indicated by genes and/or chemicals for 14 of the 18 tested samples, with little relation to FIB standards. Of 13 samples with <50 EC 100 mL−1, human pharmaceuticals or chemical indicators of wastewater treatment plant effluent occurred in six, veterinary antibiotics were detected in three, and stx1 or stx2 genes (indicating varying animal sources of STEC) were detected in eight. Only the EC eaeA gene was positively correlated with FIB concentrations. Human-source fecal pollution was indicated by the esp gene and the human pharmaceutical carbamazepine in one of the nine samples that met all FIB recreational water quality standards. Escherichia coli rfbO157 and stx2c genes, which are typically associated with cattle sources and are of potential human health significance, were detected in one sample in the absence of tested chemicals. Chemical and gene-based indicators of fecal contamination may be present even when FIB standards are met, and some may, unlike FIB, indicate potential sources. Application of multiple water quality indicators with variable environmental persistence and fate may yield greater confidence in fecal pollution assessment and may inform remediation decisions
","language":"English","publisher":"Alliance of Crop, Soil, and Environmental Science Societies","doi":"10.2134/jeq2008.0173","issn":"00472","usgsCitation":"Haack, S., Duris, J., Fogarty, L., Kolpin, D., Focazio, M., Furlong, E., and Meyer, M.T., 2009, Comparing wastewater chemicals, indicator bacteria concentrations, and bacterial pathogen genes as fecal pollution indicators: Journal of Environmental Quality, v. 38, no. 1, p. 248-258, https://doi.org/10.2134/jeq2008.0173.","productDescription":"11 p.","startPage":"248","endPage":"258","costCenters":[{"id":452,"text":"National Water Quality Laboratory","active":true,"usgs":true},{"id":589,"text":"Toxic Substances Hydrology Program","active":true,"usgs":true}],"links":[{"id":241300,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":213652,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.2134/jeq2008.0173"}],"volume":"38","issue":"1","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"5059f83be4b0c8380cd4cf6b","contributors":{"authors":[{"text":"Haack, S.K.","contributorId":26457,"corporation":false,"usgs":true,"family":"Haack","given":"S.K.","email":"","affiliations":[],"preferred":false,"id":438062,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Duris, J.W.","contributorId":62835,"corporation":false,"usgs":true,"family":"Duris","given":"J.W.","email":"","affiliations":[],"preferred":false,"id":438064,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Fogarty, L.R.","contributorId":27236,"corporation":false,"usgs":true,"family":"Fogarty","given":"L.R.","email":"","affiliations":[],"preferred":false,"id":438063,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Kolpin, D.W.","contributorId":87565,"corporation":false,"usgs":true,"family":"Kolpin","given":"D.W.","email":"","affiliations":[],"preferred":false,"id":438066,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Focazio, M. J.","contributorId":62997,"corporation":false,"usgs":true,"family":"Focazio","given":"M. J.","affiliations":[],"preferred":false,"id":438065,"contributorType":{"id":1,"text":"Authors"},"rank":5},{"text":"Furlong, E. T. 0000-0002-7305-4603","orcid":"https://orcid.org/0000-0002-7305-4603","contributorId":98346,"corporation":false,"usgs":true,"family":"Furlong","given":"E. T.","affiliations":[],"preferred":false,"id":438068,"contributorType":{"id":1,"text":"Authors"},"rank":6},{"text":"Meyer, M. T.","contributorId":92279,"corporation":false,"usgs":true,"family":"Meyer","given":"M.","email":"","middleInitial":"T.","affiliations":[],"preferred":false,"id":438067,"contributorType":{"id":1,"text":"Authors"},"rank":7}]}} ,{"id":70032785,"text":"70032785 - 2009 - Naturally acidic surface and ground waters draining porphyry-related mineralized areas of the Southern Rocky Mountains, Colorado and New Mexico","interactions":[],"lastModifiedDate":"2018-10-12T08:41:22","indexId":"70032785","displayToPublicDate":"2009-01-01T00:00:00","publicationYear":"2009","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":"Naturally acidic surface and ground waters draining porphyry-related mineralized areas of the Southern Rocky Mountains, Colorado and New