Commonly measured water quality parameters were compared to heat as tracers of stream water exchange with ground water. Temperature, specific conductance, and chloride were sampled at various frequencies in the stream and adjacent wells over a 2-year period. Strong seasonal variations in stream water were observed for temperature and specific conductance. In observation wells where the temperature response correlated to stream water, chloride and specific conductance values were similar to stream water values as well, indicating significant stream water exchange with ground water. At sites where ground water temperature fluctuations were negligible, chloride and/or specific conductance values did not correlate to stream water values, indicating that ground water was not significantly influenced by exchange with stream water. Best-fit simulation modeling was performed at two sites to derive temperature-based estimates of hydraulic conductivities of the alluvial sediments between the stream and wells. These estimates were used in solute transport simulations for a comparison of measured and simulated values for chloride and specific conductance. Simulation results showed that hydraulic conductivities vary seasonally and annually. This variability was a result of seasonal changes in temperature-dependent hydraulic conductivity and scouring or clogging of the streambed. Specific conductance fits were good, while chloride data were difficult to fit due to the infrequent (quarterly) stream water chloride measurements during the study period. Combined analyses of temperature, chloride, and specific conductance led to improved quantification of the spatial and temporal variability of stream water exchange with shallow ground water in an alluvial system.
The composition of dissolved organic carbon (DOC) in stormflow from urban areas has been greatly altered, both directly and indirectly, by human activities and there is concern that there may be public health issues associated with DOC, which has unknown composition from different sources within urban watersheds. This study evaluated changes in the concentration and composition of DOC in stormflow in the Santa Ana River and its tributaries between 1995 and 2004 using a simplified approach based on the differences in the optical properties of DOC and using operationally defined differences in molecular weight and solubility. The data show changes in the composition of DOC in stormflow during the rainy season and differences associated with runoff from different parts of the basin, including extensive upland areas burned prior to the 2004 rainy season.
Samples were collected from the Santa Ana River, which drains ~6950 km2 of the densely populated coastal area of southern California, during 23 stormflows between 1995 and 2004. Dissolved organic carbon (DOC) concentrations during the first stormflows of the ‘winter’ (November to March) rainy season increased rapidly with streamflow and were positively correlated with increased faecal indicator bacteria concentrations. DOC concentrations were not correlated with streamflow or with other constituents during stormflows later in the rainy season and DOC had increasing UV absorbance per unit carbon as the rainy season progressed. DOC concentrations in stormflow from an urban drain tributary to the river also increased during stormflow and were greater than concentrations in the river. DOC concentrations in stormflow from a tributary stream, draining urban and agricultural land that contained more than 320 000 animals, mostly dairy cows, were higher than concentrations in stormflow from the river and from the urban drain. Fires that burned large areas of the basin before the 2004 rainy season did not increase DOC concentrations in the river during stormflow after the fires – possibly because the large watershed of the river damped the effect of the fires. However, the fires increased the hydrophobic neutral organic carbon fraction of DOC in stormflow from the urban drain and the tributary stream.
[1] Starting early in 2005, the positions of GPS stations in the San Gabriel valley region of southern California showed statistically significant departures from their previous behavior. Station LONG moved up by about 47 mm, and nearby stations moved away from LONG by about 10 mm. These changes began during an extremely rainy season in southern California and coincided with a 16-m increase in water level at a nearby well in Baldwin Park and a regional uplift detected by interferometric synthetic aperture radar. No equivalent signals were seen in GPS station position time series elsewhere in southern California. Our preferred explanation, supported by the timing and by a hydrologic simulation, is deformation due to recharging of aquifers after near-record rainfall in 2004–2005. We cannot rule out an aseismic slip event, but we consider such an event unlikely because it requires slip on multiple faults and predicts other signals that are not observed.
Loads and yields of dissolved and particulate organic and inorganic carbon (DOC, POC, DIC, PIC) were measured and modeled at three locations on the Yukon River (YR) and on the Tanana and Porcupine rivers (TR, PR) in Alaska during 2001–2005. Total YR carbon export averaged 7.8 Tg C yr−1, 30% as OC and 70% as IC. Total C yields (0.39–1.03 mol C m−2 yr−1) were proportional to water yields (139–356 mm yr−1; r2 = 0.84) at all locations. Summer DOC had an aged component (fraction modern (FM) = 0.94–0.97), except in the permafrost wetland‐dominated PR, where DOC was modern. POC had FM = 0.63–0.70. DOC had high concentration, high aromaticity, and high hydrophobic content in spring and low concentration, low aromaticity, and high hydrophilic content in winter. About half of annual DOC export occurred during spring. DIC concentration and isotopic composition were strongly affected by dissolution of suspended carbonates in glacial meltwater during summer.
","language":"English","publisher":"American Geophysical Union","doi":"10.1029/2006WR005201","usgsCitation":"Striegl, R.G., Dornblaser, M.M., Aiken, G.R., Wickland, K.P., and Raymond, P.A., 2007, Carbon export and cycling by the Yukon, Tanana, and Porcupine rivers, Alaska, 2001-2005: Water Resources Research, v. 43, no. 2, Article W02411; 9 p., https://doi.org/10.1029/2006WR005201.","productDescription":"Article W02411; 9 p.","costCenters":[],"links":[{"id":477222,"rank":1,"type":{"id":40,"text":"Open Access Publisher Index Page"},"url":"https://doi.org/10.1029/2006wr005201","text":"Publisher Index Page"},{"id":241465,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"43","issue":"2","noUsgsAuthors":false,"publicationDate":"2007-02-10","publicationStatus":"PW","scienceBaseUri":"5059f363e4b0c8380cd4b789","contributors":{"authors":[{"text":"Striegl, Robert G. 0000-0002-8251-4659 rstriegl@usgs.gov","orcid":"https://orcid.org/0000-0002-8251-4659","contributorId":1630,"corporation":false,"usgs":true,"family":"Striegl","given":"Robert","email":"rstriegl@usgs.gov","middleInitial":"G.","affiliations":[{"id":36183,"text":"Hydro-Ecological Interactions Branch","active":true,"usgs":true},{"id":37277,"text":"WMA - Earth System Processes Division","active":true,"usgs":true},{"id":200,"text":"Coop Res Unit Seattle","active":true,"usgs":true},{"id":5044,"text":"National Research Program - Central Branch","active":true,"usgs":true}],"preferred":false,"id":437958,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Dornblaser, Mark M. 0000-0002-6298-3757 mmdornbl@usgs.gov","orcid":"https://orcid.org/0000-0002-6298-3757","contributorId":1636,"corporation":false,"usgs":true,"family":"Dornblaser","given":"Mark","email":"mmdornbl@usgs.gov","middleInitial":"M.","affiliations":[{"id":5044,"text":"National Research Program - Central Branch","active":true,"usgs":true},{"id":37277,"text":"WMA - Earth System Processes Division","active":true,"usgs":true}],"preferred":true,"id":437956,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Aiken, George R. 0000-0001-8454-0984 graiken@usgs.gov","orcid":"https://orcid.org/0000-0001-8454-0984","contributorId":1322,"corporation":false,"usgs":true,"family":"Aiken","given":"George","email":"graiken@usgs.gov","middleInitial":"R.","affiliations":[{"id":5044,"text":"National Research Program - Central Branch","active":true,"usgs":true},{"id":191,"text":"Colorado Water Science Center","active":true,"usgs":true}],"preferred":true,"id":437955,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Wickland, Kimberly P. 0000-0002-6400-0590 kpwick@usgs.gov","orcid":"https://orcid.org/0000-0002-6400-0590","contributorId":1835,"corporation":false,"usgs":true,"family":"Wickland","given":"Kimberly","email":"kpwick@usgs.gov","middleInitial":"P.","affiliations":[{"id":36183,"text":"Hydro-Ecological Interactions Branch","active":true,"usgs":true},{"id":37277,"text":"WMA - Earth System Processes Division","active":true,"usgs":true},{"id":5044,"text":"National Research Program - Central Branch","active":true,"usgs":true}],"preferred":true,"id":437954,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Raymond, Peter A.","contributorId":172876,"corporation":false,"usgs":false,"family":"Raymond","given":"Peter","email":"","middleInitial":"A.","affiliations":[{"id":17883,"text":"Yale School of Forestry and Environmental Studies, New Haven, CT","active":true,"usgs":false}],"preferred":false,"id":437957,"contributorType":{"id":1,"text":"Authors"},"rank":5}]}} ,{"id":70032797,"text":"70032797 - 2007 - Pre-eruption recharge of the Bishop magma system","interactions":[],"lastModifiedDate":"2019-03-25T11:09:24","indexId":"70032797","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":"Pre-eruption recharge of the Bishop magma system","docAbstract":"The 650 km3 rhyolitic Bishop Tuff (eastern California, USA), which is stratigraphically zoned with respect to temperatures of mineral equilibration, reflects a corresponding thermal gradient in the source magma chamber. Consistent with previous work, application of the new TitaniQ (Ti-in-quartz) thermometer to quartz phenocryst rims documents an ∼100 °C temperature increase with chamber depth at the time of eruption. Application of TitaniQ to quartz phenocryst cores, however, reveals lower temperatures and an earlier gradient that was less steep, with temperature increasing with depth by only ∼30 °C. In many late-erupted crystals, sharp boundaries that separate low-temperature cores from high-temperature rims cut internal cathodoluminescent growth zoning, indicating partial phenocryst dissolution prior to crystallization of the high-temperature rims. Rimward jumps in Ti concentration across these boundaries are too abrupt (e.g., 40 ppm across a distance of <10 µm) to have survived magmatic temperatures for more than ∼100 yr. We interpret these observations to indicate heating-induced partial dissolution of quartz, followed by growth of high-temperature rims (made possible by lowering of water activity due to addition of CO2) within 100 yr of the climactic 760 ka eruption. Hot mafic melts injected into deeper parts of the magma system were the likely source of heat and CO2, raising the possibility that eruption and caldera collapse owe their origin to a recharge event.
