The lithosphere beneath a continental rift should be significantly modified due to extension. To image the lithosphere beneath the Rio Grande rift (RGR), we analyzed teleseismic travel time delays of both P and S wave arrivals and solved for the attenuation of P and S waves for four seismic experiments spanning the Rio Grande rift. Two tomographic inversions of the P wave travel time data are given: an Aki-Christofferson-Husebye (ACH) block model inversion and a downward projection inversion. The tomographic inversions reveal a NE-SW to NNE-SSW trending feature at depths of 35 to 145 km with a velocity reduction of 7 to 8% relative to mantle velocities beneath the Great Plains. This region correlates with the transition zone between the Colorado Plateau and the Rio Grande rift and is bounded on the NW by the Jemez lineament, a N52°E trending zone of late Miocene to Holocene volcanism. S wave delays plotted against P wave delays are fit with a straight line giving a slope of 3.0 ± 0.4. This correlation and the absolute velocity reduction imply that temperatures in the lithosphere are close to the solidus, consistent with, but not requiring, the presence of partial melt in the mantle beneath the Rio Grande rift. The attenuation data could imply the presence of partial melt. We compare our results with other geophysical and geologic data. We propose that any north-south trending thermal (velocity) anomaly that may have existed in the upper mantle during earlier (Oligocene to late Miocene) phases of rifting and that may have correlated with the axis of the rift has diminished with time and has been overprinted with more recent structure. The anomalously low-velocity body presently underlying the transition zone between the core of the Colorado Plateau and the rift may reflect processes resulting from the modern (Pliocene to present) regional stress field (oriented WNW-ESE), possibly heralding future extension across the Jemez lineament and transition zone.
","language":"English","publisher":"American Geophysical Union","doi":"10.1029/96JB00109","issn":"01480227","usgsCitation":"Slack, P., Davis, P., Baldridge, W., Olsen, K., Glahn, A., Achauer, U., and Spence, W., 1996, The upper mantle structure of the central Rio Grande rift region from teleseismic P and S wave travel time delays and attenuation: Journal of Geophysical Research B: Solid Earth, v. 101, no. 7, p. 16003-16023, https://doi.org/10.1029/96JB00109.","productDescription":"21 p.","startPage":"16003","endPage":"16023","numberOfPages":"21","costCenters":[],"links":[{"id":226676,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"101","issue":"7","noUsgsAuthors":false,"publicationDate":"1996-07-10","publicationStatus":"PW","scienceBaseUri":"505bb151e4b08c986b3252cb","contributors":{"authors":[{"text":"Slack, P.D.","contributorId":42370,"corporation":false,"usgs":true,"family":"Slack","given":"P.D.","email":"","affiliations":[],"preferred":false,"id":381575,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Davis, P.M.","contributorId":15229,"corporation":false,"usgs":true,"family":"Davis","given":"P.M.","email":"","affiliations":[],"preferred":false,"id":381573,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Baldridge, W.S.","contributorId":63956,"corporation":false,"usgs":true,"family":"Baldridge","given":"W.S.","affiliations":[],"preferred":false,"id":381576,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Olsen, K.H.","contributorId":95201,"corporation":false,"usgs":true,"family":"Olsen","given":"K.H.","email":"","affiliations":[],"preferred":false,"id":381578,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Glahn, A.","contributorId":21293,"corporation":false,"usgs":true,"family":"Glahn","given":"A.","email":"","affiliations":[],"preferred":false,"id":381574,"contributorType":{"id":1,"text":"Authors"},"rank":5},{"text":"Achauer, U.","contributorId":91998,"corporation":false,"usgs":true,"family":"Achauer","given":"U.","affiliations":[],"preferred":false,"id":381577,"contributorType":{"id":1,"text":"Authors"},"rank":6},{"text":"Spence, W.","contributorId":7721,"corporation":false,"usgs":true,"family":"Spence","given":"W.","email":"","affiliations":[],"preferred":false,"id":381572,"contributorType":{"id":1,"text":"Authors"},"rank":7}]}} ,{"id":70019071,"text":"70019071 - 1996 - Paleomagnetism of Jurassic radiolarian chert above the Coast Range ophiolite at Stanley Mountain, California, and implications for its paleogeographic origins","interactions":[],"lastModifiedDate":"2023-12-22T00:29:40.341843","indexId":"70019071","displayToPublicDate":"1996-01-01T00:00:00","publicationYear":"1996","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1786,"text":"Geological Society of America Bulletin","active":true,"publicationSubtype":{"id":10}},"title":"Paleomagnetism of Jurassic radiolarian chert above the Coast Range ophiolite at Stanley Mountain, California, and implications for its paleogeographic origins","docAbstract":"Upper Jurassic red tuffaceous chert above the Coast Range ophiolite at Stanley Mountain, California (lat 35°N, long 240°E), contains three components of remanent magnetization. The first component (A; removed by ≈100–≈200°C) has a direction near the present-day field for southern California and is probably a recently acquired thermoviscous magnetization. A second component (B; removed between ≈100 and ≈600°C) is identical to that observed by previous workers in samples of underlying pillow basalt and overlying terrigenous sedimentary rocks. This component has constant normal polarity and direction throughout the entire section, although these rocks were deposited during a mixed polarity interval of the geomagnetic field. The B magnetization, therefore, is inferred to be a secondary magnetization acquired during accretion, uplift, or Miocene volcanism prior to regional clockwise rotation. The highest temperature component (C; removed between ≈480 and 680°C) is of dual polarity and is tentatively interpreted as a primary magnetization, although it fails a reversal test possibly due to contamination by B. Separation of the B and C components is best shown by samples with negative-inclination C directions, and a corrected mean direction using only these samples indicates an initial paleolatitude of 32°N ± 8°. Paleobiogeographic models relating radiolarian faunal distribution patterns to paleolatitude have apparently been incorrectly calibrated using the overprint B component. Few other paleomagnetic data have been incorporated in these models, and faunal distribution patterns are poorly known and mostly unquantified. The available data, therefore, do not support formation of the Coast Range ophiolite at Stanley Mountain near the paleoequator or accretion at ≈10°N paleolatitude, as has been previously suggested based on paleomagnetic data, but indicate deposition near expected paleolatitudes for North America (35°N ± 4°) during Late Jurassic time.
