Gillnet selectivity for lake trout (Salvelinus namaycush) was estimated indirectly from catches in nets of 102-, 114-, 127-, 140-, and 152-mm stretch measure. Mesh selectivity was modeled as a nonlinear response surface that describes changes in the mean, standard deviation, and skewness of fish lengths across mesh sizes. Gillnet selectivity for lake trout was described by five parameters that explained 88% of the variation in wedged and entangled catches, 81% of the variation in wedged catches, and 82% of the variation in entangled catches. Combined catches of wedged and entangled lake trout were therefore described more parsimoniously than separate catches of wedged and entangled lake trout. Peak selectivity of wedged and entangled fish increased from 588 to 663 mm total length as mesh size increased from 102 to 152 mm, and relative selectivity peaked at a total length of 638 mm. The estimated lake trout population size-frequency indicated that gillnet catches were negatively biased toward both small and large lake trout. As a consequence of this bias, survival of Lake Superior lake trout across ages 9-11 was underestimated by about 20% when the catch curve was not adjusted for gillnet selectivity.
","language":"English","publisher":"NRC Research Press","doi":"10.1139/f97-156","usgsCitation":"Hansen, M.J., Madenjian, C.P., Selgeby, J.H., and Helser, T., 1997, Gillnet selectivity for lake trout (Salvelinus namaycush) in Lake Superior: Canadian Journal of Fisheries and Aquatic Sciences, v. 54, no. 11, p. 2483-2490, https://doi.org/10.1139/f97-156.","productDescription":"8 p.","startPage":"2483","endPage":"2490","onlineOnly":"N","additionalOnlineFiles":"N","costCenters":[{"id":324,"text":"Great Lakes Science Center","active":true,"usgs":true}],"links":[{"id":133709,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"54","issue":"11","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4ac5e4b07f02db679ddd","contributors":{"authors":[{"text":"Hansen, Michael J. 0000-0001-8522-3876 michaelhansen@usgs.gov","orcid":"https://orcid.org/0000-0001-8522-3876","contributorId":5006,"corporation":false,"usgs":true,"family":"Hansen","given":"Michael","email":"michaelhansen@usgs.gov","middleInitial":"J.","affiliations":[{"id":324,"text":"Great Lakes Science Center","active":true,"usgs":true}],"preferred":true,"id":309287,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Madenjian, Charles P. 0000-0002-0326-164X cmadenjian@usgs.gov","orcid":"https://orcid.org/0000-0002-0326-164X","contributorId":2200,"corporation":false,"usgs":true,"family":"Madenjian","given":"Charles","email":"cmadenjian@usgs.gov","middleInitial":"P.","affiliations":[{"id":324,"text":"Great Lakes Science Center","active":true,"usgs":true}],"preferred":true,"id":309286,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Selgeby, James H.","contributorId":89828,"corporation":false,"usgs":true,"family":"Selgeby","given":"James","email":"","middleInitial":"H.","affiliations":[],"preferred":false,"id":309289,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Helser, Thomas E.","contributorId":27411,"corporation":false,"usgs":true,"family":"Helser","given":"Thomas E.","affiliations":[],"preferred":false,"id":309288,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}} ,{"id":70019273,"text":"70019273 - 1997 - Hydrochemical evolution of sodium-sulfate and sodium-chloride groundwater beneath the Northern Chihuahuan Desert, Trans-Pecos, Texas, USA","interactions":[],"lastModifiedDate":"2024-03-06T12:08:56.099588","indexId":"70019273","displayToPublicDate":"1997-01-01T00:00:00","publicationYear":"1997","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1923,"text":"Hydrogeology Journal","active":true,"publicationSubtype":{"id":10}},"title":"Hydrochemical evolution of sodium-sulfate and sodium-chloride groundwater beneath the Northern Chihuahuan Desert, Trans-Pecos, Texas, USA","docAbstract":"Groundwater beneath the northern Chihuahuan Desert, Trans-Pecos, Texas, USA, occurs in both carbonate and siliciclastic aquifers beneath a thick unsaturated zone in shallow Rio Grande alluvium. Groundwater hydrochemical evolution was investigated by analyzing soils, soils leachates, bolson-fill sediments, water from the unsaturated zone, and groundwater from three major aquifers. Ionic relations, mineral saturation states, and geochemical modeling show that groundwater compositions are controlled by reactions in the unsaturated zone, mineralogy of unsaturated sediments and aquifers, position in the groundwater flow system, and extensive irrigation. Recharge to aquifers unaffected by irrigation is initially a Ca-HCO3 type as a result of dissolving carbonate surficial salts. With continued flow and mineral-water interaction, saturation with calcite and dolomite is maintained, gypsum is dissolved, and aqueous Ca and Mg are exchanged for adsorbed Na to produce a Na-SO4 water. Groundwater in Rio Grande alluvium is a Na-Cl type, reflecting river-water composition and the effects of irrigation, evapotranspiration, and surficial salt recycling. These results document two hydrochemical evolution paths for groundwater in arid lands. If recharge is dilute precipitation, significant changes in water chemistry can occur in unsaturated media, ion exchange can be as important as dissolution-precipitation reactions in determining groundwater composition, and mineral-water reactions ultimately control groundwater composition. If recharge is return flow of irrigation water that already contains appreciable solutes, mineral-water reactions are less important than irrigation-water composition in determining groundwater chemistry.
A new mechanical model for the cause of the New Madrid seismic zone in the central United States is analyzed. The model contains a subhorizontal detachment fault which is assumed to be near the domed top surface of locally thickened anomalous lower crust (“rift pillow”). Regional horizontal compression induces slip on the fault, and the slip creates a stress concentration in the upper crust above the rift pillow dome. In the coseismic stage of the model earthquake cycle, where the three largest magnitude 7–8 earthquakes in 1811–1812 are represented by a single model mainshock on a vertical northeast trending fault, the model mainshock has a moment equivalent to a magnitude 8 event. During the interseismic stage, corresponding to the present time, slip on the detachment fault exerts a right-lateral shear stress on the locked vertical fault whose failure produces the model mainshock. The sense of shear is generally consistent with the overall sense of slip of 1811–1812 and later earthquakes. Predicted rates of horizontal strain at the ground surface are about 10−7 year−1 and are comparable to some observed rates. The model implies that rift pillow geometry is a significant influence on the maximum possible earthquake magnitude.
","language":"English","publisher":"American Geophysical Union","doi":"10.1029/97JB02716","issn":"01480227","usgsCitation":"Stuart, W., Hildenbrand, T., and Simpson, R., 1997, Stressing of the New Madrid seismic zone by a lower crust detachment fault: Journal of Geophysical Research B: Solid Earth, v. 102, no. 12, p. 27623-27633, https://doi.org/10.1029/97JB02716.","productDescription":"11 p.","startPage":"27623","endPage":"27633","numberOfPages":"11","costCenters":[],"links":[{"id":480012,"rank":2,"type":{"id":40,"text":"Open Access Publisher Index Page"},"url":"https://doi.org/10.1029/97jb02716","text":"Publisher Index Page"},{"id":226537,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"102","issue":"12","noUsgsAuthors":false,"publicationDate":"1997-12-10","publicationStatus":"PW","scienceBaseUri":"505b9b6fe4b08c986b31ceb0","contributors":{"authors":[{"text":"Stuart, W.D.","contributorId":65865,"corporation":false,"usgs":true,"family":"Stuart","given":"W.D.","email":"","affiliations":[],"preferred":false,"id":381680,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Hildenbrand, T.G.","contributorId":83892,"corporation":false,"usgs":true,"family":"Hildenbrand","given":"T.G.","email":"","affiliations":[],"preferred":false,"id":381682,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Simpson, R.W.","contributorId":76738,"corporation":false,"usgs":true,"family":"Simpson","given":"R.W.","email":"","affiliations":[],"preferred":false,"id":381681,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70019267,"text":"70019267 - 1997 - Land subsidence caused by the East Mesa geothermal field, California, observed using SAR interferometry","interactions":[],"lastModifiedDate":"2024-02-10T14:31:35.092861","indexId":"70019267","displayToPublicDate":"1997-01-01T00:00:00","publicationYear":"1997","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":"Land subsidence caused by the East Mesa geothermal field, California, observed using SAR interferometry","docAbstract":"Interferometric combination of pairs of synthetic aperture radar (SAR) images acquired by the ERS-1 satellite maps the deformation field associated with the activity of the East Mesa geothermal plant, located in southern California. SAR interferometry is applied to this flat area without the need of a digital terrain model. Several combinations are used to ascertain the nature of the phenomenon. Short term interferograms reveal surface phase changes on agricultural fields similar to what had been observed previously with SEASAT radar data. Long term (2 years) interferograms allow the study of land subsidence and improve prior knowledge of the displacement field, and agree with existing, sparse levelling data. This example illustrates the power of the interferometric technique for deriving accurate industrial intelligence as well as its potential for legal action, in cases involving environmental damages.
