Oil spillage from natural sources is very common in the waters of southern California. Active oil extraction and shipping is occurring concurrently within the region and it is of great interest to resource managers to be able to distinguish between natural seepage and anthropogenic oil spillage.
The major goal of this study was to establish the geologic setting, sources, and ultimate dispersal of natural oil seeps in the offshore southern Santa Maria Basin and Santa Barbara Basins. Our surveys focused on likely areas of hydrocarbon seepage that are known to occur between Point Arguello and Ventura, California.
Our approach was to 1) document the locations and geochemically fingerprint natural seep oils or tar; 2) geochemically fingerprint coastal tar residues and potential tar sources in this region, both onshore and offshore; 3) establish chemical correlations between offshore active seeps and coastal residues thus linking seep sources to oil residues; 4) measure the rate of natural seepage of individual seeps and attempt to assess regional natural oil and gas seepage rates; and 5) interpret the petroleum system history for the natural seeps.
To document the location of sub-sea oil seeps, we first looked into previous studies within and near our survey area. We measured the concentration of methane gas in the water column in areas of reported seepage and found numerous gas plumes and measured high concentrations of methane in the water column. The result of this work showed that the seeps were widely distributed between Point Conception east to the vicinity of Coal Oil Point, and that they by in large occur within the 3-mile limit of California State waters. Subsequent cruises used sidescan and high resolution seismic to map the seafloor, from just south of Point Arguello, east to near Gaviota, California. The results of the methane survey guided the exploration of the area west of Point Conception east to Gaviota using a combination of seismic instruments. The seafloor was mapped by sidescan sonar, and numerous lines of high -resolution seismic surveys were conducted over areas of interest.
Biomarker and stable carbon isotope ratios were used to infer the age, lithology, organic matter input, and depositional environment of the source rocks for 388 samples of produced crude oil, seep oil, and tarballs mainly from coastal California. These samples were used to construct a chemometric fingerprint (multivariate statistics) decision tree to classify 288 additional samples, including tarballs of unknown origin collected from Monterey and San Mateo County beaches after a storm in early 2007. A subset of 9 of 23 active offshore platform oils and one inactive platform oil representing a few oil reservoirs from the western Santa Barbara Channel were used in this analysis, and thus this model is not comprehensive and the findings are not conclusive. The platform oils included in this study are from west to east: Irene, Hildago, Harvest, Hermosa, Heritage, Harmony, Hondo, Holly, Platform A, and Hilda (now removed).
The results identify three “tribes” of 13C-rich oil samples inferred to originate from thermally mature equivalents of the clayey-siliceous, carbonaceous marl, and lower calcareous-siliceous members of the Monterey Formation. Tribe 1 contains four oil families having geochemical traits of clay-rich marine shale source rock deposited under suboxic conditions with substantial higher-plant input. Tribe 2 contains four oil families with intermediate traits, except for abundant 28,30-bisnorhopane, indicating suboxic to anoxic marine marl source rock with hemipelagic input. Tribe 3 contains five oil families with traits of distal marine carbonate source rock deposited under anoxic conditions with pelagic but little or no higher-plant input. Tribes 1 and 2 occur mainly south of Point Conception in paleogeographic settings where deep burial of the Monterey Formation source rock favored generation from all three members or their equivalents. In this area, oil from the clayey-siliceous and carbonaceous marl members (Tribes 1 and 2) may overwhelm that from the lower calcareous-siliceous member (Tribe 3) because the latter is thinner and less oil-prone than the overlying members. Tribe 3 occurs mainly north of Point Conception, where shallow burial caused preferential generation from the underlying lower calcareous-siliceous member or another unit with similar characteristics.
It is very desirable to be able to clearly distinguish the naturally occurring seep oils from the anthropogenically derived platform oils. Within the “training set” of oils and tars (388 samples), the biomarker parameters are sometimes sufficient to allow unique discrimination of individual platform oils. More often however, platform samples and seep samples with sources geographically close to each other are too similar to each other, with respect to the biomarker parameters, to definitively differentiate them on that basis alone. In some cases other parameters can be helpful. These other parameters are related to the degree of biogeochemical degradation or weathering that the oils or tars have experienced. These components include the typical oil distribution of n-alkane hydrocarbons and isoprenoids pristane and phytane. All of the platform oils in our sample set contain these components. On the other hand, the seep oils or tars have been exposed to significant biodegradation while in the near subsurface. The majority, but not all of seep oils or tars have been biodegraded up to or beyond the loss of n-alkanes and isoprenoids. Seep oils found in the vicinity of Coal Oil Point or Arroyo Burro are apparently the least weathered and are particularly likely to retain significant n-alkanes and isoprenoids. Therefore the combination of chemometric fingerprinting and the presence or absence of n-alkanes and isoprenoids help to differentiate anthropogenic production oils versus natural seeps oils and tars. The differentiation is not always definitive because of the close chemical similarity of some samples and the variability in the biodegradation progression. This is the case near Coal Oil Point, and near Platform A (Dos Cuadros Field) where seep oils and Platform Holly and Platform A oils are genetically very similar and cannot be definitively distinguished after a period of a few days of weathering. In contrast, oils from the Point Conception platforms can be distinguished on the basis of chemometric fingerprinting alone. In the middle of this spectrum are oils from Platforms Harmony, Heritage, and Hondo, where it is expected that oil weathering would take on the order of two weeks to a month to produce tarballs similar to those seen near Point Conception. In this case there is a much greater degree of weathering needed to proceed from produced oil to the biodegraded tar characteristic of tarball stranded on the beach.
Tar deposition on beaches was monitored as part of cooperative with the County of Santa Barbara Energy Division and the U.S. Geological Survey during 2001-2003. We found tar deposition varies on a seasonal basis. In general, tarballs accumulate at a faster rate or remain longer on all beaches during the summer and fall months. The reasons for this are unclear based on our limited observations, however we speculate that factors such as prevailing winds and currents combined with more quiescent wave conditions favors the accumulation and preservation of tarballs on the beach during the summer and fall months. In contrast, winter storms, with much greater wave action remove beach sand and other materials, and stormy seas tend to break up oil that might weather into tarballs. Natural seepage is affected by the spring/neap tidal cycle; however, the link to tar deposition is unclear. Longer periods of monitoring are needed to address the variability in the data and provide a more robust statistical analysis.
