Models of continental crustal magmagenesis commonly invoke the interaction of mafic mantle-derived magma and continental crust to explain geochemical and petrologic characteristics of crustal volcanic and plutonic rocks. This interaction and the specific mechanisms of crustal contamination associated with it are poorly understood. An excellent opportunity to study the progressive effects of crustal contamination is offered by the composite plutons of the Alaska Range, a series of nine early Tertiary, multiply intruded, compositionally zoned (Peridotite to granite) plutons. Large initial Sr and Nd isotopic contrasts between the crustal country rock and likely parental magmas allow evaluation of the mechanisms and extents of crustal contamination that accompanied the crystallization of these ultra-mafic through granitic rocks. Three contamination processes are distinguished in these plutons. The most obvious of these is assimilation of crustal country rock concurrent with magmatic fractional crystallization (AFC), as indicated by a general trend toward crustal-like isotopic signatures with increasing differentiation. Second, many ultramafic and mafic rocks have late-stage phenocryst reaction and orthocumulate textures that suggest interaction with felsic melt. These rocks also have variable and enriched isotopic compositions that suggest that this felsic melt was isotopically enriched and probably derived from crustal country rock. Partial melt from the flysch country rock may have reacted with and contaminated these partly crystalline magmas following the precipitation and accumulation of the cumulus phenocrysts but before complete solidification of the magma. This suggests that in magmatic mush (especially of ultramafic composition) crystallizing in continental crust, a second distinct process of crustal contamination may be super imposed on AFC or magma mixing involving the main magma body. Finally, nearly all rocks, including mafic and ultramafic rocks, have (87Sr/86Sr)i that are too high, and ε(T) Nd that are too low, to represent the expected isotopic composition of typical depleted mantle. However, gabbro xenoliths with typical depicted-mantle isotopic compositions are found in the plutons. This situation requires either an additional enriched mantle component to provide the parental magma for these plutons, or some mechanism of crustal contamination of the parent magma that did not cause significant crystallization and differentiation of the magma to more felsic compositions. Thermodynamic modeling indicates that assimilation of alkali-and water-rich partial melt of the metapelite country rock by fractionating, near-liquidus basaltic magma could cause significant contamination while suppressing significant crystallization and differentiation.
","language":"English","publisher":"Oxford Academic","doi":"10.1093/petrology/37.2.261","issn":"00223530","usgsCitation":"Reiners, P., Nelson, B., and Nelson, S., 1996, Evidence for multiple mechanisms of crustal contamination of magma from compositionally zoned plutons and associated ultramafic intrusions of the Alaska Range: Journal of Petrology, v. 37, no. 2, p. 261-292, https://doi.org/10.1093/petrology/37.2.261.","productDescription":"32 p.","startPage":"261","endPage":"292","numberOfPages":"32","costCenters":[],"links":[{"id":227426,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"37","issue":"2","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a0d4ce4b0c8380cd52f23","contributors":{"authors":[{"text":"Reiners, P.W.","contributorId":34241,"corporation":false,"usgs":true,"family":"Reiners","given":"P.W.","email":"","affiliations":[],"preferred":false,"id":379720,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Nelson, B.K.","contributorId":85344,"corporation":false,"usgs":true,"family":"Nelson","given":"B.K.","email":"","affiliations":[],"preferred":false,"id":379722,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Nelson, S.W.","contributorId":67869,"corporation":false,"usgs":true,"family":"Nelson","given":"S.W.","email":"","affiliations":[],"preferred":false,"id":379721,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70018472,"text":"70018472 - 1996 - Depositional controls on coal distribution and quality in the Eocene Brunner Coal Measures, Buller Coalfield, South Island, New Zealand","interactions":[],"lastModifiedDate":"2012-03-12T17:19:24","indexId":"70018472","displayToPublicDate":"1996-01-01T00:00:00","publicationYear":"1996","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2033,"text":"International Journal of Coal Geology","active":true,"publicationSubtype":{"id":10}},"title":"Depositional controls on coal distribution and quality in the Eocene Brunner Coal Measures, Buller Coalfield, South Island, New Zealand","docAbstract":"The Buller Coalfield on the West Coast of the South Island, New Zealand, contains the Eocene Brunner Coal Measures. The coal measures unconformably overlie Paleozoic-Cretaceous basement rocks and are conformably overlain by, and laterally interfinger with, the Eocene marine Kaiata Formation. This study examines the lithofacies frameworks of the coal measures in order to interpret their depositional environments. The lower part of the coal measures is dominated by conglomeratic lithofacies that rest on a basal erosional surface and thicken in paleovalleys incised into an undulating peneplain surface. These lithofacies are overlain by sandstone, mudstone and organic-rich lithofacies of the upper part of the coal measures. The main coal seam of the organic-rich lithofacies is thick (10-20 m), extensive, locally split, and locally absent. This seam and associated coal seams in the Buller Coalfield are of low- to high-volatile bituminous rank (vitrinite reflectance between 0.65% and 1.75%). The main seam contains a variable percentage of ash and sulphur. These values are related to the thickening and areal distribution of the seam, which in turn, were controlled by the nature of clastic deposition and peat-forming mire systems, marine transgression and local tidal incursion. The conglomeratic lithofacies represent deposits of trunk and tributary braided streams that rapidly aggraded incised paleovalleys during sea-level stillstands. The main seam represents a deposit of raised mires that initially developed as topogenous mires on abandoned margins of inactive braidbelts. Peat accumulated in mires as a response to a rise in the water table, probably initially due to gradual sea-level rise and climate, and the resulting raised topography served as protection from floods. The upper part of the coal measures consists of sandstone lithofacies of flu vial origin and bioturbated sandstone, mudstone and organic-rich lithofacies, which represent deposits of paralic (deltaic, barrier shoreface, tidal and mire) and marine environments. The fluvial sandstone lithofacies accumulated in channels during a sea-level stillstand. The channels were infilled by coeval braided and meandering streams prior to transgression. Continued transgression, ranging from tidal channel-estuarine incursions to widespread but uneven paleoshoreline encroachment, accompanied by moderate basin subsidence, is marked by a stacked, back-stepping geometry of bioturbated sandstone and marine mudstone lithofacies. Final retrogradation (sea-level highstand) is marked by backfilling of estuaries and by rapid landward deposition of the marine Kaiata Formation in the late Eocene.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"International Journal of Coal Geology","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1016/0166-5162(95)00028-3","issn":"01665162","usgsCitation":"Flores, R.M., and Sykes, R., 1996, Depositional controls on coal distribution and quality in the Eocene Brunner Coal Measures, Buller Coalfield, South Island, New Zealand: International Journal of Coal Geology, v. 29, no. 4, p. 291-336, https://doi.org/10.1016/0166-5162(95)00028-3.","startPage":"291","endPage":"336","numberOfPages":"46","costCenters":[],"links":[{"id":205895,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/0166-5162(95)00028-3"},{"id":227341,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"29","issue":"4","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"5059febbe4b0c8380cd4eec8","contributors":{"authors":[{"text":"Flores, R. M.","contributorId":106899,"corporation":false,"usgs":true,"family":"Flores","given":"R.","email":"","middleInitial":"M.","affiliations":[],"preferred":false,"id":379714,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Sykes, R.","contributorId":51930,"corporation":false,"usgs":true,"family":"Sykes","given":"R.","email":"","affiliations":[],"preferred":false,"id":379713,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70018469,"text":"70018469 - 1996 - Kinematics of the Eastern California shear zone: Evidence for slip transfer from Owens and Saline Valley fault zones to Fish Lake Valley fault zone","interactions":[],"lastModifiedDate":"2024-01-20T01:19:44.729313","indexId":"70018469","displayToPublicDate":"1996-01-01T00:00:00","publicationYear":"1996","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1796,"text":"Geology","active":true,"publicationSubtype":{"id":10}},"title":"Kinematics of the Eastern California shear zone: Evidence for slip transfer from Owens and Saline Valley fault zones to Fish Lake Valley fault zone","docAbstract":"Late Quaternary slip rates and satellite-based geodetic data for the western Great Basin constrain regional fault-slip distribution and evolution. The geologic slip rate on the Fish Lake Valley fault zone (the northwest extension of the Furnace Creek fault zone) increases northward from about 3 to 5 mm/yr, in agreement with modeled geodetic data. The increase coincides with the intersections of the Deep Springs fault, connected to the Owens Valley fault zone, and of other faults connected to the Saline Valley fault. The combined geologic and geodetic data suggest that (1) the northwest-striking faults of the Eastern California shear zone north of the Garlock fault are connected by north- to northeast-striking normal faults that transfer slip in a series of right steps, and (2) the amount and distribution of slip among the many faults of this broad, complex plate boundary have changed through time.