We use numerical simulations of transonic flow through a crack to study the dynamics of the formation of shock waves downstream from a nozzle-like constriction inside the crack. The model solves the full set of Navier-Stokes equations in two dimensions via an explicit multifield finite difference representation. The crack walls are assumed to be perfectly rigid, and elastic coupling to the solid is not considered. The simulations demonstrate how the behavior of unsteady shock waves near the walls can produce recurring step-like pressure transients in the flow, which in turn induce resonance of the fluid-filled crack. The motion of the shock waves is governed primarily by smooth, low-amplitude pressure fluctuations at the outlet of the crack. The force induced on the walls scales with the amplitude of the shock, which is a function of the magnitude of the inlet pressure, aperture of the constriction, and thickness of the boundary layer. The applied force also scales in proportion to the spatial extent of the shock excursion, which depends on the fluctuation rate of outlet pressure. Using the source parameters of long-period (LP) events at Redoubt Volcano, Alaska, as a guide for our simulations, we infer that coupling of the shock to the walls occurs for crack inlet to outlet pressure ratios pi/po>2.31 and that the position of the shock front becomes most sensitive to outlet pressure fluctuations for flow regimes with pi/po>2.48. For such regimes, fluctuations of outlet pressure of up to ±0.5 MPa at rates up to 3 MPa/s are sufficient to induce pressure transients with magnitudes up to 12.5 MPa over 0.1–2.5 m of the walls within ∼0.5 s. These flow parameters may be adequate for triggering the LP events in the precursory swarm to the December 14, 1989, eruption of Redoubt. According to the flow model the recurrence rate and amplitudes of L.P events are inferred to be a manifestation of the response of a shallow hydrothermal reservoir to the sustained injection of superheated steam from a magma column roofing below this reservoir.
","language":"English","publisher":"American Geophysical Union","doi":"10.1029/97JB00023","issn":"01480227","usgsCitation":"Morrissey, M., and Chouet, B., 1997, A numerical investigation of choked flow dynamics and its application to the triggering mechanism of long-period events at Redoubt Volcano, Alaska: Journal of Geophysical Research B: Solid Earth, v. 102, no. B4, p. 7965-7983, https://doi.org/10.1029/97JB00023.","productDescription":"19 p.","startPage":"7965","endPage":"7983","numberOfPages":"19","costCenters":[],"links":[{"id":227711,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"102","issue":"B4","noUsgsAuthors":false,"publicationDate":"1997-04-10","publicationStatus":"PW","scienceBaseUri":"5059e4c8e4b0c8380cd4691b","contributors":{"authors":[{"text":"Morrissey, M.M.","contributorId":41477,"corporation":false,"usgs":true,"family":"Morrissey","given":"M.M.","email":"","affiliations":[],"preferred":false,"id":383154,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Chouet, B. A.","contributorId":31813,"corporation":false,"usgs":true,"family":"Chouet","given":"B. A.","affiliations":[],"preferred":false,"id":383153,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70019945,"text":"70019945 - 1997 - Inverse models: A necessary next step in ground-water modeling","interactions":[],"lastModifiedDate":"2024-03-08T01:09:08.216874","indexId":"70019945","displayToPublicDate":"1997-01-01T00:00:00","publicationYear":"1997","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":3825,"text":"Groundwater","active":true,"publicationSubtype":{"id":10}},"title":"Inverse models: A necessary next step in ground-water modeling","docAbstract":"Inverse models using, for example, nonlinear least-squares regression, provide capabilities that help modelers take full advantage of the insight available from ground-water models. However, lack of information about the requirements and benefits of inverse models is an obstacle to their widespread use. This paper presents a simple ground-water flow problem to illustrate the requirements and benefits of the nonlinear least-squares regression method of inverse modeling and discusses how these attributes apply to field problems. The benefits of inverse modeling include: (1) expedited determination of best fit parameter values; (2) quantification of the (a) quality of calibration, (b) data shortcomings and needs, and (c) confidence limits on parameter estimates and predictions; and (3) identification of issues that are easily overlooked during nonautomated calibration.
Analysis of frequent trilateration observations from the two-color electronic distance measuring networks in California demonstrate that the noise power spectra are dominated by white noise at higher frequencies and power law behavior at lower frequencies. In contrast, Earth scientists typically have assumed that only white noise is present in a geodetic time series, since a combination of infrequent measurements and low precision usually preclude identifying the time-correlated signature in such data. After removing a linear trend from the two-color data, it becomes evident that there are primarily two recognizable types of time-correlated noise present in the residuals. The first type is a seasonal variation in displacement which is probably a result of measuring to shallow surface monuments installed in clayey soil which responds to seasonally occurring rainfall; this noise is significant only for a small fraction of the sites analyzed. The second type of correlated noise becomes evident only after spectral analysis of line length changes and shows a functional relation at long periods between power and frequency of 1/ƒα, where ƒ is frequency and α≈2. With α=2, this type of correlated noise is termed random-walk noise, and its source is mainly thought to be small random motions of geodetic monuments with respect to the Earth's crust, though other sources are possible. Because the line length changes in the two-color networks are measured at irregular intervals, power spectral techniques cannot reliably estimate the level of 1/ƒα noise. Rather, we also use here a maximum likelihood estimation technique which assumes that there are only two sources of noise in the residual time series (white noise and random-walk noise) and estimates the amount of each. From this analysis we find that the random-walk noise level averages about 1.3 mm/√yr and that our estimates of the white noise component confirm theoretical limitations of the measurement technique. In addition, the seasonal noise can be as large as 3 mm in amplitude but typically is less than 0.5 mm. Because of the presence of random-walk noise in these time series, modeling and interpretation of the geodetic data must account for this source of error. By way of example we show that estimating the time-varying strain tensor (a form of spatial averaging) from geodetic data having both random-walk and white noise error components results in seemingly significant variations in the rate of strain accumulation; spatial averaging does reduce the size of both noise components but not their relative influence on the resulting strain accumulation model.