","language":"English","publisher":"U.S. Geological Survey","doi":"10.3133/ofr20091225","collaboration":"A study in cooperation with the Minerals Management Service and the Energy Division, County of Santa Barbara, California; Also released as MMS report 2009-030; This study was funded in part by the U. S. Department of the Interior, Minerals Management Service (MMS), through an Interagency Agreement No. 18985 with the U.S. Geological Survey, Western Coastal and Marine Geology Team, as part of the MMS Environmental Studies Program.","usgsCitation":"Lorenson, T., Hostettler, F.D., Rosenbauer, R.J., Peters, K., Dougherty, J.A., Kvenvolden, K.A., Gutmacher, C.E., Wong, F.L., and Normark, W.R., 2009, Natural offshore oil seepage and related tarball accumulation on the California coastline — Santa Barbara Channel and the southern Santa Maria Basin; source identification and inventory: U.S. Geological Survey Open-File Report 2009-1225, Report: iii, 116 p.; Appendixes, https://doi.org/10.3133/ofr20091225.","productDescription":"Report: iii, 116 p.; Appendixes","onlineOnly":"N","additionalOnlineFiles":"Y","costCenters":[{"id":520,"text":"Pacific Coastal and Marine Science Center","active":true,"usgs":true},{"id":645,"text":"Western Coastal and Marine Geology","active":false,"usgs":true}],"links":[{"id":125640,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr_2009_1225.jpg"},{"id":402029,"rank":3,"type":{"id":36,"text":"NGMDB Index Page"},"url":"https://ngmdb.usgs.gov/Prodesc/proddesc_90302.htm"},{"id":13337,"rank":100,"type":{"id":15,"text":"Index Page"},"url":"https://pubs.usgs.gov/of/2009/1225/","linkFileType":{"id":5,"text":"html"}}],"country":"United States","state":"California","otherGeospatial":"Santa Barbara Channel, Santa Maria Basin","geographicExtents":"{\n \"type\": \"FeatureCollection\",\n \"features\": [\n {\n \"type\": \"Feature\",\n \"properties\": {},\n \"geometry\": {\n \"type\": \"Polygon\",\n \"coordinates\": [\n [\n [\n -121.014404296875,\n 34.134541681937364\n ],\n [\n -119.32250976562499,\n 34.134541681937364\n ],\n [\n -119.32250976562499,\n 35.146862906756304\n ],\n [\n -121.014404296875,\n 35.146862906756304\n ],\n [\n -121.014404296875,\n 34.134541681937364\n ]\n ]\n ]\n }\n }\n ]\n}","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b00e4b07f02db6982ee","contributors":{"authors":[{"text":"Lorenson, T.D. tlorenson@usgs.gov","contributorId":2622,"corporation":false,"usgs":true,"family":"Lorenson","given":"T.D.","email":"tlorenson@usgs.gov","affiliations":[{"id":186,"text":"Coastal and Marine Geology Program","active":true,"usgs":true}],"preferred":false,"id":304163,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Hostettler, Frances D. fdhostet@usgs.gov","contributorId":3383,"corporation":false,"usgs":true,"family":"Hostettler","given":"Frances","email":"fdhostet@usgs.gov","middleInitial":"D.","affiliations":[],"preferred":true,"id":304164,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Rosenbauer, Robert J. brosenbauer@usgs.gov","contributorId":204,"corporation":false,"usgs":true,"family":"Rosenbauer","given":"Robert","email":"brosenbauer@usgs.gov","middleInitial":"J.","affiliations":[{"id":520,"text":"Pacific Coastal and Marine Science Center","active":true,"usgs":true}],"preferred":true,"id":304161,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Peters, Kenneth E.","contributorId":10897,"corporation":false,"usgs":true,"family":"Peters","given":"Kenneth E.","affiliations":[],"preferred":false,"id":304167,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Dougherty, Jennifer A.","contributorId":6114,"corporation":false,"usgs":true,"family":"Dougherty","given":"Jennifer","email":"","middleInitial":"A.","affiliations":[],"preferred":false,"id":304166,"contributorType":{"id":1,"text":"Authors"},"rank":5},{"text":"Kvenvolden, Keith A. kkvenvolden@usgs.gov","contributorId":3384,"corporation":false,"usgs":true,"family":"Kvenvolden","given":"Keith","email":"kkvenvolden@usgs.gov","middleInitial":"A.","affiliations":[{"id":520,"text":"Pacific Coastal and Marine Science Center","active":true,"usgs":true}],"preferred":true,"id":304165,"contributorType":{"id":1,"text":"Authors"},"rank":6},{"text":"Gutmacher, Christina E.","contributorId":28272,"corporation":false,"usgs":true,"family":"Gutmacher","given":"Christina","email":"","middleInitial":"E.","affiliations":[],"preferred":false,"id":304168,"contributorType":{"id":1,"text":"Authors"},"rank":7},{"text":"Wong, Florence L. 0000-0002-3918-5896 fwong@usgs.gov","orcid":"https://orcid.org/0000-0002-3918-5896","contributorId":1990,"corporation":false,"usgs":true,"family":"Wong","given":"Florence","email":"fwong@usgs.gov","middleInitial":"L.","affiliations":[{"id":520,"text":"Pacific Coastal and Marine Science Center","active":true,"usgs":true}],"preferred":true,"id":304162,"contributorType":{"id":1,"text":"Authors"},"rank":8},{"text":"Normark, William R.","contributorId":69570,"corporation":false,"usgs":true,"family":"Normark","given":"William","email":"","middleInitial":"R.","affiliations":[],"preferred":false,"id":304169,"contributorType":{"id":1,"text":"Authors"},"rank":9}]}} ,{"id":98098,"text":"sir20095270 - 2009 - Hydrogeologic Framework, Groundwater Movement, and Water Budget in Tributary Subbasins and Vicinity, Lower Skagit River Basin, Skagit and Snohomish Counties, Washington","interactions":[],"lastModifiedDate":"2012-03-08T17:16:29","indexId":"sir20095270","displayToPublicDate":"2010-01-09T00:00:00","publicationYear":"2009","noYear":false,"publicationType":{"id":18,"text":"Report"},"publicationSubtype":{"id":5,"text":"USGS Numbered Series"},"seriesTitle":{"id":334,"text":"Scientific Investigations Report","code":"SIR","onlineIssn":"2328-0328","printIssn":"2328-031X","active":true,"publicationSubtype":{"id":5}},"seriesNumber":"2009-5270","title":"Hydrogeologic Framework, Groundwater Movement, and Water Budget in Tributary Subbasins and Vicinity, Lower Skagit River Basin, Skagit and Snohomish Counties, Washington","docAbstract":"A study to characterize the groundwater-flow system in four tributary subbasins and vicinity of the lower Skagit River basin was conducted by the U.S. Geological Survey to assist Skagit County and the Washington State Department of Ecology in evaluating the effects of potential groundwater withdrawals and consumptive use on tributary streamflows.\r\n\r\nThis report presents information used to characterize the groundwater and surface-water flow system in the subbasins, and includes descriptions of the geology and hydrogeologic framework of the subbasins; groundwater recharge and discharge; groundwater levels and flow directions; seasonal groundwater-level fluctuations; interactions between aquifers and the surface-water system; and a water budget for the subbasins.\r\n\r\nThe study area covers about 247 mi2 along the Skagit River and its tributary subbasins (East Fork Nookachamps Creek, Nookachamps Creek, Carpenter Creek, and Fisher Creek) in southwestern Skagit County and northwestern Snohomish County, Washington. The geology of the area records a complex history of accretion along the continental margin, mountain building, deposition of terrestrial and marine sediments, igneous intrusion, and the repeated advance and retreat of continental glaciers. A simplified surficial geologic map was developed from previous mapping in the area, and geologic units were grouped into nine hydrogeologic units consisting of aquifers and confining units. A surficial hydrogeologic unit map was constructed and, with lithologic information from 296 drillers'logs, was used to produce unit extent and thickness maps and four hydrogeologic sections.\r\n\r\nGroundwater in unconsolidated aquifers generally flows towards the northwest and west in the direction of the Skagit River and Puget Sound. This generalized flow pattern is likely complicated by the presence of low-permeability confining units that separate discontinuous bodies of aquifer material and act as local groundwater-flow barriers. Groundwater-flow directions in the sedimentary aquifer likely reflect local topographic relief (radial flow from bedrock highs) and more regional westward flow from the mountains to the Puget Sound. The largest groundwater-level fluctuations observed during the monitoring period (October 2006 through September 2008) occurred in wells completed in the sedimentary aquifer, and ranged from about 3 to 27 feet. Water levels in wells completed in unconsolidated hydrogeologic units exhibited seasonal variations ranging from less than 1 to about 10 feet.\r\n\r\nSynoptic streamflow measurements made in August 2007 and June 2008 indicate a total groundwater discharge to creeks in the tributary subbasin area of about 13.15 and 129.6 cubic feet per second (9,520 and 93,830 acre-feet per year), respectively. Streamflow measurements illustrate a general pattern in which the upper reaches of creeks in the study area tended to gain flow from the groundwater system, and lower creek reaches tended to lose water. Large inflows from tributaries to major creeks in the study area suggest the presence of groundwater discharge from upland areas underlain by bedrock.\r\n\r\nThe groundwater system within the subbasins received an average (September 1, 2006 to August 31, 2008) of about 92,400 acre-feet or about 18 inches of recharge from precipitation a year. Most of this recharge (65 percent) discharges to creeks, and only about 3 percent is withdrawn from wells. The remaining groundwater recharge (32 percent) leaves the subbasin groundwater system as discharge to the Skagit River and Puget Sound.