Aniakchak caldera, located on the Alaska Peninsula of southwest Alaska, formerly contained a large lake (estimated volume 3.7 × 109 m3) that rapidly drained as a result of failure of the caldera rim sometime after ca. 3400 yr B.P. The peak discharge of the resulting flood was estimated using three methods: (1) flow-competence equations, (2) step-backwater modeling, and (3) a dam-break model. The results of the dam-break model indicate that the peak discharge at the breach in the caldera rim was at least 7.7 × 104 m3 s−1, and the maximum possible discharge was ≈1.1 × 106 m3 s−1. Flow-competence estimates of discharge, based on the largest boulders transported by the flood, indicate that the peak discharge values, which were a few kilometers downstream of the breach, ranged from 6.4 × 105 to 4.8 × 106 m3 s−1. Similar but less variable results were obtained by step-backwater modeling. Finally, discharge estimates based on regression equations relating peak discharge to the volume and depth of the impounded water, although limited by constraining assumptions, provide results within the range of values determined by the other methods. The discovery and documentation of a flood, caused by the failure of the caldera rim at Aniakchak caldera, underscore the significance and associated hydrologic hazards of potential large floods at other lake-filled calderas.
","language":"English","publisher":"GSA","doi":"10.1130/0016-7606(1996)108<0861:ACFCBD>2.3.CO;2","issn":"00167606","usgsCitation":"Waythomas, C.F., Walder, J.S., McGimsey, R.G., and Neal, C., 1996, A catastrophic flood caused by drainage of a caldera lake at Aniakchak Volcano, Alaska, and implications for volcanic hazards assessment: Geological Society of America Bulletin, v. 108, no. 7, p. 861-871, https://doi.org/10.1130/0016-7606(1996)108<0861:ACFCBD>2.3.CO;2.","productDescription":"11 p.","startPage":"861","endPage":"871","costCenters":[{"id":615,"text":"Volcano Hazards Program","active":true,"usgs":true}],"links":[{"id":227342,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"108","issue":"7","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"5059e33be4b0c8380cd45ec5","contributors":{"authors":[{"text":"Waythomas, C. F.","contributorId":10065,"corporation":false,"usgs":true,"family":"Waythomas","given":"C.","email":"","middleInitial":"F.","affiliations":[],"preferred":false,"id":379862,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Walder, J. S.","contributorId":32561,"corporation":false,"usgs":true,"family":"Walder","given":"J.","email":"","middleInitial":"S.","affiliations":[],"preferred":false,"id":379863,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"McGimsey, R. G.","contributorId":93921,"corporation":false,"usgs":true,"family":"McGimsey","given":"R.","email":"","middleInitial":"G.","affiliations":[],"preferred":false,"id":379865,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Neal, C.A. 0000-0002-7697-7825","orcid":"https://orcid.org/0000-0002-7697-7825","contributorId":91122,"corporation":false,"usgs":true,"family":"Neal","given":"C.A.","affiliations":[],"preferred":false,"id":379864,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}} ,{"id":70018608,"text":"70018608 - 1996 - A scan-angle correction for thermal infrared multispectral data using side lapping images","interactions":[],"lastModifiedDate":"2024-02-10T14:49:52.892313","indexId":"70018608","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":"A scan-angle correction for thermal infrared multispectral data using side lapping images","docAbstract":"Thermal infrared multispectral scanner (TIMS) images, acquired with side lapping flight lines, provide dual angle observations of the same area on the ground and can thus be used to estimate variations in the atmospheric transmission with scan angle. The method was tested using TIMS aircraft data for six flight lines with about 30% sidelap for an area within Joshua Tree National Park, California. Generally the results correspond to predictions for the transmission scan-angle coefficient based on a standard atmospheric model although some differences were observed at the longer wavelength channels. A change was detected for the last pair of lines that may indicate either spatial or temporal atmospheric variation. The results demonstrate that the method provides information for correcting regional survey data (requiring multiple adjacent flight lines) that can be important in detecting subtle changes in lithology.
No abstract available.