","language":"English","publisher":"Geological Society of America","doi":"10.1130/G23316A.1","issn":"00917613","usgsCitation":"Wark, D., Hildreth, W., Spear, F., Cherniak, D., and Watson, E., 2007, Pre-eruption recharge of the Bishop magma system: Geology, v. 35, no. 3, p. 235-238, https://doi.org/10.1130/G23316A.1.","productDescription":"4 p.","startPage":"235","endPage":"238","numberOfPages":"4","costCenters":[{"id":615,"text":"Volcano Hazards Program","active":true,"usgs":true}],"links":[{"id":241464,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"country":"United States","state":"California","otherGeospatial":"Bishop Tuff","volume":"35","issue":"3","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a80dae4b0c8380cd7b22e","contributors":{"authors":[{"text":"Wark, D.A.","contributorId":87379,"corporation":false,"usgs":true,"family":"Wark","given":"D.A.","email":"","affiliations":[],"preferred":false,"id":437951,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Hildreth, W. 0000-0002-7925-4251","orcid":"https://orcid.org/0000-0002-7925-4251","contributorId":100487,"corporation":false,"usgs":true,"family":"Hildreth","given":"W.","affiliations":[],"preferred":false,"id":437953,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Spear, F.S.","contributorId":49189,"corporation":false,"usgs":true,"family":"Spear","given":"F.S.","email":"","affiliations":[],"preferred":false,"id":437950,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Cherniak, D.J.","contributorId":27276,"corporation":false,"usgs":true,"family":"Cherniak","given":"D.J.","email":"","affiliations":[],"preferred":false,"id":437949,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Watson, E.B.","contributorId":91308,"corporation":false,"usgs":true,"family":"Watson","given":"E.B.","email":"","affiliations":[],"preferred":false,"id":437952,"contributorType":{"id":1,"text":"Authors"},"rank":5}]}} ,{"id":70032796,"text":"70032796 - 2007 - Phase equilibria constraints on the chemical and physical evolution of the campanian ignimbrite","interactions":[],"lastModifiedDate":"2012-03-12T17:21:24","indexId":"70032796","displayToPublicDate":"2007-01-01T00:00:00","publicationYear":"2007","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2420,"text":"Journal of Petrology","active":true,"publicationSubtype":{"id":10}},"title":"Phase equilibria constraints on the chemical and physical evolution of the campanian ignimbrite","docAbstract":"The Campanian Ignimbrite is a > 200 km3 trachyte-phonolite pyroclastic deposit that erupted at 39.3 ?? 0.1 ka within the Campi Flegrei west of Naples, Italy. Here we test the hypothesis that Campanian Ignimbrite magma was derived by isobaric crystal fractionation of a parental basaltic trachyandesitic melt that reacted and came into local equilibrium with small amounts (5-10 wt%) of crustal rock (skarns and foid-syenites) during crystallization. Comparison of observed crystal and magma compositions with results of phase equilibria assimilation-fractionation simulations (MELTS) is generally very good. Oxygen fugacity was approximately buffered along QFM+1 (where QFM is the quartz-fayalite-magnetite buffer) during isobaric fractionation at 0.15 GPa (???6 km depth). The parental melt, reconstructed from melt inclusion and host clinopyroxene compositions, is found to be basaltic trachyandesite liquid (51.1 wt% SiO2, 9.3 wt% MgO, 3 wt% H2O). A significant feature of phase equilibria simulations is the existence of a pseudo-invariant temperature, ???883??C, at which the fraction of melt remaining in the system decreases abruptly from ???0.5 to < 0.1. Crystallization at the pseudo-invariant point leads to abrupt changes in the composition, properties (density, dissolved water content), and physical state (viscosity, volume fraction fluid) of melt and magma. A dramatic decrease in melt viscosity (from 1700 Pa s to ???200 Pa s), coupled with a change in the volume fraction of water in magma (from ??? 0.1 to 0.8) and a dramatic decrease in melt and magma density acted as a destabilizing eruption trigger. Thermal models suggest a timescale of ??? 200 kyr from the beginning of fractionation until eruption, leading to an apparent rate of evolved magma generation of about 10-3 km3/year. In situ crystallization and crystal settling in density-stratified regions, as well as in convectively mixed, less evolved subjacent magma, operate rapidly enough to match this apparent volumetric rate of evolved magma production. ?? Copyright 2007 Oxford University Press.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Journal of Petrology","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1093/petrology/egl068","issn":"00223530","usgsCitation":"Fowler, S.J., Spera, F., Bohrson, W., Belkin, H., and de Vivo, B., 2007, Phase equilibria constraints on the chemical and physical evolution of the campanian ignimbrite: Journal of Petrology, v. 48, no. 3, p. 459-493, https://doi.org/10.1093/petrology/egl068.","startPage":"459","endPage":"493","numberOfPages":"35","costCenters":[],"links":[{"id":477036,"rank":10000,"type":{"id":40,"text":"Open Access Publisher Index Page"},"url":"https://doi.org/10.1093/petrology/egl068","text":"Publisher Index Page"},{"id":241430,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":213772,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1093/petrology/egl068"}],"volume":"48","issue":"3","noUsgsAuthors":false,"publicationDate":"2006-11-13","publicationStatus":"PW","scienceBaseUri":"505a787ae4b0c8380cd786e4","contributors":{"authors":[{"text":"Fowler, S. J.","contributorId":18586,"corporation":false,"usgs":false,"family":"Fowler","given":"S.","email":"","middleInitial":"J.","affiliations":[],"preferred":false,"id":437944,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Spera, F. J.","contributorId":89315,"corporation":false,"usgs":false,"family":"Spera","given":"F. J.","affiliations":[],"preferred":false,"id":437947,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Bohrson, W.A.","contributorId":102092,"corporation":false,"usgs":false,"family":"Bohrson","given":"W.A.","affiliations":[],"preferred":false,"id":437948,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Belkin, H. E. 0000-0001-7879-6529","orcid":"https://orcid.org/0000-0001-7879-6529","contributorId":38160,"corporation":false,"usgs":true,"family":"Belkin","given":"H. E.","affiliations":[],"preferred":false,"id":437945,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"de Vivo, B.","contributorId":50549,"corporation":false,"usgs":false,"family":"de Vivo","given":"B.","affiliations":[],"preferred":false,"id":437946,"contributorType":{"id":1,"text":"Authors"},"rank":5}]}} ,{"id":70032794,"text":"70032794 - 2007 - Simulation of Intra- or transboundary surface-water-rights hierarchies using the farm process for MODFLOW-2000","interactions":[],"lastModifiedDate":"2018-09-27T11:10:26","indexId":"70032794","displayToPublicDate":"2007-01-01T00:00:00","publicationYear":"2007","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2501,"text":"Journal of Water Resources Planning and Management","active":true,"publicationSubtype":{"id":10}},"title":"Simulation of Intra- or transboundary surface-water-rights hierarchies using the farm process for MODFLOW-2000","docAbstract":"Water-rights driven surface-water allocations for irrigated agriculture can be simulated using the farm process for MODFLOW-2000. This paper describes and develops a model, which simulates routed surface-water deliveries to farms limited by streamflow, equal-appropriation allotments, or a ranked prior-appropriation system. Simulated diversions account for deliveries to all farms along a canal according to their water-rights ranking and for conveyance losses and gains. Simulated minimum streamflow requirements on diversions help guarantee supplies to senior farms located on downstream diverting canals. Prior appropriation can be applied to individual farms or to groups of farms modeled as “virtual farms” representing irrigation districts, irrigated regions in transboundary settings, or natural vegetation habitats. The integrated approach of jointly simulating canal diversions, surface-water deliveries subject to water-rights constraints, and groundwater allocations is verified on numerical experiments based on a realistic, but hypothetical, system of ranked virtual farms. Results are discussed in light of transboundary water appropriation and demonstrate the approach’s suitability for simulating effects of water-rights hierarchies represented by international treaties, interstate stream compacts, intrastate water rights, or ecological requirements.