Mexico","docAbstract":"Acidic, metal-rich waters produced by the oxidative weathering and resulting leaching of major and trace elements from pyritic rocks can adversely affect water quality in receiving streams and riparian ecosystems. Five study areas in the southern Rocky Mountains with naturally acidic waters associated with porphyry mineralization were studied to document variations in water chemistry and processes that control the chemical variations. Study areas include the Upper Animas River watershed, East Alpine Gulch, Mount Emmons, and Handcart Gulch in Colorado and the Red River in New Mexico. Although host-rock lithologies in all these areas range from Precambrian gneisses to Cretaceous sedimentary units to Tertiary volcanic complexes, the mineralization is Tertiary in age and associated with intermediate to felsic composition, porphyritic plutons. Pyrite is ubiquitous, ranging from ???1 to >5 vol.%. Springs and headwater streams have pH values as low as 2.6, SO4 up to 3700 mg/L and high dissolved metal concentrations (for example: Fe up to 400 mg/L; Cu up to 3.5 mg/L; and Zn up to 14.4 mg/L). Intensity of hydrothermal alteration and presence of sulfides are the primary controls of water chemistry of these naturally acidic waters. Subbasins underlain by intensely hydrothermally altered lithologies are poorly vegetated and quite susceptible to storm-induced surface runoff. Within the Red River study area, results from a storm runoff study documented downstream changes in river chemistry: pH decreased from 7.80 to 4.83, alkalinity decreased from 49.4 to <1 mg/L, SO4 increased from 162 to 314 mg/L, dissolved Fe increased from to 0.011 to 0.596 mg/L, and dissolved Zn increased from 0.056 to 0.607 mg/L. Compared to mine drainage in the same study areas, the chemistry of naturally acidic waters tends to overlap but not reach the extreme concentrations of metals and acidity as some mine waters. The chemistry of waters draining these mineralized but unmined areas can be used to estimate premining conditions at sites with similar geologic and hydrologic conditions. For example, the US Geological Survey was asked to estimate premining ground-water chemistry at the Questa Mo mine, and the proximal analog approach was used because a mineralized but unmined area was located adjacent to the mine property. By comparing and contrasting water chemistry from different porphyry mineralized areas, this study not only documents the range in concentrations of constituents of interest but also provides insight into the primary controls of water chemistry.","language":"English","publisher":"Elsevier","doi":"10.1016/j.apgeochem.2008.11.014","issn":"08832","usgsCitation":"Verplanck, P., Nordstrom, D.K., Bove, D.J., Plumlee, G., and Runkel, R., 2009, Naturally acidic surface and ground waters draining porphyry-related mineralized areas of the Southern Rocky Mountains, Colorado and New Mexico: Applied Geochemistry, v. 24, no. 2, p. 255-267, https://doi.org/10.1016/j.apgeochem.2008.11.014.","productDescription":"13 p.","startPage":"255","endPage":"267","costCenters":[{"id":589,"text":"Toxic Substances Hydrology Program","active":true,"usgs":true}],"links":[{"id":241267,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":213621,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/j.apgeochem.2008.11.014"}],"volume":"24","issue":"2","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a6388e4b0c8380cd7253d","contributors":{"authors":[{"text":"Verplanck, P. L. 0000-0002-3653-6419","orcid":"https://orcid.org/0000-0002-3653-6419","contributorId":106565,"corporation":false,"usgs":true,"family":"Verplanck","given":"P. L.","affiliations":[],"preferred":false,"id":437900,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Nordstrom, D. Kirk 0000-0003-3283-5136 dkn@usgs.gov","orcid":"https://orcid.org/0000-0003-3283-5136","contributorId":749,"corporation":false,"usgs":true,"family":"Nordstrom","given":"D.","email":"dkn@usgs.gov","middleInitial":"Kirk","affiliations":[{"id":37277,"text":"WMA - Earth System Processes Division","active":true,"usgs":true},{"id":5044,"text":"National Research Program - Central