","language":"English","publisher":"U.S. Geological Survey","doi":"10.3133/wri954235","usgsCitation":"Sepulveda, N., Perez-Blair, F., DeLong, L.L., and Lopez Trujillo, D., 1996, Real-time rainfall-runoff model of the Carraizo-reservoir basin in Puerto Rico: U.S. Geological Survey Water-Resources Investigations Report 95-4235, vii, 112 p., https://doi.org/10.3133/wri954235.","productDescription":"vii, 112 p.","costCenters":[{"id":5051,"text":"FLWSC-Orlando","active":true,"usgs":true}],"links":[{"id":410225,"rank":2,"type":{"id":36,"text":"NGMDB Index Page"},"url":"https://ngmdb.usgs.gov/Prodesc/proddesc_48319.htm","linkFileType":{"id":5,"text":"html"}},{"id":54493,"rank":1,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/wri/1995/4235/report.pdf","linkFileType":{"id":1,"text":"pdf"}},{"id":157000,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/wri/1995/4235/report-thumb.jpg"}],"country":"United States","state":"Puerto Rico","otherGeospatial":"Carraizo-reservoir basin","geographicExtents":"{\n \"type\": \"FeatureCollection\",\n \"features\": [\n {\n \"type\": \"Feature\",\n \"properties\": {},\n \"geometry\": {\n \"coordinates\": [\n [\n [\n -66.125,\n 18.3306\n ],\n [\n -66.125,\n 18.0781\n ],\n [\n -65.8136,\n 18.0781\n ],\n [\n -65.8136,\n 18.3306\n ],\n [\n -66.125,\n 18.3306\n ]\n ]\n ],\n \"type\": \"Polygon\"\n }\n }\n ]\n}","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4a7fe4b07f02db648658","contributors":{"authors":[{"text":"Sepulveda, Nicasio 0000-0002-6333-1865 nsepul@usgs.gov","orcid":"https://orcid.org/0000-0002-6333-1865","contributorId":1454,"corporation":false,"usgs":true,"family":"Sepulveda","given":"Nicasio","email":"nsepul@usgs.gov","affiliations":[{"id":5051,"text":"FLWSC-Orlando","active":true,"usgs":true}],"preferred":true,"id":194837,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Perez-Blair, Francisco","contributorId":102521,"corporation":false,"usgs":true,"family":"Perez-Blair","given":"Francisco","email":"","affiliations":[],"preferred":false,"id":194840,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"DeLong, L. L.","contributorId":44530,"corporation":false,"usgs":true,"family":"DeLong","given":"L.","email":"","middleInitial":"L.","affiliations":[],"preferred":false,"id":194838,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Lopez Trujillo, Dianne","contributorId":54851,"corporation":false,"usgs":true,"family":"Lopez Trujillo","given":"Dianne","email":"","affiliations":[],"preferred":false,"id":194839,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}} ,{"id":70187936,"text":"70187936 - 1996 - Hazard ranking of contaminated sediments based on chemical analysis, laboratory toxicity tests, and benthic community composition: Prioritizing sites for remedial action","interactions":[],"lastModifiedDate":"2017-05-24T15:49:18","indexId":"70187936","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":"Hazard ranking of contaminated sediments based on chemical analysis, laboratory toxicity tests, and benthic community composition: Prioritizing sites for remedial action","docAbstract":"The U.S. Environmental Protection Agency (U.S. EPA) organized a research program to assess the extent of and possible methods for managing contaminated sediments. As part of this program, we developed a method by which multiple forms of information on sediment contamination (i.e., chemistry, laboratory toxicity, and benthic community composition) could be combined to rank the relative hazard to aquatic life of a series of sediment samples. The process that was developed incorporates chemistry and bioavailability into the ranking as toxic units in pore water based on U.S. EPA Ambient Water Quality Criteria (AWQC). Laboratory toxicity is incorporated into the ranking process as mean response relative to control response. Benthic community information is incorporated into the ranking process through the use of relative tolerance to pollution among benthic invertebrate taxa, from which the mean tolerance to pollution of the benthic community is calculated. The three resulting ranks are then averaged to produce a relative ranking of risk to aquatic life among sediment samples. Our results demonstrate that, as long as a moderate list of laboratory toxicity test results are included in the ranking process (i.e., tests from a fish, a zooplankter, a benthic invertebrate, a phytoplankter, and a microbe), the resultant rankings among samples does not significantly change with inclusion of more laboratory toxicity test results. Without any benthic community structure information, with only laboratory toxicity test results from Microtox,® and with only a short list of chemicals, relative ranking among sites changes drastically. Our results demonstrate the general utility of the ranking process as one way of assessing the relative hazard among many sites when resource limitations necessitate prioritization of sites for remediation.
","language":"English","publisher":"Elsevier","doi":"10.1016/S0380-1330(96)70986-3","usgsCitation":"Wildhaber, M.L., and Schmitt, C.J., 1996, Hazard ranking of contaminated sediments based on chemical analysis, laboratory toxicity tests, and benthic community composition: Prioritizing sites for remedial action: Journal of Great Lakes Research, v. 22, no. 3, p. 639-652, https://doi.org/10.1016/S0380-1330(96)70986-3.","productDescription":"14 p.","startPage":"639","endPage":"652","costCenters":[{"id":192,"text":"Columbia Environmental Research Center","active":true,"usgs":true}],"links":[{"id":341719,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"22","issue":"3","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"59269bcfe4b0b7ff9fb489c4","contributors":{"authors":[{"text":"Wildhaber, Mark L. 0000-0002-6538-9083 mwildhaber@usgs.gov","orcid":"https://orcid.org/0000-0002-6538-9083","contributorId":1386,"corporation":false,"usgs":true,"family":"Wildhaber","given":"Mark","email":"mwildhaber@usgs.gov","middleInitial":"L.","affiliations":[{"id":192,"text":"Columbia Environmental Research Center","active":true,"usgs":true}],"preferred":true,"id":696047,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Schmitt, Christopher J. 0000-0001-6804-2360 cjschmitt@usgs.gov","orcid":"https://orcid.org/0000-0001-6804-2360","contributorId":491,"corporation":false,"usgs":true,"family":"Schmitt","given":"Christopher","email":"cjschmitt@usgs.gov","middleInitial":"J.","affiliations":[{"id":192,"text":"Columbia Environmental Research Center","active":true,"usgs":true}],"preferred":true,"id":696048,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70018497,"text":"70018497 - 1996 - Chemical weathering rates of a soil chronosequence on granitic alluvium: I. Quantification of mineralogical and surface area changes and calculation of primary silicate reaction rates","interactions":[],"lastModifiedDate":"2012-03-12T17:19:25","indexId":"70018497","displayToPublicDate":"1996-01-01T00:00:00","publicationYear":"1996","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1759,"text":"Geochimica et Cosmochimica Acta","active":true,"publicationSubtype":{"id":10}},"title":"Chemical weathering rates of a soil chronosequence on granitic alluvium: I. Quantification of mineralogical and surface area changes and calculation of primary silicate reaction rates","docAbstract":"Mineral weathering rates are determined for a series of soils ranging in age from 0.2-3000 Ky developed on alluvial terraces near Merced in the Central Valley of California. Mineralogical and elemental abundances exhibit time-dependent trends documenting the chemical evolution of granitic sand to residual kaolinite and quartz. Mineral losses with time occur in the order: hornblende > plagioclase > K-feldspar. Maximum volume decreases of >50% occur in the older soils. BET surface areas of the bulk soils increase with age, as do specific surface areas of aluminosilicate mineral fractions such as plagioclase, which increases from 0.4-1.5 m2 g-1 over 600 Ky. Quartz surface areas are lower and change less with time (0.11-0.23 m2 g-1). BET surface areas correspond to increasing external surface roughness (?? = 10-600) and relatively constant internal surface area (??? 1.3 m2 g-1). SEM observations confirm both surface pitting and development of internal porosity. A numerical model describes aluminosilicate dissolution rates as a function of changes in residual mineral abundance, grain size distributions, and mineral surface areas with time. A simple geometric treatment, assuming spherical grains and no surface roughness, predicts average dissolution rates (plagioclase, 10-17.4; K-feldspar, 10-17.8; and hornblende, 10-17.5 mol cm-1 s-1) that are constant with time and comparable to previous estimates of soil weathering. Average rates, based on BET surface area measurements and variable surface roughnesses, are much slower (plagioclase, 10-19.9; K-feldspar, 10-20.5; and hornblende 10-20.1 mol cm-2 s-1). Rates for individual soil horizons decrease by a factor of 101.5 over 3000 Ky indicating that the surface reactivities of minerals decrease as the physical surface areas increase. Rate constants based on BET estimates for the Merced soils are factors of 103-104 slower than reported experimental dissolution rates determined from freshly prepared silicates with low surface roughness (?? <10). This study demonstrates that the utility of experimental rate constants to predict weathering in soils is limited without consideration of variable surface areas and processes that control the evolution of surface reactivity with time.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Geochimica et Cosmochimica Acta","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1016/0016-7037(96)00106-8","issn":"00167037","usgsCitation":"White, A.F., Blum, A., Schulz, M.S., Bullen, T., Harden, J., and Peterson, M.L., 1996, Chemical weathering rates of a soil chronosequence on granitic alluvium: I. Quantification of mineralogical and surface area changes and calculation of primary silicate reaction rates: Geochimica et Cosmochimica Acta, v. 60, no. 14, p. 2533-2550, https://doi.org/10.1016/0016-7037(96)00106-8.","startPage":"2533","endPage":"2550","numberOfPages":"18","costCenters":[],"links":[{"id":227120,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":205854,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/0016-7037(96)00106-8"}],"volume":"60","issue":"14","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"5059f59ae4b0c8380cd4c2fb","contributors":{"authors":[{"text":"White, A. F.","contributorId":36546,"corporation":false,"usgs":true,"family":"White","given":"A.","email":"","middleInitial":"F.","affiliations":[],"preferred":false,"id":379821,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Blum, A.E.","contributorId":100514,"corporation":false,"usgs":true,"family":"Blum","given":"A.E.","email":"","affiliations":[],"preferred":false,"id":379825,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Schulz, M. S.","contributorId":7299,"corporation":false,"usgs":true,"family":"Schulz","given":"M.","email":"","middleInitial":"S.","affiliations":[],"preferred":false,"id":379820,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Bullen, T.D.","contributorId":79911,"corporation":false,"usgs":true,"family":"Bullen","given":"T.D.","email":"","affiliations":[],"preferred":false,"id":379824,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Harden, J.W. 0000-0002-6570-8259","orcid":"https://orcid.org/0000-0002-6570-8259","contributorId":38585,"corporation":false,"usgs":true,"family":"Harden","given":"J.W.","affiliations":[],"preferred":false,"id":379822,"contributorType":{"id":1,"text":"Authors"},"rank":5},{"text":"Peterson, M. L.","contributorId":49930,"corporation":false,"usgs":false,"family":"Peterson","given":"M.","email":"","middleInitial":"L.","affiliations":[],"preferred":false,"id":379823,"contributorType":{"id":1,"text":"Authors"},"rank":6}]}} ,{"id":70019311,"text":"70019311 - 1996 - The generation of HCl in the system CaCl2-H2O: Vapor-liquid relations from 380-500°C","interactions":[],"lastModifiedDate":"2015-05-21T13:37:58","indexId":"70019311","displayToPublicDate":"1996-01-01T00:00:00","publicationYear":"1996","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1759,"text":"Geochimica et Cosmochimica Acta","active":true,"publicationSubtype":{"id":10}},"title":"The generation of HCl in the system CaCl2-H2O: Vapor-liquid relations from 380-500°C","docAbstract":"We determined vapor-liquid relations (P-T-x) and derived critical parameters for the system CaCl2-H2O from 380-500??C. Results show that the two-phase region of this system is extremely large and occupies a significant portion of the P-T space to which circulation of fluids in the Earth's crust is constrained. Results also show the system generates significant amounts of HCl (as much as 0.1 mol/kg) in the vapor phase buffered by the liquid at surprisingly high pressures (???230 bars at 380??C, <580 bars at 500??C), presumably by hydrolysis of CaCl2: CaCl2 + 2H2O = Ca(OH)2 + 2HCl. We interpret the abundance of HCl in the vapor as due to its preference for the vapor phase, and by the preference of Ca(OH)2 for either the liquid phase or solid. The recent recognition of the abundance of