","language":"English","publisher":"American Geophysical Union","doi":"10.1029/96JB02945","issn":"01480227","usgsCitation":"Langbein, J., and Johnson, H., 1997, Correlated errors in geodetic time series: Implications for time-dependent deformation: Journal of Geophysical Research B: Solid Earth, v. 102, no. B1, p. 591-603, https://doi.org/10.1029/96JB02945.","productDescription":"13 p.","startPage":"591","endPage":"603","numberOfPages":"13","costCenters":[],"links":[{"id":480067,"rank":2,"type":{"id":40,"text":"Open Access Publisher Index Page"},"url":"https://doi.org/10.1029/96jb02945","text":"Publisher Index Page"},{"id":226907,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"102","issue":"B1","noUsgsAuthors":false,"publicationDate":"1997-01-10","publicationStatus":"PW","scienceBaseUri":"5059fc21e4b0c8380cd4e12e","contributors":{"authors":[{"text":"Langbein, J.","contributorId":16990,"corporation":false,"usgs":true,"family":"Langbein","given":"J.","affiliations":[],"preferred":false,"id":381753,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Johnson, H.","contributorId":61163,"corporation":false,"usgs":true,"family":"Johnson","given":"H.","affiliations":[],"preferred":false,"id":381754,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70019271,"text":"70019271 - 1997 - Deep-coal potential in the Appalachian Coal Basin, USA: The Kentucky model","interactions":[],"lastModifiedDate":"2012-03-12T17:19:16","indexId":"70019271","displayToPublicDate":"1997-01-01T00:00:00","publicationYear":"1997","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":3108,"text":"Prace - Panstwowego Instytutu Geologicznego","active":true,"publicationSubtype":{"id":10}},"title":"Deep-coal potential in the Appalachian Coal Basin, USA: The Kentucky model","docAbstract":"The Eastern Kentucky Coal Field is located in the Appalachian Basin of the United States and occupies an area of approximately 15,000 square kilometers. The coal beds range from a few centimeters to several meters in thickness and consist of high-grade bituminous coal. Currently the amount of coal mined by surface methods exceeds underground extraction; however, there is a steady and gradual shift toward underground mining. In the future, as near-surface resources are depleted, this trend toward increased underground mining will continue. Knowledge about deeper coals is essential for future economic development of resources. Preliminary investigations indicate that coal-bearing strata with deep-mining potential exist in several parts of eastern Kentucky, especially along the Eastern Kentucky Syncline. Eastern Kentucky coals are Westphalian A through D; however, current production is from major beds of Westphalian A and B. Because coals that occur above drainage are more easily accessible and are generally of better quality, most of the current mining takes place in formations that are at or near the surface. In the future, however, due to environmental regulations and increased demands, it will be necessary to attempt to utilize deeper coals about which little is known. Future development of deep resources will require data from boreholes and high-resolution geophysical-logging techniques. There is also potential for coal-bed methane from the deeper coals which could be an important resource in the Appalachian Coal Basin where a natural gas distribution system already exists.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Prace - Panstwowego Instytutu Geologicznego","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","issn":"08669465","usgsCitation":"Haney, D.C., and Chesnut, D., 1997, Deep-coal potential in the Appalachian Coal Basin, USA: The Kentucky model: Prace - Panstwowego Instytutu Geologicznego, no. 157 PART 2, p. 336-337.","startPage":"336","endPage":"337","numberOfPages":"2","costCenters":[],"links":[{"id":226956,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"issue":"157 PART 2","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"5059fe2ce4b0c8380cd4eb80","contributors":{"authors":[{"text":"Haney, D. C.","contributorId":97854,"corporation":false,"usgs":true,"family":"Haney","given":"D.","email":"","middleInitial":"C.","affiliations":[],"preferred":false,"id":382199,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Chesnut, D.R. Jr.","contributorId":100548,"corporation":false,"usgs":true,"family":"Chesnut","given":"D.R.","suffix":"Jr.","email":"","affiliations":[],"preferred":false,"id":382200,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70019784,"text":"70019784 - 1997 - An increase in herbivory of cottonwood in yellowstone national park","interactions":[],"lastModifiedDate":"2012-03-12T17:19:20","indexId":"70019784","displayToPublicDate":"1997-01-01T00:00:00","publicationYear":"1997","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2900,"text":"Northwest Science","onlineIssn":"2161-9859","printIssn":"0029-344X","active":true,"publicationSubtype":{"id":10}},"title":"An increase in herbivory of cottonwood in yellowstone national park","docAbstract":"This study examined an effect of elk (Cervus elaphus nelsoni) on narrowleaf cottonwood (Populus angustifolia) in northern Yellowstone National Park, where stands consist of old trees and younger, densely-branched bushes. The elk herd increased from a census of 3,172 in 1968 to a census of 18,913 in 1988. The purposes of this study were to: 1) document the height-growth of cottonwood bushes, 2) determine if the height of browsing corresponded with snow depth, and 3) determine if there has been a recent increase in cottonwood herbivory. In 5 stands of different age (ranging ca. 9-45 y old), I measured the height of live previous-year-growth and the height of the oldest stems killed by browsing. The tallest previous-year-growth was 80 cm; all stems taller than 29 cm had been browsed. Stems were killed by browsing closer to the ground in younger stands (respectively, 87, 62, 28, 14, and 9 cm; P < 0.001). There was no change in mid-winter snow depth during the period 1950-1994. The 2 stands established since 1977 had relatively small variances in the height at which stems were killed by browsing (21 and 15 cm2), a uniformity likely caused by intense herbivory since respective stand creation. The large variances in the height of browse-killed stems in older stands (745, 399, and 291 cm2) were likely caused by an initial period of light-to-moderate herbivory followed by an increase in herbivory that killed the stem tips at the heights existing at the time. The bush growth-form apparently results from an increase in herbivory that occurred between 1968 and 1977, a period in which the elk winter census increased from 3,172 to 8,981. The weight of evidence suggests that EuroAmerican influences have caused the northern elk herd to increase in number since the establishment of the park. If herbivory does not decrease, cottonwood may be eliminated from Yellowstone's northern range.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Northwest Science","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","issn":"0029344X","usgsCitation":"Keigley, R., 1997, An increase in herbivory of cottonwood in yellowstone national park: Northwest Science, v. 71, no. 2, p. 127-136.","startPage":"127","endPage":"136","numberOfPages":"10","costCenters":[],"links":[{"id":228135,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"71","issue":"2","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"5059ea76e4b0c8380cd48899","contributors":{"authors":[{"text":"Keigley, R.B.","contributorId":85115,"corporation":false,"usgs":true,"family":"Keigley","given":"R.B.","email":"","affiliations":[],"preferred":false,"id":383900,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}} ,{"id":70019262,"text":"70019262 - 1997 - Isotopic and trace element compositions of upper mantle and lower crustal xenoliths, Cima volcanic field, California: Implications for evolution of the subcontinental lithospheric mantle","interactions":[],"lastModifiedDate":"2012-03-12T17:19:11","indexId":"70019262","displayToPublicDate":"1997-01-01T00:00:00","publicationYear":"1997","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":"Isotopic and trace element compositions of upper mantle and lower crustal xenoliths, Cima volcanic field, California: Implications for evolution of the subcontinental lithospheric mantle","docAbstract":"Ultramafic and mafic xenoliths from the Cima volcanic field, southern California, provide evidence of episodic modification of the upper mantle and underplating of the crust beneath a portion of the southern Basin and Range province. The upper mantle xenoliths include spinel peridotite and anhydrous and hydrous pyroxenite, some cut by igneous-textured pyroxenite-gabbro veins and dikes and some by veins of amphibole ?? plagioclase. Igneous-textured pyroxenites and gabbros like the dike rocks also occur abundantly as isolated xenoliths inferred to represent underplated crust. Mineral and whole rock trace element compositions among and within the different groups of xenoliths are highly variable, reflecting multiple processes that include magma-mantle wall rock reactions, episodic intrusion and it filtration of basaltic melts of varied sources into the mantle wall rock, and fractionation. Nd, Sr, and Pb isotopic compositions mostly of clinopyroxene and plagioclase mineral separates show distinct differences between mantle xenoliths (??Nd = -5.7 to +3.4; 87Sr/86Sr = 0.7051 - 0.7073; 206Pb/204Pb = 19.045 - 19.195) and the igneous-textured xenoliths (??Nd = +7.7 to +11.7; 87Sr/86Sr = 0.7027 - 0.7036 with one carbonate-affected outlier at 0.7054; and 206Pb/204Pb = 18.751 - 19.068), so that they cannot be related. The igneous-textured pyroxenites and gabbros are similar in their isotopic compositions to the host basaltic rocks, which have ??Nd of+5.1 to +9.3; 87Sr/86Sr of 0.7028 - 0.7050, and 206Pb/204Pb of 18.685 - 21.050. The igneous-textured pyroxenites and gabbros are therefore inferred to be related to the host rocks as earlier cogenetic intrusions in the mantle and in the lower crust. Two samples of peridotite, one modally metasomatized by amphibole and the other by plagioclase, have isotopic compositions intermediate between the igneous-textured xenoliths and the mantle rock, suggesting mixing, but also derivation of the metasomatizing magmas from two separate and distinct sources. Sm-Nd two-mineral \"isochrons\" yield apparent ages for petrographically identical rocks believed to be coeval ranging from -0 to 113 ?? 26 Ma, indicating the unreliability of dating these rocks with this method. Amphibole and plagioclase megacrysts are isotopically like the host basalts and probably originate by mechanical breakup of veins comagmatic with the host basaltic rocks. Unlike other Basin and Range localities, Cima Cr-diopside group isotopic compositions do not overlap with those of the host basalts. Copyright 1997 by the American Geophysical Union.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Journal of Geophysical Research B: Solid Earth","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","issn":"01480227","usgsCitation":"Mukasa, S., and Wilshire, H.G., 1997, Isotopic and trace element compositions of upper mantle and lower crustal xenoliths, Cima volcanic field, California: Implications for evolution of the subcontinental lithospheric mantle: Journal of Geophysical Research B: Solid Earth, v. 102, no. B9, p. 20133-20148.","startPage":"20133","endPage":"20148","numberOfPages":"16","costCenters":[],"links":[{"id":226780,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"102","issue":"B9","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a3f98e4b0c8380cd64640","contributors":{"authors":[{"text":"Mukasa, S.B.","contributorId":89568,"corporation":false,"usgs":true,"family":"Mukasa","given":"S.B.","email":"","affiliations":[],"preferred":false,"id":382167,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Wilshire, H. G.","contributorId":36125,"corporation":false,"usgs":false,"family":"Wilshire","given":"H.","middleInitial":"G.","affiliations":[],"preferred":false,"id":382166,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":1014901,"text":"1014901 - 1997 - The loss of hyperosmoregulatory ability in migrating juvenile American shad, Alosa sapidissima","interactions":[],"lastModifiedDate":"2017-11-06T10:35:53","indexId":"1014901","displayToPublicDate":"1997-01-01T00:00:00","publicationYear":"1997","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}},"displayTitle":"The loss of hyperosmoregulatory ability in migrating juvenile American shad, Alosa sapidissima","title":"The loss of hyperosmoregulatory ability in migrating juvenile American shad, Alosa sapidissima","docAbstract":"Investigations on juvenile American shad (Alosa sapidissima) revealed several physiological changes associated with downstream migration. Plasma chloride decreased 20% in wild juvenile shad during the autumn migration. Migrants had lower condition factor and hematocrit than non-migrant shad captured by beach seining. Gill Na + ,K + -ATPase activity of migrant shad was higher than non-migrant; a 2.5-fold increase was observed in 1993, while a 57% increase was observed in 1994. Similar changes were observed in laboratory studies of shad maintained in fresh water under simulated natural temperature and photoperiod. Plasma chloride dropped 68% and gill Na + ,K + -ATPase activity increased 3-fold over a 3-month period. Decreased plasma chloride was associated with increased mortality. Increases in gill Na + ,K + -ATPase activity decreases in plasma chloride and osmolality, and incidence of mortality were delayed and moderated, but not eliminated, in shad maintained at constant temperature (24°C). Shad did not survive in fresh water past December regardless of temperature regime. In seawater, all shad survived and showed no perturbation of plasma chloride at 24°C or simulated natural temperature (above 4°C). The decline in hyperosmoregulatory ability, as influenced by declining temperatures, may serve as a proximate cue for autumnal migration.