This paper examines the rationale behind the semiempirical formulation of a generalized viscoplastic fluid (GVF) model in the light of the Reiner-Rivlin constitutive theory and the viscoplastic theory, thereby identifying the parameters that control the rheology of granular flow. The shear-rate number ( N ) proves to be among the most significant parameters identified from the GVF model. As N → 0 and N →∞, the GVF model can reduce asymptotically to the theoretical stress versus shear-rate relations in the macroviscous and grain-inertia regimes, respectively, where the grain concentration ( C ) also plays a major role in the rheology of granular flow. Using available data obtained from the rotating-cylinder experiments of neutrally buoyant solid spheres dispersing in an interstitial fluid, the shear stress for granular flow in transition between the two regimes proves dependent on N and C in addition to some material constants, such as the coefficient of restitution. The insufficiency of data on rotating-cylinder experiments cannot presently allow the GVF model to predict how a granular flow may behave in the entire range of N ; however, the analyzed data provide an insight on the interrelation among the relevant dimensionless parameters.
","language":"English","publisher":"ASCE","doi":"10.1061/(ASCE)0733-9399(1996)122:5(469)","issn":"07339399","usgsCitation":"Chen, C., and Ling, C.#., 1996, Granular-flow rheology: Role of shear-rate number in transition regime: Journal of Engineering Mechanics, v. 122, no. 5, p. 469-479, https://doi.org/10.1061/(ASCE)0733-9399(1996)122:5(469).","productDescription":"11 p.","startPage":"469","endPage":"479","numberOfPages":"11","costCenters":[],"links":[{"id":227116,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"122","issue":"5","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a29c7e4b0c8380cd5ac1a","contributors":{"authors":[{"text":"Chen, Chiu-Lan","contributorId":100979,"corporation":false,"usgs":true,"family":"Chen","given":"Chiu-Lan","email":"","affiliations":[],"preferred":false,"id":379660,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Ling, C. #NAME?","contributorId":14133,"corporation":false,"usgs":true,"family":"Ling","given":"C.","email":"","middleInitial":"#NAME?","affiliations":[],"preferred":false,"id":379659,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70018447,"text":"70018447 - 1996 - Groundwater inflow measurements in wetland systems","interactions":[],"lastModifiedDate":"2018-03-08T15:30:04","indexId":"70018447","displayToPublicDate":"1996-01-01T00:00:00","publicationYear":"1996","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":"Groundwater inflow measurements in wetland systems","docAbstract":"Our current understanding of wetlands is insufficient to assess the effects of past and future wetland loss. While knowledge of wetland hydrology is crucial, groundwater flows are often neglected or uncertain. In this paper, groundwater inflows were estimated in wetlands in southwestern Wisconsin using traditional Darcy's law calculations and three independent methods that included (1) stable isotope mass balances, (2) temperature profile modeling, and (3) numerical water balance modeling techniques. Inflows calculated using Darcy's law were lower than inflows estimated using the other approaches and ranged from 0.02 to 0.3 cm/d. Estimates obtained using the other methods generally were higher (0.1 to 1.1 cm/d) and showed similar spatial trends. An areal map of groundwater flux generated by the water balance model demonstrated that areas of both recharge and discharge exist in what is considered a regional discharge area. While each method has strengths and weaknesses, the use of more than one method can reduce uncertainty in the estimates.
","language":"English","publisher":"American Geophysical Union","doi":"10.1029/95WR03724","usgsCitation":"Hunt, R.J., Krabbenhoft, D.P., and Anderson, M.P., 1996, Groundwater inflow measurements in wetland systems: Water Resources Research, v. 32, no. 3, p. 495-507, https://doi.org/10.1029/95WR03724.","productDescription":"13 p.","startPage":"495","endPage":"507","costCenters":[],"links":[{"id":227604,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"32","issue":"3","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a2da7e4b0c8380cd5bf89","contributors":{"authors":[{"text":"Hunt, Randy J.","contributorId":25903,"corporation":false,"usgs":false,"family":"Hunt","given":"Randy","email":"","middleInitial":"J.","affiliations":[],"preferred":false,"id":379610,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Krabbenhoft, David P. 0000-0003-1964-5020 dpkrabbe@usgs.gov","orcid":"https://orcid.org/0000-0003-1964-5020","contributorId":1658,"corporation":false,"usgs":true,"family":"Krabbenhoft","given":"David","email":"dpkrabbe@usgs.gov","middleInitial":"P.","affiliations":[{"id":37947,"text":"Upper Midwest Water Science Center","active":true,"usgs":true},{"id":5044,"text":"National Research Program - Central Branch","active":true,"usgs":true},{"id":37464,"text":"WMA - Laboratory & Analytical Services Division","active":true,"usgs":true},{"id":677,"text":"Wisconsin Water Science Center","active":true,"usgs":true}],"preferred":true,"id":379611,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Anderson, Mary P.","contributorId":147842,"corporation":false,"usgs":false,"family":"Anderson","given":"Mary","email":"","middleInitial":"P.","affiliations":[{"id":16925,"text":"University of Wisconsin-Madison","active":true,"usgs":false}],"preferred":false,"id":379612,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70018713,"text":"70018713 - 1996 - New USGS seismic hazard maps for the United States","interactions":[],"lastModifiedDate":"2012-03-12T17:19:27","indexId":"70018713","displayToPublicDate":"1996-01-01T00:00:00","publicationYear":"1996","noYear":false,"publicationType":{"id":24,"text":"Conference Paper"},"publicationSubtype":{"id":19,"text":"Conference Paper"},"title":"New USGS seismic hazard maps for the United States","docAbstract":"The US Geological Survey (USGS) is preparing new seismic national maps for release in April 1996. The new maps plot probabilistic ground motions for return times of about 500, 1000, and 2500 years. Deterministic (scenario) ground-motion maps are being prepared for selected faults in the western US. Due to the diversity of tectonic settings in the US, mapping methodologies for different regions had to be modified. A four-model approach is used to eliminate the need for drawing seismic source zones to determine seismic activity levels. A logic tree approach is used to incorporate alternative models of seismic hazard and alternative relations of seismic attenuation.","largerWorkTitle":"Proceedings of the Conference on Natural Disaster Reduction","conferenceTitle":"Proceedings of the 1996 Conference on Natural Disaster Reduction","conferenceDate":"3 December 1996 through 5 December 1996","conferenceLocation":"Washington, DC, USA","language":"English","usgsCitation":"Frankel, A., Mueller, C., Perkins, D., Barnhard, T., Leyendecker, E., Safak, E., Hanson, S., Dickman, N., and Hopper, M., 1996, New USGS seismic hazard maps for the United States, in Proceedings of the Conference on Natural Disaster Reduction, Washington, DC, USA, 3 December 1996 through 5 December 1996, p. 173-174.","startPage":"173","endPage":"174","numberOfPages":"2","costCenters":[],"links":[{"id":227180,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a653fe4b0c8380cd72b4c","contributors":{"editors":[{"text":"Housner G.W.Chung R.M.","contributorId":128376,"corporation":true,"usgs":false,"organization":"Housner G.W.Chung R.M.","id":536433,"contributorType":{"id":2,"text":"Editors"},"rank":1}],"authors":[{"text":"Frankel, A. 0000-0001-9119-6106","orcid":"https://orcid.org/0000-0001-9119-6106","contributorId":41593,"corporation":false,"usgs":true,"family":"Frankel","given":"A.","affiliations":[],"preferred":false,"id":380528,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Mueller, C.","contributorId":40201,"corporation":false,"usgs":true,"family":"Mueller","given":"C.","email":"","affiliations":[],"preferred":false,"id":380527,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Perkins, D.","contributorId":83589,"corporation":false,"usgs":true,"family":"Perkins","given":"D.","affiliations":[],"preferred":false,"id":380531,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Barnhard, T.","contributorId":63458,"corporation":false,"usgs":true,"family":"Barnhard","given":"T.","email":"","affiliations":[],"preferred":false,"id":380529,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Leyendecker, E.","contributorId":68049,"corporation":false,"usgs":true,"family":"Leyendecker","given":"E.","affiliations":[],"preferred":false,"id":380530,"contributorType":{"id":1,"text":"Authors"},"rank":5},{"text":"Safak, E.","contributorId":104070,"corporation":false,"usgs":true,"family":"Safak","given":"E.","email":"","affiliations":[],"preferred":false,"id":380532,"contributorType":{"id":1,"text":"Authors"},"rank":6},{"text":"Hanson, S.","contributorId":35781,"corporation":false,"usgs":true,"family":"Hanson","given":"S.","affiliations":[],"preferred":false,"id":380526,"contributorType":{"id":1,"text":"Authors"},"rank":7},{"text":"Dickman, N.","contributorId":17279,"corporation":false,"usgs":true,"family":"Dickman","given":"N.","email":"","affiliations":[],"preferred":false,"id":380524,"contributorType":{"id":1,"text":"Authors"},"rank":8},{"text":"Hopper, M.","contributorId":25999,"corporation":false,"usgs":true,"family":"Hopper","given":"M.","affiliations":[],"preferred":false,"id":380525,"contributorType":{"id":1,"text":"Authors"},"rank":9}]}} ,{"id":85643,"text":"85643 - 1996 - Hydrologic modification to improve habitat in riverine lakes: Management objectives, experimental approach, and initial conditions","interactions":[],"lastModifiedDate":"2012-02-02T00:04:06","indexId":"85643","displayToPublicDate":"1996-01-01T00:00:00","publicationYear":"1996","noYear":false,"publicationType":{"id":5,"text":"Book chapter"},"publicationSubtype":{"id":24,"text":"Book Chapter"},"title":"Hydrologic modification to improve habitat in riverine lakes: Management objectives, experimental approach, and initial conditions","docAbstract":"The Finger Lakes habitat-rehabilitation project is intended to improve physical and chemical conditions for fish in six connected back water lakes in Navigation Pool 5 of the upper Missouri River. The primary management objective is to improve water temperature, dissolved oxygen concentration and current velocity during winter for bluegills, Lepomis macrochirus, and black crappies, Pomoxis nigromaculatus, two of the primary sport fishes in the lakes. The lakes will be hydrologically altered by Installing culverts to Introduce controlled flows of oxygenated water into four lakes, and an existing unregulated culvert on a fifth lake will be equipped with a control gate to regulate inflow. These habitat modifications constitute a manipulative field experiment that will compare pre-project (1991 to summer 1993) and post-project (fall 1993 to 1996) conditions in the lakes, including hydrology, chemistry, rooted vegetation, and fish and macroinvertebrate communities. Initial data indicate that the Finger Lakes differ in water chemistry, hydrology, and macrophyte abundance. Macroinvertebrate communities also differed among lakes: species diversity was highest in lakes with dense aquatic macrophytes. The system seems to support a single fish community, although some species concentrated in individual lakes at different times. The introduction of similar flows into five of the lakes will probably reduce the existing physical and chemical differences among lakes. However, our ability to predict the effects of hydrologic modification on fish populations is limited by uncertainties concerning both the interactions of temperature, oxygen and current in winter and the biological responses of primary and secondary producers. Results from this study should provide guidance for similar habitat-rehabilitation projects in large rivers.","largerWorkType":{"id":4,"text":"Book"},"largerWorkTitle":"Problems of Aquatic Toxicology, Biotesting, and Water Quality Management","largerWorkSubtype":{"id":4,"text":"Other Government Series"},"language":"English","publisher":"Environmental Protection Agency","publisherLocation":"Athens, GA","usgsCitation":"Johnson, B.L., Barko, J.W., Gerasimov, Y., James, W., Litvinov, A., Naimo, T.J., Wiener, J.G., Gaugush, R.F., Rogala, J.T., and Rogers, S.J., 1996, Hydrologic modification to improve habitat in riverine lakes: Management objectives, experimental approach, and initial conditions, chap. of Problems of Aquatic Toxicology, Biotesting, and Water Quality Management, 239-258.","productDescription":"239-258","costCenters":[{"id":606,"text":"Upper Midwest Environmental Sciences Center","active":true,"usgs":true}],"links":[{"id":128638,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4a1ae4b07f02db606ae3","contributors":{"editors":[{"text":"Schoettger, R.A.","contributorId":19519,"corporation":false,"usgs":true,"family":"Schoettger","given":"R.A.","affiliations":[],"preferred":false,"id":504629,"contributorType":{"id":2,"text":"Editors"},"rank":1}],"authors":[{"text":"Johnson, Barry L. bljohnson@usgs.gov","contributorId":608,"corporation":false,"usgs":true,"family":"Johnson","given":"Barry","email":"bljohnson@usgs.gov","middleInitial":"L.","affiliations":[],"preferred":true,"id":296182,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Barko, John W.","contributorId":65413,"corporation":false,"usgs":true,"family":"Barko","given":"John","email":"","middleInitial":"W.","affiliations":[],"preferred":false,"id":296187,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Gerasimov, Yuri","contributorId":73538,"corporation":false,"usgs":true,"family":"Gerasimov","given":"Yuri","email":"","affiliations":[],"preferred":false,"id":296188,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"James, William F.","contributorId":75472,"corporation":false,"usgs":true,"family":"James","given":"William F.","affiliations":[],"preferred":false,"id":296189,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Litvinov, Alexander","contributorId":25891,"corporation":false,"usgs":true,"family":"Litvinov","given":"Alexander","affiliations":[],"preferred":false,"id":296186,"contributorType":{"id":1,"text":"Authors"},"rank":5},{"text":"Naimo, Teresa J.","contributorId":8039,"corporation":false,"usgs":true,"family":"Naimo","given":"Teresa","email":"","middleInitial":"J.","affiliations":[],"preferred":false,"id":296185,"contributorType":{"id":1,"text":"Authors"},"rank":6},{"text":"Wiener, James G.","contributorId":93853,"corporation":false,"usgs":false,"family":"Wiener","given":"James","email":"","middleInitial":"G.","affiliations":[{"id":17913,"text":"River Studies Center, University of Wisconsin-La Crosse","active":true,"usgs":false}],"preferred":false,"id":296191,"contributorType":{"id":1,"text":"Authors"},"rank":7},{"text":"Gaugush, Robert F. rgaugush@usgs.gov","contributorId":5873,"corporation":false,"usgs":true,"family":"Gaugush","given":"Robert","email":"rgaugush@usgs.gov","middleInitial":"F.","affiliations":[{"id":606,"text":"Upper Midwest Environmental Sciences Center","active":true,"usgs":true}],"preferred":true,"id":296184,"contributorType":{"id":1,"text":"Authors"},"rank":8},{"text":"Rogala, James T. 0000-0002-1954-4097 jrogala@usgs.gov","orcid":"https://orcid.org/0000-0002-1954-4097","contributorId":2651,"corporation":false,"usgs":true,"family":"Rogala","given":"James","email":"jrogala@usgs.gov","middleInitial":"T.","affiliations":[{"id":606,"text":"Upper Midwest Environmental Sciences Center","active":true,"usgs":true}],"preferred":true,"id":296183,"contributorType":{"id":1,"text":"Authors"},"rank":9},{"text":"Rogers, Sara J.","contributorId":85534,"corporation":false,"usgs":true,"family":"Rogers","given":"Sara","email":"","middleInitial":"J.","affiliations":[{"id":606,"text":"Upper Midwest Environmental Sciences Center","active":true,"usgs":true}],"preferred":false,"id":296190,"contributorType":{"id":1,"text":"Authors"},"rank":10}]}} ,{"id":70018811,"text":"70018811 - 1996 - Improved method for measuring water imbibition rates on low-permeability porous media","interactions":[],"lastModifiedDate":"2025-07-30T16:28:47.73829","indexId":"70018811","displayToPublicDate":"1996-01-01T00:00:00","publicationYear":"1996","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":3420,"text":"Soil Science Society of America Journal","active":true,"publicationSubtype":{"id":10}},"title":"Improved method for measuring water imbibition rates on low-permeability porous media","docAbstract":"Existing methods for measuring water imbibition rates are inadequate when imbibition rates are small (e.g., clay soils and many igneous rocks). We developed an improved laboratory method for performing imbibition measurements on soil or rock cores with a wide range of hydraulic properties. Core specimens are suspended from an electronic strain gauge (load cell) in a closed chamber while maintaining the lower end of the core in contact with a free water surface in a constant water level reservoir. The upper end of the core is open to the atmosphere. During imbibition, mass increase of the core is recorded continuously by a datalogger that converts the load cell voltage signal into mass units using a calibration curve. Computer automation allows imbibition rate measurement on as many as eight cores simultaneously and independently. Performance of each component of the imbibition apparatus was evaluated using a set of rock cores (2.5 cm in diameter and 2–5 cm in length) from a signle lithostratigraphic unit composed of non-to-moderately welded ash-flow tuff (a glass-rich pyroclastic rock partially fused by heat and pressure) with porosities ranging from 0.094 to 0.533 m3 m-3. Reproducibility of sample handling and testing procedures was demonstrated using replicate measurements. Precision and accuracy of load cell measurements were assessed using mass balance calculations and indicated agreement within a few tenths of a percent of total mass. Computed values of sorptivity, S, ranged from 8.83 × 10-6 to 4.55 × 10-4 m s-0.5. The developed method should prove useful for measuring imbibition rates on a wide range of porous materials.