Branch","active":true,"usgs":true}],"preferred":false,"id":437898,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Bove, D. J.","contributorId":70767,"corporation":false,"usgs":true,"family":"Bove","given":"D.","email":"","middleInitial":"J.","affiliations":[],"preferred":false,"id":437896,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Plumlee, G.S.","contributorId":80698,"corporation":false,"usgs":true,"family":"Plumlee","given":"G.S.","email":"","affiliations":[],"preferred":false,"id":437897,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Runkel, R.L.","contributorId":97529,"corporation":false,"usgs":true,"family":"Runkel","given":"R.L.","affiliations":[],"preferred":false,"id":437899,"contributorType":{"id":1,"text":"Authors"},"rank":5}]}} ,{"id":70032745,"text":"70032745 - 2009 - Effects of the herbicide diuron on cordgrass (Spartina foliosa) reflectance and photosynthetic parameters","interactions":[],"lastModifiedDate":"2018-10-15T06:54:11","indexId":"70032745","displayToPublicDate":"2009-01-01T00:00:00","publicationYear":"2009","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1584,"text":"Estuaries and Coasts","active":true,"publicationSubtype":{"id":10}},"title":"Effects of the herbicide diuron on cordgrass (Spartina foliosa) reflectance and photosynthetic parameters","docAbstract":"Early indicators of salt marsh plant stress are needed to detect stress before it is manifested as changes in biomass and coverage. We explored a variety of leaf-level spectral reflectance and fluorescence variables as indicators of stress in response to the herbicide diuron. Diuron, a Photosystem II inhibitor, is heavily used in areas adjacent to estuaries, but its ecological effects are just beginning to be recognized. In a greenhouse experiment, we exposed Spartina foliosa, the native cordgrass in California salt marshes, to two levels of diuron. After plant exposure to diuron for 28 days, all spectral reflectance indices and virtually all fluorescence parameters indicated reduced pigment and photosynthetic function, verified as reduced CO2 assimilation. Diuron exposure was not evident, however, in plant morphometry, indicating that reflectance and fluorescence were effective indicators of sub-lethal diuron exposure. Several indices (spectral reflectance index ARI and fluorescence parameters EQY, Fo, and maximum rETR) were sensitive to diuron concentration. In field trials, most of the indices as well as biomass, % cover, and canopy height varied predictably and significantly across a pesticide gradient. In the field, ARI and Fo regressed most significantly and strongly with pesticide levels. The responses of ARI and Fo in both the laboratory and the field make these indices promising as sensitive, rapid, non-destructive indicators of responses of S. foliosa to herbicides in the field. These techniques are employed in remote sensing and could potentially provide a link between landscapes of stressed vegetation and the causative stressor(s), which is crucial for effective regulation of pollution.
","language":"English","publisher":"Springer","doi":"10.1007/s12237-008-9114-z","issn":"15592","usgsCitation":"Williams, S., Carranza, A., Kunzelman, J., Datta, S., and Kuivila, K., 2009, Effects of the herbicide diuron on cordgrass (Spartina foliosa) reflectance and photosynthetic parameters: Estuaries and Coasts, v. 32, no. 1, p. 146-157, https://doi.org/10.1007/s12237-008-9114-z.","productDescription":"12 p.","startPage":"146","endPage":"157","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":241772,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":214084,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1007/s12237-008-9114-z"}],"volume":"32","issue":"1","noUsgsAuthors":false,"publicationDate":"2008-11-14","publicationStatus":"PW","scienceBaseUri":"505a0805e4b0c8380cd51931","contributors":{"authors":[{"text":"Williams, S.L.","contributorId":71398,"corporation":false,"usgs":true,"family":"Williams","given":"S.L.","email":"","affiliations":[],"preferred":false,"id":437714,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Carranza, A.","contributorId":84076,"corporation":false,"usgs":true,"family":"Carranza","given":"A.","email":"","affiliations":[],"preferred":false,"id":437715,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Kunzelman, J.","contributorId":39206,"corporation":false,"usgs":true,"family":"Kunzelman","given":"J.","email":"","affiliations":[],"preferred":false,"id":437713,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Datta, S.","contributorId":19754,"corporation":false,"usgs":true,"family":"Datta","given":"S.","email":"","affiliations":[],"preferred":false,"id":437711,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Kuivila, Kathryn 