[1] Inflation and deflation of large calderas is traditionally interpreted as being induced by volume change of a discrete source embedded in an elastic or viscoelastic half-space, though it has also been suggested that hydrothermal fluids may play a role. To test the latter hypothesis, we carry out numerical simulations of hydrothermal fluid flow and poroelastic deformation in calderas by coupling two numerical codes: (1) TOUGH2 [Pruess et al., 1999], which simulates flow in porous or fractured media, and (2) BIOT2 [Hsieh, 1996], which simulates fluid flow and deformation in a linearly elastic porous medium. In the simulations, high-temperature water (350°C) is injected at variable rates into a cylinder (radius 50 km, height 3–5 km). A sensitivity analysis indicates that small differences in the values of permeability and its anisotropy, the depth and rate of hydrothermal injection, and the values of the shear modulus may lead to significant variations in the magnitude, rate, and geometry of ground surface displacement, or uplift. Some of the simulated uplift rates are similar to observed uplift rates in large calderas, suggesting that the injection of aqueous fluids into the shallow crust may explain some of the deformation observed in calderas.
Studies of female waterfowl nutrient reserve use during egg production require a precise understanding of ovarian follicle dynamics to correctly interpret breeding status, and, therefore, derive proper inference. Concerns over numerical declines of North American scaup have increased the need to better understand the role of female condition in reproductive performance. We quantified ovarian follicle dynamics of female Greater Scaup (Aythya marila) breeding on the Yukon–Kuskokwim Delta, Alaska, using a method that accounts for within day variation in follicle size. We considered several models for describing changes in follicle growth with the best supported model estimating the duration of rapid follicle growth (RFG) to be 5.20 ± 0.52 days (±95% confidence intervals) for each developing follicle. Average diameter and dry mass of preovulatory follicles were estimated to be 9.36 mm and 0.26 g, respectively, at the onset of RFG, and these follicle characteristics were 41.47 mm and 15.57 g, respectively, at ovulation. The average diameter of postovulatory follicles immediately following ovulation was estimated to be 17.35 mm, regressing quickly over several days. In addition, we derived predictive equations using diameter and dry mass to estimate the number of days before, and after, ovulation for pre- and postovulatory follicles, as well as an equation to estimate dry mass of damaged follicles. Our results allow precise definition of RFG and nest initiation dates, clutch size, and the daily energetic and nutritional demands of egg production at the individual level. This study provides the necessary foundation for additional work on Greater Scaup reproductive energetics and physiology, and offers an approach for quantifying ovarian follicle dynamics in other species.
","language":"English","publisher":"Wiley","doi":"10.1111/j.1557-9263.2006.00086.x","issn":"02738570","usgsCitation":"Gorman, K.B., Flint, P.L., Esler, D., and Williams, T., 2007, Ovarian follicle dynamics of female Greater Scaup during egg production: Journal of Field Ornithology, v. 78, no. 1, p. 64-73, https://doi.org/10.1111/j.1557-9263.2006.00086.x.","productDescription":"10 p.","startPage":"64","endPage":"73","onlineOnly":"N","additionalOnlineFiles":"N","costCenters":[{"id":114,"text":"Alaska Science Center","active":true,"usgs":true}],"links":[{"id":241495,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":213834,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1111/j.1557-9263.2006.00086.x"}],"volume":"78","issue":"1","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a71cce4b0c8380cd76778","contributors":{"authors":[{"text":"Gorman, Kristen B.","contributorId":42437,"corporation":false,"usgs":true,"family":"Gorman","given":"Kristen","email":"","middleInitial":"B.","affiliations":[],"preferred":false,"id":437800,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Flint, Paul L. 0000-0002-8758-6993 pflint@usgs.gov","orcid":"https://orcid.org/0000-0002-8758-6993","contributorId":3284,"corporation":false,"usgs":true,"family":"Flint","given":"Paul","email":"pflint@usgs.gov","middleInitial":"L.","affiliations":[{"id":117,"text":"Alaska Science Center Biology WTEB","active":true,"usgs":true},{"id":114,"text":"Alaska Science Center","active":true,"usgs":true}],"preferred":true,"id":437801,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Esler, Daniel 0000-0001-5501-4555 desler@usgs.gov","orcid":"https://orcid.org/0000-0001-5501-4555","contributorId":5465,"corporation":false,"usgs":true,"family":"Esler","given":"Daniel","email":"desler@usgs.gov","affiliations":[{"id":116,"text":"Alaska Science Center Biology MFEB","active":true,"usgs":true},{"id":12437,"text":"Simon Fraser University, Centre for Wildlife Ecology","active":true,"usgs":false},{"id":114,"text":"Alaska Science Center","active":true,"usgs":true}],"preferred":true,"id":437799,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Williams, T.D.","contributorId":53968,"corporation":false,"usgs":false,"family":"Williams","given":"T.D.","email":"","affiliations":[{"id":6953,"text":"Monterey Bay Aquarium","active":true,"usgs":false}],"preferred":false,"id":437802,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}} ,{"id":70032731,"text":"70032731 - 2007 - Subaqueous geology and a filling model for Crater Lake, Oregon","interactions":[],"lastModifiedDate":"2019-03-04T11:45:52","indexId":"70032731","displayToPublicDate":"2007-01-01T00:00:00","publicationYear":"2007","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1919,"text":"Hydrobiologia","onlineIssn":"1573-5117","printIssn":"0018-8158","active":true,"publicationSubtype":{"id":10}},"title":"Subaqueous geology and a filling model for Crater Lake, Oregon","docAbstract":"Results of a detailed bathymetric survey of Crater Lake conducted in 2000, combined with previous results of submersible and dredge sampling, form the basis for a geologic map of the lake floor and a model for the filling of Crater Lake with water. The most prominent landforms beneath the surface of Crater Lake are andesite volcanoes that were active as the lake was filling with water, following caldera collapse during the climactic eruption of Mount Mazama 7700 cal. yr B.P. The Wizard Island volcano is the largest and probably was active longest, ceasing eruptions when the lake was 80 m lower than present. East of Wizard Island is the central platform volcano and related lava flow fields on the caldera floor. Merriam Cone is a symmetrical andesitic volcano that apparently was constructed subaqueously during the same period as the Wizard Island and central platform volcanoes. The youngest postcaldera volcanic feature is a small rhyodacite dome on the east flank of the Wizard Island edifice that dates from 4800 cal. yr B.P. The bathymetry also yields information on bedrock outcrops and talus/debris slopes of the caldera walls. Gravity flows transport sediment from wall sources to the deep basins of the lake. Several debris-avalanche deposits, containing blocks up to 280 m long, are present on the caldera floor and occur below major embayments in the caldera walls. Geothermal phenomena on the lake floor are bacterial mats, pools of solute-rich warm water, and fossil subaqueous hot spring deposits. Lake level is maintained by a balance between precipitation and inflow versus evaporation and leakage. High-resolution bathymetry reveals a series of up to nine drowned beaches in the upper 30 m of the lake that we propose reflect stillstands subsequent to filling of Crater Lake. A prominent wave-cut platform between 4 m depth and present lake level that commonly is up to 40 m wide suggests that the surface of Crater Lake has been at this elevation for a very long time. Lake level apparently is limited by leakage through a permeable layer in the northeast caldera wall. The deepest drowned beach approximately corresponds to the base of the permeable layer. Among a group of lake filling models, our preferred one is constrained by the drowned beaches, the permeable layer in the caldera wall, and paleoclimatic data. We used a precipitation rate 70% of modern as a limiting case. Satisfactory models require leakage to be proportional to elevation and the best fit model has a linear combination of 45% leakage proportional to elevation and 55% of leakage proportional to elevation above the base of the permeable layer. At modern precipitation rates, the lake would have taken 420 yr to fill, or a maximum of 740 yr if precipitation was 70% of the modern value. The filling model provides a chronology for prehistoric passage zones on postcaldera volcanoes that ceased erupting before the lake was filled.