","language":"English","publisher":"Wiley","doi":"10.2136/sssaj1996.03615995006000010007x","issn":"03615995","usgsCitation":"Humphrey, M., Istok, J., Flint, L.E., and Flint, A.L., 1996, Improved method for measuring water imbibition rates on low-permeability porous media: Soil Science Society of America Journal, v. 60, no. 1, p. 28-34, https://doi.org/10.2136/sssaj1996.03615995006000010007x.","productDescription":"7 p.","startPage":"28","endPage":"34","costCenters":[{"id":154,"text":"California Water Science Center","active":true,"usgs":true}],"links":[{"id":227093,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"60","issue":"1","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a395be4b0c8380cd618c3","contributors":{"authors":[{"text":"Humphrey, M.D.","contributorId":63181,"corporation":false,"usgs":true,"family":"Humphrey","given":"M.D.","email":"","affiliations":[],"preferred":false,"id":380825,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Istok, J.D.","contributorId":34165,"corporation":false,"usgs":true,"family":"Istok","given":"J.D.","affiliations":[],"preferred":false,"id":380823,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Flint, L. E. 0000-0002-7868-441X","orcid":"https://orcid.org/0000-0002-7868-441X","contributorId":38180,"corporation":false,"usgs":true,"family":"Flint","given":"L.","middleInitial":"E.","affiliations":[],"preferred":false,"id":380824,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Flint, A. L.","contributorId":102453,"corporation":false,"usgs":true,"family":"Flint","given":"A.","email":"","middleInitial":"L.","affiliations":[],"preferred":false,"id":380826,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}} ,{"id":70018889,"text":"70018889 - 1996 - Reactive solute transport in an acidic stream: Experimental pH increase and simulation of controls on pH, aluminum, and iron","interactions":[],"lastModifiedDate":"2019-02-20T09:13:36","indexId":"70018889","displayToPublicDate":"1996-01-01T00:00:00","publicationYear":"1996","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1565,"text":"Environmental Science & Technology","onlineIssn":"1520-5851","printIssn":"0013-936X","active":true,"publicationSubtype":{"id":10}},"title":"Reactive solute transport in an acidic stream: Experimental pH increase and simulation of controls on pH, aluminum, and iron","docAbstract":"Solute transport simulations quantitatively constrained hydrologic and geochemical hypotheses about field observations of a pH modification in an acid mine drainage stream. Carbonate chemistry, the formation of solid phases, and buffering interactions with the stream bed were important factors in explaining the behavior of pH, aluminum, and iron. The precipitation of microcrystalline gibbsite accounted for the behavior of aluminum; precipitation of Fe(OH)3 explained the general pattern of iron solubility. The dynamic experiment revealed limitations on assumptions that reactions were controlled only by equilibrium chemistry. Temporal variation in relative rates of photoreduction and oxidation influenced iron behavior. Kinetic limitations on ferrous iron oxidation and hydrous oxide precipitation and the effects of these limitations on field filtration were evident. Kinetic restraints also characterized interaction between the water column and the stream bed, including sorption and desorption of protons from iron oxides at the sediment-water interface and post-injection dissolution of the precipitated aluminum solid phase.","language":"English","publisher":"ACS","doi":"10.1021/es960055u","issn":"0013936X","usgsCitation":"Broshears, R.E., Runkel, R., Kimball, B.A., McKnight, D.M., and Bencala, K., 1996, Reactive solute transport in an acidic stream: Experimental pH increase and simulation of controls on pH, aluminum, and iron: Environmental Science & Technology, v. 30, no. 10, p. 3016-3024, https://doi.org/10.1021/es960055u.","productDescription":"9 p.","startPage":"3016","endPage":"3024","costCenters":[{"id":589,"text":"Toxic Substances Hydrology Program","active":true,"usgs":true}],"links":[{"id":205776,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1021/es960055u"},{"id":226711,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"30","issue":"10","noUsgsAuthors":false,"publicationDate":"1996-09-26","publicationStatus":"PW","scienceBaseUri":"505a9586e4b0c8380cd81a87","contributors":{"authors":[{"text":"Broshears, R. E.","contributorId":75552,"corporation":false,"usgs":true,"family":"Broshears","given":"R.","email":"","middleInitial":"E.","affiliations":[],"preferred":false,"id":381028,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Runkel, R.L.","contributorId":97529,"corporation":false,"usgs":true,"family":"Runkel","given":"R.L.","affiliations":[],"preferred":false,"id":381030,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Kimball, B. A.","contributorId":87583,"corporation":false,"usgs":false,"family":"Kimball","given":"B.","email":"","middleInitial":"A.","affiliations":[],"preferred":false,"id":381029,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"McKnight, Diane M.","contributorId":59773,"corporation":false,"usgs":false,"family":"McKnight","given":"Diane","email":"","middleInitial":"M.","affiliations":[{"id":16833,"text":"INSTAAR, University of Colorado","active":true,"usgs":false}],"preferred":false,"id":381027,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Bencala, K.E.","contributorId":105312,"corporation":false,"usgs":true,"family":"Bencala","given":"K.E.","email":"","affiliations":[],"preferred":false,"id":381031,"contributorType":{"id":1,"text":"Authors"},"rank":5}]}} ,{"id":70018952,"text":"70018952 - 1996 - Atrazine concentrations in near-surface aquifers: A censored regression approach","interactions":[],"lastModifiedDate":"2019-02-20T10:10:48","indexId":"70018952","displayToPublicDate":"1996-01-01T00:00:00","publicationYear":"1996","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":"Atrazine concentrations in near-surface aquifers: A censored regression approach","docAbstract":"In 1991, the U.S. Geological Survey (USGS) conducted a study to investigate the occurrence of atrazine (2-chloro-4-ethylamino-6- isopropylamino-s-triazine) and other agricultural chemicals in near-surface aquifers in the midcontinental USA. Because about 83% of the atrazine concentrations from the USGS study were censored, standard statistical estimation procedures could not be used. To determine factors that affect atrazine concentrations in groundwater while accommodating the high degree of data censoring. Tobit models were used (normal homoscedastic, normal heteroscedastic, lognormal homoscedastic, and lognormal heteroscedastic). Empirical results suggest that the lognormal heteroscedastic Tobit model is the model of choice for this type of study. This model determined the following factors to have the strongest effect on atrazine concentrations in groundwater: percent of pasture within 3.2 km, percent of forest within 3.2 km (2 mi), mean open interval of the well, primary water use of a well, aquifer class (unconsolidated or bedrock), aquifer type (unconfined or confined), existence of a stream within 30 m (100 ft), existence of a stream within 30 m to 0.4 km (0.25 mi), and existence of a stream within 0.4 to 3.2 km. Examining the elasticities of the continuous explanatory factors provides further insight into their effects on atrazine concentrations in groundwater. This study documents a viable statistical method that can be used to accommodate the complicating presence of censured data, a feature that commonly occurs in environmental data.","language":"English","publisher":"ACSESS","doi":"10.2134/jeq1996.00472425002500050010x","issn":"00472425","usgsCitation":"Liu, S., Yen, S., and Kolpin, D., 1996, Atrazine concentrations in near-surface aquifers: A censored regression approach: Journal of Environmental Quality, v. 25, no. 5, p. 992-999, https://doi.org/10.2134/jeq1996.00472425002500050010x.","productDescription":"8 p.","startPage":"992","endPage":"999","costCenters":[],"links":[{"id":226896,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"25","issue":"5","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"5059eecbe4b0c8380cd49f84","contributors":{"authors":[{"text":"Liu, S.","contributorId":93170,"corporation":false,"usgs":true,"family":"Liu","given":"S.","affiliations":[],"preferred":false,"id":381181,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Yen, S.T.","contributorId":106659,"corporation":false,"usgs":true,"family":"Yen","given":"S.T.","email":"","affiliations":[],"preferred":false,"id":381182,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Kolpin, D.W.","contributorId":87565,"corporation":false,"usgs":true,"family":"Kolpin","given":"D.W.","email":"","affiliations":[],"preferred":false,"id":381180,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70018984,"text":"70018984 - 1996 - Verification of vertically rotating flume using non-newtonian fluids","interactions":[],"lastModifiedDate":"2024-12-12T16:42:21.20532","indexId":"70018984","displayToPublicDate":"1996-01-01T00:00:00","publicationYear":"1996","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2338,"text":"Journal of Hydraulic Engineering","active":true,"publicationSubtype":{"id":10}},"title":"Verification of vertically rotating flume using non-newtonian fluids","docAbstract":"Three tests on non-Newtonian fluids were used to verify the use of a vertically rotating flume (VRF) for the study of the rheological properties of debris flow. The VRF is described and a procedure for the analysis of results of tests made with the VRF is presented. The major advantages of the VRF are a flow field consistent with that found in nature, a large particle-diameter threshold, inexpensive operation, and verification using several different materials; the major limitations are a lack of temperature control and a certain error incurred from the use of the Bingham plastic model to describe a more complex phenomenon. Because the VRF has been verified with non-Newtonian fluids as well as Newtonian fluids, it can be used to measure the rheological properties of coarse-grained debris-flow materials.
