Spatial complexity in channel geometry indicates that accurate prediction of sediment transport requires modeling in at least two dimensions. However, a one‐dimensional model may be the only practical or possible alternative, especially for longer river reaches of practical concern in river management or landscape modeling. We have developed a one‐dimensional model of the Colorado River through upper Grand Canyon that addresses this problem by reach averaging the channel properties and predicting changes in sand storage using separate source and sink functions coupled to the sand routing model. The model incorporates results from the application of a two‐dimensional model of flow, sand transport, and bed evolution, and a new algorithm for setting the near‐bed sand boundary condition for sand transported over an exposed bouldery bed. Model predictions were compared to measurements of sand discharge during intermittent tributary inputs and varying discharges controlled by dam releases. The model predictions generally agree well with the timing and magnitude of measured sand discharges but tend to overpredict sand discharge during the early stages of a high release designed to redistribute sand to higher‐elevation deposits.
","language":"English","publisher":"American Geophysical Union","doi":"10.1029/2005WR004824","usgsCitation":"Wiele, S., Wilcock, P., and Grams, P., 2007, Reach‐averaged sediment routing model of a canyon river: Water Resources Research, v. 43, no. 2, Article W02425; 16 p., https://doi.org/10.1029/2005WR004824.","productDescription":"Article W02425; 16 p.","costCenters":[],"links":[{"id":240911,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"43","issue":"2","noUsgsAuthors":false,"publicationDate":"2007-02-22","publicationStatus":"PW","scienceBaseUri":"505a9578e4b0c8380cd81a2b","contributors":{"authors":[{"text":"Wiele, S.M.","contributorId":100027,"corporation":false,"usgs":true,"family":"Wiele","given":"S.M.","affiliations":[],"preferred":false,"id":439028,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Wilcock, P.R.","contributorId":36709,"corporation":false,"usgs":true,"family":"Wilcock","given":"P.R.","email":"","affiliations":[],"preferred":false,"id":439026,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Grams, P.E.","contributorId":64032,"corporation":false,"usgs":true,"family":"Grams","given":"P.E.","email":"","affiliations":[],"preferred":false,"id":439027,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70033024,"text":"70033024 - 2007 - The geochemistry of groundwater resources in the Jordan Valley: The impact of the Rift Valley brines","interactions":[],"lastModifiedDate":"2023-09-06T11:30:20.570742","indexId":"70033024","displayToPublicDate":"2007-01-01T00:00:00","publicationYear":"2007","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":835,"text":"Applied Geochemistry","active":true,"publicationSubtype":{"id":10}},"title":"The geochemistry of groundwater resources in the Jordan Valley: The impact of the Rift Valley brines","docAbstract":"The chemical composition of groundwater in the Jordan Valley, along the section between the Sea of Galilee and the Dead Sea, is investigated in order to evaluate the origin of the groundwater resources and, in particular, to elucidate the role of deep brines on the chemical composition of the regional groundwater resources in the Jordan Valley. Samples were collected from shallow groundwater in research boreholes on two sites in the northern and southern parts of the Jordan Valley, adjacent to the Jordan River. Data is also compiled from previous published studies. Geochemical data (e.g., Br/Cl, Na/Cl and SO4/Cl ratios) and B, O, Sr and S isotopic compositions are used to define groundwater groups, to map their distribution in the Jordan valley, and to evaluate their origin. The combined geochemical tools enabled the delineation of three major sources of solutes that differentially affect the quality of groundwater in the Jordan Valley: (1) flow and mixing with hypersaline brines with high Br/Cl (>2 × 10−3) and low Na/Cl (<0.8) ratios; (2) dissolution of highly soluble salts (e.g., halite, gypsum) in the host sediments resulting in typically lower Br/Cl signal (<2 × 10−3); and (3) recharge of anthropogenic effluents, primarily derived from evaporated agricultural return flow that has interacted (e.g., base-exchange reactions) with the overlying soil. It is shown that shallow saline groundwaters influenced by brine mixing exhibit a north–south variation in their Br/Cl and Na/Cl ratios. This chemical trend was observed also in hypersaline brines in the Jordan valley, which suggests a local mixing process between the water bodies.
Ninety eight pharmaceuticals and other organic compounds (POOCs) that were amended to samples of chlorinated drinking-water were extracted and analyzed 1, 3, 6, 8, and 10 days after amendment to determine whether the total chlorine residual reacted with the amended POOCs in drinking water in a time frame similar to the residence time of drinking water in a water distribution system.
Results indicated that if all 98 were present in the finished drinking water from a drinking-water treatment plant using free chlorine at 1.2 mg/L as the distribution system disinfectant residual, 52 POOCs would be present in the drinking water after 10 days at approximately the same concentration as in the newly finished drinking water. Concentrations of 16 POOCs would be reduced by 32% to 92%, and 22 POOCs would react completely with residual chlorine within 24 h. Thus, the presence of free chlorine residual is an effective means for transforming some POOCs during distribution.