","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Hydrobiologia","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1007/s10750-006-0343-5","issn":"00188158","usgsCitation":"Nathenson, M., Bacon, C., and Ramsey, D., 2007, Subaqueous geology and a filling model for Crater Lake, Oregon: Hydrobiologia, v. 574, no. 1, p. 13-27, https://doi.org/10.1007/s10750-006-0343-5.","productDescription":"15 p.","startPage":"13","endPage":"27","numberOfPages":"15","costCenters":[{"id":615,"text":"Volcano Hazards Program","active":true,"usgs":true},{"id":617,"text":"Volcano Science Center","active":true,"usgs":true}],"links":[{"id":477074,"rank":10000,"type":{"id":41,"text":"Open Access External Repository Page"},"url":"https://zenodo.org/record/1232804","text":"External Repository"},{"id":241599,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":213925,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1007/s10750-006-0343-5"}],"volume":"574","issue":"1","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505b9cffe4b08c986b31d59f","contributors":{"authors":[{"text":"Nathenson, M.","contributorId":46632,"corporation":false,"usgs":true,"family":"Nathenson","given":"M.","email":"","affiliations":[],"preferred":false,"id":437663,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Bacon, C. R. 0000-0002-2165-5618","orcid":"https://orcid.org/0000-0002-2165-5618","contributorId":21522,"corporation":false,"usgs":true,"family":"Bacon","given":"C. R.","affiliations":[{"id":617,"text":"Volcano Science Center","active":true,"usgs":true}],"preferred":false,"id":437662,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Ramsey, D.W.","contributorId":95219,"corporation":false,"usgs":true,"family":"Ramsey","given":"D.W.","email":"","affiliations":[],"preferred":false,"id":437664,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70032730,"text":"70032730 - 2007 - Upper cretaceous microbial petroleum systems in north-central Montana","interactions":[],"lastModifiedDate":"2015-04-03T11:19:53","indexId":"70032730","displayToPublicDate":"2007-01-01T00:00:00","publicationYear":"2007","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2789,"text":"Mountain Geologist","active":true,"publicationSubtype":{"id":10}},"title":"Upper cretaceous microbial petroleum systems in north-central Montana","docAbstract":"Cenomanian to Campanian rocks of north-central Montana contain shallow economic accumulations of dry natural gas derived from microbial methanogenesis. The methanogens utilized carbon dioxide derived from organic matter in the marginal marine sediments and hydrogen from in situ pore water to generate methane. The most recent USGS assessment of the shallow gas resources of eastern Montana used a petroleum systems approach, identifying the critical components of a petroleum system (source rock, reservoir rock, seal rock, and trap) and their temporal relationships. As a part of this effort, geochemical data from natural gas wells and associated formation waters were used to identify two microbial gas systems and the timing of methanogenesis.
\nTwo microbial gas families are identified in north-central Montana based on stable carbon isotope and gas composition. The Montana Group gas family has heavier δ13C methane values, slightly lighter δD methane values, and a lower carbon dioxide and nitrogen content than the Colorado Group gas family. The two gas families may reflect, in part, the source rock depositional environments, with the Colorado Group rocks representing a more offshore marine depositional environment and the Montana Group rocks representing proximal marine, deltaic and nonmarine depositional environments. Assuming the gas families reflect only source rock characteristics, two microbial petroleum systems can be defined. The first petroleum system, called the Colorado Group microbial gas system, consists of Colorado Group rocks with the shales in the Belle Fourche Formation, Greenhorn Formation, and the Carlile Shale as the presumed source rocks and the interbedded Phillips and Bowdoin sandstones and the Greenhorn Formation limestones as reservoirs. The second petroleum system, called the Montana Group microbial gas system, consists of the Montana Group rocks that include the Gammon Shale and possibly the Claggett Shale as source rocks and the Eagle Sandstone and the Judith River Formation as reservoirs. The Niobrara Formation is tentatively placed in the former system. The geographic extent of the two microbial systems is much larger than the study area and includes an area at least from the Alberta basin to the northwest to the Powder River basin to the southeast. Upper Cretaceous microbial gas accumulations have been recognized along these basin margins at burial depths less than 3000 ft, but have not been recognized within the deeper parts of the basins because subsequent charge of thermogenic oil and gas masks the preexisting microbial gas accumulations.
\nMethanogenesis began soon after the deposition (early-stage methanogenesis) of the Cenomanian to Campanian source sediments, and was either sustained or rejuvenated by episodic meteoric water influx until sometime in the Paleogene. Methanogenesis probably continued until CO2 and hydrogen were depleted or the pore size was compacted to below tolerance levels of the methanogens. The composition of the Montana and Colorado Group gases and coproduced formation water precludes a scenario of late-stage methanogenesis like the Antrim gas system in the Michigan basin. Some portion of the methane charge was originally dissolved in the pore waters, and subsequent reduction in hydrostatic pressure caused the methane to exsolve and migrate into local stratigraphic and structural traps. The critical moment of the microbial gas systems is this timing of exsolution rather than the time of generation (methanogenesis). Other studies suggest that the reduction in hydrostatic pressure may have been caused by multiple geologic events including the lowering of sea level in the Late Cretaceous, and subsequent uplift and erosion events, the youngest of which began about 5 Ma.
","language":"English","publisher":"Rocky Mountain Association of Geologists","publisherLocation":"Denver, CO","usgsCitation":"Lillis, P.G., 2007, Upper cretaceous microbial petroleum systems in north-central Montana: Mountain Geologist, v. 44, no. 1, p. 11-35.","productDescription":"25 p.","startPage":"11","endPage":"35","numberOfPages":"25","onlineOnly":"N","additionalOnlineFiles":"N","costCenters":[{"id":164,"text":"Central Energy Resources Science Center","active":true,"usgs":true}],"links":[{"id":241566,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":299336,"rank":1,"type":{"id":15,"text":"Index Page"},"url":"https://archives.datapages.com/data/mountain-geologist-rmag/data/044/044001/11_rmag-mg440011.htm"}],"country":"United States","state":"Montana","geographicExtents":"{\n \"type\": \"FeatureCollection\",\n \"features\": [\n {\n \"type\": \"Feature\",\n \"properties\": {},\n \"geometry\": {\n \"type\": \"Polygon\",\n \"coordinates\": [\n [\n [\n -113.499755859375,\n 46.521075663842836\n ],\n [\n -113.499755859375,\n 49.009050809382046\n ],\n [\n -106.490478515625,\n 49.009050809382046\n ],\n [\n -106.490478515625,\n 46.521075663842836\n ],\n [\n -113.499755859375,\n 46.521075663842836\n ]\n ]\n ]\n }\n }\n ]\n}","volume":"44","issue":"1","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505bbd50e4b08c986b328f6d","contributors":{"authors":[{"text":"Lillis, Paul G. 0000-0002-7508-1699 plillis@usgs.gov","orcid":"https://orcid.org/0000-0002-7508-1699","contributorId":1817,"corporation":false,"usgs":true,"family":"Lillis","given":"Paul","email":"plillis@usgs.gov","middleInitial":"G.","affiliations":[{"id":164,"text":"Central Energy Resources Science Center","active":true,"usgs":true}],"preferred":true,"id":437661,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}} ,{"id":70032729,"text":"70032729 - 2007 - Heat transport in the Red Lake Bog, Glacial Lake Agassiz Peatlands","interactions":[],"lastModifiedDate":"2018-10-17T09:12:48","indexId":"70032729","displayToPublicDate":"2007-01-01T00:00:00","publicationYear":"2007","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1924,"text":"Hydrological Processes","active":true,"publicationSubtype":{"id":10}},"title":"Heat transport in the Red Lake Bog, Glacial Lake Agassiz Peatlands","docAbstract":"We report the results of an investigation on the processes controlling heat transport in peat under a large bog in the Glacial Lake Agassiz Peatlands. For 2 years, starting in July 1998, we recorded temperature at 12 depth intervals from 0 to 400 cm within a vertical peat profile at the crest of the bog at sub‐daily intervals. We also recorded air temperature 1 m above the peat surface. We calculate a peat thermal conductivity of 0·5 W m−1 °C−1 and model vertical heat transport through the peat using the SUTRA model. The model was calibrated to the first year of data, and then evaluated against the second year of collected heat data. The model results suggest that advective pore‐water flow is not necessary to transport heat within the peat profile and most of the heat is transferred by thermal conduction alone in these waterlogged soils. In the spring season, a zero‐curtain effect controls the transport of heat through shallow depths of the peat. Changes in local climate and the resulting changes in thermal transport still may cause non‐linear feedbacks in methane emissions related to the generation of methane deeper within the peat profile as regional temperatures increase.