","language":"English","publisher":"ASCE","doi":"10.1061/(ASCE)0733-9429(1996)122:8(456)","issn":"07339429","usgsCitation":"Huizinga, R., 1996, Verification of vertically rotating flume using non-newtonian fluids: Journal of Hydraulic Engineering, v. 122, no. 8, p. 456-459, https://doi.org/10.1061/(ASCE)0733-9429(1996)122:8(456).","productDescription":"4 p.","startPage":"456","endPage":"459","numberOfPages":"4","costCenters":[],"links":[{"id":226670,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"122","issue":"8","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505bc221e4b08c986b32a942","contributors":{"authors":[{"text":"Huizinga, R.J.","contributorId":36970,"corporation":false,"usgs":true,"family":"Huizinga","given":"R.J.","affiliations":[],"preferred":false,"id":381306,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}} ,{"id":70018991,"text":"70018991 - 1996 - Late Paleocene Arctic Ocean shallow-marine temperatures from mollusc stable isotopes","interactions":[],"lastModifiedDate":"2014-01-13T11:36:51","indexId":"70018991","displayToPublicDate":"1996-01-01T00:00:00","publicationYear":"1996","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":3002,"text":"Paleoceanography","active":true,"publicationSubtype":{"id":10}},"title":"Late Paleocene Arctic Ocean shallow-marine temperatures from mollusc stable isotopes","docAbstract":"Late Paleocene high-latitude (80°N) Arctic Ocean shallow-marine temperatures are estimated from molluscan δ18O time series. Sampling of individual growth increments of two specimens of the bivalve Camptochlamys alaskensis provides a high-resolution record of shell stable isotope composition. The heavy carbon isotopic values of the specimens support a late Paleocene age for the youngest marine beds of the Prince Creek Formation exposed near Ocean Point, Alaska. The oxygen isotopic composition of regional freshwater runoff is estimated from the mean δ18O value of two freshwater bivalves collected from approximately coeval fluviatile beds. Over a 30 – 34‰ range of salinity, values assumed to represent the tolerance of C. alaskensis, the mean annual shallow-marine temperature recorded by these individuals is between 11° and 22°C. These values could represent maximum estimates of the mean annual temperature because of a possible warm-month bias imposed on the average δ18O value by slowing or cessation of growth in winter months. The amplitude of the molluscan δ18O time series probably records most of the seasonality in shallow-marine temperature. The annual temperature range indicated is approximately 6°C, suggesting very moderate high-latitude marine temperature seasonality during the late Paleocene. On the basis of analogy with modern Chlamys species, C. alaskensis probably inhabited water depths of 30–50 m. The seasonal temperature range derived from δ18O is therefore likely to be damped relative to the full range of annual sea surface temperatures. High-resolution sampling of molluscan shell material across inferred growth bands represents an important proxy record of seasonality of marine and freshwater conditions applicable at any latitude. If applied to other regions and time periods, the approach used here would contribute substantially to the paleoclimate record of seasonality.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Paleoceanography","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1029/96PA00813","issn":"08838305","usgsCitation":"Bice, K.L., Arthur, M.A., and Marincovich, L., 1996, Late Paleocene Arctic Ocean shallow-marine temperatures from mollusc stable isotopes: Paleoceanography, v. 11, no. 3, p. 241-249, https://doi.org/10.1029/96PA00813.","startPage":"241","endPage":"249","numberOfPages":"9","costCenters":[],"links":[{"id":226765,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":280871,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1029/96PA00813"}],"volume":"11","issue":"3","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a44fee4b0c8380cd66f53","contributors":{"authors":[{"text":"Bice, Karen L.","contributorId":107045,"corporation":false,"usgs":true,"family":"Bice","given":"Karen","email":"","middleInitial":"L.","affiliations":[],"preferred":false,"id":381324,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Arthur, Michael A.","contributorId":90018,"corporation":false,"usgs":true,"family":"Arthur","given":"Michael","email":"","middleInitial":"A.","affiliations":[],"preferred":false,"id":381323,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Marincovich, Louie Jr.","contributorId":53403,"corporation":false,"usgs":true,"family":"Marincovich","given":"Louie","suffix":"Jr.","email":"","affiliations":[],"preferred":false,"id":381322,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70019030,"text":"70019030 - 1996 - Cryptic trace-element alteration of Anorthosite, Stillwater complex, Montana","interactions":[],"lastModifiedDate":"2012-03-12T17:19:15","indexId":"70019030","displayToPublicDate":"1996-01-01T00:00:00","publicationYear":"1996","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1177,"text":"Canadian Mineralogist","active":true,"publicationSubtype":{"id":10}},"title":"Cryptic trace-element alteration of Anorthosite, Stillwater complex, Montana","docAbstract":"Evidence of cryptic alteration and correlations among K, Ba, and LREE concentrations indicate that a post-cumulus, low-density aqueous fluid phase significantly modified the trace-element contents of samples from Anorthosite zones I and II of the Stillwater Complex, Montana. Concentrations of Ba, Ca, Co, Cr, Cu, Fe, Hf, K, Li, Mg, Mn, Na, Ni, Sc, Sr, Th, Zn, and the rare-earth elements (REE) were measured in whole rocks and plagioclase separates from five traverses across the two main plagioclase cumulate (anorthosite) zones and the contiguous cumulates of the Stillwater Complex in an attempt to better understand the origin and solidification of the anorthosites. However, nearly the entire observed compositional range for many trace elements can be duplicated at a single locality by discriminating between samples rich in oikocrystic pyroxene and those which are composed almost entirely of plagioclase and show anhedral-granular texture. Plagioclase separates with high trace-element contents were obtained from the pyroxene-poor samples, for which maps of K concentration show plagioclase grains to contain numerous fractures hosting a fine-grained, K-rich phase, presumed to be sericite. Secondary processes in layered intrusions have the potential to cause cryptic disturbance, and the utmost care must be taken to ensure that samples provide information about primary processes. Although plagioclase from Anorthosite zones I and II shows significant compositional variation, there are no systematic changes in the major- or trace-element compositions of plagioclase over as much as 630 m of anorthosite thickness or 18 km of strike length. Plagioclase in the two major anorthosite zones shows little distinction in trace-element concentrations from plagioclase in the cumulates immediately below, between, and above these zones.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Canadian Mineralogist","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","issn":"00084476","usgsCitation":"Czamanske, G., and Loferski, P., 1996, Cryptic trace-element alteration of Anorthosite, Stillwater complex, Montana: Canadian Mineralogist, v. 34, no. 3, p. 559-576.","startPage":"559","endPage":"576","numberOfPages":"18","costCenters":[],"links":[{"id":226768,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"34","issue":"3","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"5059fcf6e4b0c8380cd4e54b","contributors":{"authors":[{"text":"Czamanske, G.K.","contributorId":26300,"corporation":false,"usgs":true,"family":"Czamanske","given":"G.K.","email":"","affiliations":[],"preferred":false,"id":381456,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Loferski, P. J.","contributorId":12841,"corporation":false,"usgs":true,"family":"Loferski","given":"P. J.","affiliations":[],"preferred":false,"id":381455,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70018224,"text":"70018224 - 1996 - Geochemistry of aquatic humic substances in the Lake Fryxell basin, Antarctica","interactions":[],"lastModifiedDate":"2020-01-07T12:56:16","indexId":"70018224","displayToPublicDate":"1996-01-01T00:00:00","publicationYear":"1996","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1007,"text":"Biogeochemistry","active":true,"publicationSubtype":{"id":10}},"title":"Geochemistry of aquatic humic substances in the Lake Fryxell basin, Antarctica","docAbstract":"Dissolved organic carbon (DOC) in Lake Fryxell, 10 streams flowing into the lake, and the moat surrounding the lake was studied to determine the influence of sources and biogeochemical processes on its distribution and chemical nature. Lake Fryxell is an amictic, permanently ice-covered lake in the McMurdo Dry Valleys which contains benthic and planktonic microbial populations, but receives essentially no input of organic material from the ahumic soils of the watershed. Biological activity in the water column does not appear to influence the DOC depth profile, which is similar to the profiles for conservative inorganic constituents. DOC values for the streams