0000-0001-7940-489X kkuivila@usgs.gov","orcid":"https://orcid.org/0000-0001-7940-489X","contributorId":190790,"corporation":false,"usgs":true,"family":"Kuivila","given":"Kathryn","email":"kkuivila@usgs.gov","affiliations":[{"id":154,"text":"California Water Science Center","active":true,"usgs":true},{"id":518,"text":"Oregon Water Science Center","active":true,"usgs":true}],"preferred":true,"id":437712,"contributorType":{"id":1,"text":"Authors"},"rank":5}]}} ,{"id":70032721,"text":"70032721 - 2009 - Flow and geochemistry of groundwater beneath a back-barrier lagoon: The subterranean estuary at Chincoteague Bay, Maryland, USA","interactions":[],"lastModifiedDate":"2018-10-05T10:18:08","indexId":"70032721","displayToPublicDate":"2009-01-01T00:00:00","publicationYear":"2009","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2662,"text":"Marine Chemistry","active":true,"publicationSubtype":{"id":10}},"title":"Flow and geochemistry of groundwater beneath a back-barrier lagoon: The subterranean estuary at Chincoteague Bay, Maryland, USA","docAbstract":"To better understand large-scale interactions between fresh and saline groundwater beneath an Atlantic coastal estuary, an offshore drilling and sampling study was performed in a large barrier-bounded lagoon, Chincoteague Bay, Maryland, USA. Groundwater that was significantly fresher than overlying bay water was found in shallow plumes up to 8 m thick extending more than 1700 m offshore. Groundwater saltier than bay surface water was found locally beneath the lagoon and the barrier island, indicating recharge by saline water concentrated by evaporation prior to infiltration. Steep salinity and nutrient gradients occur within a few meters of the sediment surface in most locations studied, with buried peats and estuarine muds acting as confining units. Groundwater ages were generally more than 50 years in both fresh and brackish waters as deep as 23 m below the bay bottom. Water chemistry and isotopic data indicate that freshened plumes beneath the estuary are mixtures of water originally recharged on land and varying amounts of estuarine surface water that circulated through the bay floor, possibly at some distance from the sampling location. Ammonium is the dominant fixed nitrogen species in saline groundwater beneath the estuary at the locations sampled. Isotopic and dissolved-gas data from one location indicate that denitrification within the subsurface flow system removed terrestrial nitrate from fresh groundwater prior to discharge along the western side of the estuary. Similar situations, with one or more shallow semi-confined flow systems where groundwater geochemistry is strongly influenced by circulation of surface estuary water through organic-rich sediments, may be common on the Atlantic margin and elsewhere.
","language":"English","publisher":"Elsevier","doi":"10.1016/j.marchem.2009.01.004","issn":"03044","usgsCitation":"Bratton, J., Böhlke, J., Krantz, D., and Tobias, C., 2009, Flow and geochemistry of groundwater beneath a back-barrier lagoon: The subterranean estuary at Chincoteague Bay, Maryland, USA: Marine Chemistry, v. 113, no. 1-2, p. 78-92, https://doi.org/10.1016/j.marchem.2009.01.004.","productDescription":"15 p.","startPage":"78","endPage":"92","costCenters":[{"id":589,"text":"Toxic Substances Hydrology Program","active":true,"usgs":true}],"links":[{"id":476365,"rank":10000,"type":{"id":41,"text":"Open Access External Repository Page"},"url":"https://hdl.handle.net/1912/2963","text":"External Repository"},{"id":241424,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":213767,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/j.marchem.2009.01.004"}],"volume":"113","issue":"1-2","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a1238e4b0c8380cd54210","contributors":{"authors":[{"text":"Bratton, J.F.","contributorId":94354,"corporation":false,"usgs":true,"family":"Bratton","given":"J.F.","email":"","affiliations":[],"preferred":false,"id":437627,"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":437628,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Krantz, D.E.","contributorId":9838,"corporation":false,"usgs":true,"family":"Krantz","given":"D.E.","email":"","affiliations":[],"preferred":false,"id":437626,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Tobias, C.R.","contributorId":9442,"corporation":false,"usgs":true,"family":"Tobias","given":"C.R.","email":"","affiliations":[],"preferred":false,"id":437625,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}} ,{"id":70032558,"text":"70032558 - 2009 - Newly recognized hosts for uranium in the Hanford Site vadose zone","interactions":[],"lastModifiedDate":"2018-10-05T10:23:14","indexId":"70032558","displayToPublicDate":"2009-01-01T00:00:00","publicationYear":"2009","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":"Newly recognized hosts for uranium in the Hanford Site vadose zone","docAbstract":"Uranium contaminated sediments from the U.S. Department of Energy’s Hanford Site have been investigated using electron microscopy. Six classes of solid hosts for uranium were identified. Preliminary sediment characterization was carried out using optical petrography, and electron microprobe analysis (EMPA) was used to locate materials that host uranium. All of the hosts are fine-grained and intergrown with other materials at spatial scales smaller than the analytical volume of the electron microprobe. A focused ion beam (FIB) was used to prepare electron-transparent specimens of each host for the transmission electron microscope (TEM). The hosts were identified as: (1) metatorbernite [Cu(UO2)2(PO4)2·8H2O]; (2) coatings on sediment clasts comprised mainly of phyllosilicates; (3) an amorphous zirconium (oxyhydr)oxide found in clast coatings; (4) amorphous and poorly crystalline materials that line voids within basalt lithic fragments; (5) amorphous palagonite surrounding fragments of basaltic glass; and (6) Fe- and Mn-oxides. These findings demonstrate the effectiveness of combining EMPA, FIB, and TEM to identify solid-phase contaminant hosts. Furthermore, they highlight the complexity of U geochemistry in the Hanford vadose zone, and illustrate the importance of microscopic transport in controlling the fate of contaminant metals in the environment.
","language":"English","publisher":"Elsevier","doi":"10.1016/j.gca.2008.12.004","issn":"00167","usgsCitation":"Stubbs, J., Veblen, L., Elbert, D., Zachara, J., Davis, J., and Veblen, D., 2009, Newly recognized hosts for uranium in the Hanford Site vadose zone: Geochimica et Cosmochimica Acta, v. 73, no. 6, p. 1563-1576, https://doi.org/10.1016/j.gca.2008.12.004.","productDescription":"14 p.","startPage":"1563","endPage":"1576","costCenters":[{"id":589,"text":"Toxic Substances Hydrology Program","active":true,"usgs":true}],"links":[{"id":241517,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":213854,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/j.gca.2008.12.004"}],"volume":"73","issue":"6","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a662ce4b0c8380cd72d43","contributors":{"authors":[{"text":"Stubbs, J.E.","contributorId":99384,"corporation":false,"usgs":true,"family":"Stubbs","given":"J.E.","email":"","affiliations":[],"preferred":false,"id":436811,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Veblen, L.A.","contributorId":37967,"corporation":false,"usgs":true,"family":"Veblen","given":"L.A.","email":"","affiliations":[],"preferred":false,"id":436808,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Elbert, D.C.","contributorId":104293,"corporation":false,"usgs":true,"family":"Elbert","given":"D.C.","email":"","affiliations":[],"preferred":false,"id":436812,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Zachara, J.M.","contributorId":96896,"corporation":false,"usgs":true,"family":"Zachara","given":"J.M.","email":"","affiliations":[],"preferred":false,"id":436810,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Davis, J.A.","contributorId":71694,"corporation":false,"usgs":true,"family":"Davis","given":"J.A.","email":"","affiliations":[],"preferred":false,"id":436809,"contributorType":{"id":1,"text":"Authors"},"rank":5},{"text":"Veblen, D.R.","contributorId":25300,"corporation":false,"usgs":true,"family":"Veblen","given":"D.R.","email":"","affiliations":[],"preferred":false,"id":436807,"contributorType":{"id":1,"text":"Authors"},"rank":6}]}} ]}