","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Science of the Total Environment","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","publisher":"Elsevier","doi":"10.1016/j.scitotenv.2006.11.003","issn":"00489697","usgsCitation":"Gibs, J., Stackelberg, P.E., Furlong, E.T., Meyer, M.T., Zaugg, S.D., and Lippincott, R., 2007, Persistence of pharmaceuticals and other organic compounds in chlorinated drinking water as a function of time: Science of the Total Environment, v. 373, no. 1, p. 240-249, https://doi.org/10.1016/j.scitotenv.2006.11.003.","productDescription":"10 p.","startPage":"240","endPage":"249","costCenters":[{"id":589,"text":"Toxic Substances Hydrology Program","active":true,"usgs":true}],"links":[{"id":240744,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":213148,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/j.scitotenv.2006.11.003"}],"volume":"373","issue":"1","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a76eee4b0c8380cd7839d","contributors":{"authors":[{"text":"Gibs, Jacob jgibs@usgs.gov","contributorId":1729,"corporation":false,"usgs":true,"family":"Gibs","given":"Jacob","email":"jgibs@usgs.gov","affiliations":[],"preferred":true,"id":438981,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Stackelberg, Paul E. 0000-0002-1818-355X pestack@usgs.gov","orcid":"https://orcid.org/0000-0002-1818-355X","contributorId":1069,"corporation":false,"usgs":true,"family":"Stackelberg","given":"Paul","email":"pestack@usgs.gov","middleInitial":"E.","affiliations":[{"id":474,"text":"New York Water Science Center","active":true,"usgs":true}],"preferred":true,"id":438978,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Furlong, Edward T. 0000-0002-7305-4603 efurlong@usgs.gov","orcid":"https://orcid.org/0000-0002-7305-4603","contributorId":740,"corporation":false,"usgs":true,"family":"Furlong","given":"Edward","email":"efurlong@usgs.gov","middleInitial":"T.","affiliations":[{"id":191,"text":"Colorado Water Science Center","active":true,"usgs":true},{"id":5046,"text":"Branch of Analytical Serv (NWQL)","active":true,"usgs":true},{"id":503,"text":"Office of Water Quality","active":true,"usgs":true},{"id":27111,"text":"National Water Quality Program","active":true,"usgs":true}],"preferred":true,"id":438983,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Meyer, Michael T. 0000-0001-6006-7985 mmeyer@usgs.gov","orcid":"https://orcid.org/0000-0001-6006-7985","contributorId":866,"corporation":false,"usgs":true,"family":"Meyer","given":"Michael","email":"mmeyer@usgs.gov","middleInitial":"T.","affiliations":[{"id":353,"text":"Kansas Water Science Center","active":false,"usgs":true}],"preferred":true,"id":438982,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Zaugg, Steven D. sdzaugg@usgs.gov","contributorId":768,"corporation":false,"usgs":true,"family":"Zaugg","given":"Steven","email":"sdzaugg@usgs.gov","middleInitial":"D.","affiliations":[],"preferred":true,"id":438980,"contributorType":{"id":1,"text":"Authors"},"rank":5},{"text":"Lippincott, R.L.","contributorId":73817,"corporation":false,"usgs":true,"family":"Lippincott","given":"R.L.","email":"","affiliations":[],"preferred":false,"id":438979,"contributorType":{"id":1,"text":"Authors"},"rank":6}]}} ,{"id":70033014,"text":"70033014 - 2007 - Vertical spatial sensitivity and exploration depth of low-induction-number electromagnetic-induction instruments","interactions":[],"lastModifiedDate":"2018-04-02T15:24:51","indexId":"70033014","displayToPublicDate":"2007-01-01T00:00:00","publicationYear":"2007","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":3674,"text":"Vadose Zone Journal","active":true,"publicationSubtype":{"id":10}},"title":"Vertical spatial sensitivity and exploration depth of low-induction-number electromagnetic-induction instruments","docAbstract":"Vertical spatial sensitivity and effective depth of exploration (d e) of low-induction-number (LIN) instruments over a layered soil were evaluated using a complete numerical solution to Maxwell's equations. Previous studies using approximate mathematical solutions predicted a vertical spatial sensitivity for instruments operating under LIN conditions that, for a given transmitter-receiver coil separation (s), coil orientation, and transmitter frequency, should depend solely on depth below the land surface. When not operating under LIN conditions, vertical spatial sensitivity and de also depend on apparent soil electrical conductivity (??a) and therefore the induction number (??). In this new evaluation, we determined the range of ??a and ?? values for which the LIN conditions hold and how de changes when they do not. Two-layer soil models were simulated with both horizontal (HCP) and vertical (VCP) coplanar coil orientations. Soil layers were given electrical conductivity values ranging from 0.1 to 200 mS m-1. As expected, de decreased as ??a increased. Only the least electrically conductive soil produced the de expected when operating under LIN conditions. For the VCP orientation, this was 1.6s, decreasing to 0.8s in the most electrically conductive soil. For the HCP orientation, de decreased from 0.76s to 0.51s. Differences between this and previous studies are attributed to inadequate representation of skin-depth effect and scattering at interfaces between layers. When using LIN instruments to identify depth to water tables, interfaces between soil layers, and variations in salt or moisture content, it is important to consider the dependence of de on ??a. ?? Soil Science Society of America.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Vadose Zone Journal","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.2136/vzj2006.0120","issn":"15391663","usgsCitation":"Callegary, J., Ferre, T., and Groom, R., 2007, Vertical spatial sensitivity and exploration depth of low-induction-number electromagnetic-induction instruments: Vadose Zone Journal, v. 6, no. 1, p. 158-167, https://doi.org/10.2136/vzj2006.0120.","startPage":"158","endPage":"167","numberOfPages":"10","costCenters":[],"links":[{"id":476982,"rank":10000,"type":{"id":41,"text":"Open Access External Repository Page"},"url":"http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.503.2650","text":"External Repository"},{"id":240711,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":213118,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.2136/vzj2006.0120"}],"volume":"6","issue":"1","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505bc242e4b08c986b32aa15","contributors":{"authors":[{"text":"Callegary, J.B.","contributorId":71769,"corporation":false,"usgs":true,"family":"Callegary","given":"J.B.","affiliations":[],"preferred":false,"id":438977,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Ferre, T.P.A.","contributorId":196167,"corporation":false,"usgs":false,"family":"Ferre","given":"T.P.A.","email":"","affiliations":[],"preferred":false,"id":438975,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Groom, R.W.","contributorId":59634,"corporation":false,"usgs":true,"family":"Groom","given":"R.W.","email":"","affiliations":[],"preferred":false,"id":438976,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70032998,"text":"70032998 - 2007 - Longterm trends in nest counts of colonial seabirds in South Carolina, USA","interactions":[],"lastModifiedDate":"2012-03-12T17:21:37","indexId":"70032998","displayToPublicDate":"2007-01-01T00:00:00","publicationYear":"2007","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":3731,"text":"Waterbirds","onlineIssn":"19385390","printIssn":"15244695","active":true,"publicationSubtype":{"id":10}},"title":"Longterm trends in nest counts of colonial seabirds in South Carolina, USA","docAbstract":"We analyzed temporal and spatial trends in annual nest counts of Brown Pelicans (Pelecanus occidentalis), Royal Terns (Sterna maxima), and Sandwich Terns (Sterna sandvicensis) throughout South Carolina from 1969 through 2005. There was an increase in the number of active pelican nests from 1969 through the mid 1980s, although this was followed by a steady decline that continued through 2005. Numbers of Royal Tern nests have declined during the study period, especially since 1990. In contrast, annual counts of active Sandwich Tern nests remained relatively stable through the mid 1980s, then increased substantially and have since remained stable. During the early years of the study, a greater proportion of nests from each species occurred on colonies within the Cape Romain region, although this distribution appears to have shifted with a greater proportion of nests now occurring along the southern coast. At the statewide level and at each of the primary colonies, we observed a positive correlation in counts of Brown Pelican and Royal Tern nests. Mechanisms underlying the observed trends are unclear. We suggest that priorities for research include (1) determination of diet and foraging locales for all three species, (2) impacts of ectoparasites on condition and survival of pelican chicks, and (3) metapopulation structure of all three species. Management activities should focus primarily on protection of colony sites.