","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Hydrological Processes","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","publisher":"John Wiley & Sons, Ltd. ","doi":"10.1002/hyp.6239","issn":"08856087","usgsCitation":"McKenzie, J., Siegel, D.I., Rosenberry, D.O., Glaser, P., and Voss, C.I., 2007, Heat transport in the Red Lake Bog, Glacial Lake Agassiz Peatlands: Hydrological Processes, v. 21, no. 3, p. 369-378, https://doi.org/10.1002/hyp.6239.","productDescription":"10 p.","startPage":"369","endPage":"378","costCenters":[{"id":589,"text":"Toxic Substances Hydrology Program","active":true,"usgs":true}],"links":[{"id":213865,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1002/hyp.6239"},{"id":241530,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"country":"United States","state":"Minnesota","otherGeospatial":"Glacial Lake Agassiz Peatlands","geographicExtents":"{\n \"type\": \"FeatureCollection\",\n \"features\": [\n {\n \"type\": \"Feature\",\n \"properties\": {},\n \"geometry\": {\n \"type\": \"Polygon\",\n \"coordinates\": [\n [\n [\n -95.6667,\n 48.065232067568\n ],\n [\n -95.6667,\n 48.73083222613515\n ],\n [\n -93.8232421875,\n 48.73083222613515\n ],\n [\n -93.8232421875,\n 48.065232067568\n ],\n [\n -95.6667,\n 48.065232067568\n ]\n ]\n ]\n }\n }\n ]\n}","volume":"21","issue":"3","noUsgsAuthors":false,"publicationDate":"2006-12-21","publicationStatus":"PW","scienceBaseUri":"505a3006e4b0c8380cd5d2e7","contributors":{"authors":[{"text":"McKenzie, J.M.","contributorId":75759,"corporation":false,"usgs":true,"family":"McKenzie","given":"J.M.","email":"","affiliations":[],"preferred":false,"id":437658,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Siegel, D. I.","contributorId":77562,"corporation":false,"usgs":true,"family":"Siegel","given":"D.","email":"","middleInitial":"I.","affiliations":[],"preferred":false,"id":437659,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Rosenberry, Donald O. 0000-0003-0681-5641 rosenber@usgs.gov","orcid":"https://orcid.org/0000-0003-0681-5641","contributorId":1312,"corporation":false,"usgs":true,"family":"Rosenberry","given":"Donald","email":"rosenber@usgs.gov","middleInitial":"O.","affiliations":[{"id":5044,"text":"National Research Program - Central Branch","active":true,"usgs":true},{"id":438,"text":"National Research Program - Western Branch","active":true,"usgs":true}],"preferred":true,"id":437657,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Glaser, P.H.","contributorId":13791,"corporation":false,"usgs":true,"family":"Glaser","given":"P.H.","email":"","affiliations":[],"preferred":false,"id":437656,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Voss, Clifford I. 0000-0001-5923-2752 cvoss@usgs.gov","orcid":"https://orcid.org/0000-0001-5923-2752","contributorId":1559,"corporation":false,"usgs":true,"family":"Voss","given":"Clifford","email":"cvoss@usgs.gov","middleInitial":"I.","affiliations":[{"id":438,"text":"National Research Program - Western Branch","active":true,"usgs":true}],"preferred":true,"id":437660,"contributorType":{"id":1,"text":"Authors"},"rank":5}]}} ,{"id":70032727,"text":"70032727 - 2007 - Hydrologic response of the Crow Wing Watershed, Minnesota, to mid-Holocene climate change","interactions":[],"lastModifiedDate":"2012-03-12T17:21:24","indexId":"70032727","displayToPublicDate":"2007-01-01T00:00:00","publicationYear":"2007","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1786,"text":"Geological Society of America Bulletin","active":true,"publicationSubtype":{"id":10}},"title":"Hydrologic response of the Crow Wing Watershed, Minnesota, to mid-Holocene climate change","docAbstract":"In this study, we have integrated a suite of Holocene paleoclimatic proxies with mathematical modeling in an attempt to obtain a comprehensive picture of how watersheds respond to past climate change. A three-dimensional surface-water-groundwater model was developed to assess the effects of mid-Holocene climate change on water resources within the Crow Wing Watershed, Upper Mississippi Basin in north central Minnesota. The model was first calibrated to a 50 yr historical record of average annual surface-water discharge, monthly groundwater levels, and lake-level fluctuations. The model was able to reproduce reasonably well long-term historical records (1949-1999) of water-table and lake-level fluctuations across the watershed as well as stream discharge near the watershed outlet. The calibrated model was then used to reproduce paleogroundwater and lake levels using climate reconstructions based on pollen-transfer functions from Williams Lake just outside the watershed. Computed declines in mid-Holocene lake levels for two lakes at opposite ends of the watershed were between 6 and 18 m. Simulated streamflow near the outlet of the watershed decreased to 70% of modern average annual discharge after ???200 yr. The area covered by wetlands for the entire watershed was reduced by ???16%. The mid-Holocene hydrologic changes indicated by these model results and corroborated by several lake-core records across the Crow Wing Watershed may serve as a useful proxy of the hydrologic response to future warm, dry climatic forecasts (ca. 2050) made by some atmospheric general-circulation models for the glaciated Midwestern United States. ?? 2007 Geological Society of America.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Geological Society of America Bulletin","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1130/B26003.1","issn":"00167606","usgsCitation":"Person, M., Roy, P., Wright, H., Gutowski, W., Ito, E., Winter, T., Rosenberry, D., and Cohen, D., 2007, Hydrologic response of the Crow Wing Watershed, Minnesota, to mid-Holocene climate change: Geological Society of America Bulletin, v. 119, no. 3-4, p. 363-376, https://doi.org/10.1130/B26003.1.","startPage":"363","endPage":"376","numberOfPages":"14","costCenters":[],"links":[{"id":477108,"rank":10000,"type":{"id":41,"text":"Open Access External Repository Page"},"url":"https://lib.dr.iastate.edu/ge_at_pubs/95","text":"External Repository"},{"id":241494,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":213833,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1130/B26003.1"}],"volume":"119","issue":"3-4","noUsgsAuthors":false,"publicationDate":"2007-03-15","publicationStatus":"PW","scienceBaseUri":"505a3686e4b0c8380cd607a0","contributors":{"authors":[{"text":"Person, M.","contributorId":20876,"corporation":false,"usgs":true,"family":"Person","given":"M.","email":"","affiliations":[],"preferred":false,"id":437645,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Roy, P.","contributorId":107109,"corporation":false,"usgs":true,"family":"Roy","given":"P.","email":"","affiliations":[],"preferred":false,"id":437650,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Wright, H.","contributorId":7083,"corporation":false,"usgs":true,"family":"Wright","given":"H.","email":"","affiliations":[],"preferred":false,"id":437644,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Gutowski, W. Jr.","contributorId":58850,"corporation":false,"usgs":true,"family":"Gutowski","given":"W.","suffix":"Jr.","affiliations":[],"preferred":false,"id":437648,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Ito, E.","contributorId":24956,"corporation":false,"usgs":true,"family":"Ito","given":"E.","email":"","affiliations":[],"preferred":false,"id":437646,"contributorType":{"id":1,"text":"Authors"},"rank":5},{"text":"Winter, T.","contributorId":89333,"corporation":false,"usgs":true,"family":"Winter","given":"T.","affiliations":[],"preferred":false,"id":437649,"contributorType":{"id":1,"text":"Authors"},"rank":6},{"text":"Rosenberry, D.","contributorId":39338,"corporation":false,"usgs":true,"family":"Rosenberry","given":"D.","email":"","affiliations":[],"preferred":false,"id":437647,"contributorType":{"id":1,"text":"Authors"},"rank":7},{"text":"Cohen, D.","contributorId":108299,"corporation":false,"usgs":true,"family":"Cohen","given":"D.","email":"","affiliations":[],"preferred":false,"id":437651,"contributorType":{"id":1,"text":"Authors"},"rank":8}]}} ,{"id":70032209,"text":"70032209 - 2007 - Effects of upland disturbance and instream restoration on hydrodynamics and ammonium uptake in headwater streams","interactions":[],"lastModifiedDate":"2012-03-12T17:21:56","indexId":"70032209","displayToPublicDate":"2007-01-01T00:00:00","publicationYear":"2007","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2564,"text":"Journal of the North American Benthological Society","onlineIssn":"1937-237X","printIssn":"0887-3593","active":true,"publicationSubtype":{"id":10}},"title":"Effects of upland disturbance and instream restoration on hydrodynamics and ammonium uptake in headwater streams","docAbstract":"Delivery of water, sediments, nutrients, and organic matter to stream ecosystems is strongly influenced by the catchment of the stream and can be altered greatly by upland soil and vegetation disturbance. At the Fort Benning Military Installation (near Columbus, Georgia), spatial variability in intensity of military training results in a wide range of intensities of upland disturbance in stream catchments. A set of 8 streams in catchments spanning this upland disturbance gradient was selected for investigation of the impact of disturbance intensity on hydrodynamics and nutrient uptake. The size of transient storage zones and rates of NH4+ uptake in all study streams were among the lowest reported in the literature. Upland disturbance did not appear to influence stream hydrodynamics strongly, but it caused significant decreases in instream nutrient uptake. In October 2003, coarse woody debris (CWD) was added to 1/2 of the study streams (spanning the disturbance gradient) in an attempt to increase hydrodynamic and structural complexity, with the goals of enhancing biotic habitat and increasing nutrient uptake rates. CWD additions had positive short-term (within 1 mo) effects on hydrodynamic complexity (water velocity decreased and transient storage zone cross-sectional area, relative size of the transient storage zone, fraction of the median travel time attributable to transient storage over a standardized length of 200 m, and the hydraulic retention factor increased) and nutrient uptake (NH4+ uptake rates increased). Our results suggest that water quality in streams with intense upland disturbances can be improved by enhancing instream biotic nutrient uptake capacity through measures such as restoring stream CWD. ?? 2007 by The North American Benthological Society.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Journal of the North American Benthological Society","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1899/0887-3593(2007)26[38:EOUDAI]2.0.CO;2","issn":"08873593","usgsCitation":"Roberts, B., Mulholland, P.J., and Houser, J., 2007, Effects of upland disturbance and instream restoration on hydrodynamics and ammonium uptake in headwater streams: Journal of the North American Benthological Society, v. 26, no. 1, p. 38-53, https://doi.org/10.1899/0887-3593(2007)26[38:EOUDAI]2.0.CO;2.","startPage":"38","endPage":"53","numberOfPages":"16","costCenters":[],"links":[{"id":215067,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1899/0887-3593(2007)26[38:EOUDAI]2.0.CO;2"},{"id":242836,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"26","issue":"1","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a081ce4b0c8380cd519a7","contributors":{"authors":[{"text":"Roberts, B.J.","contributorId":35144,"corporation":false,"usgs":true,"family":"Roberts","given":"B.J.","affiliations":[],"preferred":false,"id":435043,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Mulholland, P. J.","contributorId":89081,"corporation":false,"usgs":false,"family":"Mulholland","given":"P.","email":"","middleInitial":"J.","affiliations":[],"preferred":false,"id":435044,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Houser, J.N.","contributorId":91603,"corporation":false,"usgs":true,"family":"Houser","given":"J.N.","email":"","affiliations":[],"preferred":false,"id":435045,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70032206,"text":"70032206 - 2007 - Relating low‐flow characteristics to the base flow recession time constant at partial record stream gauges","interactions":[],"lastModifiedDate":"2018-04-03T12:03:15","indexId":"70032206","displayToPublicDate":"2007-01-01T00:00:00","publicationYear":"2007","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":3722,"text":"Water Resources Research","onlineIssn":"1944-7973","printIssn":"0043-1397","active":true,"publicationSubtype":{"id":10}},"title":"Relating low‐flow characteristics to the base flow recession time constant at partial record stream gauges","docAbstract":"Base flow recession information is helpful for regional estimation of low‐flow characteristics. However, analyses that exploit such information generally require a continuous record of streamflow at the estimation site to characterize base flow recession. Here we propose a simple method for characterizing base flow recession at low‐flow partial record stream gauges (i.e., sites with very few streamflow measurements under low‐streamflow conditions), and we use that characterization as the basis for a practical new approach to low‐flow regression. In a case study the introduction of a base flow recession time constant, estimated from a single pair of strategically timed streamflow measurements, approximately halves the root‐mean‐square estimation error relative to that of a conventional drainage area regression. Additional streamflow measurements can be used to reduce the error further.