","language":"English","publisher":"NRC Research Press","doi":"10.1139/f97-144","usgsCitation":"Zydlewski, J.D., and McCormick, S., 1997, The loss of hyperosmoregulatory ability in migrating juvenile American shad, Alosa sapidissima: Canadian Journal of Fisheries and Aquatic Sciences, v. 54, no. 10, p. 2377-2387, https://doi.org/10.1139/f97-144.","productDescription":"11 p.","startPage":"2377","endPage":"2387","costCenters":[{"id":365,"text":"Leetown Science Center","active":true,"usgs":true}],"links":[{"id":197398,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"54","issue":"10","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4a82e4b07f02db64ae5a","contributors":{"authors":[{"text":"Zydlewski, Joseph D. 0000-0002-2255-2303 jzydlewski@usgs.gov","orcid":"https://orcid.org/0000-0002-2255-2303","contributorId":2004,"corporation":false,"usgs":true,"family":"Zydlewski","given":"Joseph","email":"jzydlewski@usgs.gov","middleInitial":"D.","affiliations":[{"id":199,"text":"Coop Res Unit Leetown","active":true,"usgs":true},{"id":198,"text":"Coop Res Unit Atlanta","active":true,"usgs":true},{"id":365,"text":"Leetown Science Center","active":true,"usgs":true}],"preferred":false,"id":321484,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"McCormick, S. D. 0000-0003-0621-6200","orcid":"https://orcid.org/0000-0003-0621-6200","contributorId":20278,"corporation":false,"usgs":true,"family":"McCormick","given":"S. D.","affiliations":[{"id":365,"text":"Leetown Science Center","active":true,"usgs":true}],"preferred":false,"id":321485,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70020310,"text":"70020310 - 1997 - Resistance formulas in hydraulics-based models for routing debris flows","interactions":[],"lastModifiedDate":"2012-03-12T17:20:16","indexId":"70020310","displayToPublicDate":"1997-01-01T00:00:00","publicationYear":"1997","noYear":false,"publicationType":{"id":24,"text":"Conference Paper"},"publicationSubtype":{"id":19,"text":"Conference Paper"},"title":"Resistance formulas in hydraulics-based models for routing debris flows","docAbstract":"The one-dimensional, cross-section-averaged flow equations formulated for routing debris flows down a narrow valley are identical to those for clear-water flow, except for the differences in the values of the flow parameters, such as the momentum (or energy) correction factor, resistance coefficient, and friction slope. Though these flow parameters for debris flow in channels with cross-sections of arbitrary geometric shape can only be determined empirically, the theoretical values of such parameters for debris flow in wide channels exist. This paper aims to derive the theoretical resistance coefficient and friction slope for debris flow in wide channels using a rheological model for highly-concentrated, rapidly-sheared granular flows, such as the generalized viscoplastic fluid (GVF) model. Formulating such resistance coefficient or friction slope is equivalent to developing a generally applicable resistance formula for routing debris flows. Inclusion of a nonuniform term in the expression of the resistance formula proves useful in removing the customary assumption that the spatially varied resistance at any section is equal to what would take place with the same rate of flow passing the same section under conditions of uniformity. This in effect implies an improvement in the accuracy of unsteady debris-flow computation.","largerWorkTitle":"International Conference on Debris-Flow Hazards Mitigation: Mechanics, Prediction, and Assessment, Proceedings","conferenceTitle":"Proceedings of the 1997 1st International Conference on Debris-Flow Hazards Mitigation: Mechanics, Prediction, and Assessment","conferenceDate":"7 August 1997 through 9 August 1997","conferenceLocation":"San Francisco, CA, USA","language":"English","publisher":"ASCE","publisherLocation":"New York, NY, United States","usgsCitation":"Chen, C., and Ling, C., 1997, Resistance formulas in hydraulics-based models for routing debris flows, in International Conference on Debris-Flow Hazards Mitigation: Mechanics, Prediction, and Assessment, Proceedings, San Francisco, CA, USA, 7 August 1997 through 9 August 1997, p. 360-372.","startPage":"360","endPage":"372","numberOfPages":"13","costCenters":[],"links":[{"id":231212,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505aa9c0e4b0c8380cd85f60","contributors":{"authors":[{"text":"Chen, Cheng-lung","contributorId":30752,"corporation":false,"usgs":true,"family":"Chen","given":"Cheng-lung","email":"","affiliations":[],"preferred":false,"id":385766,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Ling, Chi-Hai","contributorId":55154,"corporation":false,"usgs":true,"family":"Ling","given":"Chi-Hai","email":"","affiliations":[],"preferred":false,"id":385767,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70019779,"text":"70019779 - 1997 - The history of a continent from U-Pb ages of zircons from Orinoco River sand and Sm-Nd isotopes in Orinoco basin river sediments","interactions":[],"lastModifiedDate":"2013-01-20T17:04:56","indexId":"70019779","displayToPublicDate":"1997-01-01T00:00:00","publicationYear":"1997","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1213,"text":"Chemical Geology","active":true,"publicationSubtype":{"id":10}},"title":"The history of a continent from U-Pb ages of zircons from Orinoco River sand and Sm-Nd isotopes in Orinoco basin river sediments","docAbstract":"We report SHRIMP U-Pb ages of 49 zircons from a sand sample from the lower Orinoco River, Venezuela, and Nd model ages of the fine sediment load from the main river and tributaries. The U-Pb ages reflect individual magmatic or metamorphic events, the Sm-Nd model ages reflect average crustal-residence ages of the sediment sources. Together they allow delineation of the crust-formation history of the basement precursors of the sediments. The U-Pb ages range from 2.83 to 0.15 Ga, and most are concordant or nearly so. Discrete age groupings occur at ??? 2.8, ??? 2.1, and ??? 1.1 Ga. The oldest group contains only three samples but is isolated from its closest neighbors by a ??? 600 Ma age gap. Larger age groupings at ??? 2.1 and ??? 1.1 Ga make up about a third and a quarter of the total number of analyses, respectively. The remaining analyses scatter along concordia, and most are younger than 1.6 Ga. The ??? 2.8 and ??? 2.1 Ga ages correspond to periods of crust formation of the Imataca and Trans-Amazonian provinces of the Guyana Shield, respectively, and record intervals of short but intensive continental growth. These ages coincide with ??? 2.9 and ??? 2.1 Ga Nd model ages of sediments from tributaries draining the Archean and Proterozoic provinces of the Guyana Shield, respectively, indicating that the U-Pb ages record the geological history of the crystalline basement of the Orinoco basin. Zircons with ages corresponding to the major orogenies of the North Atlantic continents (the Superior at ??? 2.7 Ga and Hudsonian at 1.7-1.9 Ga) were not found in the Orinoco sample. The age distribution may indicate that South and North America were separated throughout their history. Nd model ages of sediments from the lower Orinoco River and Andean tributaries are ??? 1.9 Ga, broadly within the range displayed by major rivers and dusts. This age does not coincide with known thermal events in the region and reflects mixing of sources with different crust-formation ages. The igneous and metamorphic history of these sources, as recorded by the detrital zircons, is that of the Orinoco basin basement. This implies that, despite evidence of fast sedimentary recycling, global similarities in Nd crustal-residence ages, and the probability of cross-continent mixing through continental drift, the sedimentary material carried by individual rivers is mainly derived from the crystalline basement in the basin. The global semblance in Nd isotope ratios in major river sediments and atmospheric dusts results from the averaging effect of large-scale sampling of the continents, which are heterogeneous in age on smaller regional scales. A large portion of the continental crust in the Orinoco basin formed during the Trans-Amazonian orogeny at 2.0-2.1 Ga, and smaller portions formed both earlier, at ??? 