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Waterbirds","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1675/1524-4695(2007)030[0040:LTINCO]2.0.CO;2","issn":"15244695","usgsCitation":"Jodice, P., Murphy, T., Sanders, F., and Ferguson, L., 2007, Longterm trends in nest counts of colonial seabirds in South Carolina, USA: Waterbirds, v. 30, no. 1, p. 40-51, https://doi.org/10.1675/1524-4695(2007)030[0040:LTINCO]2.0.CO;2.","startPage":"40","endPage":"51","numberOfPages":"12","costCenters":[],"links":[{"id":213329,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1675/1524-4695(2007)030[0040:LTINCO]2.0.CO;2"},{"id":240942,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"30","issue":"1","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a49c7e4b0c8380cd688a3","contributors":{"authors":[{"text":"Jodice, P.G.R.","contributorId":79846,"corporation":false,"usgs":true,"family":"Jodice","given":"P.G.R.","email":"","affiliations":[],"preferred":false,"id":438905,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Murphy, T.M.","contributorId":67295,"corporation":false,"usgs":true,"family":"Murphy","given":"T.M.","email":"","affiliations":[],"preferred":false,"id":438904,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Sanders, F.J.","contributorId":45525,"corporation":false,"usgs":true,"family":"Sanders","given":"F.J.","email":"","affiliations":[],"preferred":false,"id":438903,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Ferguson, L.M.","contributorId":105911,"corporation":false,"usgs":true,"family":"Ferguson","given":"L.M.","email":"","affiliations":[],"preferred":false,"id":438906,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}} ,{"id":70032997,"text":"70032997 - 2007 - Dominance of organic nitrogen from headwater streams to large rivers across the conterminous United States","interactions":[],"lastModifiedDate":"2012-03-12T17:21:37","indexId":"70032997","displayToPublicDate":"2007-01-01T00:00:00","publicationYear":"2007","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1836,"text":"Global Biogeochemical Cycles","active":true,"publicationSubtype":{"id":10}},"title":"Dominance of organic nitrogen from headwater streams to large rivers across the conterminous United States","docAbstract":"The frequency and magnitude of hypoxic areas in coastal waterbodies are increasing across the globe, partially in response to the increase in nitrogen delivery from the landscape (Diaz, 2001; Rabalais et al., 2002). Although studies of annual total nitrogen and nitrate yields have greatly improved understanding of the contaminant sources that contribute to riverine nitrogen loads (Alexander et al., 2000; Caraco and Cole, 1999), the emphasis of these studies on annual timescales and selected nitrogen forms is not sufficient to understand the factors that control the cycling, transport, and fate of reactive nitrogen. Here we use data from 850 river stations to calculate long-term mean-annual and interannual loads of organic, ammonia, and nitrate-nitrite nitrogen suitable for spatial analysis. We find that organic nitrogen is the dominant nitrogen pool within rivers across most of the United States and is significant even in basins with high anthropogenic sources of nitrogen. Downstream organic nitrogen patterns illustrate that organic nitrogen is an abundant fraction of the nitrogen loads in all regions. Although the longitudinal patterns are not consistent across regions, these patterns are suggestive of cycling between ON and NO3- on seasonal timescales influenced by land use, stream morphology, and riparian connectivity with active floodplains. Future regional studies need to incorporate multinitrogen species at intraannual timescales, as well as stream characteristics beyond channel depth, to elucidate the roles of nitrogen sources and in-stream transformations on the fate and reactivity of riverine nitrogen transported to coastal seas.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Global Biogeochemical Cycles","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1029/2006GB002730","issn":"08866236","usgsCitation":"Scott, D., Harvey, J., Alexander, R., and Schwarz, G., 2007, Dominance of organic nitrogen from headwater streams to large rivers across the conterminous United States: Global Biogeochemical Cycles, v. 21, no. 1, https://doi.org/10.1029/2006GB002730.","costCenters":[],"links":[{"id":476985,"rank":10000,"type":{"id":40,"text":"Open Access Publisher Index Page"},"url":"https://doi.org/10.1029/2006gb002730","text":"Publisher Index Page"},{"id":213328,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1029/2006GB002730"},{"id":240941,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"21","issue":"1","noUsgsAuthors":false,"publicationDate":"2007-01-18","publicationStatus":"PW","scienceBaseUri":"505a03a5e4b0c8380cd505b0","contributors":{"authors":[{"text":"Scott, D.","contributorId":94107,"corporation":false,"usgs":true,"family":"Scott","given":"D.","affiliations":[],"preferred":false,"id":438902,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Harvey, J.","contributorId":40809,"corporation":false,"usgs":true,"family":"Harvey","given":"J.","email":"","affiliations":[],"preferred":false,"id":438900,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Alexander, R.","contributorId":33345,"corporation":false,"usgs":true,"family":"Alexander","given":"R.","affiliations":[],"preferred":false,"id":438899,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Schwarz, G.","contributorId":72595,"corporation":false,"usgs":true,"family":"Schwarz","given":"G.","email":"","affiliations":[],"preferred":false,"id":438901,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}} ,{"id":70032987,"text":"70032987 - 2007 - Hydrothermal circulation at Mount St. Helens determined by self-potential measurements","interactions":[],"lastModifiedDate":"2023-10-06T11:55:44.401729","indexId":"70032987","displayToPublicDate":"2007-01-01T00:00:00","publicationYear":"2007","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2499,"text":"Journal of Volcanology and Geothermal Research","active":true,"publicationSubtype":{"id":10}},"title":"Hydrothermal circulation at Mount St. Helens determined by self-potential measurements","docAbstract":"The distribution of hydrothermal circulation within active volcanoes is of importance in identifying regions of hydrothermal alteration which may in turn control explosivity, slope stability and sector collapse. Self-potential measurements, indicative of fluid circulation, were made within the crater of Mount St. Helens in 2000 and 2001. A strong dipolar anomaly in the self-potential field was detected on the north face of the 1980–86 lava dome. This anomaly reaches a value of negative one volt on the lower flanks of the dome and reverses sign toward the dome summit. The anomaly pattern is believed to result from a combination of thermoelectric, electrokinetic, and fluid disruption effects within and surrounding the dome. Heat supplied from a cooling dacite magma very likely drives a shallow hydrothermal convection cell within the dome. The temporal stability of the SP field, low surface recharge rate, and magmatic component to fumarole condensates and thermal waters suggest the hydrothermal system is maintained by water vapor exsolved from the magma and modulated on short time scales by surface recharge.