\r\n","language":"ENGLISH","publisher":"U.S. Geological Survey","doi":"10.3133/sir20095270","collaboration":"Prepared in cooperation with the Skagit County Public Works Department, Washington State Department of Ecology, and Skagit County Public Utility District No. 1","usgsCitation":"Savoca, M.E., Johnson, K.H., Sumioka, S.S., Olsen, T.D., Fasser, E.T., and Huffman, R.L., 2009, Hydrogeologic Framework, Groundwater Movement, and Water Budget in Tributary Subbasins and Vicinity, Lower Skagit River Basin, Skagit and Snohomish Counties, Washington: U.S. Geological Survey Scientific Investigations Report 2009-5270, Report: viii, 47 p.; Plate 1 (43 x 28 inches); Plate 2 (42 x 30 inches), https://doi.org/10.3133/sir20095270.","productDescription":"Report: viii, 47 p.; Plate 1 (43 x 28 inches); Plate 2 (42 x 30 inches)","onlineOnly":"N","additionalOnlineFiles":"Y","costCenters":[{"id":622,"text":"Washington Water Science Center","active":true,"usgs":true}],"links":[{"id":125282,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/sir_2009_5270.jpg"},{"id":13334,"rank":100,"type":{"id":15,"text":"Index Page"},"url":"https://pubs.usgs.gov/sir/2009/5270/","linkFileType":{"id":5,"text":"html"}}],"geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -122.5,48.25 ], [ -122.5,48.5 ], [ -122,48.5 ], [ -122,48.25 ], [ -122.5,48.25 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4a50e4b07f02db628e1c","contributors":{"authors":[{"text":"Savoca, Mark E. mesavoca@usgs.gov","contributorId":1961,"corporation":false,"usgs":true,"family":"Savoca","given":"Mark","email":"mesavoca@usgs.gov","middleInitial":"E.","affiliations":[{"id":622,"text":"Washington Water Science Center","active":true,"usgs":true}],"preferred":true,"id":304149,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Johnson, Kenneth H. johnson@usgs.gov","contributorId":3103,"corporation":false,"usgs":true,"family":"Johnson","given":"Kenneth","email":"johnson@usgs.gov","middleInitial":"H.","affiliations":[{"id":622,"text":"Washington Water Science Center","active":true,"usgs":true}],"preferred":true,"id":304150,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Sumioka, Steven S.","contributorId":8159,"corporation":false,"usgs":true,"family":"Sumioka","given":"Steven","email":"","middleInitial":"S.","affiliations":[],"preferred":false,"id":304152,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Olsen, Theresa D. 0000-0003-4099-4057 tdolsen@usgs.gov","orcid":"https://orcid.org/0000-0003-4099-4057","contributorId":1644,"corporation":false,"usgs":true,"family":"Olsen","given":"Theresa","email":"tdolsen@usgs.gov","middleInitial":"D.","affiliations":[{"id":622,"text":"Washington Water Science Center","active":true,"usgs":true}],"preferred":true,"id":304148,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Fasser, Elisabeth T. 0000-0002-3945-6633 efasser@usgs.gov","orcid":"https://orcid.org/0000-0002-3945-6633","contributorId":3973,"corporation":false,"usgs":true,"family":"Fasser","given":"Elisabeth","email":"efasser@usgs.gov","middleInitial":"T.","affiliations":[{"id":622,"text":"Washington Water Science Center","active":true,"usgs":true}],"preferred":true,"id":304151,"contributorType":{"id":1,"text":"Authors"},"rank":5},{"text":"Huffman, Raegan L. 0000-0001-8523-5439 rhuffman@usgs.gov","orcid":"https://orcid.org/0000-0001-8523-5439","contributorId":1638,"corporation":false,"usgs":true,"family":"Huffman","given":"Raegan","email":"rhuffman@usgs.gov","middleInitial":"L.","affiliations":[{"id":622,"text":"Washington Water Science Center","active":true,"usgs":true}],"preferred":true,"id":304147,"contributorType":{"id":1,"text":"Authors"},"rank":6}]}} ,{"id":70042435,"text":"70042435 - 2009 - Effects of Groundwater Development on Uranium: Central Valley, California, USA","interactions":[],"lastModifiedDate":"2013-04-09T19:34:21","indexId":"70042435","displayToPublicDate":"2010-01-01T00:00:00","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":"Effects of Groundwater Development on Uranium: Central Valley, California, USA","docAbstract":"Uranium (U) concentrations in groundwater in several parts of the eastern San Joaquin Valley, California, have exceeded federal and state drinking water standards during the last 20 years. The San Joaquin Valley is located within the Central Valley of California and is one of the most productive agricultural areas in the world. Increased irrigation and pumping associated with agricultural and urban development during the last 100 years have changed the chemistry and magnitude of groundwater recharge, and increased the rate of downward groundwater movement. Strong correlations between U and bicarbonate suggest that U is leached from shallow sediments by high bicarbonate water, consistent with findings of previous work in Modesto, California. Summer irrigation of crops in agricultural areas and, to lesser extent, of landscape plants and grasses in urban areas, has increased Pco2 concentrations in the soil zone and caused higher temperature and salinity of groundwater recharge. Coupled with groundwater pumping, this process, as evidenced by increasing bicarbonate concentrations in groundwater over the last 100 years, has caused shallow, young groundwater with high U concentrations to migrate to deeper parts of the groundwater system that are tapped by public-supply wells. Continued downward migration of U-affected groundwater and expansion of urban centers into agricultural areas will likely be associated with increased U concentrations in public-supply wells. The results from this study illustrate the potential longterm effects of groundwater development and irrigation-supported agriculture on water quality in arid and semiarid regions around the world.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Ground Water","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","publisher":"Wiley","doi":"10.1111/j.1745-6584.2009.00635.x","usgsCitation":"Jurgens, B., Fram, M.S., Belitz, K., Burow, K.R., and Landon, M.K., 2009, Effects of Groundwater Development on Uranium: Central Valley, California, USA: Ground Water, v. 48, no. 6, p. 913-928, https://doi.org/10.1111/j.1745-6584.2009.00635.x.","startPage":"913","endPage":"928","numberOfPages":"16","ipdsId":"IP-006319","costCenters":[{"id":154,"text":"California Water Science Center","active":true,"usgs":true}],"links":[{"id":270746,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":270744,"type":{"id":11,"text":"Document"},"url":"https://oh.water.usgs.gov/tanc/pubs/Jurgens&Others_2009.pdf"},{"id":270745,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1111/j.1745-6584.2009.00635.x"}],"country":"United States","state":"California","volume":"48","issue":"6","noUsgsAuthors":false,"publicationDate":"2010-11-03","publicationStatus":"PW","scienceBaseUri":"5165386ae4b077fa94dadf9c","contributors":{"authors":[{"text":"Jurgens, Bryant C. 0000-0002-1572-113X bjurgens@usgs.gov","orcid":"https://orcid.org/0000-0002-1572-113X","contributorId":1503,"corporation":false,"usgs":true,"family":"Jurgens","given":"Bryant C.","email":"bjurgens@usgs.gov","affiliations":[{"id":154,"text":"California Water Science Center","active":true,"usgs":true}],"preferred":false,"id":471521,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Fram, Miranda S. 0000-0002-6337-059X mfram@usgs.gov","orcid":"https://orcid.org/0000-0002-6337-059X","contributorId":1156,"corporation":false,"usgs":true,"family":"Fram","given":"Miranda","email":"mfram@usgs.gov","middleInitial":"S.","affiliations":[{"id":154,"text":"California Water Science Center","active":true,"usgs":true}],"preferred":true,"id":471520,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Belitz, Kenneth 0000-0003-4481-2345 kbelitz@usgs.gov","orcid":"https://orcid.org/0000-0003-4481-2345","contributorId":442,"corporation":false,"usgs":true,"family":"Belitz","given":"Kenneth","email":"kbelitz@usgs.gov","affiliations":[{"id":27111,"text":"National Water Quality Program","active":true,"usgs":true},{"id":451,"text":"National Water Quality Assessment Program","active":true,"usgs":true},{"id":503,"text":"Office of Water Quality","active":true,"usgs":true},{"id":466,"text":"New England Water Science Center","active":true,"usgs":true},{"id":376,"text":"Massachusetts Water Science Center","active":true,"usgs":true}],"preferred":true,"id":471519,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Burow, Karen R. 0000-0001-6006-6667 krburow@usgs.gov","orcid":"https://orcid.org/0000-0001-6006-6667","contributorId":1504,"corporation":false,"usgs":true,"family":"Burow","given":"Karen","email":"krburow@usgs.gov","middleInitial":"R.","affiliations":[{"id":154,"text":"California Water Science Center","active":true,"usgs":true}],"preferred":true,"id":471522,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Landon, Matthew K. 0000-0002-5766-0494 landon@usgs.gov","orcid":"https://orcid.org/0000-0002-5766-0494","contributorId":392,"corporation":false,"usgs":true,"family":"Landon","given":"Matthew","email":"landon@usgs.gov","middleInitial":"K.","affiliations":[{"id":154,"text":"California Water Science Center","active":true,"usgs":true}],"preferred":true,"id":471518,"contributorType":{"id":1,"text":"Authors"},"rank":5}]}} ,{"id":70042340,"text":"70042340 - 2009 - Pore-water chemistry from the ICDP-USGS coer hole in the Chesapeake Bay impact structure--Implications for paleohydrology, microbial habitat, and water resources","interactions":[],"lastModifiedDate":"2013-03-10T12:03:32","indexId":"70042340","displayToPublicDate":"2010-01-01T00:00:00","publicationYear":"2009","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":3459,"text":"Special Paper of the Geological Society of America","active":true,"publicationSubtype":{"id":10}},"title":"Pore-water chemistry from the ICDP-USGS coer hole in the Chesapeake Bay impact structure--Implications for paleohydrology, microbial habitat, and water resources","docAbstract":"We investigated the groundwater system of the Chesapeake Bay impact structure by analyzing the pore-water chemistry in cores taken from a 1766-m-deep drill hole 10 km north of Cape Charles, Virginia. Pore water was extracted using high-speed centrifuges from over 100 cores sampled from a 1300 m section of the drill hole. The pore-water samples were analyzed for major cations and anions, stable isotopes of water and sulfate, dissolved and total carbon, and bioavailable iron. The results reveal a broad transition between fresh and saline water from 100 to 500 m depth in the post-impact sediment section, and an underlying syn-impact section that is almost entirely filled with brine. The presence of brine in the lowermost post-impact section and the trend in the dissolved chloride with depth suggest a transport process dominated by molecular diffusion and slow, compaction-driven, upward flow. Major ion results indicate residual effects of diagenesis from heating, and a pre-impact origin for the brine. High levels of dissolved organic carbon (6-95 mg/L) and the distribution of electron acceptors indicate an environment that may be favorable for microbial activity throughout the drilled section. The concentration and extent of the brine is much greater than had previously been observed, suggesting its occurrence may be common in the inner crater. However, groundwater flow conditions in the structure may reduce the salt-water-intrusion hazard associated with the brine.