CaCl2 in deep brines of the Earth's crust and their hydrothermal mobilization makes the hydrolysis of CaCl2 geologically important. The boiling of Ca-rich brines produces abundant HCl buffered by the presence of the liquid at moderate pressures. The resultant Ca(OH)2 generated by this process reacts with silicates to form a variety of alteration products, such as epidote, whereas the vapor produces acid-alteration of rocks through which it ascends.","language":"English","publisher":"Elsevier","doi":"10.1016/0016-7037(95)00365-7","issn":"00167037","usgsCitation":"Bischoff, J.L., Rosenbauer, R.J., and Fournier, R.O., 1996, The generation of HCl in the system CaCl2-H2O: Vapor-liquid relations from 380-500°C: Geochimica et Cosmochimica Acta, v. 60, no. 1, p. 7-16, https://doi.org/10.1016/0016-7037(95)00365-7.","productDescription":"10 p.","startPage":"7","endPage":"16","onlineOnly":"N","additionalOnlineFiles":"N","costCenters":[],"links":[{"id":205800,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/0016-7037(95)00365-7"},{"id":226875,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"60","issue":"1","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505bac3de4b08c986b323370","contributors":{"authors":[{"text":"Bischoff, James L. jbischoff@usgs.gov","contributorId":1389,"corporation":false,"usgs":true,"family":"Bischoff","given":"James","email":"jbischoff@usgs.gov","middleInitial":"L.","affiliations":[],"preferred":true,"id":382311,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Rosenbauer, Robert J. brosenbauer@usgs.gov","contributorId":204,"corporation":false,"usgs":true,"family":"Rosenbauer","given":"Robert","email":"brosenbauer@usgs.gov","middleInitial":"J.","affiliations":[{"id":520,"text":"Pacific Coastal and Marine Science Center","active":true,"usgs":true}],"preferred":true,"id":382312,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Fournier, Robert O.","contributorId":73202,"corporation":false,"usgs":true,"family":"Fournier","given":"Robert","email":"","middleInitial":"O.","affiliations":[],"preferred":false,"id":382313,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70019306,"text":"70019306 - 1996 - Friction-term response to boundary-condition type in flow models","interactions":[],"lastModifiedDate":"2024-12-12T16:48:02.312178","indexId":"70019306","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":"Friction-term response to boundary-condition type in flow models","docAbstract":"The friction-slope term in the unsteady open-channel flow equations is examined using two numerical models based on different formulations of the governing equations and employing different solution methods. The purposes of the study are to analyze, evaluate, and demonstrate the behavior of the term in a set of controlled numerical experiments using varied types and combinations of boundary conditions. Results of numerical experiments illustrate that a given model can respond inconsistently for the identical resistance-coefficient value under different types and combinations of boundary conditions. Findings also demonstrate that two models employing different dependent variables and solution methods can respond similarly for the identical resistance-coefficient value under similar types and combinations of boundary conditions. Discussion of qualitative considerations and quantitative experimental results provides insight into the proper treatment, evaluation, and significance of the friction-slope term, thereby offering practical guidelines for model implementation and calibration.
","language":"English","publisher":"ASCE","doi":"https://doi.org/10.1061/(ASCE)0733-9429(1996)122:2(73)","issn":"07339429","usgsCitation":"Schaffranek, R., and Lai, C., 1996, Friction-term response to boundary-condition type in flow models: Journal of Hydraulic Engineering, v. 122, no. 2, p. 73-81, https://doi.org/https://doi.org/10.1061/(ASCE)0733-9429(1996)122:2(73).","productDescription":"9 p.","startPage":"73","endPage":"81","numberOfPages":"9","costCenters":[],"links":[{"id":226783,"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":"505a13ede4b0c8380cd54826","contributors":{"authors":[{"text":"Schaffranek, R.W.","contributorId":61468,"corporation":false,"usgs":true,"family":"Schaffranek","given":"R.W.","affiliations":[],"preferred":false,"id":382304,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Lai, C.","contributorId":27622,"corporation":false,"usgs":true,"family":"Lai","given":"C.","email":"","affiliations":[],"preferred":false,"id":382303,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70019338,"text":"70019338 - 1996 - Direct simulation of groundwater age","interactions":[],"lastModifiedDate":"2018-03-08T15:45:15","indexId":"70019338","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":"Direct simulation of groundwater age","docAbstract":"A new method is proposed to simulate groundwater age directly, by use of an advection-dispersion transport equation with a distributed zero-order source of unit (1) strength, corresponding to the rate of aging. The dependent variable in the governing equation is the mean age, a mass-weighted average age. The governing equation is derived from residence-time-distribution concepts for the case of steady flow. For the more general case of transient flow, a transient governing equation for age is derived from mass-conservation principles applied to conceptual “age mass.” The age mass is the product of the water mass and its age, and age mass is assumed to be conserved during mixing. Boundary conditions include zero age mass flux across all noflow and inflow boundaries and no age mass dispersive flux across outflow boundaries. For transient-flow conditions, the initial distribution of age must be known. The solution of the governing transport equation yields the spatial distribution of the mean groundwater age and includes diffusion, dispersion, mixing, and exchange processes that typically are considered only through tracer-specific solute transport simulation. Traditional methods have relied on advective transport to predict point values of groundwater travel time and age. The proposed method retains the simplicity and tracer-independence of advection-only models, but incorporates the effects of dispersion and mixing on volume-averaged age. Example simulations of age in two idealized regional aquifer systems, one homogeneous and the other layered, demonstrate the agreement between the proposed method and traditional particle-tracking approaches and illustrate use of the proposed method to determine the effects of diffusion, dispersion, and mixing on groundwater age.