The major element relationships in ferromanganese (Fe-Mn) crusts from Afanasiy-Nikitin seamount (ANS), eastern equatorial Indian Ocean, appear to be atypical. High positive correlations (r = 0.99) between Mn/Co and Fe/Co ratios, and lack of correlation of those ratios with Co, Ce, and Ce/Co, indicate that the ANS Fe-Mn crusts are distinct from Pacific seamount Fe-Mn crusts, and reflect region-specific chemical characteristics. The platinum group elements (PGE: Ir, Ru, Rh, Pt, and Pd) and Au in ANS Fe-Mn crusts are derived from seawater and are mainly of terrestrial origin, with a minor cosmogenic component. The Ru/Rh (0.5–2) and Pt/Ru ratios (7–28) are closely comparable to ratios in continental basalts, whereas Pd/Ir ratios exhibit values (<2) similar to CI-chondrite (∼1). The chondrite-normalized PGE patterns are similar to those of igneous rocks, except that Pd is relatively depleted. The water depth of Fe-Mn crust formation appears to have a first-order control on both major element and PGE enrichments. These relationships are defined statistically by significant (r > 0.75) correlations between water depth and Mn/Co, Fe/Co, Ce/Co, Co, and the PGEs. Fractionation of the PGE-Au from seawater during colloidal precipitation of the major-oxide phases is indicated by well-defined linear positive correlations (r > 0.8) of Co and Ce with Ir, Ru, Rh, and Pt; Au/Co with Mn/Co; and by weak or no correlations of Pd with water depth, Co-normalized major-element ratios, and with the other PGE (r < 0.5). The strong enrichment of Pt (up to 1 ppm) relative to the other PGE and its positive correlations with Ce and Co demonstrate a common link for the high concentrations of all three elements, which likely involves an oxidation reaction on the Mn-oxide and Fe-oxyhydroxide surfaces. The documented fractionation of PGE-Au and their positive association with redox sensitive Co and Ce may have applications in reconstructing past-ocean redox conditions and water masses.
We analyzed monthly boat electrofishing data to characterize the littoral fish assemblages of five regions of the Sacramento-San Joaquin Delta (northern, southern, eastern, western, and central), California, during two sampling periods, 1980-1983 (1980s) and 2001-2003 (2000s), to provide information pertinent to the restoration of fish populations in this highly altered estuary. During the 1980s, almost 11,000 fish were captured, including 13 native species and 24 alien species. During the 2000s, just over 39,000 fish were captured, including 15 native species and 24 alien species. Catch per unit effort (CPUE) of total fish, alien fish, and centrarchid fish were greater in the 2000s compared with the 1980s, largely because of increased centrarchid fish CPUE. These differences in CPUE were associated with the spread of submerged aquatic vegetation (SAV), particularly an alien aquatic macrophyte Egeria densa. Native fish CPUE declined from the 1980s to the 2000s, but there was no single factor that could explain the decline. Native fish were most abundant in the northern region during both sampling periods. Nonmetric multidimensional scaling indicated similar patterns of fish assemblage composition during the two sampling periods, with the northern and western regions characterized by the presence of native species. The separation of the northern and western regions from the other regions was most distinct in the 2000s. Our results suggest that native fish restoration efforts will be most successful in the northern portion of the Delta. Management decisions on the Delta should include consideration of possible effects on SAV in littoral habitats and the associated fish assemblages and ecological processes.