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Special Paper of the Geological Society of America","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","publisher":"Geological Society of America","doi":"10.1130/2009.2458(36)","usgsCitation":"Sanford, W.E., Voytek, M.A., Powars, D.S., Jones, B.F., Cozzarelli, I.M., Eganhouse, R., and Cockell, C.S., 2009, Pore-water chemistry from the ICDP-USGS coer hole in the Chesapeake Bay impact structure--Implications for paleohydrology, microbial habitat, and water resources: Special Paper of the Geological Society of America, v. 458, p. 867-890, https://doi.org/10.1130/2009.2458(36).","startPage":"867","endPage":"890","ipdsId":"IP-007144","costCenters":[{"id":146,"text":"Branch of Regional Research-Eastern Region","active":false,"usgs":true}],"links":[{"id":269016,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":269015,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1130/2009.2458(36)"}],"country":"United States","volume":"458","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"53cd6bdfe4b0b2908510432a","contributors":{"authors":[{"text":"Sanford, Ward E. 0000-0002-6624-0280 wsanford@usgs.gov","orcid":"https://orcid.org/0000-0002-6624-0280","contributorId":2268,"corporation":false,"usgs":true,"family":"Sanford","given":"Ward","email":"wsanford@usgs.gov","middleInitial":"E.","affiliations":[{"id":436,"text":"National Research Program - Eastern Branch","active":true,"usgs":true},{"id":37778,"text":"WMA - Integrated Modeling and Prediction Division","active":true,"usgs":true}],"preferred":true,"id":471338,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Voytek, Mary A.","contributorId":91943,"corporation":false,"usgs":true,"family":"Voytek","given":"Mary","email":"","middleInitial":"A.","affiliations":[],"preferred":false,"id":471341,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Powars, David S. 0000-0002-6787-8964 dspowars@usgs.gov","orcid":"https://orcid.org/0000-0002-6787-8964","contributorId":1181,"corporation":false,"usgs":true,"family":"Powars","given":"David","email":"dspowars@usgs.gov","middleInitial":"S.","affiliations":[{"id":243,"text":"Eastern Geology and Paleoclimate Science Center","active":true,"usgs":true},{"id":40020,"text":"Florence Bascom Geoscience Center","active":true,"usgs":true}],"preferred":true,"id":471335,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Jones, Blair F. bfjones@usgs.gov","contributorId":2784,"corporation":false,"usgs":true,"family":"Jones","given":"Blair","email":"bfjones@usgs.gov","middleInitial":"F.","affiliations":[{"id":436,"text":"National Research Program - Eastern Branch","active":true,"usgs":true}],"preferred":true,"id":471339,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Cozzarelli, Isabelle M. 0000-0002-5123-1007 icozzare@usgs.gov","orcid":"https://orcid.org/0000-0002-5123-1007","contributorId":1693,"corporation":false,"usgs":true,"family":"Cozzarelli","given":"Isabelle","email":"icozzare@usgs.gov","middleInitial":"M.","affiliations":[{"id":436,"text":"National Research Program - Eastern Branch","active":true,"usgs":true},{"id":49175,"text":"Geology, Energy & Minerals Science Center","active":true,"usgs":true}],"preferred":true,"id":471336,"contributorType":{"id":1,"text":"Authors"},"rank":5},{"text":"Eganhouse, Robert P. eganhous@usgs.gov","contributorId":2031,"corporation":false,"usgs":true,"family":"Eganhouse","given":"Robert P.","email":"eganhous@usgs.gov","affiliations":[{"id":436,"text":"National Research Program - Eastern Branch","active":true,"usgs":true}],"preferred":true,"id":471337,"contributorType":{"id":1,"text":"Authors"},"rank":6},{"text":"Cockell, Charles S.","contributorId":22646,"corporation":false,"usgs":true,"family":"Cockell","given":"Charles","email":"","middleInitial":"S.","affiliations":[],"preferred":false,"id":471340,"contributorType":{"id":1,"text":"Authors"},"rank":7}]}} ,{"id":70043343,"text":"70043343 - 2009 - Fractionation of stable isotopes in perchlorate and nitrate during in situ biodegradation in a sandy aquifer","interactions":[],"lastModifiedDate":"2018-10-12T08:24:54","indexId":"70043343","displayToPublicDate":"2010-01-01T00:00:00","publicationYear":"2009","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1529,"text":"Environmental Chemistry","active":true,"publicationSubtype":{"id":10}},"title":"Fractionation of stable isotopes in perchlorate and nitrate during in situ biodegradation in a sandy aquifer","docAbstract":"An in situ experiment was performed in a shallow alluvial aquifer in Maryland to quantify the fractionation of stable isotopes in perchlorate (Cl and O) and nitrate (N and O) during biodegradation. An emulsified soybean oil substrate that was previously injected into this aquifer provided the electron donor necessary for biological perchlorate reduction and denitrification. During the field experiment, groundwater extracted from an upgradient well was pumped into an injection well located within the in situ oil barrier, and then groundwater samples were withdrawn for the next 30 h. After correction for dilution (using Br– as a conservative tracer of the injectate), perchlorate concentrations decreased by 78% and nitrate concentrations decreased by 82% during the initial 8.6 h after the injection. The observed ratio of fractionation effects of O and Cl isotopes in perchlorate (e18O/e37Cl) was 2.6, which is similar to that observed in the laboratory using pure cultures (2.5). Denitrification by indigenous bacteria fractionated O and N isotopes in nitrate at a ratio of ~0.8 (e18O/e15N), which is within the range of values reported previously for denitrification. However, the magnitudes of the individual apparent in situ isotope fractionation effects for perchlorate and nitrate were appreciably smaller than those reported in homogeneous closed systems (0.2 to 0.6 times), even after adjustment for dilution. These results indicate that (1) isotope fractionation factor ratios (e18O/e37Cl, e18O/e15N) derived from homogeneous laboratory systems (e.g. pure culture studies) can be used qualitatively to confirm the occurrence of in situ biodegradation of both perchlorate and nitrate, but (2) the magnitudes of the individual apparent e values cannot be used quantitatively to estimate the in situ extent of biodegradation of either anion.","language":"English","publisher":"CSIRO","doi":"10.1071/EN09008","usgsCitation":"Hatzinger, P., Bohlke, J., Sturchio, N., Gu, B., Heraty, L., and Borden, R., 2009, Fractionation of stable isotopes in perchlorate and nitrate during in situ biodegradation in a sandy aquifer: Environmental Chemistry, v. 6, no. 1, p. 44-52, https://doi.org/10.1071/EN09008.","productDescription":"14 p.","startPage":"44","endPage":"52","ipdsId":"IP-011369","costCenters":[{"id":146,"text":"Branch of Regional Research-Eastern Region","active":false,"usgs":true},{"id":589,"text":"Toxic Substances Hydrology Program","active":true,"usgs":true}],"links":[{"id":269008,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"country":"United States","volume":"6","issue":"1","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"53cd5a41e4b0b290850f93b5","contributors":{"authors":[{"text":"Hatzinger, P.B.","contributorId":12663,"corporation":false,"usgs":true,"family":"Hatzinger","given":"P.B.","affiliations":[],"preferred":false,"id":473443,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Bohlke, John Karl 0000-0001-5693-6455","orcid":"https://orcid.org/0000-0001-5693-6455","contributorId":84641,"corporation":false,"usgs":true,"family":"Bohlke","given":"John Karl","affiliations":[],"preferred":false,"id":473446,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Sturchio, N.C.","contributorId":16580,"corporation":false,"usgs":true,"family":"Sturchio","given":"N.C.","affiliations":[],"preferred":false,"id":473444,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Gu, B.","contributorId":8670,"corporation":false,"usgs":true,"family":"Gu","given":"B.","email":"","affiliations":[],"preferred":false,"id":473442,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Heraty, L.J.","contributorId":7090,"corporation":false,"usgs":true,"family":"Heraty","given":"L.J.","affiliations":[],"preferred":false,"id":473441,"contributorType":{"id":1,"text":"Authors"},"rank":5},{"text":"Borden, R.C.","contributorId":61260,"corporation":false,"usgs":true,"family":"Borden","given":"R.C.","email":"","affiliations":[],"preferred":false,"id":473445,"contributorType":{"id":1,"text":"Authors"},"rank":6}]}} ,{"id":70161856,"text":"70161856 - 2009 - 2008 Spawning Cisco Investigations in the Canadian Waters of Lake Superior","interactions":[],"lastModifiedDate":"2016-06-23T14:48:40","indexId":"70161856","displayToPublicDate":"2010-01-01T00:00:00","publicationYear":"2009","noYear":false,"publicationType":{"id":18,"text":"Report"},"publicationSubtype":{"id":6,"text":"USGS Unnumbered Series"},"title":"2008 Spawning Cisco Investigations in the Canadian Waters of Lake Superior","docAbstract":"The Great Lakes Science Center of the United States Geological Survey (USGS) is working cooperatively with the Ontario Ministry of Natural Resources (OMNR) on a threeyear study to develop standard procedures for acoustic and midwater trawl (AC-MT) assessments of spawning cisco Coregonus artedi that the OMNR can carry forward as a management activity. In year two (2008), we conducted an AC-MT survey of the northern shore from Nipigon Bay to Thunder Bay. Spawning-cisco (> 250 mm total length) densities were lowest near Nipigon Bay (<10/ha), moderate in and around Black Bay (15- 30/ha), and highest in Thunder Bay (118/ha). Rainbow smelt Osmerus mordax densities were highest in Nipigon (2,179/ha) and Black (3,219/ha) bays, and lowest in Thunder Bay (961/ha). We combined our AC-MT survey results with commercial catch records to estimate exploitation fractions of female cisco in Thunder Bay during the 2008 fishery at 4% for ages 1-5, 8.7% for ages 6-12, and 4.4% for ages ≥ 13. Lake Superior fishery managers recently recommended that annual exploitation of adult female lake cisco be kept below 10-15%. Recruitment of cisco since 2003 has been low and there is a strong probability the Thunder Bay stock will decline into the future. Using a simple population dynamics approach we estimated that if the current total allowable catch (TAC) quota is held constant, exploitation fractions could exceed 10% by 2010 and 15% by 2011. Our 2008 collections suggested the survey of Black Bay was likely conducted before all spawners had returned there to spawn. Our data also suggested that cisco collected in Black Bay and east of this site in mid-November may be from the same stock. During November 2009 we will attempt to get better definition of the area occupied by cisco around Black Bay and also determine when surveys should be conducted at this location.
","language":"English","publisher":"U.S. Geological Survey","publisherLocation":"Reston, VA","doi":"10.3133/70161856","usgsCitation":"Yule, D., Addison, P.A., Evrard, L.M., Cullis, K.I., and Cholwek, G.A., 2009, 2008 Spawning Cisco Investigations in the Canadian Waters of Lake Superior, 47 p., https://doi.org/10.3133/70161856.","productDescription":"47 p.","numberOfPages":"47","onlineOnly":"N","additionalOnlineFiles":"N","ipdsId":"IP-014726","costCenters":[{"id":324,"text":"Great Lakes Science Center","active":true,"usgs":true}],"links":[{"id":324306,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/usgs_thumb.jpg"},{"id":313995,"type":{"id":11,"text":"Document"},"url":"https://www.glsc.usgs.gov/products/reports/1970178148"}],"publishingServiceCenter":{"id":6,"text":"Columbus PSC"},"noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"576d082ce4b07657d1a37543","contributors":{"authors":[{"text":"Yule, Daniel 0000-0002-0117-5115 dyule@usgs.gov","orcid":"https://orcid.org/0000-0002-0117-5115","contributorId":139532,"corporation":false,"usgs":true,"family":"Yule","given":"Daniel","email":"dyule@usgs.gov","affiliations":[{"id":324,"text":"Great Lakes Science Center","active":true,"usgs":true}],"preferred":true,"id":587943,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Addison, Peter A.","contributorId":105987,"corporation":false,"usgs":true,"family":"Addison","given":"Peter","email":"","middleInitial":"A.","affiliations":[],"preferred":false,"id":587947,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Evrard, Lori M. 0000-0001-8582-5818 levrard@usgs.gov","orcid":"https://orcid.org/0000-0001-8582-5818","contributorId":2720,"corporation":false,"usgs":true,"family":"Evrard","given":"Lori","email":"levrard@usgs.gov","middleInitial":"M.","affiliations":[{"id":324,"text":"Great Lakes Science Center","active":true,"usgs":true}],"preferred":true,"id":587945,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Cullis, Ken I.","contributorId":150786,"corporation":false,"usgs":false,"family":"Cullis","given":"Ken","email":"","middleInitial":"I.","affiliations":[{"id":13173,"text":"Ontario Ministry of Natural Resources, Upper Great Lakes Management Unit","active":true,"usgs":false}],"preferred":false,"id":587948,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Cholwek, Gary A. gcholwek@usgs.gov","contributorId":2719,"corporation":false,"usgs":true,"family":"Cholwek","given":"Gary","email":"gcholwek@usgs.gov","middleInitial":"A.","affiliations":[{"id":324,"text":"Great Lakes Science Center","active":true,"usgs":true}],"preferred":true,"id":587944,"contributorType":{"id":1,"text":"Authors"},"rank":5}]}} ,{"id":70043368,"text":"70043368 - 2009 - Geochemical Evolution of Great Salt Lake, Utah, USA","interactions":[],"lastModifiedDate":"2013-03-10T11:46:29","indexId":"70043368","displayToPublicDate":"2010-01-01T00:00:00","publicationYear":"2009","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":866,"text":"Aquatic Geochemistry","active":true,"publicationSubtype":{"id":10}},"title":"Geochemical Evolution of Great Salt Lake, Utah, USA","docAbstract":"\"The Great Salt Lake (GSL) of Utah, USA, is the largest saline lake in North\nAmerica, and its brines are some of the most concentrated anywhere in the world. The lake\noccupies a closed basin system whose chemistry reflects solute inputs from the weathering\nof a diverse suite of rocks in its drainage basin. GSL is the remnant of a much larger\nlacustrine body, Lake Bonneville, and it has a long history of carbonate deposition. Inflow\nto the lake is from three major rivers that drain mountain ranges to the east and empty into\nthe southern arm of the lake, from precipitation directly on the lake, and from minor\ngroundwater inflow. Outflow is by evaporation. The greatest solute inputs are from calcium\nbicarbonate river waters mixed with sodium chloride-type springs and groundwaters. Prior\nto 1930 the lake concentration inversely tracked lake volume, which reflected climatic\nvariation in the drainage, but since then salt precipitation and re-solution, primarily halite\nand mirabilite, have periodically modified lake-brine chemistry through density stratification\nand compositional differentiation. In addition, construction of a railway causeway\nhas restricted circulation, nearly isolating the northern from the southern part of the lake,\nleading to halite precipitation in the north. These and other conditions have created brine\ndifferentiation, mixing, and fractional precipitation of salts as major factors in solute\nevolution. Pore fluids and diagenetic reactions have been identified as important sources\nand especially sinks for CaCO3, Mg, and K in the lake, depending on the concentration\ngradient and clays.\"","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Aquatic Geochemistry","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","publisher":"Springer","doi":"10.1007/s10498-008-9047-y","usgsCitation":"Jones, B.F., Naftz, D.L., Spencer, R.J., and Oviatt, C., 2009, Geochemical Evolution of Great Salt Lake, Utah, USA: Aquatic Geochemistry, v. 15, no. 1-2, p. 95-121, https://doi.org/10.1007/s10498-008-9047-y.","startPage":"95","endPage":"121","numberOfPages":"26","ipdsId":"IP-010605","costCenters":[{"id":146,"text":"Branch of Regional Research-Eastern Region","active":false,"usgs":true}],"links":[{"id":269005,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":269003,"type":{"id":11,"text":"Document"},"url":"https://water.usgs.gov/nrp/proj.bib/Publications/2009/jones_naftz_etal_2009.pdf"},{"id":269004,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1007/s10498-008-9047-y"}],"country":"United States","volume":"15","issue":"1-2","noUsgsAuthors":false,"publicationDate":"2008-12-02","publicationStatus":"PW","scienceBaseUri":"53cd5ab0e4b0b290850f9888","contributors":{"authors":[{"text":"Jones, Blair F. bfjones@usgs.gov","contributorId":2784,"corporation":false,"usgs":true,"family":"Jones","given":"Blair","email":"bfjones@usgs.gov","middleInitial":"F.","affiliations":[{"id":436,"text":"National Research Program - Eastern Branch","active":true,"usgs":true}],"preferred":true,"id":473472,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Naftz, David L. 0000-0003-1130-6892 dlnaftz@usgs.gov","orcid":"https://orcid.org/0000-0003-1130-6892","contributorId":1041,"corporation":false,"usgs":true,"family":"Naftz","given":"David","email":"dlnaftz@usgs.gov","middleInitial":"L.","affiliations":[{"id":610,"text":"Utah Water Science Center","active":true,"usgs":true},{"id":5050,"text":"WY-MT Water Science Center","active":true,"usgs":true}],"preferred":true,"id":473471,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Spencer, Ronald J.","contributorId":62480,"corporation":false,"usgs":true,"family":"Spencer","given":"Ronald","email":"","middleInitial":"J.","affiliations":[],"preferred":false,"id":473474,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Oviatt, Charles G.","contributorId":13503,"corporation":false,"usgs":true,"family":"Oviatt","given":"Charles G.","affiliations":[],"preferred":false,"id":473473,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}} ,{"id":70043324,"text":"70043324 - 2009 - A simple technique for continuous measurement of time-variable gas transfer in surface