","language":"English","publisher":"American Geophysical Union","doi":"10.1029/95WR03401","usgsCitation":"Goode, D., 1996, Direct simulation of groundwater age: Water Resources Research, v. 32, no. 2, p. 289-296, https://doi.org/10.1029/95WR03401.","productDescription":"8 p.","startPage":"289","endPage":"296","costCenters":[{"id":532,"text":"Pennsylvania Water Science Center","active":true,"usgs":true}],"links":[{"id":480178,"rank":1,"type":{"id":40,"text":"Open Access Publisher Index Page"},"url":"https://doi.org/10.1029/95wr03401","text":"Publisher Index Page"},{"id":226693,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"32","issue":"2","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a01b2e4b0c8380cd4fd08","contributors":{"authors":[{"text":"Goode, Daniel J. 0000-0002-8527-2456 djgoode@usgs.gov","orcid":"https://orcid.org/0000-0002-8527-2456","contributorId":2433,"corporation":false,"usgs":true,"family":"Goode","given":"Daniel J.","email":"djgoode@usgs.gov","affiliations":[{"id":532,"text":"Pennsylvania Water Science Center","active":true,"usgs":true}],"preferred":false,"id":382393,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}} ,{"id":70018433,"text":"70018433 - 1996 - Calculation of earthquake rupture histories using a hybrid global search algorithm: Application to the 1992 Landers, California, earthquake","interactions":[],"lastModifiedDate":"2013-01-22T15:39:21","indexId":"70018433","displayToPublicDate":"1996-01-01T00:00:00","publicationYear":"1996","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":3071,"text":"Physics of the Earth and Planetary Interiors","active":true,"publicationSubtype":{"id":10}},"title":"Calculation of earthquake rupture histories using a hybrid global search algorithm: Application to the 1992 Landers, California, earthquake","docAbstract":"A method is presented for the simultaneous calculation of slip amplitudes and rupture times for a finite fault using a hybrid global search algorithm. The method we use combines simulated annealing with the downhill simplex method to produce a more efficient search algorithm then either of the two constituent parts. This formulation has advantages over traditional iterative or linearized approaches to the problem because it is able to escape local minima in its search through model space for the global optimum. We apply this global search method to the calculation of the rupture history for the Landers, California, earthquake. The rupture is modeled using three separate finite-fault planes to represent the three main fault segments that failed during this earthquake. Both the slip amplitude and the time of slip are calculated for a grid work of subfaults. The data used consist of digital, teleseismic P and SH body waves. Long-period, broadband, and short-period records are utilized to obtain a wideband characterization of the source. The results of the global search inversion are compared with a more traditional linear-least-squares inversion for only slip amplitudes. We use a multi-time-window linear analysis to relax the constraints on rupture time and rise time in the least-squares inversion. Both inversions produce similar slip distributions, although the linear-least-squares solution has a 10% larger moment (7.3 ?? 1026 dyne-cm compared with 6.6 ?? 1026 dyne-cm). Both inversions fit the data equally well and point out the importance of (1) using a parameterization with sufficient spatial and temporal flexibility to encompass likely complexities in the rupture process, (2) including suitable physically based constraints on the inversion to reduce instabilities in the solution, and (3) focusing on those robust rupture characteristics that rise above the details of the parameterization and data set.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Physics of the Earth and Planetary Interiors","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","publisher":"Elsevier","publisherLocation":"Amsterdam, Netherlands","doi":"10.1016/0031-9201(95)03108-1","issn":"00319201","usgsCitation":"Hartzell, S., and Liu, P., 1996, Calculation of earthquake rupture histories using a hybrid global search algorithm: Application to the 1992 Landers, California, earthquake: Physics of the Earth and Planetary Interiors, v. 95, no. 1-2, p. 79-99, https://doi.org/10.1016/0031-9201(95)03108-1.","startPage":"79","endPage":"99","numberOfPages":"21","costCenters":[],"links":[{"id":227383,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":266262,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/0031-9201(95)03108-1"}],"volume":"95","issue":"1-2","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"5059f302e4b0c8380cd4b547","contributors":{"authors":[{"text":"Hartzell, S.","contributorId":12603,"corporation":false,"usgs":true,"family":"Hartzell","given":"S.","email":"","affiliations":[],"preferred":false,"id":379555,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Liu, P.","contributorId":98443,"corporation":false,"usgs":true,"family":"Liu","given":"P.","email":"","affiliations":[],"preferred":false,"id":379556,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70018179,"text":"70018179 - 1996 - Unrealistic parameter estimates in inverse modelling: A problem or a benefit for model calibration?","interactions":[],"lastModifiedDate":"2012-03-12T17:19:12","indexId":"70018179","displayToPublicDate":"1996-01-01T00:00:00","publicationYear":"1996","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1934,"text":"IAHS-AISH Publication","active":true,"publicationSubtype":{"id":10}},"title":"Unrealistic parameter estimates in inverse modelling: A problem or a benefit for model calibration?","docAbstract":"Estimation of unrealistic parameter values by inverse modelling is useful for constructed model discrimination. This utility is demonstrated using the three-dimensional, groundwater flow inverse model MODFLOWP to estimate parameters in a simple synthetic model where the true conditions and character of the errors are completely known. When a poorly constructed model is used, unreasonable parameter values are obtained even when using error free observations and true initial parameter values. This apparent problem is actually a benefit because it differentiates accurately and inaccurately constructed models. The problems seem obvious for a synthetic problem in which the truth is known, but are obscure when working with field data. Situations in which unrealistic parameter estimates indicate constructed model problems are illustrated in applications of inverse modelling to three field sites and to complex synthetic test cases in which it is shown that prediction accuracy also suffers when constructed models are inaccurate.