","language":"English","publisher":"Springer","doi":"10.1007/BF02782979","usgsCitation":"Brown, L., and Michniuk, D., 2007, Littoral fish assemblages of the alien-dominated Sacramento-San Joaquin Delta, California, 1980-1983 and 2001-2003: Estuaries and Coasts, v. 30, no. 1, p. 186-200, https://doi.org/10.1007/BF02782979.","productDescription":"15 p.","startPage":"186","endPage":"200","costCenters":[{"id":154,"text":"California Water Science Center","active":true,"usgs":true}],"links":[{"id":240774,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"country":"United States","state":"California","otherGeospatial":"Sacramento–San Joaquin Delta","geographicExtents":"{\n \"type\": \"FeatureCollection\",\n \"features\": [\n {\n \"type\": \"Feature\",\n \"properties\": {},\n \"geometry\": {\n \"type\": \"Polygon\",\n \"coordinates\": [\n [\n [\n -122.03887939453125,\n 37.92686760148135\n ],\n [\n -121.4208984375,\n 37.92686760148135\n ],\n [\n -121.4208984375,\n 38.158316657442\n ],\n [\n -122.03887939453125,\n 38.158316657442\n ],\n [\n -122.03887939453125,\n 37.92686760148135\n ]\n ]\n ]\n }\n }\n ]\n}","volume":"30","issue":"1","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a48b5e4b0c8380cd6808a","contributors":{"authors":[{"text":"Brown, L. R. 0000-0001-6702-4531","orcid":"https://orcid.org/0000-0001-6702-4531","contributorId":66391,"corporation":false,"usgs":true,"family":"Brown","given":"L. R.","affiliations":[],"preferred":false,"id":438837,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Michniuk, D.","contributorId":8296,"corporation":false,"usgs":true,"family":"Michniuk","given":"D.","email":"","affiliations":[],"preferred":false,"id":438836,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70032983,"text":"70032983 - 2007 - Colored dissolved organic matter in Tampa Bay, Florida","interactions":[],"lastModifiedDate":"2022-11-14T17:20:47.244238","indexId":"70032983","displayToPublicDate":"2007-01-01T00:00:00","publicationYear":"2007","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":"Colored dissolved organic matter in Tampa Bay, Florida","docAbstract":"Absorption and fluorescence of colored dissolved organic matter (CDOM) and concentrations of dissolved organic carbon (DOC), chlorophyll and total suspended solids in Tampa Bay and its adjacent rivers were examined in June and October of 2004. Except in Old Tampa Bay (OTB), the spatial distribution of CDOM showed a conservative relationship with salinity in June, 2004 (aCDOM(400) = − 0.19 × salinity + 6.78, R2 = 0.98, n = 17, salinity range = 1.1–32.5) with little variations in absorption spectral slope and fluorescence efficiency. This indicates that CDOM distribution was dominated by mixing. In October, 2004, CDOM distribution was nonconservative with an average absorption coefficient (aCDOM(400), ∼ 7.76 m-1) about seven times higher than that in June (∼ 1.11 m-1). The nonconservative behavior was caused largely by CDOM removal at intermediate salinities (e.g., aCDOM(400) removal > 15% at salinity ∼ 13.0), which likely resulted from photobleaching due to stronger stratification. The spatial and seasonal distributions of CDOM in Tampa Bay showed that the two largest rivers, the Alafia River (AR) and Hillsborough River (HR) were dominant CDOM sources to most of the bay. In OTB, however, CDOM showed distinctive differences: lower absorption coefficient, higher absorption spectral slopes, and lower ratios of CDOM absorption to DOC and higher fluorescence efficiency. These differences may have stemmed from (1) changes in CDOM composition by more intensive photobleaching due to the longer residence time of water mass in OTB; (2) other sources of CDOM than the HR/AR inputs, such as local creeks, streams, groundwater, and/or bottom re-suspension. Average CDOM absorption in Tampa Bay at 443 nm, aCDOM(443), was about five times higher in June and about ten times higher in October than phytoplankton pigment absorption, aph(443), indicating that blue light attenuation in the water column was dominated by CDOM rather than by phytoplankton absorption throughout the year.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Marine Chemistry","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","publisher":"Elsevier","doi":"10.1016/j.marchem.2006.12.007","issn":"03044203","usgsCitation":"Chen, Z., Hu, C., Conmy, R., Muller-Karger, F., and Swarzenski, P., 2007, Colored dissolved organic matter in Tampa Bay, Florida: Marine Chemistry, v. 104, no. 1-2, p. 98-109, https://doi.org/10.1016/j.marchem.2006.12.007.","productDescription":"12 p.","startPage":"98","endPage":"109","numberOfPages":"12","costCenters":[{"id":186,"text":"Coastal and Marine Geology Program","active":true,"usgs":true}],"links":[{"id":213147,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/j.marchem.2006.12.007"},{"id":240743,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"country":"United States","state":"Florida","otherGeospatial":"Tampa Bay","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -82.755578,27.520902 ], [ -82.755578,27.838234 ], [ -82.449468,27.838234 ], [ -82.449468,27.520902 ], [ -82.755578,27.520902 ] ] ] } } ] }","volume":"104","issue":"1-2","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"5059f7c6e4b0c8380cd4ccce","contributors":{"authors":[{"text":"Chen, Z.","contributorId":26117,"corporation":false,"usgs":true,"family":"Chen","given":"Z.","email":"","affiliations":[],"preferred":false,"id":438831,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Hu, C.","contributorId":75748,"corporation":false,"usgs":true,"family":"Hu","given":"C.","email":"","affiliations":[],"preferred":false,"id":438834,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Conmy, R.N.","contributorId":83745,"corporation":false,"usgs":true,"family":"Conmy","given":"R.N.","affiliations":[],"preferred":false,"id":438835,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Muller-Karger, F.","contributorId":68512,"corporation":false,"usgs":true,"family":"Muller-Karger","given":"F.","affiliations":[],"preferred":false,"id":438833,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Swarzenski, P. 0000-0003-0116-0578","orcid":"https://orcid.org/0000-0003-0116-0578","contributorId":49156,"corporation":false,"usgs":true,"family":"Swarzenski","given":"P.","affiliations":[],"preferred":false,"id":438832,"contributorType":{"id":1,"text":"Authors"},"rank":5}]}} ,{"id":70032966,"text":"70032966 - 2007 - Late quaternary temperature record from buried soils of the North American Great Plains","interactions":[],"lastModifiedDate":"2017-04-12T16:20:33","indexId":"70032966","displayToPublicDate":"2007-01-01T00:00:00","publicationYear":"2007","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1796,"text":"Geology","active":true,"publicationSubtype":{"id":10}},"title":"Late quaternary temperature record from buried soils of the North American Great Plains","docAbstract":"We present the first comprehensive late Quaternary record of North American Great Plains temperature by assessing the behavior of the stable isotopic composition (δ13C) of buried soils. After examining the relationship between the δ13C of topsoil organic matter and July temperature from 61 native prairies within a latitudinal range of 46°–38°N, we applied the resulting regression equation to 64 published δ13C values from buried soils of the same region to construct a temperature curve for the past 12 k.y. Estimated temperatures from 12 to 10 ka (1 k.y. = 1000 14C yr B.P.) fluctuated with a periodicity of ∼1 k.y. with two cool excursions between −4.5 and −3.5 °C and two warmer excursions between −1 and 0 °C, relative to modern. Early Holocene temperatures from ca. 10–7.5 ka were −1.0 to −2.0 °C before rising to +1.0 °C in the middle Holocene between 6.0 and 4.5 ka. After a cool interlude from 4.2 to 2.6 ka, when temperatures dropped to slightly below modern, another warm interval ensued from 2.6 to 1 ka as temperatures increased to ∼+0.5 °C. A final decline in temperature to below modern occurred beginning ca. 0.5 ka. Cooler than present temperatures in the Great Plains indicate telecommunications with cool-water episodes in the Gulf of Mexico and North Atlantic potentially governed by a combination of glacial meltwater pulses and low solar irradiance.