varied with biomass in the stream channel, and ranged from 0.2 to 9.7 mg C/L. Fulvic acids in the streams were a lower percentage of the total DOC than in the lake. These samples contain recent carbon and appear to be simpler mixtures of compounds than the lake samples, indicating that they have undergone less humification. The fulvic acids from just above the sediments of the lake have a high sulfur content and are highly aliphatic. The main transformations occurring as these fractions diffuse upward in the water column are 1) loss of sulfur groups through the oxycline and 2) decrease in aliphatic carbon and increase in the heterogeneity of aliphatic moieties. The fraction of modem 14C content of the lake fulvic acids range from a minimum of 0.68 (approximately 3000 years old) at 15m depth to 0.997 (recent material) just under the ice. The major processes controlling the DOC in the lake appear to be: 1) The transport of organic matter by the inflow streams resulting in the addition of recent organic material to the moat and upper waters of the lake; 2) The diffusion of organic matter composed of relict organic material and organic carbon resulting from the degradation of algae and bacteria from the bottom waters or sediments of the lake into overlying glacial melt water; 3) The addition of recent organic matter to the bottom waters of the lake from the moat.","language":"English","publisher":"Springer","doi":"10.1007/BF00000900","issn":"01682563","usgsCitation":"Aiken, G., McKnight, D., Harnish, R., and Wershaw, R., 1996, Geochemistry of aquatic humic substances in the Lake Fryxell basin, Antarctica: Biogeochemistry, v. 34, no. 3, p. 157-188, https://doi.org/10.1007/BF00000900.","productDescription":"32 p.","startPage":"157","endPage":"188","numberOfPages":"32","costCenters":[{"id":589,"text":"Toxic Substances Hydrology Program","active":true,"usgs":true}],"links":[{"id":227016,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"34","issue":"3","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a16ede4b0c8380cd552fa","contributors":{"authors":[{"text":"Aiken, G.","contributorId":82066,"corporation":false,"usgs":true,"family":"Aiken","given":"G.","affiliations":[],"preferred":false,"id":378920,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"McKnight, D.","contributorId":48713,"corporation":false,"usgs":true,"family":"McKnight","given":"D.","email":"","affiliations":[],"preferred":false,"id":378917,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Harnish, R.","contributorId":72143,"corporation":false,"usgs":true,"family":"Harnish","given":"R.","affiliations":[],"preferred":false,"id":378919,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Wershaw, R.","contributorId":64797,"corporation":false,"usgs":true,"family":"Wershaw","given":"R.","affiliations":[],"preferred":false,"id":378918,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}} ,{"id":70018174,"text":"70018174 - 1996 - Seismic velocities for hydrate-bearing sediments using weighted equation","interactions":[],"lastModifiedDate":"2018-04-09T12:40:17","indexId":"70018174","displayToPublicDate":"1996-01-01T00:00:00","publicationYear":"1996","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2314,"text":"Journal of Geophysical Research B: Solid Earth","active":true,"publicationSubtype":{"id":10}},"title":"Seismic velocities for hydrate-bearing sediments using weighted equation","docAbstract":"A weighted equation based on the three-phase time-average and Wood equations is applied to derive a relationship between the compressional wave (P wave) velocity and the amount of hydrates filling the pore space. The proposed theory predicts accurate P wave velocities of marine sediments in the porosity range of 40-80% and provides a practical means of estimating the amount of in situ hydrate using seismic velocity. The shear (S) wave velocity is derived under the assumption that the P to S wave velocity ratio of the hydrated sediments is proportional to the weighted average of the P to S wave velocity ratios of the constituent components of the sediment. In the case that all constituent components are known, a weighted equation using multiphase time-average and Wood equations is possible. However, this study showed that a three-phase equation with modified matrix velocity, compensated for the clay content, is sufficient to accurately predict the compressional wave velocities for the marine sediments. This theory was applied to the laboratory measurements of the P and S wave velocities in permafrost samples to infer the amount of ice in the unconsolidated sediment. The results are comparable to the results obtained by repeatedly applying the two-phase wave scattering theory. The theory predicts that the Poisson's ratio of the hydrated sediments decreases as the hydrate concentration increases and the porosity decreases. In consequence, the amplitude versus offset (AVO) data for the bottom-simulating reflections may reveal positive, negative, or no AVO anomalies depending on the concentration of hydrates in the sediments.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Journal of Geophysical Research B: Solid Earth","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1029/96JB01886","issn":"01480227","usgsCitation":"Lee, M.W., Hutchinson, D.R., Collett, T.S., and Dillon, W.P., 1996, Seismic velocities for hydrate-bearing sediments using weighted equation: Journal of Geophysical Research B: Solid Earth, v. 101, no. 9, p. 20347-20358, https://doi.org/10.1029/96JB01886.","productDescription":"12 p.","startPage":"20347","endPage":"20358","costCenters":[{"id":678,"text":"Woods Hole Coastal and Marine Science Center","active":true,"usgs":true}],"links":[{"id":227673,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"101","issue":"9","noUsgsAuthors":false,"publicationDate":"1996-09-10","publicationStatus":"PW","scienceBaseUri":"505b8b73e4b08c986b31783d","contributors":{"authors":[{"text":"Lee, Myung W.","contributorId":84358,"corporation":false,"usgs":true,"family":"Lee","given":"Myung","middleInitial":"W.","affiliations":[],"preferred":false,"id":378764,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Hutchinson, D. R.","contributorId":31770,"corporation":false,"usgs":true,"family":"Hutchinson","given":"D.","email":"","middleInitial":"R.","affiliations":[],"preferred":false,"id":378763,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Collett, T. S. 0000-0002-7598-4708","orcid":"https://orcid.org/0000-0002-7598-4708","contributorId":86342,"corporation":false,"usgs":true,"family":"Collett","given":"T.","email":"","middleInitial":"S.","affiliations":[],"preferred":false,"id":378766,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Dillon, William P. bdillon@usgs.gov","contributorId":79820,"corporation":false,"usgs":true,"family":"Dillon","given":"William","email":"bdillon@usgs.gov","middleInitial":"P.","affiliations":[{"id":678,"text":"Woods Hole Coastal and Marine Science Center","active":true,"usgs":true}],"preferred":false,"id":378765,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}} ,{"id":70177023,"text":"70177023 - 1996 - A preliminary evaluation of sediment quality assessment values for freshwater ecosystems","interactions":[],"lastModifiedDate":"2016-10-14T14:24:14","indexId":"70177023","displayToPublicDate":"1996-01-01T00:00:00","publicationYear":"1996","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2330,"text":"Journal of Great Lakes Research","active":true,"publicationSubtype":{"id":10}},"title":"A preliminary evaluation of sediment quality assessment values for freshwater ecosystems","docAbstract":"Sediment quality assessment values were developed using a weight of evidence approach in which matching biological and chemical data from numerous modelling, laboratory, and field studies performed on freshwater sediments were compiled and analyzed. Two assessment values (a threshold effect level (TEL) and a probable effect level(PEL)) were derived for 23 substances, including eight trace metals, six individual polycyclic aromatic hydrocarbons (PAHs), total polychlorinated biphenyls (PCBs), and eight pesticides. The two values defined three ranges of chemical concentrations; those that were (1) rarely, (2) occasionally, and (3) frequently associated with adverse biological effects. An evaluation of the percent incidence of adverse biological effects within the three concentration ranges indicated that the reliability of the TELs (i.e., the degree to which the TELs represent concentrations within the data set below which adverse effects rarely occur) was consistently good. However, this preliminary evaluation indicated that most of the PELs were less reliable (i.e., they did not adequately represent concentrations within the data set above which adverse effects frequently occur). Nonetheless, these values were often comparable to other biological effects-based assessment values (which were themselves reliable), which increased the level of confidence that could be placed in our values. This method is being used as a basis for developing national sediment quality guidelines for freshwater systems in Canada and sediment effect concentrations as part of the Assessment and Remediation of Contaminated Sediments (ARCS) program in the Great Lakes.