waters","interactions":[],"lastModifiedDate":"2018-10-03T10:36:42","indexId":"70043324","displayToPublicDate":"2010-01-01T00:00:00","publicationYear":"2009","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2622,"text":"Limnology and Oceanography: Methods","active":true,"publicationSubtype":{"id":10}},"title":"A simple technique for continuous measurement of time-variable gas transfer in surface waters","docAbstract":"Mass balance models of dissolved gases in streams, lakes, and rivers serve as the basis for estimating wholeecosystem rates for various biogeochemical processes. Rates of gas exchange between water and the atmosphere are important and error-prone components of these models. Here we present a simple and efficient modification of the SF6 gas tracer approach that can be used concurrently while collecting other dissolved gas samples for dissolved gas mass balance studies in streams. It consists of continuously metering SF6-saturated water directly into the stream at a low rate of flow. This approach has advantages over pulse injection of aqueous solutions or bubbling large amounts of SF6 into the stream. By adding the SF6 as a saturated solution, we minimize the possibility that other dissolved gas measurements are affected by sparging and/or bubble injecta. Because the SF6 is added continuously we have a record of changing gas transfer velocity (GTV) that is contemporaneous with the sampling of other nonconservative ambient dissolved gases. Over a single diel period, a 30% variation in GTV was observed in a second-order stream (Sugar Creek, Indiana, USA). The changing GTV could be attributed in part to changes in temperature and windspeed that occurred on hourly to diel timescales.","language":"English","publisher":"ASLO","doi":"10.4319/lom.2009.7.185","usgsCitation":"Tobias, C., Bohlke, J., Harvey, J.W., and Busenberg, E., 2009, A simple technique for continuous measurement of time-variable gas transfer in surface waters: Limnology and Oceanography: Methods, v. 7, p. 185-195, https://doi.org/10.4319/lom.2009.7.185.","productDescription":"11 p.","startPage":"185","endPage":"195","ipdsId":"IP-004332","costCenters":[{"id":146,"text":"Branch of Regional Research-Eastern Region","active":false,"usgs":true},{"id":589,"text":"Toxic Substances Hydrology Program","active":true,"usgs":true}],"links":[{"id":270737,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"country":"United States","volume":"7","noUsgsAuthors":false,"publicationDate":"2009-02-12","publicationStatus":"PW","scienceBaseUri":"51653860e4b077fa94dadf5b","contributors":{"authors":[{"text":"Tobias, Craig R.","contributorId":23410,"corporation":false,"usgs":false,"family":"Tobias","given":"Craig R.","affiliations":[{"id":32398,"text":"University of North Carolina Wilmington","active":true,"usgs":false}],"preferred":false,"id":473392,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Bohlke, John Karl 0000-0001-5693-6455","orcid":"https://orcid.org/0000-0001-5693-6455","contributorId":84641,"corporation":false,"usgs":true,"family":"Bohlke","given":"John Karl","affiliations":[],"preferred":false,"id":473393,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Harvey, Judson W. 0000-0002-2654-9873 jwharvey@usgs.gov","orcid":"https://orcid.org/0000-0002-2654-9873","contributorId":1796,"corporation":false,"usgs":true,"family":"Harvey","given":"Judson","email":"jwharvey@usgs.gov","middleInitial":"W.","affiliations":[{"id":436,"text":"National Research Program - Eastern Branch","active":true,"usgs":true}],"preferred":true,"id":473390,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Busenberg, Eurybiades ebusenbe@usgs.gov","contributorId":2271,"corporation":false,"usgs":true,"family":"Busenberg","given":"Eurybiades","email":"ebusenbe@usgs.gov","affiliations":[{"id":436,"text":"National Research Program - Eastern Branch","active":true,"usgs":true}],"preferred":true,"id":473391,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}} ,{"id":70043242,"text":"70043242 - 2009 - Declining global per capita agricultural production and warming oceans threaten food security","interactions":[],"lastModifiedDate":"2013-04-09T19:28:04","indexId":"70043242","displayToPublicDate":"2010-01-01T00:00:00","publicationYear":"2009","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1683,"text":"Food Security","active":true,"publicationSubtype":{"id":10}},"title":"Declining global per capita agricultural production and warming oceans threaten food security","docAbstract":"Despite accelerating globalization, most people still eat food that is grown locally. Developing countries with weak purchasing power tend to import as little food as possible from global markets, suffering consumption deficits during times of high prices or production declines. Local agricultural production, therefore, is critical to both food security and economic development among the rural poor. The level of local agricultural production, in turn, will be determined by the amount and quality of arable land, the amount and quality of agricultural inputs (fertilizer, seeds, pesticides, etc.), as well as farm-related technology, practices and policies. This paper discusses several emerging threats to global and regional food security, including declining yield gains that are failing to keep up with population increases, and warming in the tropical Indian Ocean and its impact on rainfall. If yields continue to grow more slowly than per capita harvested area, parts of Africa, Asia and Central and Southern America will experience substantial declines in per capita cereal production. Global per capita cereal production will potentially decline by 14% between 2008 and 2030. Climate change is likely to further affect food production, particularly in regions that have very low yields due to lack of technology. Drought, caused by anthropogenic warming in the Indian and Pacific Oceans, may also reduce 21st century food availability in some countries by disrupting moisture transports and bringing down dry air over crop growing areas. The impacts of these circulation changes over Asia remain uncertain. For Africa, however, Indian Ocean warming appears to have already reduced rainfall during the main growing season along the eastern edge of tropical Africa, from southern Somalia to northern parts of the Republic of South Africa. Through a combination of quantitative modeling of food balances and an examination of climate change, this study presents an analysis of emerging threats to global food security.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Food Security","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","publisher":"Springer","doi":"10.1007/s12571-009-0026-y","usgsCitation":"Funk, C.C., and Brown, M.E., 2009, Declining global per capita agricultural production and warming oceans threaten food security: Food Security, v. 1, no. 3, p. 271-289, https://doi.org/10.1007/s12571-009-0026-y.","startPage":"271","endPage":"289","ipdsId":"IP-010410","costCenters":[{"id":222,"text":"Earth Resources Observation and Science (EROS) Center","active":true,"usgs":true}],"links":[{"id":476020,"rank":0,"type":{"id":40,"text":"Open Access Publisher Index Page"},"url":"https://doi.org/10.1007/s12571-009-0026-y","text":"Publisher Index Page"},{"id":270740,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":270738,"type":{"id":11,"text":"Document"},"url":"https://link.springer.com/content/pdf/10.1007%2Fs12571-009-0026-y"},{"id":270739,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1007/s12571-009-0026-y"}],"country":"United States","volume":"1","issue":"3","noUsgsAuthors":false,"publicationDate":"2009-07-25","publicationStatus":"PW","scienceBaseUri":"51653869e4b077fa94dadf98","contributors":{"authors":[{"text":"Funk, Christopher C. 0000-0002-9254-6718 cfunk@usgs.gov","orcid":"https://orcid.org/0000-0002-9254-6718","contributorId":721,"corporation":false,"usgs":true,"family":"Funk","given":"Christopher","email":"cfunk@usgs.gov","middleInitial":"C.","affiliations":[{"id":223,"text":"Earth Resources Observation and Science (EROS) Center (Geography)","active":false,"usgs":true}],"preferred":false,"id":473234,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Brown, Molly E.","contributorId":62490,"corporation":false,"usgs":true,"family":"Brown","given":"Molly","email":"","middleInitial":"E.","affiliations":[],"preferred":false,"id":473235,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70209246,"text":"70209246 - 2009 - Deglaciation in the southeastern Laurentide Sector and the Hudson Valley – 15,000 Years of vegetational and climate history","interactions":[],"lastModifiedDate":"2020-03-27T06:33:39","indexId":"70209246","displayToPublicDate":"2009-12-31T11:57:37","publicationYear":"2009","noYear":false,"publicationType":{"id":24,"text":"Conference Paper"},"publicationSubtype":{"id":19,"text":"Conference Paper"},"title":"Deglaciation in the southeastern Laurentide Sector and the Hudson Valley – 15,000 Years of vegetational and climate history","docAbstract":"In this field trip, we provide a review of the significant controversy concerning the timing of deglaciation in the Hudson and Wallkill Valleys. We outline the differences in methodology and chronology with a circular route throughout the Hudson and Wallkill valleys. We begin the trip at Lake Mohonk near New Paltz led by Kirsten Menking and Dorothy Peteet, then continue to the “black dirt” region of the Wallkill Valley where John Rayburn has contributed a new GIS model of deglaciation in the Wallkill Valley and Guy Robinson will review the history of fossil mammals, including mammoths. From this point we travel southeast to a rare exposure of glaciolacustrine beds on the west side of the Huson River, described by Byron Stone and John Rayburn, and on to Croton Marsh at Croton Point, New York where Dorothy Peteet will review the marsh histories of the region.