","language":"English","publisher":"Geological Society of America","doi":"10.1130/G23345A.1","issn":"00917613","usgsCitation":"Nordt, L., Von Fischer, J., and Tieszen, L., 2007, Late quaternary temperature record from buried soils of the North American Great Plains: Geology, v. 35, no. 2, p. 159-162, https://doi.org/10.1130/G23345A.1.","productDescription":"4 p.","startPage":"159","endPage":"162","numberOfPages":"4","costCenters":[{"id":222,"text":"Earth Resources Observation and Science (EROS) Center","active":true,"usgs":true}],"links":[{"id":241005,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":213384,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1130/G23345A.1"}],"volume":"35","issue":"2","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a4559e4b0c8380cd6723e","contributors":{"authors":[{"text":"Nordt, L.","contributorId":65207,"corporation":false,"usgs":true,"family":"Nordt","given":"L.","email":"","affiliations":[],"preferred":false,"id":438738,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Von Fischer, J.","contributorId":77277,"corporation":false,"usgs":true,"family":"Von Fischer","given":"J.","affiliations":[],"preferred":false,"id":438739,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Tieszen, L.","contributorId":22887,"corporation":false,"usgs":true,"family":"Tieszen","given":"L.","email":"","affiliations":[],"preferred":false,"id":438737,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70032965,"text":"70032965 - 2007 - DIN retention-transport through four hydrologically connected zones in a headwater catchment of the Upper Mississippi River","interactions":[],"lastModifiedDate":"2023-10-06T11:10:47.274618","indexId":"70032965","displayToPublicDate":"2007-01-01T00:00:00","publicationYear":"2007","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":"DIN retention-transport through four hydrologically connected zones in a headwater catchment of the Upper Mississippi River","docAbstract":"Dissolved inorganic nitrogen (DIN) retention-transport through a headwater catchment was synthesized from studies encompassing four distinct hydrologic zones of the Shingobee River Headwaters near the origin of the Mississippi River. The hydrologic zones included: (1) hillslope ground water (ridge to bankside riparian); (2) alluvial riparian ground water; (3) ground water discharged through subchannel sediments (hyporheic zone); and (4) channel surface water. During subsurface hillslope transport through Zone 1, DIN, primarily nitrate, decreased from ∼3 mg-N/l to <0.1 mg-N/l. Ambient seasonal nitrate:chloride ratios in hillslope flow paths indicated both dilution and biotic processing caused nitrate loss. Biologically available organic carbon controlled biotic nitrate retention during hillslope transport. In the alluvial riparian zone (Zone 2) biologically available organic carbon controlled nitrate depletion although processing of both ambient and amended nitrate was faster during the summer than winter. In the hyporheic zone (Zone 3) and stream surface water (Zone 4) DIN retention was primarily controlled by temperature. Perfusion core studies using hyporheic sediment indicated sufficient organic carbon in bed sediments to retain ground water DIN via coupled nitrification-denitrification. Numerical simulations of seasonal hyporheic sediment nitrification-denitrification rates from perfusion cores adequately predicted surface water ammonium but not nitrate when compared to 5 years of monthly field data (1989-93). Mass balance studies in stream surface water indicated proportionally higher summer than winter N retention. Watershed DIN retention was effective during summer under the current land use of intermittently grazed pasture. However, more intensive land use such as row crop agriculture would decrease nitrate retention efficiency and increase loads to surface water. Understanding DIN retention capacity throughout the system, including special channel features such as sloughs, wetlands and floodplains that provide surface water-ground water connectivity, will be required to develop effective nitrate management strategies.
Historically, Tampa Bay has been impacted heavily by a wide range of anthropogenic perturbations that may include, agricultural-, shipping-, phosphate mining/distribution-related activities, as well as a burgeoning coastal population. Due to the presence of U-rich underlying sediments, elevated activities of U- and Th-series daughter products may be naturally released into this system. This region is also known for summer thunderstorms and corresponding increases in precipitation and surface water runoff. Only limited work has been conducted on the partitioning of particle-reactive radionuclides (such as 7Be, 210Pb, and 234Th) in such a dynamic coastal system. We investigated both the removal residence time and partitioning of these radionuclides between filter-retained particulate matter (≥ 0.5 μm) and the filtrate (< 0.5 μm) phase during late spring (June 2003) and mid summer (August 2003) in the water column of Tampa Bay.
\nOur results indicate that the partitioning of 7Be, 210Pb, and 234Th between filtrate and filter-retained phase is controlled foremost by enhanced bottom resuspension events during summer thunderstorms. As a consequence, no significant relationship exists between the distribution coefficients (Kd values) of these isotopes and the concentration of suspended particulate matter (SPM). Relatively faster recycling rates of atmospheric water vapor derived from the ocean results in lower atmospheric depositional fluxes of 210Pb to the study site than predicted. The relationship between 7Be and 210Pb in bulk (wet + dry) deposition is compared to their respective water column activities. The residence times of particulate and dissolved 234Th, 7Be and 210Pb, as well the distribution coefficients of these radionuclides, are then compared to values reported in other coastal systems.