2.8 Ga, and later, after 1.6 Ga. These observations, which are consistent with the relative sizes of crustal age provinces in the Orinoco basin, indicate that sediments from the lower Orinoco and Andean tributaries contain 25-35% of material added to the crust since Trans-Amazonian times. Nd model ages of these sediments underestimate the average crust-formation age of the basement of the Orinoco basin by only about 10%. If this relationship holds in other river basins, then Nd model ages of major rivers and wind blown particulates indicate that the mean age of the continental crust is ??? 1.9-2 Ga. ?? 1997 Elsevier Science B.V.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Chemical Geology","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","publisher":"Elsevier","doi":"10.1016/S0009-2541(97)00039-9","issn":"00092541","usgsCitation":"Goldstein, S., Arndt, N., and Stallard, R., 1997, The history of a continent from U-Pb ages of zircons from Orinoco River sand and Sm-Nd isotopes in Orinoco basin river sediments: Chemical Geology, v. 139, no. 1-4, p. 271-286, https://doi.org/10.1016/S0009-2541(97)00039-9.","startPage":"271","endPage":"286","numberOfPages":"16","costCenters":[],"links":[{"id":479993,"rank":1,"type":{"id":40,"text":"Open Access Publisher Index Page"},"url":"https://doi.org/10.1016/s0009-2541(97)00039-9","text":"Publisher Index Page"},{"id":266041,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/S0009-2541(97)00039-9"},{"id":228020,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"139","issue":"1-4","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505bacbbe4b08c986b3236da","contributors":{"authors":[{"text":"Goldstein, S.L.","contributorId":40357,"corporation":false,"usgs":true,"family":"Goldstein","given":"S.L.","email":"","affiliations":[],"preferred":false,"id":383885,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Arndt, N.T.","contributorId":95887,"corporation":false,"usgs":true,"family":"Arndt","given":"N.T.","email":"","affiliations":[],"preferred":false,"id":383886,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Stallard, R.F.","contributorId":30247,"corporation":false,"usgs":true,"family":"Stallard","given":"R.F.","email":"","affiliations":[],"preferred":false,"id":383884,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70019658,"text":"70019658 - 1997 - Geochemical mole-balance modeling with uncertain data","interactions":[],"lastModifiedDate":"2019-02-08T16:15:35","indexId":"70019658","displayToPublicDate":"1997-01-01T00:00:00","publicationYear":"1997","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":"Geochemical mole-balance modeling with uncertain data","docAbstract":"Geochemical mole-balance models are sets of chemical reactions that quantitatively account for changes in the chemical and isotopic composition of water along a flow path. A revised mole-balance formulation that includes an uncertainty term for each chemical and isotopic datum is derived. The revised formulation is comprised of mole-balance equations for each element or element redox state, alkalinity, electrons, solvent water, and each isotope; a charge-balance equation and an equation that relates the uncertainty terms for pH, alkalinity, and total dissolved inorganic carbon for each aqueous solution; inequality constraints on the size of the uncertainty terms; and inequality constraints on the sign of the mole transfer of reactants. The equations and inequality constraints are solved by a modification of the simplex algorithm combined with an exhaustive search for unique combinations of aqueous solutions and reactants for which the equations and inequality constraints can be solved and the uncertainty terms minimized. Additional algorithms find only the simplest mole-balance models and determine the ranges of mixing fractions for each solution and mole transfers for each reactant that are consistent with specified limits on the uncertainty terms. The revised formulation produces simpler and more robust mole-balance models and allows the significance of mixing fractions and mole transfers to be evaluated. In an example from the central Oklahoma aquifer, inclusion of up to 5% uncertainty in the chemical data can reduce the number of reactants in mole-balance models from seven or more to as few as three, these being cation exchange, dolomite dissolution, and silica precipitation. In another example from the Madison aquifer, inclusion of the charge-balance constraint requires significant increases in the mole transfers of calcite, dolomite, and organic matter, which reduce the estimated maximum carbon 14 age of the sample by about 10,000 years, from 22,700 years to 12,600 years.
","language":"English","publisher":"American Geophysical Union","doi":"10.1029/97WR01125","usgsCitation":"Parkhurst, D.L., 1997, Geochemical mole-balance modeling with uncertain data: Water Resources Research, v. 33, no. 8, p. 1957-1970, https://doi.org/10.1029/97WR01125.","productDescription":"14 p.","startPage":"1957","endPage":"1970","costCenters":[{"id":589,"text":"Toxic Substances Hydrology Program","active":true,"usgs":true}],"links":[{"id":487270,"rank":1,"type":{"id":40,"text":"Open Access Publisher Index Page"},"url":"https://doi.org/10.1029/97wr01125","text":"Publisher Index Page"},{"id":228012,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"33","issue":"8","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a1689e4b0c8380cd551ac","contributors":{"authors":[{"text":"Parkhurst, David L. 0000-0003-3348-1544 dlpark@usgs.gov","orcid":"https://orcid.org/0000-0003-3348-1544","contributorId":1088,"corporation":false,"usgs":true,"family":"Parkhurst","given":"David","email":"dlpark@usgs.gov","middleInitial":"L.","affiliations":[{"id":5044,"text":"National Research Program - Central Branch","active":true,"usgs":true}],"preferred":true,"id":383473,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}} ,{"id":70019811,"text":"70019811 - 1997 - Modeling structural influences on soil water retention","interactions":[],"lastModifiedDate":"2019-02-13T05:42:47","indexId":"70019811","displayToPublicDate":"1997-01-01T00:00:00","publicationYear":"1997","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":"Modeling structural influences on soil water retention","docAbstract":"A new model quantities the effect of soil structure, considered as the arrangement of particles in the soil, on soil water retention. The model partitions the pore space into texture-related and structure-related components, the textural component being what can be deduced to exist if the arrangement of the particles were random, and the structural component being the remainder. An existing model, based on particle-size distributions, represents the textural component, and a new model, based on aggregate-size distributions, represents the structural component. This new model makes use of generalized properties that vary little from one medium to another, thereby eliminating any need for empirically tilted parameters. It postulates a particular character of the structural pore space that in same ways resembles texture-related pore space, but with pore shape related to the breadth of the aggregate-size distribution. To predict a soil water retention curve, this model requires the soil's porosity and particle- and aggregate-size distributions. Tested with measurements for 17 samples from two sources, it fits the data much better than does a model based on texture alone. Goodness of fit indicated by correlation coefficients ranged from 0.908 to 0.998 for the new model, compared with a range of 0.686 in 0.955 for the texture-based model.","language":"English","publisher":"ACSESS","doi":"10.2136/sssaj1997.03615995006100030002x","issn":"03615995","usgsCitation":"Nimmo, J., 1997, Modeling structural influences on soil water retention: Soil Science Society of America Journal, v. 61, no. 3, p. 712-719, https://doi.org/10.2136/sssaj1997.03615995006100030002x.","productDescription":"8 p.","startPage":"712","endPage":"719","costCenters":[{"id":589,"text":"Toxic Substances Hydrology Program","active":true,"usgs":true}],"links":[{"id":227935,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"61","issue":"3","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a5c32e4b0c8380cd6facc","contributors":{"authors":[{"text":"Nimmo, J. R. 