","language":"English","publisher":"American Geophysical Union","doi":"10.1029/2006WR005293","usgsCitation":"Eng, K., and Milly, P., 2007, Relating low‐flow characteristics to the base flow recession time constant at partial record stream gauges: Water Resources Research, v. 43, no. 1, Article W01201; 8 p., https://doi.org/10.1029/2006WR005293.","productDescription":"Article W01201; 8 p.","costCenters":[],"links":[{"id":477172,"rank":1,"type":{"id":40,"text":"Open Access Publisher Index Page"},"url":"https://doi.org/10.1029/2006wr005293","text":"Publisher Index Page"},{"id":242774,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"43","issue":"1","noUsgsAuthors":false,"publicationDate":"2007-01-05","publicationStatus":"PW","scienceBaseUri":"50e4a626e4b0e8fec6cdc0e3","contributors":{"authors":[{"text":"Eng, Ken 0000-0001-6838-5849 keng@usgs.gov","orcid":"https://orcid.org/0000-0001-6838-5849","contributorId":3580,"corporation":false,"usgs":true,"family":"Eng","given":"Ken","email":"keng@usgs.gov","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":435031,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Milly, P. C. D.","contributorId":100489,"corporation":false,"usgs":true,"family":"Milly","given":"P. C. D.","affiliations":[],"preferred":false,"id":435032,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70032182,"text":"70032182 - 2007 - Variability of kokanee and rainbow trout food habits, distribution, and population dynamics, in an ultraoligotrophic lake with no manipulative management","interactions":[],"lastModifiedDate":"2017-11-15T09:53:25","indexId":"70032182","displayToPublicDate":"2007-01-01T00:00:00","publicationYear":"2007","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1919,"text":"Hydrobiologia","onlineIssn":"1573-5117","printIssn":"0018-8158","active":true,"publicationSubtype":{"id":10}},"title":"Variability of kokanee and rainbow trout food habits, distribution, and population dynamics, in an ultraoligotrophic lake with no manipulative management","docAbstract":"Crater Lake is a unique environment to evaluate the ecology of introduced kokanee and rainbow trout because of its otherwise pristine state, low productivity, absence of manipulative management, and lack of lotic systems for fish spawning. Between 1986 and 2004, kokanee displayed a great deal of variation in population demographics with a pattern that reoccurred in about 10 years. We believe that the reoccurring pattern resulted from density dependent growth, and associated changes in reproduction and abundance, driven by prey resource limitation that resulted from low lake productivity exacerbated by prey consumption when kokanee were abundant. Kokanee fed primarily on small-bodied prey from the mid-water column; whereas rainbow trout fed on large-bodied prey from the benthos and lake surface. Cladoceran zooplankton abundance may be regulated by kokanee. And kokanee growth and reproductive success may be influenced by the availability of Daphnia pulicaria, which was absent in zooplankton samples collected annually from 1990 to 1995, and after 1999. Distribution and diel migration of kokanee varied over the duration of the study and appeared to be most closely associated with prey availability, maximization of bioenergetic efficiency, and fish density. Rainbow trout were less abundant than were kokanee and exhibited less variation in population demographics, distribution, and food habits. There is some evidence that the population dynamics of rainbow trout were in-part related to the availability of kokanee as prey. ?? 2007 Springer Science+Business Media B.V.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Hydrobiologia","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1007/s10750-006-0355-1","issn":"00188158","usgsCitation":"Buktenica, M., Girdner, S., Larson, G., and McIntire, C.D., 2007, Variability of kokanee and rainbow trout food habits, distribution, and population dynamics, in an ultraoligotrophic lake with no manipulative management: Hydrobiologia, v. 574, no. 1, p. 235-264, https://doi.org/10.1007/s10750-006-0355-1.","startPage":"235","endPage":"264","numberOfPages":"30","costCenters":[{"id":290,"text":"Forest and Rangeland Ecosystem Science Center","active":false,"usgs":true}],"links":[{"id":242404,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":214660,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1007/s10750-006-0355-1"}],"volume":"574","issue":"1","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505bc139e4b08c986b32a4b7","contributors":{"authors":[{"text":"Buktenica, M.W.","contributorId":68263,"corporation":false,"usgs":true,"family":"Buktenica","given":"M.W.","affiliations":[],"preferred":false,"id":434908,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Girdner, S.F.","contributorId":71773,"corporation":false,"usgs":true,"family":"Girdner","given":"S.F.","affiliations":[],"preferred":false,"id":434909,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Larson, G.L.","contributorId":103021,"corporation":false,"usgs":true,"family":"Larson","given":"G.L.","email":"","affiliations":[],"preferred":false,"id":434910,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"McIntire, C. D.","contributorId":35274,"corporation":false,"usgs":false,"family":"McIntire","given":"C.","email":"","middleInitial":"D.","affiliations":[],"preferred":false,"id":434907,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}} ,{"id":70032179,"text":"70032179 - 2007 - Aquifer-scale controls on the distribution of nitrate and ammonium in ground water near La Pine, Oregon, USA","interactions":[],"lastModifiedDate":"2023-10-03T11:25:27.364711","indexId":"70032179","displayToPublicDate":"2007-01-01T00:00:00","publicationYear":"2007","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2342,"text":"Journal of Hydrology","active":true,"publicationSubtype":{"id":10}},"title":"Aquifer-scale controls on the distribution of nitrate and ammonium in ground water near La Pine, Oregon, USA","docAbstract":"Geochemical and isotopic tools were applied at aquifer, transect, and subtransect scales to provide a framework for understanding sources, transport, and fate of dissolved inorganic N in a sandy aquifer near La Pine, Oregon. NO3 is a common contaminant in shallow ground water in this area, whereas high concentrations of NH4-N (up to 39 mg/L) are present in deep ground water. N concentrations, N/Cl ratios, tracer-based apparent ground-water ages, N isotope data, and hydraulic gradients indicate that septic tank effluent is the primary source of NO3. N isotope data, N/Cl and N/C relations, 3H data, and hydraulic considerations point to a natural, sedimentary organic matter source for the high concentrations of NH4, and are inconsistent with an origin as septic tank N. Low recharge rates and flow velocities have largely restricted anthropogenic NO3 to isolated plumes within several meters of the water table. A variety of geochemical and isotopic data indicate that denitrification also affects NO3 gradients in the aquifer. Ground water in the La Pine aquifer evolves from oxic to increasingly reduced conditions. Suboxic conditions are achieved after about 15-30 y of transport below the water table. NO3 is denitrified near the oxic/suboxic boundary. Denitrification in the La Pine aquifer is characterized well at the aquifer scale with a redox boundary approach that inherently captures spatial variability in the distribution of electron donors.