","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Marine Chemistry","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","publisher":"Elsevier","doi":"10.1016/j.marchem.2006.06.012","issn":"03044203","usgsCitation":"Baskaran, M., and Swarzenski, P., 2007, Seasonal variations on the residence times and partitioning of short-lived radionuclides (234Th, 7Be and 210Pb) and depositional fluxes of 7Be and 210Pb in Tampa Bay, Florida: Marine Chemistry, v. 104, no. 1-2, p. 27-42, https://doi.org/10.1016/j.marchem.2006.06.012.","productDescription":"16 p.","startPage":"27","endPage":"42","numberOfPages":"16","costCenters":[{"id":186,"text":"Coastal and Marine Geology Program","active":true,"usgs":true}],"links":[{"id":213205,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/j.marchem.2006.06.012"},{"id":240808,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"country":"United States","state":"Florida","otherGeospatial":"Tampa Bay","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -82.7,27.6 ], [ -82.7,28.0 ], [ -82.4,28.0 ], [ -82.4,27.6 ], [ -82.7,27.6 ] ] ] } } ] }","volume":"104","issue":"1-2","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505b88f5e4b08c986b316c64","contributors":{"authors":[{"text":"Baskaran, M.","contributorId":96627,"corporation":false,"usgs":true,"family":"Baskaran","given":"M.","affiliations":[],"preferred":false,"id":438690,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Swarzenski, P.W. 0000-0003-0116-0578","orcid":"https://orcid.org/0000-0003-0116-0578","contributorId":29487,"corporation":false,"usgs":true,"family":"Swarzenski","given":"P.W.","affiliations":[],"preferred":false,"id":438689,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70032954,"text":"70032954 - 2007 - Submarine groundwater discharge to Tampa Bay: Nutrient fluxes and biogeochemistry of the coastal aquifer","interactions":[],"lastModifiedDate":"2017-10-04T13:25:02","indexId":"70032954","displayToPublicDate":"2007-01-01T00:00:00","publicationYear":"2007","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":"Submarine groundwater discharge to Tampa Bay: Nutrient fluxes and biogeochemistry of the coastal aquifer","docAbstract":"To separately quantify the roles of fresh and saline submarine groundwater discharge (SGD), relative to that of rivers, in transporting nutrients to Tampa Bay, Florida, we used three approaches (Darcy's Law calculations, a watershed water budget, and a 222Rn mass-balance) to estimate rate of SGD from the Pinellas peninsula. Groundwater samples were collected in 69 locations in the coastal aquifer to examine biogeochemical conditions, nutrient concentrations and stoichiometry, and salinity structure. Salinity structure was also examined using stationary electrical resistivity measurements. The coastal aquifer along the Pinellas peninsula was chemically reducing in all locations sampled, and that condition influences nitrogen (N) form and mobility of N and PO43−. Concentrations of NH4+, PO43− and ratio of dissolved inorganic N (DIN) to PO43− were all related to measured oxidation/reduction potential (pε) of the groundwater. Ratio of DIN: PO43− was below Redfield ratio in both fresh and saline groundwater. Nitrogen occurred almost exclusively in reduced forms, NH4+ and dissolved organic nitrogen (DON), suggesting that anthropogenic N is exported from the watershed in those forms. In comparison to other SGD studies, rate of PO43− flux in the seepage zone (μM m− 2 d− 1) in Tampa Bay was higher than previous estimates, likely due to 1) high watershed population density, 2) chemically reducing conditions, and 3) high ion concentrations in fresh groundwater. Estimates of freshwater groundwater flux indicate that the ratio of groundwater discharge to stream flow is ∼ 20 to 50%, and that the magnitudes of both the total dissolved nitrogen and PO43− loads due to fresh SGD are ∼ 40 to 100% of loads carried by streams. Estimates of SGD based on radon inventories in near-shore waters were 2 to 5 times greater than the estimates of freshwater groundwater discharge, suggesting that brackish and saline SGD is also an important process in Tampa Bay and results in flux of regenerated N and P from sediment to surface water.
","language":"English","publisher":"Elsevier","doi":"10.1016/j.marchem.2006.10.012","issn":"03044203","usgsCitation":"Kroeger, K.D., Swarzenski, P.W., Greenwood, J., and Reich, C., 2007, Submarine groundwater discharge to Tampa Bay: Nutrient fluxes and biogeochemistry of the coastal aquifer: Marine Chemistry, v. 104, no. 1-2, p. 85-97, https://doi.org/10.1016/j.marchem.2006.10.012.","productDescription":"13 p.","startPage":"85","endPage":"97","costCenters":[{"id":186,"text":"Coastal and Marine Geology Program","active":true,"usgs":true},{"id":678,"text":"Woods Hole Coastal and Marine Science Center","active":true,"usgs":true}],"links":[{"id":476989,"rank":1,"type":{"id":41,"text":"Open Access External Repository Page"},"url":"https://hdl.handle.net/1912/1598","text":"External Repository"},{"id":240807,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"country":"United States","state":"Florida","otherGeospatial":"Tampa Bay","geographicExtents":"{\n \"type\": \"FeatureCollection\",\n \"features\": [\n {\n \"type\": \"Feature\",\n \"properties\": {},\n \"geometry\": {\n \"type\": \"Polygon\",\n \"coordinates\": [\n [\n [\n -83.07449340820312,\n 27.281484559967133\n ],\n [\n -82.02941894531249,\n 27.281484559967133\n ],\n [\n -82.02941894531249,\n 28.32493342862181\n ],\n [\n -83.07449340820312,\n 28.32493342862181\n ],\n [\n -83.07449340820312,\n 27.281484559967133\n ]\n ]\n ]\n }\n }\n ]\n}","volume":"104","issue":"1-2","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505b9d28e4b08c986b31d68d","contributors":{"authors":[{"text":"Kroeger, Kevin D. 0000-0002-4272-2349 kkroeger@usgs.gov","orcid":"https://orcid.org/0000-0002-4272-2349","contributorId":1603,"corporation":false,"usgs":true,"family":"Kroeger","given":"Kevin","email":"kkroeger@usgs.gov","middleInitial":"D.","affiliations":[{"id":41100,"text":"Coastal