A recent review of literature relating to the last glacial recession in the Hudson Valley indicates that the timing of de - glaciation is very controversial (Peteet et al., 2006; Peteet, in review; Balco et al., 2006; Balco et al., 2009; Schaefer, 2007). Some questions to consider:
1) How does timing of new lake basal dates at the margin of the ice (Staten Island) compare with sites to the north and inland (ie. Mohonk)?
2) What is the vegetational history of the region and how does it compare with Deevey’s classical southern New England stratigraphy?
3) What is the latest model of the deglaciation of the Wallkill Valley?
4) What have the Hudson marshes added to our understanding of the vegetation and landscape history, particularly in the last few millennia?
","largerWorkType":{"id":4,"text":"Book"},"largerWorkTitle":"Field trip guidebook: New York State Geological Association 81st annual meeting, September 25-27, 2009","largerWorkSubtype":{"id":12,"text":"Conference publication"},"conferenceTitle":"New York State Geological Association 81st annual meeting","conferenceDate":"September 25-27, 2009","conferenceLocation":"New Paltz, NY","language":"English","publisher":"New York State Geological Association","usgsCitation":"Peteet, D.M., Rayburn, J., Menking, K.M., Robinson, G., and Stone, B.D., 2009, Deglaciation in the southeastern Laurentide Sector and the Hudson Valley – 15,000 Years of vegetational and climate history, in Field trip guidebook: New York State Geological Association 81st annual meeting, September 25-27, 2009, New Paltz, NY, September 25-27, 2009, p. 4.1-4.18.","productDescription":"18 p.","startPage":"4.1","endPage":"4.18","costCenters":[{"id":241,"text":"Eastern Energy Resources Science Center","active":true,"usgs":true},{"id":40020,"text":"Florence Bascom Geoscience Center","active":true,"usgs":true}],"links":[{"id":373516,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":373515,"rank":1,"type":{"id":15,"text":"Index Page"},"url":"https://www.nysga-online.net/guidebooks/1925-2018/"}],"country":"United States","state":"New York","city":" New Paltz","otherGeospatial":"Croton Point, Hudson Valley, Lake Mohonk, Wallkill Valley","geographicExtents":"{\n \"type\": \"FeatureCollection\",\n \"features\": [\n {\n \"type\": \"Feature\",\n \"properties\": {},\n \"geometry\": {\n \"type\": \"Polygon\",\n \"coordinates\": [\n [\n [\n -74.51751708984375,\n 41.062786068733026\n ],\n [\n -73.68804931640625,\n 41.062786068733026\n ],\n [\n -73.68804931640625,\n 42.256983603767466\n ],\n [\n -74.51751708984375,\n 42.256983603767466\n ],\n [\n -74.51751708984375,\n 41.062786068733026\n ]\n ]\n ]\n }\n }\n ]\n}","noUsgsAuthors":false,"publicationStatus":"PW","contributors":{"authors":[{"text":"Peteet, Dorothy M. 0000-0003-3029-7506","orcid":"https://orcid.org/0000-0003-3029-7506","contributorId":147523,"corporation":false,"usgs":false,"family":"Peteet","given":"Dorothy","email":"","middleInitial":"M.","affiliations":[{"id":16858,"text":"Goddard Institute","active":true,"usgs":false}],"preferred":false,"id":785540,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Rayburn, John","contributorId":223595,"corporation":false,"usgs":false,"family":"Rayburn","given":"John","email":"","affiliations":[],"preferred":false,"id":785541,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Menking, Kirsten M.","contributorId":53564,"corporation":false,"usgs":true,"family":"Menking","given":"Kirsten","email":"","middleInitial":"M.","affiliations":[],"preferred":false,"id":785542,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Robinson, Guy","contributorId":223596,"corporation":false,"usgs":false,"family":"Robinson","given":"Guy","email":"","affiliations":[],"preferred":false,"id":785543,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Stone, Byron D. 0000-0001-6092-0798 bdstone@usgs.gov","orcid":"https://orcid.org/0000-0001-6092-0798","contributorId":1702,"corporation":false,"usgs":true,"family":"Stone","given":"Byron","email":"bdstone@usgs.gov","middleInitial":"D.","affiliations":[{"id":40020,"text":"Florence Bascom Geoscience Center","active":true,"usgs":true},{"id":243,"text":"Eastern Geology and Paleoclimate Science Center","active":true,"usgs":true}],"preferred":true,"id":785544,"contributorType":{"id":1,"text":"Authors"},"rank":5}]}} ,{"id":70231371,"text":"70231371 - 2009 - The Shawangunk and Martinsburg Formations revisited; sedimentology, stratigraphy, mineralogy, geochemistry, structure and paleontology","interactions":[],"lastModifiedDate":"2022-05-09T15:26:46.060634","indexId":"70231371","displayToPublicDate":"2009-12-31T10:13:52","publicationYear":"2009","noYear":false,"publicationType":{"id":24,"text":"Conference Paper"},"publicationSubtype":{"id":19,"text":"Conference Paper"},"title":"The Shawangunk and Martinsburg Formations revisited; sedimentology, stratigraphy, mineralogy, geochemistry, structure and paleontology","docAbstract":"In southeastern New York Middle Silurian Shawangunk Formation (Figure 1), containing gray conglomerate, sandstone and shale, lies unconformably above the Ordovician Martinsburg Formation, consisting of shales and graywackes. In southwestern New York, near the Port Jervis area, The Shawangunk Formation is overlain by the Bloomsburg Red Beds, the same stratigraphic sequence that occurs in Pennsylvania and New Jersey to the southwest. The Shawangunk Formation thins gradually from Port Jervis to its pinchout near Hidden Valley and Binnewater, New York. Two tongues of the upper part of the Shawangunk are: the Ellenville Tongue that extends from the Ellenville-Accord area to its feather edge just southwest of the New York-New Jersey border and, the High View Tongue that is restricted to the Wurtsboro area (Epstein and Lyttle, 1987; Epstein, 1993).
Early in the Paleozoic carbonate banks lay along the east coast of the ancient North American continent. During the Ordovician plate convergence commenced in the closing of the Iapetus Sea and a deep basin developed into which thick muds and dirty sands were deposited. These were later lithified into the Martinsburg Formation. Eventually, with continued compression, these sediments were folded and faulted during the complex deformation of the Taconic Orogeny. The trend of these folds in southeastern New York is approximately N20E. As one proceeds westward across the Wallkill Valley these structures become less intense. Subsequent to the Taconic Orogeny mountains rose to the east and coarse sediments were transported westward and deposited as the conglomerates and sandstones of the Shawangunk Formation across the beveled folds of the Martinsburg. Deposition occurred on a plain of alluviation and in a marine basin to the northwest. Erosion of the source area was intense, and the climate, based on the mineralogy of the rocks, was warm and at least semiarid. The source was composed predominately of sedimentary and low-grade metamorphic rocks with exceptionally abundant quartz veins and small local areas of gneiss and granite. As the source highlands were eroded, the steep braided streams of the Shawangunk gave way to more gentle-gradient streams of the Bloomsburg Red Beds.