","language":"English","publisher":"Elsevier","doi":"10.1016/j.jhydrol.2006.09.013","issn":"00221694","usgsCitation":"Hinkle, S.R., Bohlke, J.K., Duff, J.H., Morgan, D.S., and Weick, R.J., 2007, Aquifer-scale controls on the distribution of nitrate and ammonium in ground water near La Pine, Oregon, USA: Journal of Hydrology, v. 333, no. 2-4, p. 486-503, https://doi.org/10.1016/j.jhydrol.2006.09.013.","productDescription":"18 p.","startPage":"486","endPage":"503","numberOfPages":"18","costCenters":[{"id":589,"text":"Toxic Substances Hydrology Program","active":true,"usgs":true}],"links":[{"id":242337,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"country":"United States","state":"Oregon","city":"La Pine","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -121.75,43.5 ], [ -121.75,44 ], [ -121.33333333333333,44 ], [ -121.33333333333333,43.5 ], [ -121.75,43.5 ] ] ] } } ] }","volume":"333","issue":"2-4","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"5059ed25e4b0c8380cd4965e","contributors":{"authors":[{"text":"Hinkle, Stephen R. srhinkle@usgs.gov","contributorId":1171,"corporation":false,"usgs":true,"family":"Hinkle","given":"Stephen","email":"srhinkle@usgs.gov","middleInitial":"R.","affiliations":[{"id":518,"text":"Oregon Water Science Center","active":true,"usgs":true}],"preferred":true,"id":434887,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Bohlke, John Karl 0000-0001-5693-6455 jkbohlke@usgs.gov","orcid":"https://orcid.org/0000-0001-5693-6455","contributorId":127841,"corporation":false,"usgs":true,"family":"Bohlke","given":"John","email":"jkbohlke@usgs.gov","middleInitial":"Karl","affiliations":[{"id":436,"text":"National Research Program - Eastern Branch","active":true,"usgs":true}],"preferred":false,"id":434888,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Duff, John H. jhduff@usgs.gov","contributorId":961,"corporation":false,"usgs":true,"family":"Duff","given":"John","email":"jhduff@usgs.gov","middleInitial":"H.","affiliations":[{"id":438,"text":"National Research Program - Western Branch","active":true,"usgs":true},{"id":154,"text":"California Water Science Center","active":true,"usgs":true}],"preferred":true,"id":434886,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Morgan, David S.","contributorId":73181,"corporation":false,"usgs":true,"family":"Morgan","given":"David","email":"","middleInitial":"S.","affiliations":[],"preferred":false,"id":434885,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Weick, Rodney J.","contributorId":79560,"corporation":false,"usgs":true,"family":"Weick","given":"Rodney","email":"","middleInitial":"J.","affiliations":[],"preferred":false,"id":434889,"contributorType":{"id":1,"text":"Authors"},"rank":5}]}} ,{"id":70032178,"text":"70032178 - 2007 - S-33 constraints on the seawater sulfate contribution in modern seafloor hydrothermal vent sulfides","interactions":[],"lastModifiedDate":"2012-03-12T17:21:25","indexId":"70032178","displayToPublicDate":"2007-01-01T00:00:00","publicationYear":"2007","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1759,"text":"Geochimica et Cosmochimica Acta","active":true,"publicationSubtype":{"id":10}},"title":"S-33 constraints on the seawater sulfate contribution in modern seafloor hydrothermal vent sulfides","docAbstract":"Sulfide sulfur in mid-oceanic ridge hydrothermal vents is derived from leaching of basaltic-sulfide and seawater-derived sulfate that is reduced during high temperature water rock interaction. Conventional sulfur isotope studies, however, are inconclusive about the mass-balance between the two sources because 34S/32S ratios of vent fluid H2S and chimney sulfide minerals may reflect not only the mixing ratio but also isotope exchange between sulfate and sulfide. Here, we show that high-precision analysis of S-33 can provide a unique constraint because isotope mixing and isotope exchange result in different ??33S (?????33S-0.515 ??34S) values of up to 0.04??? even if ??34S values are identical. Detection of such small ??33S differences is technically feasible by using the SF6 dual-inlet mass-spectrometry protocol that has been improved to achieve a precision as good as 0.006??? (2??). Sulfide minerals (marcasite, pyrite, chalcopyrite, and sphalerite) and vent H2S collected from four active seafloor hydrothermal vent sites, East Pacific Rise (EPR) 9-10??N, 13??N, and 21??S and Mid-Atlantic Ridge (MAR) 37??N yield ??33S values ranging from -0.002 to 0.033 and ??34S from -0.5??? to 5.3???. The combined ??34S and ??33S systematics reveal that 73 to 89% of vent sulfides are derived from leaching from basaltic sulfide and only 11 to 27% from seawater-derived sulfate. Pyrite from EPR 13??N and marcasite from MAR 37??N are in isotope disequilibrium not only in ??34S but also in ??33S with respect to associated sphalerite and chalcopyrite, suggesting non-equilibrium sulfur isotope exchange between seawater sulfate and sulfide during pyrite precipitation. Seafloor hydrothermal vent sulfides are characterized by low ??33S values compared with biogenic sulfides, suggesting little or no contribution of sulfide from microbial sulfate reduction into hydrothermal sulfides at sediment-free mid-oceanic ridge systems. We conclude that 33S is an effective new tracer for interplay among seawater, oceanic crust and microbes in subseafloor hydrothermal sulfur cycles. ?? 2006 Elsevier Inc. All rights reserved.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Geochimica et Cosmochimica Acta","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1016/j.gca.2006.11.017","issn":"00167037","usgsCitation":"Ono, S., Shanks, W.C., Rouxel, O., and Rumble, D., 2007, S-33 constraints on the seawater sulfate contribution in modern seafloor hydrothermal vent sulfides: Geochimica et Cosmochimica Acta, v. 71, no. 5, p. 1170-1182, https://doi.org/10.1016/j.gca.2006.11.017.","startPage":"1170","endPage":"1182","numberOfPages":"13","costCenters":[],"links":[{"id":476960,"rank":10000,"type":{"id":41,"text":"Open Access External Repository Page"},"url":"https://hdl.handle.net/1912/1594","text":"External Repository"},{"id":214596,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/j.gca.2006.11.017"},{"id":242336,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"71","issue":"5","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505aaee8e4b0c8380cd872a5","contributors":{"authors":[{"text":"Ono, Shuhei","contributorId":100627,"corporation":false,"usgs":false,"family":"Ono","given":"Shuhei","email":"","affiliations":[{"id":13295,"text":"1Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139,","active":true,"usgs":false}],"preferred":false,"id":434884,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Shanks, Wayne C. III","contributorId":100527,"corporation":false,"usgs":true,"family":"Shanks","given":"Wayne","suffix":"III","email":"","middleInitial":"C.","affiliations":[],"preferred":false,"id":434883,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Rouxel, O.J.","contributorId":32001,"corporation":false,"usgs":true,"family":"Rouxel","given":"O.J.","email":"","affiliations":[],"preferred":false,"id":434881,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Rumble, D.","contributorId":80095,"corporation":false,"usgs":true,"family":"Rumble","given":"D.","affiliations":[],"preferred":false,"id":434882,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}} ,{"id":70032177,"text":"70032177 - 2007 - Suboxic deep seawater in the late Paleoproterozoic: Evidence from hematitic chert and iron formation related to seafloor-hydrothermal sulfide deposits, central Arizona, USA","interactions":[],"lastModifiedDate":"2012-03-12T17:21:56","indexId":"70032177","displayToPublicDate":"2007-01-01T00:00:00","publicationYear":"2007","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1427,"text":"Earth and Planetary Science Letters","active":true,"publicationSubtype":{"id":10}},"title":"Suboxic deep seawater in the late Paleoproterozoic: Evidence from hematitic chert and iron formation related to seafloor-hydrothermal sulfide deposits, central Arizona, USA","docAbstract":"A current model for the evolution of Proterozoic deep seawater composition involves a change from anoxic sulfide-free to sulfidic conditions 1.8??Ga. In an earlier model the deep ocean became oxic at that time. Both models are based on the secular distribution of banded iron formation (BIF) in shallow marine sequences. We here present a new model based on rare earth elements, especially redox-sensitive Ce, in hydrothermal silica-iron oxide sediments from deeper-water, open-marine settings related to volcanogenic massive sulfide (VMS) deposits. In contrast to Archean, Paleozoic, and modern hydrothermal iron oxide sediments, 1.74 to 1.71??Ga hematitic chert (jasper) and iron formation in central Arizona, USA, show moderate positive to small negative Ce anomalies, suggesting that the redox state of the deep ocean then was at a transitional, suboxic state with low concentrations of dissolved O2 but no H2S. The presence of jasper and/or iron formation related to VMS deposits in other volcanosedimentary sequences ca. 1.79-1.69??Ga, 1.40??Ga, and 1.24??Ga also reflects oxygenated and not sulfidic deep ocean waters during these time periods. Suboxic conditions in the deep ocean are consistent with the lack of shallow-marine BIF ??? 1.8 to 0.8??Ga, and likely limited nutrient concentrations in seawater and, consequently, may have constrained biological evolution. ?? 2006 Elsevier B.V. All rights reserved.