and Marine Hazards and Resources Program","active":true,"usgs":true}],"preferred":true,"id":438686,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Swarzenski, Peter W. 0000-0003-0116-0578 pswarzen@usgs.gov","orcid":"https://orcid.org/0000-0003-0116-0578","contributorId":1070,"corporation":false,"usgs":true,"family":"Swarzenski","given":"Peter","email":"pswarzen@usgs.gov","middleInitial":"W.","affiliations":[{"id":520,"text":"Pacific Coastal and Marine Science Center","active":true,"usgs":true}],"preferred":true,"id":438685,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Greenwood, Jason","contributorId":49610,"corporation":false,"usgs":true,"family":"Greenwood","given":"Jason","email":"","affiliations":[],"preferred":false,"id":438688,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Reich, Christopher","contributorId":12942,"corporation":false,"usgs":true,"family":"Reich","given":"Christopher","email":"","affiliations":[],"preferred":false,"id":438687,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}} ,{"id":70032952,"text":"70032952 - 2007 - Ra and Rn isotopes as natural tracers of submarine groundwater discharge in Tampa Bay, Florida","interactions":[],"lastModifiedDate":"2017-09-19T09:06:01","indexId":"70032952","displayToPublicDate":"2007-01-01T00:00:00","publicationYear":"2007","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":"Ra and Rn isotopes as natural tracers of submarine groundwater discharge in Tampa Bay, Florida","docAbstract":"A suite of naturally occurring radionuclides in the U/Th decay series (222Rn, 223,224,226,228Ra) were studied during wet and dry conditions in Tampa Bay, Florida, to evaluate their utility as groundwater discharge tracers, both within the bay proper and within the Alafia River/estuary — a prominent free-flowing river that empties into the bay. In Tampa Bay, almost 30% of the combined riverine inputs still remain ungauged. Consequently, groundwater/surface water (hyporheic) exchange in the discharging coastal rivers, as well as submarine groundwater discharge (SGD) within the bay, are still unresolved components of this system's water and material budgets.
\nBased on known inputs and sinks, there exists an excess of 226Ra in the water column of Tampa Bay, which can be evaluated in terms of a submarine groundwater contribution to the bay proper. Submarine groundwater discharge rates calculated using a mass balance of excess 226Ra ranged from 2.2 to 14.5 L m− 2 day− 1, depending on whether the estuarine residence time was calculated using 224Ra/xs228Ra isotope ratios, or whether a long term, averaged model-derived estuarine residence time was used. When extrapolated to the total shoreline length of the bay, such SGD rates ranged from 1.6 to 10.3 m3 m− 1 day− 1. Activities of 222Rn were also elevated in surface water and shallow groundwater of the bay, as well as in the Alafia River estuary, where upstream activities as high as 250 dpm L− 1 indicate enhanced groundwater/surface water exchange, facilitated by an active spring vent. From average nutrient concentrations of 39 shallow, brackish, groundwater samples, rates of nutrient loading into Tampa Bay by SGD rates were estimated, and these ranged from 0.2 to 1.4 × 105 mol day− 1 (PO43−), 0.9–6.2 × 105 mol day− 1 (SiO4−), 0.7–5.0 × 105 mol day− 1 (dissolved organic nitrogen, DON), and 0.2–1.4 × 106 mol day− 1 (total dissolved nitrogen, TDN). Such nutrient loading estimates, when compared to average river discharge estimates (e.g., TDN = 6.9 × 105 mol day− 1), suggest that SGD-derived nutrient fluxes to Tampa Bay are indeed important components to the overall nutrient economy of these coastal waters.
","language":"English","publisher":"Elsevier","doi":"10.1016/j.marchem.2006.08.001","issn":"03044203","usgsCitation":"Swarzenski, P., Reich, C., Kroeger, K., and Baskaran, M., 2007, Ra and Rn isotopes as natural tracers of submarine groundwater discharge in Tampa Bay, Florida: Marine Chemistry, v. 104, no. 1-2, p. 69-84, https://doi.org/10.1016/j.marchem.2006.08.001.","productDescription":"16 p.","startPage":"69","endPage":"84","costCenters":[{"id":186,"text":"Coastal and Marine Geology Program","active":true,"usgs":true},{"id":678,"text":"Woods Hole Coastal and Marine Science Center","active":true,"usgs":true}],"links":[{"id":240772,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"country":"United States","state":"Florida","otherGeospatial":"Tampa Bay","geographicExtents":"{\n \"type\": \"FeatureCollection\",\n \"features\": [\n {\n \"type\": \"Feature\",\n \"properties\": {},\n \"geometry\": {\n \"type\": \"Polygon\",\n \"coordinates\": [\n [\n [\n -83.03466796874999,\n 27.595934774495056\n ],\n [\n -82.320556640625,\n 27.595934774495056\n ],\n [\n -82.320556640625,\n 28.168875180063345\n ],\n [\n -83.03466796874999,\n 28.168875180063345\n ],\n [\n -83.03466796874999,\n 27.595934774495056\n ]\n ]\n ]\n }\n }\n ]\n}","volume":"104","issue":"1-2","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a9373e4b0c8380cd80e1c","contributors":{"authors":[{"text":"Swarzenski, P.W. 0000-0003-0116-0578","orcid":"https://orcid.org/0000-0003-0116-0578","contributorId":29487,"corporation":false,"usgs":true,"family":"Swarzenski","given":"P.W.","affiliations":[],"preferred":false,"id":438678,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Reich, C.","contributorId":41787,"corporation":false,"usgs":true,"family":"Reich","given":"C.","email":"","affiliations":[],"preferred":false,"id":438679,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Kroeger, K.D.","contributorId":26060,"corporation":false,"usgs":true,"family":"Kroeger","given":"K.D.","email":"","affiliations":[],"preferred":false,"id":438677,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Baskaran, M.","contributorId":96627,"corporation":false,"usgs":true,"family":"Baskaran","given":"M.","affiliations":[],"preferred":false,"id":438680,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}} ]}