","language":"English","publisher":"Elsevier","doi":"10.1016/S0380-1330(96)70985-1","usgsCitation":"Smith, S.L., MacDonald, D., Keenleyside, K.A., Ingersoll, C.G., and Field, L.J., 1996, A preliminary evaluation of sediment quality assessment values for freshwater ecosystems: Journal of Great Lakes Research, v. 22, no. 3, p. 624-638, https://doi.org/10.1016/S0380-1330(96)70985-1.","productDescription":"15 p.","startPage":"624","endPage":"638","costCenters":[{"id":192,"text":"Columbia Environmental Research Center","active":true,"usgs":true}],"links":[{"id":329614,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"22","issue":"3","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"5801eebfe4b0824b2d18c435","contributors":{"authors":[{"text":"Smith, Sherri L.","contributorId":175399,"corporation":false,"usgs":false,"family":"Smith","given":"Sherri","email":"","middleInitial":"L.","affiliations":[],"preferred":false,"id":651018,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"MacDonald, Donald D.","contributorId":49911,"corporation":false,"usgs":true,"family":"MacDonald","given":"Donald D.","affiliations":[],"preferred":false,"id":651019,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Keenleyside, Karen A.","contributorId":175400,"corporation":false,"usgs":false,"family":"Keenleyside","given":"Karen","email":"","middleInitial":"A.","affiliations":[],"preferred":false,"id":651020,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Ingersoll, Christopher G. 0000-0003-4531-5949 cingersoll@usgs.gov","orcid":"https://orcid.org/0000-0003-4531-5949","contributorId":2071,"corporation":false,"usgs":true,"family":"Ingersoll","given":"Christopher","email":"cingersoll@usgs.gov","middleInitial":"G.","affiliations":[{"id":192,"text":"Columbia Environmental Research Center","active":true,"usgs":true}],"preferred":true,"id":651021,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Field, L. Jay","contributorId":87032,"corporation":false,"usgs":true,"family":"Field","given":"L.","email":"","middleInitial":"Jay","affiliations":[],"preferred":false,"id":651022,"contributorType":{"id":1,"text":"Authors"},"rank":5}]}} ,{"id":70017849,"text":"70017849 - 1996 - Geomagnetic storms, the Dst ring-current myth and lognormal distributions","interactions":[],"lastModifiedDate":"2013-02-23T13:22:06","indexId":"70017849","displayToPublicDate":"1996-01-01T00:00:00","publicationYear":"1996","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2188,"text":"Journal of Atmospheric and Terrestrial Physics","active":true,"publicationSubtype":{"id":10}},"title":"Geomagnetic storms, the Dst ring-current myth and lognormal distributions","docAbstract":"The definition of geomagnetic storms dates back to the turn of the century when researchers recognized the unique shape of the H-component field change upon averaging storms recorded at low latitude observatories. A generally accepted modeling of the storm field sources as a magnetospheric ring current was settled about 30 years ago at the start of space exploration and the discovery of the Van Allen belt of particles encircling the Earth. The Dst global 'ring-current' index of geomagnetic disturbances, formulated in that period, is still taken to be the definitive representation for geomagnetic storms. Dst indices, or data from many world observatories processed in a fashion paralleling the index, are used widely by researchers relying on the assumption of such a magnetospheric current-ring depiction. Recent in situ measurements by satellites passing through the ring-current region and computations with disturbed magnetosphere models show that the Dst storm is not solely a main-phase to decay-phase, growth to disintegration, of a massive current encircling the Earth. Although a ring current certainly exists during a storm, there are many other field contributions at the middle-and low-latitude observatories that are summed to show the 'storm' characteristic behavior in Dst at these observatories. One characteristic of the storm field form at middle and low latitudes is that Dst exhibits a lognormal distribution shape when plotted as the hourly value amplitude in each time range. Such distributions, common in nature, arise when there are many contributors to a measurement or when the measurement is a result of a connected series of statistical processes. The amplitude-time displays of Dst are thought to occur because the many time-series processes that are added to form Dst all have their own characteristic distribution in time. By transforming the Dst time display into the equivalent normal distribution, it is shown that a storm recovery can be predicted with remarkable accuracy from measurements made during the Dst growth phase. In the lognormal formulation, the mean, standard deviation and field count within standard deviation limits become definitive Dst storm parameters.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Journal of Atmospheric and Terrestrial Physics","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","publisher":"Elsevier","doi":"10.1016/0021-9169(95)00103-4","issn":"00219169","usgsCitation":"Campbell, W., 1996, Geomagnetic storms, the Dst ring-current myth and lognormal distributions: Journal of Atmospheric and Terrestrial Physics, v. 58, no. 10, p. 1171-1187, https://doi.org/10.1016/0021-9169(95)00103-4.","startPage":"1171","endPage":"1187","numberOfPages":"17","costCenters":[],"links":[{"id":268032,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/0021-9169(95)00103-4"},{"id":229003,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"58","issue":"10","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a2762e4b0c8380cd59831","contributors":{"authors":[{"text":"Campbell, W.H.","contributorId":30749,"corporation":false,"usgs":true,"family":"Campbell","given":"W.H.","email":"","affiliations":[],"preferred":false,"id":377732,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}} ,{"id":1014830,"text":"1014830 - 1996 - Variability survival of larval fish: disentangling components with a generalized individual-based model","interactions":[],"lastModifiedDate":"2012-02-02T00:04:10","indexId":"1014830","displayToPublicDate":"1996-01-01T00:00:00","publicationYear":"1996","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1169,"text":"Canadian Journal of Fisheries and Aquatic Sciences","active":true,"publicationSubtype":{"id":10}},"title":"Variability survival of larval fish: disentangling components with a generalized individual-based model","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Canadian Journal of Fisheries and Aquatic Sciences","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","collaboration":"97-057/TF","usgsCitation":"Letcher, B., Rice, J., Crowder, L., and Rose, K., 1996, Variability survival of larval fish: disentangling components with a generalized individual-based model: Canadian Journal of Fisheries and Aquatic Sciences, v. 53, no. 4, p. 787-801.","productDescription":"p. 787-801","startPage":"787","endPage":"801","numberOfPages":"15","costCenters":[{"id":365,"text":"Leetown Science Center","active":true,"usgs":true}],"links":[{"id":129702,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"53","issue":"4","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4a14e4b07f02db602b9c","contributors":{"authors":[{"text":"Letcher, B. H. 0000-0003-0191-5678","orcid":"https://orcid.org/0000-0003-0191-5678","contributorId":48132,"corporation":false,"usgs":true,"family":"Letcher","given":"B.","middleInitial":"H.","affiliations":[{"id":365,"text":"Leetown Science Center","active":true,"usgs":true}],"preferred":false,"id":321301,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Rice, J. A.","contributorId":101217,"corporation":false,"usgs":true,"family":"Rice","given":"J.","middleInitial":"A.","affiliations":[],"preferred":false,"id":321303,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Crowder, L.B.","contributorId":104437,"corporation":false,"usgs":true,"family":"Crowder","given":"L.B.","email":"","affiliations":[],"preferred":false,"id":321304,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Rose, K.A.","contributorId":99086,"corporation":false,"usgs":true,"family":"Rose","given":"K.A.","email":"","affiliations":[],"preferred":false,"id":321302,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}} ,{"id":70177042,"text":"70177042 - 1996 - Acute toxicity of fire control chemicals to Daphnia magna(Straus) and Selenastrum capricornutum(Printz)","interactions":[],"lastModifiedDate":"2016-10-17T10:51:00","indexId":"70177042","displayToPublicDate":"1996-01-01T00:00:00","publicationYear":"1996","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1480,"text":"Ecotoxicology and Environmental Safety","active":true,"publicationSubtype":{"id":10}},"title":"Acute toxicity of fire control chemicals to Daphnia magna(Straus) and Selenastrum capricornutum(Printz)","docAbstract":"Acute toxicity tests were conducted exposingDaphnia magnaStraus (daphnid) in soft and hard reconstituted waters (hardness 42 and 162 mg/liter as CaCO3, respectively), andSelenastrum capricornutumPrintz (algae) in ASTM algal assay medium (hardness 15 mg/liter as CaCO3) to fire retardants Fire-Trol GTS-R, Fire-Trol LCG-R, and Phos-Chek D75-F, and foam suppressants Phos-Chek WD-881 and Silv-Ex. The chemicals were slightly toxic to practically harmless to daphnids and moderately toxic to algae. Water quality did not consistently alter the toxicity of the test chemicals to daphnids. The most toxic chemical to daphnids was Silv-Ex (48-hr EC507 mg/liter in soft and hard waters), whereas the least toxic chemical to daphnids was Fire-Trol LCG-R (48-hr EC50848 mg/liter in soft water, 813 mg/liter in hard water). The most toxic chemical to algae was Fire-Trol LCG-R (96-hr IC5010 mg/liter), and the least toxic chemical was Phos-Chek D75-F (96-hr IC5079 mg/liter). Un-ionized ammonia concentrations near the EC50or IC50value in tests with the Fire-Trol compounds were frequently equal to or above reported LC50un-ionized ammonia concentrations. Un-ionized ammonia concentrations in tests with Phos-Chek D75-F were low, thus other toxic components present in the compounds probably contributed to the toxicity. When compared to the daphnids tested in ASTM soft water, the Fire-Trol compounds were most toxic to algae, whereas Phos-Chek D75-F and the foam suppressants were most toxic to daphnids. The results of these tests are comparable to those obtained from research conducted in other laboratories with the same species and similar chemicals. Accidental entry of fire-fighting chemicals into aquatic environments could adversely affect algae and aquatic invertebrates, thus disrupting ecosystem function.