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Earth and Planetary Science Letters","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1016/j.epsl.2006.12.018","issn":"0012821X","usgsCitation":"Slack, J.F., Grenne, T., Bekker, A., Rouxel, O., and Lindberg, P.A., 2007, Suboxic deep seawater in the late Paleoproterozoic: Evidence from hematitic chert and iron formation related to seafloor-hydrothermal sulfide deposits, central Arizona, USA: Earth and Planetary Science Letters, v. 255, no. 1-2, p. 243-256, https://doi.org/10.1016/j.epsl.2006.12.018.","startPage":"243","endPage":"256","numberOfPages":"14","costCenters":[],"links":[{"id":215066,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/j.epsl.2006.12.018"},{"id":242835,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"255","issue":"1-2","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505b9d45e4b08c986b31d740","contributors":{"authors":[{"text":"Slack, J. F.","contributorId":75917,"corporation":false,"usgs":true,"family":"Slack","given":"J.","email":"","middleInitial":"F.","affiliations":[],"preferred":false,"id":434879,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Grenne, Tor","contributorId":7460,"corporation":false,"usgs":false,"family":"Grenne","given":"Tor","email":"","affiliations":[{"id":35509,"text":"Geological Survey of Norway","active":true,"usgs":false}],"preferred":false,"id":434876,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Bekker, A.","contributorId":9480,"corporation":false,"usgs":true,"family":"Bekker","given":"A.","email":"","affiliations":[],"preferred":false,"id":434877,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Rouxel, O.J.","contributorId":32001,"corporation":false,"usgs":true,"family":"Rouxel","given":"O.J.","email":"","affiliations":[],"preferred":false,"id":434878,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Lindberg, P. A.","contributorId":79189,"corporation":false,"usgs":true,"family":"Lindberg","given":"P.","email":"","middleInitial":"A.","affiliations":[],"preferred":false,"id":434880,"contributorType":{"id":1,"text":"Authors"},"rank":5}]}} ,{"id":70032174,"text":"70032174 - 2007 - Denitrification in the shallow ground water of a tile-drained, agricultural watershed","interactions":[],"lastModifiedDate":"2012-03-12T17:21:27","indexId":"70032174","displayToPublicDate":"2007-01-01T00:00:00","publicationYear":"2007","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2262,"text":"Journal of Environmental Quality","active":true,"publicationSubtype":{"id":10}},"title":"Denitrification in the shallow ground water of a tile-drained, agricultural watershed","docAbstract":"Nonpoint-source pollution of surface water by N is considered a major cause of hypoxia. Because Corn Belt watersheds have been identified as major sources of N in the Mississippi River basin, the fate and transport of N from midwestern agricultural watersheds have received considerable interest. The fate and transport of N in the shallow ground water of these watersheds still needs additional research. Our purpose was to estimate denitrification in the shallow ground water of a tile-drained, Corn Belt watershed with fine-grained soils. Over a 3-yr period, N was monitored in the surface and ground water of an agricultural watershed in central Illinois. A significant amount of N was transported past the tile drains and into shallow ground water. The ground water nitrate was isotopically heavier than tile drain nitrate, which can be explained by denitrification in the subsurface. Denitrifying bacteria were found at depths to 10 m throughout the watershed. Laboratory and push-pull tests showed that a significant fraction of nitrate could be denitrified rapidly. We estimated that the N denitrified in shallow ground water was equivalent to 0.3 to 6.4% of the applied N or 9 to 27% of N exported via surface water. These estimates varied by water year and peaked in a year of normal precipitation after 2 yr of below average precipitation. Three years of monitoring data indicate that shallow ground water in watersheds with fine-grained soils may be a significant N sink compared with N exported via surface water. ?? ASA, CSSA, SSSA.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Journal of Environmental Quality","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.2134/jeq2006.0096","issn":"00472425","usgsCitation":"Mehnert, E., Hwang, H., Johnson, T., Sanford, R., Beaumont, W., and Holm, T., 2007, Denitrification in the shallow ground water of a tile-drained, agricultural watershed: Journal of Environmental Quality, v. 36, no. 1, p. 80-90, https://doi.org/10.2134/jeq2006.0096.","startPage":"80","endPage":"90","numberOfPages":"11","costCenters":[],"links":[{"id":242800,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":215033,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.2134/jeq2006.0096"}],"volume":"36","issue":"1","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"5059fe9be4b0c8380cd4ee14","contributors":{"authors":[{"text":"Mehnert, E.","contributorId":64830,"corporation":false,"usgs":true,"family":"Mehnert","given":"E.","email":"","affiliations":[],"preferred":false,"id":434868,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Hwang, H.-H.","contributorId":6981,"corporation":false,"usgs":true,"family":"Hwang","given":"H.-H.","email":"","affiliations":[],"preferred":false,"id":434865,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Johnson, T.M.","contributorId":22332,"corporation":false,"usgs":true,"family":"Johnson","given":"T.M.","affiliations":[],"preferred":false,"id":434866,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Sanford, R.A.","contributorId":6722,"corporation":false,"usgs":true,"family":"Sanford","given":"R.A.","email":"","affiliations":[],"preferred":false,"id":434864,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Beaumont, W.C.","contributorId":38026,"corporation":false,"usgs":true,"family":"Beaumont","given":"W.C.","email":"","affiliations":[],"preferred":false,"id":434867,"contributorType":{"id":1,"text":"Authors"},"rank":5},{"text":"Holm, T.R.","contributorId":98543,"corporation":false,"usgs":true,"family":"Holm","given":"T.R.","email":"","affiliations":[],"preferred":false,"id":434869,"contributorType":{"id":1,"text":"Authors"},"rank":6}]}} ,{"id":70032145,"text":"70032145 - 2007 - Comparison of evapotranspiration rates for flatwoods and ridge citrus","interactions":[],"lastModifiedDate":"2012-03-12T17:21:25","indexId":"70032145","displayToPublicDate":"2007-01-01T00:00:00","publicationYear":"2007","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":3619,"text":"Transactions of the ASABE","active":true,"publicationSubtype":{"id":10}},"title":"Comparison of evapotranspiration rates for flatwoods and ridge citrus","docAbstract":"Florida citrus groves are typically grown in two regions of the state: flatwoods and ridge. The southern flatwoods citrus area has poorly drained fine textured sands with low organic matter in the shallow root zone. Ridge citrus is located in the northern ridge citrus zone and has fine to coarse textured sands with low water-holding capacity. Two commercial citrus groves, selected from each region, were studied from 15 July 2004 to 14 July 2005. The flatwoods citrus (FC) grove had a grass cover and used drainage ditches to remove excess water from the root zone. The ridge citrus (RC) grove had a bare soil surface with weeds periodically eliminated by tillage. Citrus crop evapotranspiration (ETc) rates at the two citrus groves were measured by the eddy correlation method, and components in the energy balance were also examined and compared. The study period had higher than average rainfall, and as a result, the two locations had similar annual ETc rates (1069 and 1044 mm for RC and FC, respectively). The ETc rates were 59% (RC) and 47% (FC) of the rainfall amounts during the study period. The annual reference crop evapotranspiration (ETo) rates were 1180 mm for RC and 1419 mm for FC, estimated using the standardized reference evapotranspiration equation. The citrus crop coefficients (Kc, ratio of ETc to ET o) were different between the two locations because of differences in latitude, ground cover, and rainfall amounts. The Kc values ranged from 0.70 between December and March to 1.05 between July and November for RC, and from 0.65 between November and May to 0.85 between June and October for FC. The results are consistent with other Kc values reported from field studies on citrus in both Florida and elsewhere using these and alternate methods.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Transactions of the ASABE","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","issn":"00012351","usgsCitation":"Jia, X., Swancar, A., Jacobs, J., Dukes, M., and Morgan, K., 2007, Comparison of evapotranspiration rates for flatwoods and ridge citrus: Transactions of the ASABE, v. 50, no. 1, p. 83-94.","startPage":"83","endPage":"94","numberOfPages":"12","costCenters":[],"links":[{"id":242334,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"50","issue":"1","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"5059f862e4b0c8380cd4d07b","contributors":{"authors":[{"text":"Jia, X.","contributorId":96911,"corporation":false,"usgs":true,"family":"Jia","given":"X.","email":"","affiliations":[],"preferred":false,"id":434721,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Swancar, A.","contributorId":43585,"corporation":false,"usgs":true,"family":"Swancar","given":"A.","affiliations":[],"preferred":false,"id":434719,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Jacobs, J.M.","contributorId":10446,"corporation":false,"usgs":true,"family":"Jacobs","given":"J.M.","email":"","affiliations":[],"preferred":false,"id":434717,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Dukes, M.D.","contributorId":89365,"corporation":false,"usgs":true,"family":"Dukes","given":"M.D.","email":"","affiliations":[],"preferred":false,"id":434720,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Morgan, K.","contributorId":18556,"corporation":false,"usgs":true,"family":"Morgan","given":"K.","affiliations":[],"preferred":false,"id":434718,"contributorType":{"id":1,"text":"Authors"},"rank":5}]}} ]}