","largerWorkType":{"id":4,"text":"Book"},"largerWorkTitle":"New York State Geological Association 81st annual meeting: Field trip guidebook","largerWorkSubtype":{"id":12,"text":"Conference publication"},"language":"English","publisher":"New York State Geological Association","usgsCitation":"Feldman, H.R., Epstein, J.B., and Smoliga, J.A., 2009, The Shawangunk and Martinsburg Formations revisited; sedimentology, stratigraphy, mineralogy, geochemistry, structure and paleontology, in New York State Geological Association 81st annual meeting: Field trip guidebook, p. 12.1-12.12.","productDescription":"12 p.","startPage":"12.1","endPage":"12.12","costCenters":[{"id":243,"text":"Eastern Geology and Paleoclimate Science Center","active":true,"usgs":true}],"links":[{"id":400330,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":400329,"rank":1,"type":{"id":15,"text":"Index Page"},"url":"https://www.nysga-online.org/guidebooks/by-year/"}],"country":"United States","state":"New York, Pennsylvania","otherGeospatial":"Shawangunk and Martinsburg Formations","geographicExtents":"{\n \"type\": \"FeatureCollection\",\n \"features\": [\n {\n \"type\": \"Feature\",\n \"properties\": {},\n \"geometry\": {\n \"type\": \"Polygon\",\n \"coordinates\": [\n [\n [\n -74.85122680664062,\n 41.21068840283448\n ],\n [\n -74.24697875976562,\n 41.21068840283448\n ],\n [\n -74.24697875976562,\n 41.51269075845857\n ],\n [\n -74.85122680664062,\n 41.51269075845857\n ],\n [\n -74.85122680664062,\n 41.21068840283448\n ]\n ]\n ]\n }\n }\n ]\n}","noUsgsAuthors":false,"publicationStatus":"PW","contributors":{"authors":[{"text":"Feldman, H. R.","contributorId":29581,"corporation":false,"usgs":true,"family":"Feldman","given":"H.","email":"","middleInitial":"R.","affiliations":[],"preferred":false,"id":842437,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Epstein, Jack B. jepstein@usgs.gov","contributorId":1412,"corporation":false,"usgs":true,"family":"Epstein","given":"Jack","email":"jepstein@usgs.gov","middleInitial":"B.","affiliations":[{"id":40020,"text":"Florence Bascom Geoscience Center","active":true,"usgs":true},{"id":243,"text":"Eastern Geology and Paleoclimate Science Center","active":true,"usgs":true}],"preferred":true,"id":842438,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Smoliga, John A.","contributorId":291480,"corporation":false,"usgs":false,"family":"Smoliga","given":"John","email":"","middleInitial":"A.","affiliations":[],"preferred":false,"id":842439,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70190734,"text":"70190734 - 2009 - Mississippi River delta plain, Louisiana coast, and inner shelf Holocene geologic framework, processes, and resources","interactions":[],"lastModifiedDate":"2019-12-21T08:36:26","indexId":"70190734","displayToPublicDate":"2009-12-31T00:00:00","publicationYear":"2009","noYear":false,"publicationType":{"id":5,"text":"Book chapter"},"publicationSubtype":{"id":24,"text":"Book Chapter"},"title":"Mississippi River delta plain, Louisiana coast, and inner shelf Holocene geologic framework, processes, and resources","docAbstract":"Extending nearly 400 km from Sabine Pass on the Texas-Louisiana border east to the Chandeleur Islands, the Louisiana coastal zone (Fig. 11.1) along the north-central Gulf of Mexico is the southern terminus of the largest drainage basin in North America (>3.3 million km2), which includes the Mississippi River delta plain where approximately 6.2 million kilograms per year of sediment is delivered to the Gulf of Mexico (Coleman 1988). The Mississippi River, active since at least Late Jurassic time (Mann and Thomas 1968), is the main distributary channel of this drainage system and during the Holocene has constructed one of the largest delta plains in the world, larger than 30,000 km2 (Coleman and Prior 1980; Coleman 1981; Coleman et al. 1998). The subsurface geology and geomorphology of the Louisiana coastal zone reffects a complex history of regional tectonic events and fluvial, deltaic, and marine sedimentary processes affected by large sea-level fluctuations. Despite the complex geology of the north-central Gulf basin, a long history of engineering studies and Scientific research investigations (see table 11.1) has led to substantial knowledge of the geologic framework and evolution of the delta plain region (see also Bird et al., chapter 1 in this volume).
Mississippi River delta plain, Louisiana coast, and inner shelf Holocene geologic framework, processes, and resources. Available from: https://www.researchgate.net/publication/262802561_Mississippi_River_delta_plain_Louisiana_coast_and_inner_shelf_Holocene_geologic_framework_processes_and_resources [accessed Sep 13, 2017].
Upscaling the spatial and temporal changes of carbon stocks and fluxes from sites to regions is challenging owing to the spatial and temporal variances and covariance of driving variables and the uncertainties in both the model and the input data. Although various modeling approaches have been developed to facilitate the upscaling process, few deal with error transfer from model input to output, and error propagation in time and space. The author has developed the General Ensemble Biogeochemical Modelling System (GEMS) for upscaling carbon stocks and fluxes from sites to regions with measures of uncertainty. This chapter describes the GEMS model, its application to regional- and larger-scale areas, and the new results that demonstrate the challenges of upscaling. GEMS relies on site-scale biogeochemical models to simulate carbon dynamics at the site scale. The spatial deployment of the site-scale model in GEMS is based on the spatial and temporal joint frequency distribution of major driving variables (e.g., land cover and land use change, climate, soils, disturbances, and management). At the site scale, GEMS uses stochastic ensemble simulations to incorporate input uncertainty to quantify uncertainty transfer from input to output, and to identify trends in both input data and simulation results. It permits one to simulate the range of possible permutations of input values and identify the trends and variance in both the input data and results. Using data assimilation techniques, GEMS simulations can be constrained by field and satellite observations, including estimates of net primary production (NPP) from the Moderate Resolution Imaging Spectroradiometer (MODIS), grain yield and cropping practices, and forest inventories. The modeling philosophy embedded in GEMS makes it ideal for assimilating information with various uncertainties to support estimating the spatial details of carbon sequestration potential as well as dynamic monitoring of the performance of carbon sequestration activities over large areas. As a case study, GEMS is applied to simulate the spatial and temporal details of carbon sources, sinks, and uncertainty in the Ridge and Valley ecoregion in the eastern United States
","largerWorkType":{"id":4,"text":"Book"},"largerWorkTitle":"Carbon sequestration and its role in the global carbon cycle","largerWorkSubtype":{"id":15,"text":"Monograph"},"language":"English","publisher":"American Geophysical Union","publisherLocation":"Washington, D.C.","doi":"10.1029/2006GM000524","usgsCitation":"Liu, S., 2009, Quantifying the spatial details of carbon sequestration potential and performance, chap. 7 of Carbon sequestration and its role in the global carbon cycle, p. 117-128, https://doi.org/10.1029/2006GM000524.","productDescription":"12 p.","startPage":"117","endPage":"128","costCenters":[{"id":222,"text":"Earth Resources Observation and Science (EROS) Center","active":true,"usgs":true}],"links":[{"id":370220,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"noUsgsAuthors":false,"publicationStatus":"PW","contributors":{"editors":[{"text":"McPherson, B.","contributorId":86593,"corporation":false,"usgs":true,"family":"McPherson","given":"B.","affiliations":[],"preferred":false,"id":777351,"contributorType":{"id":2,"text":"Editors"},"rank":1},{"text":"Sundquist, Eric T. 0000-0002-1449-8802 esundqui@usgs.gov","orcid":"https://orcid.org/0000-0002-1449-8802","contributorId":1922,"corporation":false,"usgs":true,"family":"Sundquist","given":"Eric","email":"esundqui@usgs.gov","middleInitial":"T.","affiliations":[{"id":40020,"text":"Florence Bascom Geoscience Center","active":true,"usgs":true},{"id":436,"text":"National Research Program - Eastern Branch","active":true,"usgs":true}],"preferred":true,"id":777352,"contributorType":{"id":2,"text":"Editors"},"rank":2}],"authors":[{"text":"Liu, S.","contributorId":149250,"corporation":false,"usgs":false,"family":"Liu","given":"S.","email":"","affiliations":[],"preferred":false,"id":777350,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}} ]}