","language":"English","publisher":"Elsevier","doi":"10.1006/eesa.1996.0007","usgsCitation":"McDonald, S.F., Hamilton, S., Buhl, K.J., and Heisinger, J.F., 1996, Acute toxicity of fire control chemicals to Daphnia magna(Straus) and Selenastrum capricornutum(Printz): Ecotoxicology and Environmental Safety, v. 33, no. 1, p. 62-72, https://doi.org/10.1006/eesa.1996.0007.","productDescription":"11 p.","startPage":"62","endPage":"72","costCenters":[{"id":192,"text":"Columbia Environmental Research Center","active":true,"usgs":true}],"links":[{"id":329630,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"33","issue":"1","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"5805e34fe4b0824b2d1c24c8","contributors":{"authors":[{"text":"McDonald, Susan F.","contributorId":33285,"corporation":false,"usgs":true,"family":"McDonald","given":"Susan","email":"","middleInitial":"F.","affiliations":[],"preferred":false,"id":651109,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Hamilton, Steven J.","contributorId":174108,"corporation":false,"usgs":false,"family":"Hamilton","given":"Steven J.","affiliations":[],"preferred":false,"id":651110,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Buhl, Kevin J. 0000-0002-9963-2352 kevin_buhl@usgs.gov","orcid":"https://orcid.org/0000-0002-9963-2352","contributorId":1396,"corporation":false,"usgs":true,"family":"Buhl","given":"Kevin","email":"kevin_buhl@usgs.gov","middleInitial":"J.","affiliations":[{"id":192,"text":"Columbia Environmental Research Center","active":true,"usgs":true}],"preferred":true,"id":651111,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Heisinger, James F.","contributorId":175438,"corporation":false,"usgs":false,"family":"Heisinger","given":"James","email":"","middleInitial":"F.","affiliations":[],"preferred":false,"id":651112,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}} ,{"id":70017783,"text":"70017783 - 1996 - Relationship between the present-day stress field and plate boundary forces in the Pacific Northwest","interactions":[],"lastModifiedDate":"2019-08-09T13:16:45","indexId":"70017783","displayToPublicDate":"1996-01-01T00:00:00","publicationYear":"1996","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1807,"text":"Geophysical Research Letters","active":true,"publicationSubtype":{"id":10}},"title":"Relationship between the present-day stress field and plate boundary forces in the Pacific Northwest","docAbstract":"The relationship between plate boundary forces and the observed stress field in the Pacific Northwest is established using numerical models of continental deformation. Because the orientation of the greatest horizontal principal stress throughout the Pacific Northwest differs considerably from the direction of convergence between the Juan de Fuca and North American plates, the relationship between the stress field and forces acting along the subduction zone has been unclear. To address this relationship, a two‐dimensional finite element model developed by Bird [1989] is used that incorporates critical aspects of continental deformation such as a stratified rheology and interaction between thermal and mechanical components of deformation. Boundary conditions are specified in terms of either velocity or shear traction, depending on whether the computed shear stress at the plate boundary is less than or exceeds, respectively, a prescribed limit. Shear‐stress limits on the subduction and transform plate boundaries are independently varied to determine the relative effect of forces along these boundaries on intraplate deformation. Results from this study indicate that the shear stress limit of both subduction and transform boundaries is low, and that the intraplate stress field is attributed, in part, to the normal component of relative plate motion along the transform boundaries. However, the models also indicate that although the subduction zone fault is weak, a minimum shear strength (≥ 10 MPa) for the fault is necessary to explain the observed stress field. The balance among forces along the tectonic boundaries of North America results in a surprising degree of variation in the present‐day stress field.
","language":"English","publisher":"AGU","doi":"10.1029/96GL03157","issn":"00948276","usgsCitation":"Geist, E.L., 1996, Relationship between the present-day stress field and plate boundary forces in the Pacific Northwest: Geophysical Research Letters, v. 23, no. 23, p. 3381-3384, https://doi.org/10.1029/96GL03157.","productDescription":"4 p.","startPage":"3381","endPage":"3384","costCenters":[{"id":520,"text":"Pacific Coastal and Marine Science Center","active":true,"usgs":true}],"links":[{"id":228862,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"23","issue":"23","noUsgsAuthors":false,"publicationDate":"1996-11-15","publicationStatus":"PW","scienceBaseUri":"50e4a763e4b0e8fec6cdc436","contributors":{"authors":[{"text":"Geist, Eric L. 0000-0003-0611-1150 egeist@usgs.gov","orcid":"https://orcid.org/0000-0003-0611-1150","contributorId":1956,"corporation":false,"usgs":true,"family":"Geist","given":"Eric","email":"egeist@usgs.gov","middleInitial":"L.","affiliations":[{"id":186,"text":"Coastal and Marine Geology Program","active":true,"usgs":true},{"id":520,"text":"Pacific Coastal and Marine Science Center","active":true,"usgs":true}],"preferred":true,"id":377556,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}} ,{"id":70182196,"text":"70182196 - 1996 - A bayesian approach to classification criteria for spectacled eiders","interactions":[],"lastModifiedDate":"2017-02-21T11:17:05","indexId":"70182196","displayToPublicDate":"1996-01-01T00:00:00","publicationYear":"1996","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1450,"text":"Ecological Applications","active":true,"publicationSubtype":{"id":10}},"title":"A bayesian approach to classification criteria for spectacled eiders","docAbstract":"To facilitate decisions to classify species according to risk of extinction, we used Bayesian methods to analyze trend data for the Spectacled Eider, an arctic sea duck. Trend data from three independent surveys of the Yukon-Kuskokwim Delta were analyzed individually and in combination to yield posterior distributions for population growth rates. We used classification criteria developed by the recovery team for Spectacled Eiders that seek to equalize errors of under- or overprotecting the species. We conducted both a Bayesian decision analysis and a frequentist (classical statistical inference) decision analysis. Bayesian decision analyses are computationally easier, yield basically the same results, and yield results that are easier to explain to nonscientists. With the exception of the aerial survey analysis of the 10 most recent years, both Bayesian and frequentist methods indicated that an endangered classification is warranted. The discrepancy between surveys warrants further research. Although the trend data are abundance indices, we used a preliminary estimate of absolute abundance to demonstrate how to calculate extinction distributions using the joint probability distributions for population growth rate and variance in growth rate generated by the Bayesian analysis. Recent apparent increases in abundance highlight the need for models that apply to declining and then recovering species.
","language":"English","publisher":"Wiley","doi":"10.2307/2269592","usgsCitation":"Taylor, B., Wade, P., Stehn, R., and Cochrane, J., 1996, A bayesian approach to classification criteria for spectacled eiders: Ecological Applications, v. 6, no. 4, p. 1077-1089, https://doi.org/10.2307/2269592.","productDescription":"13 p.","startPage":"1077","endPage":"1089","costCenters":[{"id":114,"text":"Alaska Science Center","active":true,"usgs":true}],"links":[{"id":335852,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"country":"United States","state":"Alaska","otherGeospatial":"Yukon-Kuskokwim Delta","volume":"6","issue":"4","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"58ac0e33e4b0ce4410e7d61e","contributors":{"authors":[{"text":"Taylor, B .L.","contributorId":181914,"corporation":false,"usgs":false,"family":"Taylor","given":"B .L.","affiliations":[],"preferred":false,"id":669944,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Wade, P.R.","contributorId":71761,"corporation":false,"usgs":true,"family":"Wade","given":"P.R.","email":"","affiliations":[],"preferred":false,"id":669945,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Stehn, R.A.","contributorId":107642,"corporation":false,"usgs":true,"family":"Stehn","given":"R.A.","email":"","affiliations":[],"preferred":false,"id":669946,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Cochrane, J.F.","contributorId":53728,"corporation":false,"usgs":true,"family":"Cochrane","given":"J.F.","email":"","affiliations":[],"preferred":false,"id":669947,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}} ,{"id":70018521,"text":"70018521 - 1996 - Key sources of uncertainty in QUAL2E model of passaic river","interactions":[],"lastModifiedDate":"2024-05-23T14:36:52.663818","indexId":"70018521","displayToPublicDate":"1996-01-01T00:00:00","publicationYear":"1996","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":"Key sources of uncertainty in QUAL2E model of passaic river","docAbstract":"Application of stream water-quality models in decision making has been hampered by a lack of data appropriate for minimization of model-simulation uncertainty. A method for determining data needed to reduce model-prediction uncertainty is illustrated in this paper. First-order reliability analysis is applied to determine (1) the model parameters that significantly affect model-prediction uncertainty; and (2) the constituents for which model-prediction uncertainty is unacceptable. Additional data are required to reduce uncertainty in the parameters that significantly affect constituents with high prediction uncertainty and consequently in model prediction. The method is demonstrated for multiconstituent water-quality modeling on the Passaic River in New Jersey applying QUAL2E. The model-prediction uncertainty of dissolved oxygen, biochemical oxygen demand, ammonia, and chlorphyll a is considered. For this example, only the reaeration rate and the algal maximum-specific-growth rate contribute significant uncertainty to model prediction. The effect of reducing the uncertainty in the reaeration rate and algal maximum-specific-growth rate on the uncertainty on predicted dissolved oxygen and chlorphyll a, respectively, is demonstrated.
","language":"English","publisher":"ASCE","doi":"10.1061/(ASCE)0733-9496(1996)122:2(105)","issn":"07339496","usgsCitation":"Melching, C., and Yoon, C., 1996, Key sources of uncertainty in QUAL2E model of passaic river: Journal of Water Resources Planning and Management, v. 122, no. 2, p. 105-113, https://doi.org/10.1061/(ASCE)0733-9496(1996)122:2(105).","productDescription":"9 p.","startPage":"105","endPage":"113","numberOfPages":"9","costCenters":[],"links":[{"id":227565,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"122","issue":"2","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a407ce4b0c8380cd64dd5","contributors":{"authors":[{"text":"Melching, Charles S.","contributorId":23973,"corporation":false,"usgs":true,"family":"Melching","given":"Charles S.","affiliations":[],"preferred":false,"id":379926,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Yoon, C.G.","contributorId":12217,"corporation":false,"usgs":true,"family":"Yoon","given":"C.G.","email":"","affiliations":[],"preferred":false,"id":379925,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ]}