0000-0001-8191-1727","orcid":"https://orcid.org/0000-0001-8191-1727","contributorId":58304,"corporation":false,"usgs":true,"family":"Nimmo","given":"J. R.","affiliations":[],"preferred":false,"id":383984,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}} ,{"id":70019686,"text":"70019686 - 1997 - Seismic source study of the Racha-Dzhava (Georgia) earthquake from aftershocks and broad-band teleseismic body-wave records: An example of active nappe tectonics","interactions":[],"lastModifiedDate":"2024-02-08T12:01:45.542941","indexId":"70019686","displayToPublicDate":"1997-01-01T00:00:00","publicationYear":"1997","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1803,"text":"Geophysical Journal International","active":true,"publicationSubtype":{"id":10}},"title":"Seismic source study of the Racha-Dzhava (Georgia) earthquake from aftershocks and broad-band teleseismic body-wave records: An example of active nappe tectonics","docAbstract":"The Racha-Dzhava earthquake (Ms=7.0) that occurred on 1991 April 29 at 09:12:48.1 GMT in the southern border of the Great Caucasus is the biggest event ever recorded in the region, stronger than the Spitak earthquake (Ms=6.9) of 1988. A field expedition to the epicentral area was organised and a temporary seismic network of 37 stations was deployed to record the aftershock activity. A very precise image of the aftershock distribution is obtained, showing an elongated cloud oriented N105°, with one branch trending N310° in the western part. The southernmost part extends over 80 km, with the depth ranging from 0 to 15 km, and dips north. The northern branch, which is about 30 km long, shows activity that ranges in depth from 5 to 15 km. The complex thrust dips northwards. A stress-tensor inversion from P-wave first-motion polarities shows a state of triaxial compression, with the major principal axis oriented roughly N-S, the minor principal axis being vertical. Body-waveform inversion of teleseismic seismograms was performed for the main shock, which can be divided into four subevents with a total rupture-time duration of 22 s. The most important part of the seismic moment was released by a gentle northerly dipping thrust. The model is consistent with the compressive tectonics of the region and is in agreement with the aftershock distribution and the stress tensor deduced from the aftershocks. The focal mechanisms of the three largest aftershocks were also inverted from body-wave records. The April 29th (Ms=6.1) and May 5th (Ms=5.4) aftershocks have thrust mechanisms on roughly E-W-oriented planes, similar to the main shock. Surprisingly, the June 15th (Ms=6.2) aftershock shows a thrust fault striking N-S. This mechanism is explained by the structural control of the rupture along the east-dipping geometry of the Dzirula Massif close to the Borzhomi-Kazbeg strike-slip fault. In fact, the orientation and shape of the stress tensor produce a thrust on a N-S oriented plane. Nappe tectonics has been identified as an important feature in the Caucasus, and the source mechanism is consistent with this observation. A hidden fault is present below the nappe, and no large surface breaks were observed due to the main shock. The epicentral region is characterized by sediments that are trapped between two crystalline basements: the Dzirula Massif, which crops out south of Chiatoura, and the Caucasus Main Range north of Oni. Most, if not all, of the rupture is controlled by the thrusting of overlapping, deformed and folded sediments over the Dzirula Massif. This event is another example of blind active faults, with the distinctive feature that the fault plane dips at a gentle angle. The Racha Range is one of the surface expressions of this blind thrust, and its growth is the consequence and evidence of similar earthquakes in the past.
","language":"English","publisher":"Oxford Academic","doi":"10.1111/j.1365-246X.1997.tb00985.x","issn":"0956540X","usgsCitation":"Fuenzalida, H., Rivera, L., Haessler, H., Legrand, D., Philip, H., Dorbath, L., McCormack, D., Arefiev, S., Langer, C., and Cisternas, A., 1997, Seismic source study of the Racha-Dzhava (Georgia) earthquake from aftershocks and broad-band teleseismic body-wave records: An example of active nappe tectonics: Geophysical Journal International, v. 130, no. 1, p. 29-46, https://doi.org/10.1111/j.1365-246X.1997.tb00985.x.","productDescription":"18 p.","startPage":"29","endPage":"46","numberOfPages":"18","costCenters":[],"links":[{"id":480040,"rank":2,"type":{"id":41,"text":"Open Access External Repository Page"},"url":"https://hal.science/hal-04578497","text":"External Repository"},{"id":227800,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"130","issue":"1","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505b8b63e4b08c986b3177c7","contributors":{"authors":[{"text":"Fuenzalida, H.","contributorId":94806,"corporation":false,"usgs":true,"family":"Fuenzalida","given":"H.","email":"","affiliations":[],"preferred":false,"id":383591,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Rivera, L.","contributorId":39535,"corporation":false,"usgs":true,"family":"Rivera","given":"L.","email":"","affiliations":[],"preferred":false,"id":383586,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Haessler, H.","contributorId":82871,"corporation":false,"usgs":true,"family":"Haessler","given":"H.","email":"","affiliations":[],"preferred":false,"id":383589,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Legrand, D.","contributorId":37093,"corporation":false,"usgs":true,"family":"Legrand","given":"D.","email":"","affiliations":[],"preferred":false,"id":383585,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Philip, H.","contributorId":43122,"corporation":false,"usgs":true,"family":"Philip","given":"H.","email":"","affiliations":[],"preferred":false,"id":383587,"contributorType":{"id":1,"text":"Authors"},"rank":5},{"text":"Dorbath, L.","contributorId":103424,"corporation":false,"usgs":true,"family":"Dorbath","given":"L.","email":"","affiliations":[],"preferred":false,"id":383594,"contributorType":{"id":1,"text":"Authors"},"rank":6},{"text":"McCormack, D.","contributorId":97648,"corporation":false,"usgs":true,"family":"McCormack","given":"D.","email":"","affiliations":[],"preferred":false,"id":383592,"contributorType":{"id":1,"text":"Authors"},"rank":7},{"text":"Arefiev, S.","contributorId":92003,"corporation":false,"usgs":true,"family":"Arefiev","given":"S.","email":"","affiliations":[],"preferred":false,"id":383590,"contributorType":{"id":1,"text":"Authors"},"rank":8},{"text":"Langer, C.","contributorId":98480,"corporation":false,"usgs":true,"family":"Langer","given":"C.","email":"","affiliations":[],"preferred":false,"id":383593,"contributorType":{"id":1,"text":"Authors"},"rank":9},{"text":"Cisternas, A.","contributorId":43509,"corporation":false,"usgs":true,"family":"Cisternas","given":"A.","email":"","affiliations":[],"preferred":false,"id":383588,"contributorType":{"id":1,"text":"Authors"},"rank":10}]}} ,{"id":1014675,"text":"1014675 - 1997 - Modeling gas transfer in a spray tower oxygen absorber","interactions":[],"lastModifiedDate":"2023-08-09T15:18:21.441007","indexId":"1014675","displayToPublicDate":"1997-01-01T00:00:00","publicationYear":"1997","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":852,"text":"Aquacultural Engineering","active":true,"publicationSubtype":{"id":10}},"title":"Modeling gas transfer in a spray tower oxygen absorber","docAbstract":"A computer model characterizing the performance of a spray tower oxygen absorption system was developed based on finite difference mass transfer calculations. Performance was assessed in terms of oxygen utilization, transfer efficiency, and economy. Pilot scale tests verified model assumptions and performance predictions. Simulation runs indicated spray tower head and oxygen feed requirements for desired changes in dissolved oxygen (DO) exceeded those required for packed column equipment. Spray tower performance was improved by increasing hydraulic loading from 35 to 85 kg m−2 s−1 and by increasing tower height from 1·25 to 2·50 m. The effluent DO concentration that minimized variable costs of oxygen transfer was lower in the spray tower than in the packed tower, indicating clean water use of the spray tower will be limited to moderate effluent DO requirement applications (DO <20 mg l−1).
","language":"English","publisher":"Elsevier","doi":"10.1016/S0144-8609(96)01011-4","usgsCitation":"Vinci, B.J., Watten, B.J., and Timmons, M., 1997, Modeling gas transfer in a spray tower oxygen absorber: Aquacultural Engineering, v. 16, p. 91-105, https://doi.org/10.1016/S0144-8609(96)01011-4.","productDescription":"15 p.","startPage":"91","endPage":"105","numberOfPages":"15","costCenters":[{"id":365,"text":"Leetown Science Center","active":true,"usgs":true}],"links":[{"id":489807,"rank":2,"type":{"id":40,"text":"Open Access Publisher Index Page"},"url":"https://doi.org/10.1016/s0144-8609(96)01011-4","text":"Publisher Index Page"},{"id":129994,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"16","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4a2de4b07f02db614228","contributors":{"authors":[{"text":"Vinci, Brian J.","contributorId":71890,"corporation":false,"usgs":true,"family":"Vinci","given":"Brian","email":"","middleInitial":"J.","affiliations":[],"preferred":false,"id":320886,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Watten, Barnaby J. 0000-0002-2227-8623 bwatten@usgs.gov","orcid":"https://orcid.org/0000-0002-2227-8623","contributorId":2002,"corporation":false,"usgs":true,"family":"Watten","given":"Barnaby","email":"bwatten@usgs.gov","middleInitial":"J.","affiliations":[{"id":365,"text":"Leetown Science Center","active":true,"usgs":true}],"preferred":true,"id":320885,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Timmons, Michael","contributorId":239537,"corporation":false,"usgs":false,"family":"Timmons","given":"Michael","email":"","affiliations":[],"preferred":false,"id":320887,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70020008,"text":"70020008 - 1997 - Formation of ferric iron crusts in Quaternary sediments of Lake Baikal, Russia, and implications for paleoclimate","interactions":[],"lastModifiedDate":"2012-03-12T17:19:19","indexId":"70020008","displayToPublicDate":"1997-01-01T00:00:00","publicationYear":"1997","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2667,"text":"Marine Geology","active":true,"publicationSubtype":{"id":10}},"title":"Formation of ferric iron crusts in Quaternary sediments of Lake Baikal, Russia, and implications for paleoclimate","docAbstract":"Phosphate-bearing, ferric iron and siliceous crusts ranging in age from Recent to approximately 65,000 yr B.P. are observed in sediments of Lake Baikal. In younger sediments the crusts are at the base of a spectrum of secondary iron and manganese oxides that accumulate near the sediment/water interface in the zone of positive oxidation potential beneath an oxygenated water column. In areas where the average Quaternary sedimentation rates have been slow (e.g. 0.026 mm/yr), the crusts are more common, and span a wider range of ages. No crusts have been found where the Quaternary sedimentation mode has been deltaic and rapid (0.15 mm/yr). Independent core correlation based on magnetic properties of the sediment suggests that crusts can be correlated over most of Academician Ridge, an area that is particularly sensitive to climatic events affecting the concentration of suspended sediment. These crusts may be indicative of periods of low suspended sediment concentration, which occur during sustained transitions from glacial periods of high detrital input, to interglacial periods of high diatom sedimentation. The crusts are dominated by iron-rich and siliceous amorphous mineral phases, with an FeO:SiO2 by weight of 3:1. Regardless of age or location in the lake the Fe phase always includes Ca, P and Mn. Extensive microprobe data for these four elements recast as normalized elemental weight percent reveal linear trends of Ca:P and Fe:P. With increasing P, Ca also increases such that the two elements maintain a linear relationship passing very close to the origin and with a mean molar Ca:P=0.3 (too low for well-characterized apatite). Conversely, with increasing P, Fe decreases (mean molar Fe:P=3.4). There is no correlation between Mn and P. Molar Fe:P ratios for vivianite (an Fe(II) phosphate mineral observed in sediments closely below some crusts) are clustered around a stoichiometric composition. The covariant increase in Ca:P and the corresponding decrease in Fe:P may be explained by: (1) coupled adsorption of aqueous Ca and P by a colloidal ferric hydrous oxide; (2) loss of Fe from a Ca-P-Fe phase; or (3) oxidation of vivianite to a metastable mineral phase that gradually loses Ca and gains Fe. The first explanation is favored, because there is no petrographic evidence for either the existence of an originating Ca-P-Fe phase, or, for the oxidation of vivianite. Further, it is suggested that by continually equalizing surface charge, Ca allows more phosphate to be adsorbed leading to thicker crusts and longer preservation after burial.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Marine Geology","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1016/S0025-3227(96)00096-5","issn":"00253227","usgsCitation":"Deike, R., Granina, L., Callender, E., and McGee, J.J., 1997, Formation of ferric iron crusts in Quaternary sediments of Lake Baikal, Russia, and implications for paleoclimate: Marine Geology, v. 139, no. 1-4, p. 21-46, https://doi.org/10.1016/S0025-3227(96)00096-5.","startPage":"21","endPage":"46","numberOfPages":"26","costCenters":[],"links":[{"id":206001,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/S0025-3227(96)00096-5"},{"id":227822,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"139","issue":"1-4","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a134fe4b0c8380cd545e2","contributors":{"authors":[{"text":"Deike, R.G.","contributorId":63953,"corporation":false,"usgs":true,"family":"Deike","given":"R.G.","affiliations":[],"preferred":false,"id":384689,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Granina, L.","contributorId":94052,"corporation":false,"usgs":true,"family":"Granina","given":"L.","affiliations":[],"preferred":false,"id":384692,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Callender, E.","contributorId":72528,"corporation":false,"usgs":true,"family":"Callender","given":"E.","email":"","affiliations":[],"preferred":false,"id":384690,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"McGee, J. J.","contributorId":92271,"corporation":false,"usgs":true,"family":"McGee","given":"J.","email":"","middleInitial":"J.","affiliations":[],"preferred":false,"id":384691,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}} ,{"id":1008600,"text":"1008600 - 1997 - A rop net and removable walkway used to quantitatively sample fishes over wetland surfaces in the dwarf mangrove of the Southern Everglades","interactions":[],"lastModifiedDate":"2016-01-06T11:23:52","indexId":"1008600","displayToPublicDate":"1997-01-01T00:00:00","publicationYear":"1997","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":3750,"text":"Wetlands","onlineIssn":"1943-6246","printIssn":"0277-5212","active":true,"publicationSubtype":{"id":10}},"title":"A rop net and removable walkway used to quantitatively sample fishes over wetland surfaces in the dwarf mangrove of the Southern Everglades","docAbstract":"We describe a 9 m2 drop net and removable walkways designed to quantify densities of small fishes in wetland habitats with low to moderate vegetation density. The method permits the collection of small, quantitative, discrete samples in ecologically sensitive areas by combining rapid net deployment from fixed sites with the carefully contained use of the fish toxicant rotenone. This method requires very little contact with the substrate, causes minimal alteration to the habitat being sampled, samples small fishes in an unbiased manner, and allows for differential sampling of microhabitats within a wetland. When used in dwarf red mangrove (Rhizophora mangle) habitat in southern Everglades National Park and adjacent areas (September 1990 to March 1993), we achieved high recovery efficiencies (78–90%) for five common species <110 mm in length. We captured 20,193 individuals of 26 species. The most abundant fishes were sheepshead minnowCyprinodon variegatus, goldspotted killifishFloridichthys carpio, rainwater killifishLucania parva, sailfin mollyPoecilia latipinna, and the exotic Mayan cichlidCichlasoma urophthalmus. The 9 m2 drop net and associated removable walkways are versatile and can be used in a variety of wetland types, including both interior and coastal wetlands with either herbaceous or woody vegetation.
","language":"English","publisher":"Springer","doi":"10.1007/BF03161424","usgsCitation":"Lorenz, J., McIvor, C., Powell, G., and Frederick, P.C., 1997, A rop net and removable walkway used to quantitatively sample fishes over wetland surfaces in the dwarf mangrove of the Southern Everglades: Wetlands, v. 17, p. 346-359, https://doi.org/10.1007/BF03161424.","productDescription":"14 p.","startPage":"346","endPage":"359","onlineOnly":"N","additionalOnlineFiles":"N","costCenters":[{"id":566,"text":"Southeast Ecological Science Center","active":true,"usgs":true}],"links":[{"id":132485,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"17","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4a5ee4b07f02db633dad","contributors":{"authors":[{"text":"Lorenz, J.J.","contributorId":67058,"corporation":false,"usgs":true,"family":"Lorenz","given":"J.J.","email":"","affiliations":[],"preferred":false,"id":318188,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"McIvor, C.C.","contributorId":38104,"corporation":false,"usgs":true,"family":"McIvor","given":"C.C.","email":"","affiliations":[],"preferred":false,"id":318186,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Powell, G.V.N.","contributorId":23894,"corporation":false,"usgs":true,"family":"Powell","given":"G.V.N.","email":"","affiliations":[],"preferred":false,"id":318185,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Frederick, P. C.","contributorId":66645,"corporation":false,"usgs":true,"family":"Frederick","given":"P.","email":"","middleInitial":"C.","affiliations":[],"preferred":false,"id":318187,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}} ,{"id":70019454,"text":"70019454 - 1997 - Applications of the 190Pt-186Os isotope system to geochemistry and cosmochemistry","interactions":[],"lastModifiedDate":"2023-12-15T00:18:30.721831","indexId":"70019454","displayToPublicDate":"1997-01-01T00:00:00","publicationYear":"1997","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}},"displayTitle":"Applications of the 190Pt-186Os isotope system to geochemistry and cosmochemistry","title":"Applications of the 190Pt-186Os isotope system to geochemistry and cosmochemistry","docAbstract":"Platinum is fractionated from osmium primarily as a consequence of processes involving sulfide and metal crystallization. Consequently, the 190Pt186Os isotope system (190Pt → 186Os + α) shows promise for dating some types of magmatic sulfide ores and evolved iron meteorites. The first 190Pt 186Os isochrons are presented here for ores from the ca. 251 Ma Noril'sk, Siberia plume, and for group IIAB magmatic iron meteorites. Given the known age of the Noril'sk system, a decay constant for 190Pt is determined to be 1.542 × 10−12a−1, with ±1% uncertainty. The isochron generated for the IIAB irons is consistent with this decay constant and the known age of the group. The 186Os/188Os ratios of presumably young, mantle-derived osmiridiums and also the carbonaceous chondrite Allende were measured to high-precision to constrain the composition of the modern upper mantle. These compositions overlap, indicating that the upper mantle is chondritic within the level of resolution now available. Our best estimate for this 186Os/188Os ratio is 0.119834 ± 2 (2σM). The 190Pt/186Os ratios determined for six enstatite chondrites average 0.001659 ± 75, which is very similar to published values for carbonaceous chondrites. Using this ratio and the presumed composition of the modern upper mantle and chondrites, a solar system initial 186Os/188Os ratio of 0.119820 is calculated. In comparison to the modern upper mantle composition, the 186Os/188Os ratio of the Noril'sk plume was approximately 0.012% enriched in 186Os. Possible reasons for this heterogeneity include the recycling of Pt-rich crust into the mantle source of the plume and derivation of the osmium from the outer core. Derivation of the osmium from the outer core is our favored model.
","language":"English","publisher":"Elsevier","doi":"10.1016/S0016-7037(97)00270-6","issn":"00167037","usgsCitation":"Walker, R., Morgan, J.W., Beary, E., Smoliar, M., Czamanske, G., and Horan, M., 1997, Applications of the 190Pt-186Os isotope system to geochemistry and cosmochemistry: Geochimica et Cosmochimica Acta, v. 61, no. 22, p. 4799-4807, https://doi.org/10.1016/S0016-7037(97)00270-6.","productDescription":"9 p.","startPage":"4799","endPage":"4807","costCenters":[],"links":[{"id":226791,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"61","issue":"22","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"5059eccae4b0c8380cd494ba","contributors":{"authors":[{"text":"Walker, R.J.","contributorId":105859,"corporation":false,"usgs":true,"family":"Walker","given":"R.J.","email":"","affiliations":[],"preferred":false,"id":382791,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Morgan, J. W.","contributorId":92384,"corporation":false,"usgs":true,"family":"Morgan","given":"J.","email":"","middleInitial":"W.","affiliations":[],"preferred":false,"id":382789,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Beary, E.S.","contributorId":29967,"corporation":false,"usgs":true,"family":"Beary","given":"E.S.","affiliations":[],"preferred":false,"id":382787,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Smoliar, M.I.","contributorId":96843,"corporation":false,"usgs":true,"family":"Smoliar","given":"M.I.","email":"","affiliations":[],"preferred":false,"id":382790,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Czamanske, G.K.","contributorId":26300,"corporation":false,"usgs":true,"family":"Czamanske","given":"G.K.","email":"","affiliations":[],"preferred":false,"id":382786,"contributorType":{"id":1,"text":"Authors"},"rank":5},{"text":"Horan, M.F.","contributorId":75282,"corporation":false,"usgs":true,"family":"Horan","given":"M.F.","email":"","affiliations":[],"preferred":false,"id":382788,"contributorType":{"id":1,"text":"Authors"},"rank":6}]}} ,{"id":70020203,"text":"70020203 - 1997 - A reconnaissance study of oxygen, hydrogen and strontium isotopes in geochemically diverse lakes, Western Nebraska, USA","interactions":[],"lastModifiedDate":"2012-03-12T17:19:43","indexId":"70020203","displayToPublicDate":"1997-01-01T00:00:00","publicationYear":"1997","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2411,"text":"Journal of Paleolimnology","active":true,"publicationSubtype":{"id":10}},"title":"A reconnaissance study of oxygen, hydrogen and strontium isotopes in geochemically diverse lakes, Western Nebraska, USA","docAbstract":"Reconnaissance ??18O,, ??D, and ??87Sr data for fifteen lakes in the Western Lakes Region of the Sand Hills of Nebraska indicate dynamic hydrologic systems. The rather narrow range of ??87Sr from lake water (1.1 to 2.1) and groundwater (0.9 to 1.7) indicates that the groundwater is generally unradiogenic. Groundwater residence times and relatively unradiogenic volcanic ash within the dune sediments control the ??87Sr values. Based on the mutual variations of ??18O and ??D, the lakes can be divided into three groups. In Group 1, both ??18O and ??D values increase from spring to fall. The ??18O and ??D values in Group 2 decreased from spring to fall. Group 3 are ephemeral lakes that went dry some time during 1992. The data and isotopic modeling show that variations in the ratio of evaporation relative to groundwater inflow, local humidity conditions, and the ??(a) has substantial influence on the isotopic composition. In addition, isotopic behavior in ephemeral hakes can be rather unusual because of the changing activities of water and mineral precipitation and redissolution. The annual and interannual isotopic variability of these lakes which is reflected in the paleonvironmental indicators may be the rule rather than the exception in these types of systems.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Journal of Paleolimnology","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1023/A:1007913010057","issn":"09212728","usgsCitation":"Gosselin, D., Nabelek, P., Peterman, Z.E., and Sibray, S., 1997, A reconnaissance study of oxygen, hydrogen and strontium isotopes in geochemically diverse lakes, Western Nebraska, USA: Journal of Paleolimnology, v. 17, no. 1, p. 51-65, https://doi.org/10.1023/A:1007913010057.","startPage":"51","endPage":"65","numberOfPages":"15","costCenters":[],"links":[{"id":206844,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1023/A:1007913010057"},{"id":230927,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"17","issue":"1","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"5059e53ae4b0c8380cd46c01","contributors":{"authors":[{"text":"Gosselin, D.C.","contributorId":93237,"corporation":false,"usgs":true,"family":"Gosselin","given":"D.C.","email":"","affiliations":[],"preferred":false,"id":385379,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Nabelek, P.E.","contributorId":102657,"corporation":false,"usgs":true,"family":"Nabelek","given":"P.E.","email":"","affiliations":[],"preferred":false,"id":385381,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Peterman, Z. E.","contributorId":63781,"corporation":false,"usgs":true,"family":"Peterman","given":"Z.","email":"","middleInitial":"E.","affiliations":[],"preferred":false,"id":385378,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Sibray, S.","contributorId":101041,"corporation":false,"usgs":true,"family":"Sibray","given":"S.","affiliations":[],"preferred":false,"id":385380,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}} ]}