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"IAHS-AISH Publication","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","issn":"01447815","usgsCitation":"Poeter, E.P., and Hill, M.C., 1996, Unrealistic parameter estimates in inverse modelling: A problem or a benefit for model calibration?: IAHS-AISH Publication, v. 237, p. 277-285.","startPage":"277","endPage":"285","numberOfPages":"9","costCenters":[],"links":[{"id":227014,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"237","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505bbce1e4b08c986b328e53","contributors":{"authors":[{"text":"Poeter, E. P.","contributorId":63851,"corporation":false,"usgs":false,"family":"Poeter","given":"E.","email":"","middleInitial":"P.","affiliations":[],"preferred":false,"id":378777,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Hill, M. C.","contributorId":48993,"corporation":false,"usgs":true,"family":"Hill","given":"M.","email":"","middleInitial":"C.","affiliations":[],"preferred":false,"id":378776,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70018610,"text":"70018610 - 1996 - Comparison of the in situ and desorption sediment-water partitioning of polycyclic aromatic hydrocarbons and polychlorinated biphenyls","interactions":[],"lastModifiedDate":"2023-10-16T17:26:36.576191","indexId":"70018610","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}},"displayTitle":"Comparison of the in situ and desorption sediment-water partitioning of polycyclic aromatic hydrocarbons and polychlorinated biphenyls","title":"Comparison of the in situ and desorption sediment-water partitioning of polycyclic aromatic hydrocarbons and polychlorinated biphenyls","docAbstract":"In situ sediment−porewater partitioning of polycyclic aromatic hydrocarbons (PAHs) measured in three cores from Boston Harbor, MA, has led us to suggest that only a fraction of the total measured sediment PAH concentration is available for equilibrium partitioning (AEP fraction). To test this, aqueous PAH concentrations were measured in laboratory desorption experiments using subsamples of the same Boston Harbor sediments. The observed concentrations were consistent with what we predicted from the field-derived AEP values: Caqueous = (Csediment × AEP)/(foc × Koc) where foc is the fraction organic carbon in the sediment and Koc is the organic carbon normalized sediment−water partition coefficient. Equilibrium partitioning models based on the total measured sediment PAH concentrations overestimated the measured aqueous PAH concentrations by as much as 100 times in some cases. Only a small fraction of the sediment phenanthrene and pyrene concentrations (1−40%) appeared to be available for equilibrium partitioning. Both in situ and laboratory desorption aqueous polychlorinated biphenyl (PCB) concentrations were consistent with equilibrium partitioning models and the assumption that 100% of these compounds was available for equilibrium partitioning. These results are particularly important to efforts to predict the environmental mobility and bioavailability of the PAHs.
","language":"English","publisher":"American Chemical Society","doi":"10.1021/es950218z","issn":"0013936X","usgsCitation":"Mcgroddy, S., Farrington, J., and Gschwend, P., 1996, Comparison of the in situ and desorption sediment-water partitioning of polycyclic aromatic hydrocarbons and polychlorinated biphenyls: Environmental Science & Technology, v. 30, no. 1, p. 172-177, https://doi.org/10.1021/es950218z.","productDescription":"6 p.","startPage":"172","endPage":"177","costCenters":[],"links":[{"id":227616,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"country":"United States","state":"Massachusetts","otherGeospatial":"Boston Harbor, Fort Point Channel, Spectacle Island","geographicExtents":"{\n \"type\": \"FeatureCollection\",\n \"features\": [\n {\n \"type\": \"Feature\",\n \"properties\": {},\n \"geometry\": {\n \"coordinates\": [\n [\n [\n -71.05683424005889,\n 42.34563911821937\n ],\n [\n -71.05486162710089,\n 42.345693791242354\n ],\n [\n -71.05318490608666,\n 42.3478077783453\n ],\n [\n -71.05298764479056,\n 42.34824514611182\n ],\n [\n -71.0525931221991,\n 42.34853672293204\n ],\n [\n -71.05143421208611,\n 42.35006747905015\n ],\n [\n -71.05143421208611,\n 42.35028615545252\n ],\n [\n -71.05099037417042,\n 42.350796397432674\n ],\n [\n -71.05081777053648,\n 42.35094218009502\n ],\n [\n -71.04889447290194,\n 42.35338398942224\n ],\n [\n -71.0482533736909,\n 42.3540764255479\n ],\n [\n -71.04734104019745,\n 42.35467774546839\n ],\n [\n -71.04608349943679,\n 42.35504217898318\n ],\n [\n -71.04492458932381,\n 42.3550239573575\n ],\n [\n -71.04953557211367,\n 42.35622657331251\n ],\n [\n -71.05180407701545,\n 42.3530013240794\n ],\n [\n -71.05200133831156,\n 42.3530013240794\n ],\n [\n -71.05249449155068,\n 42.35254576706279\n ],\n [\n -71.052395860903,\n 42.35232709852173\n ],\n [\n -71.05683424005889,\n 42.34563911821937\n ]\n ]\n ],\n \"type\": \"Polygon\"\n }\n },\n {\n \"type\": \"Feature\",\n \"properties\": {},\n \"geometry\": {\n \"coordinates\": [\n [\n [\n -70.98436332272189,\n 42.322513257101946\n ],\n [\n -70.98386479531038,\n 42.32632809465244\n ],\n [\n -70.98398942716324,\n 42.327046806266\n ],\n [\n -70.98339119426879,\n 42.327433801425656\n ],\n [\n -70.98354075249237,\n 42.32798664752431\n ],\n [\n -70.98456273368697,\n 42.32833678087388\n ],\n [\n -70.98663162244684,\n 42.32852106080114\n ],\n [\n -70.98720492897057,\n 42.32841049290943\n ],\n [\n -70.98827676290584,\n 42.328355208891\n ],\n [\n -70.99049520988936,\n 42.32761808399823\n ],\n [\n -70.99116822189524,\n 42.326880950468365\n ],\n [\n -70.9912430010074,\n 42.32630966604205\n ],\n [\n -70.99049520988936,\n 42.32548037296499\n ],\n [\n -70.98967263965987,\n 42.32514865267336\n ],\n [\n -70.98840139475874,\n 42.32439306103535\n ],\n [\n -70.98807735194156,\n 42.32336101877024\n ],\n [\n -70.98797764645863,\n 42.32245796790039\n ],\n [\n -70.98947322869476,\n 42.321776063757284\n ],\n [\n -70.98887499580033,\n 42.32083612971536\n ],\n [\n -70.98787794097645,\n 42.321204732973996\n ],\n [\n -70.98797764645863,\n 42.32054124555404\n ],\n [\n -70.98815213105297,\n 42.31998833402639\n ],\n [\n -70.98787794097645,\n 42.319324833779916\n ],\n [\n -70.98673132792896,\n 42.31893778873879\n ],\n [\n -70.9858090522166,\n 42.3189746502741\n ],\n [\n -70.98546008302867,\n 42.31973030698447\n ],\n [\n -70.98496155561635,\n 42.32039380295541\n ],\n [\n -70.98403927990395,\n 42.3215180440458\n ],\n [\n -70.98406420627468,\n 42.321868213397664\n ],\n [\n -70.98436332272189,\n 42.322513257101946\n ]\n ]\n ],\n \"type\": \"Polygon\"\n }\n }\n ]\n}","volume":"30","issue":"1","noUsgsAuthors":false,"publicationDate":"1995-12-27","publicationStatus":"PW","scienceBaseUri":"5059f8ade4b0c8380cd4d208","contributors":{"authors":[{"text":"Mcgroddy, S.E.","contributorId":60793,"corporation":false,"usgs":true,"family":"Mcgroddy","given":"S.E.","email":"","affiliations":[],"preferred":false,"id":380216,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Farrington, J.W.","contributorId":89160,"corporation":false,"usgs":true,"family":"Farrington","given":"J.W.","email":"","affiliations":[],"preferred":false,"id":380217,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Gschwend, P.M.","contributorId":24115,"corporation":false,"usgs":true,"family":"Gschwend","given":"P.M.","affiliations":[],"preferred":false,"id":380215,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70018996,"text":"70018996 - 1996 - Limestone characterization to model damage from acidic precipitation: Effect of pore structure on mass transfer","interactions":[],"lastModifiedDate":"2012-03-12T17:19:14","indexId":"70018996","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":"Limestone characterization to model damage from acidic precipitation: Effect of pore structure on mass transfer","docAbstract":"The pore structure of Salem limestone is investigated, and conclusions regarding the effect of the pore geometry on modeling moisture and contaminant transport are discussed based on thin section petrography, scanning electron microscopy, mercury intrusion porosimetry, and nitrogen adsorption analyses. These investigations are compared to and shown to compliment permeability and capillary pressure measurements for this common building stone. Salem limestone exhibits a bimodal pore size distribution in which the larger pores provide routes for convective mass transfer of contaminants into the material and the smaller pores lead to high surface area adsorption and reaction sites. Relative permeability and capillary pressure measurements of the air/water system indicate that Salem limestone exhibits high capillarity end low effective permeability to water. Based on stone characterization, aqueous diffusion and convection are believed to be the primary transport mechanisms for pollutants in this stone. The extent of contaminant accumulation in the stone depends on the mechanism of partitioning between the aqueous and solid phases. The described characterization techniques and modeling approach can be applied to many systems of interest such as acidic damage to limestone, mass transfer of contaminants in concrete and other porous building materials, and modeling pollutant transport in subsurface moisture zones.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Environmental Science and Technology","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1021/es950583q","issn":"0013936X","usgsCitation":"Leith, S., Reddy, M., Irez, W., and Heymans, M., 1996, Limestone characterization to model damage from acidic precipitation: Effect of pore structure on mass transfer: Environmental Science & Technology, v. 30, no. 7, p. 2202-2210, https://doi.org/10.1021/es950583q.","startPage":"2202","endPage":"2210","numberOfPages":"9","costCenters":[],"links":[{"id":205798,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1021/es950583q"},{"id":226855,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"30","issue":"7","noUsgsAuthors":false,"publicationDate":"1996-06-26","publicationStatus":"PW","scienceBaseUri":"505a4784e4b0c8380cd678a5","contributors":{"authors":[{"text":"Leith, S.D.","contributorId":12634,"corporation":false,"usgs":true,"family":"Leith","given":"S.D.","email":"","affiliations":[],"preferred":false,"id":381339,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Reddy, M.M.","contributorId":24363,"corporation":false,"usgs":true,"family":"Reddy","given":"M.M.","email":"","affiliations":[],"preferred":false,"id":381340,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Irez, W.F.","contributorId":9783,"corporation":false,"usgs":true,"family":"Irez","given":"W.F.","email":"","affiliations":[],"preferred":false,"id":381338,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Heymans, M.J.","contributorId":39140,"corporation":false,"usgs":true,"family":"Heymans","given":"M.J.","email":"","affiliations":[],"preferred":false,"id":381341,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}} ,{"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":70018513,"text":"70018513 - 1996 - Coral ages and island subsidence, Hilo drill hole","interactions":[],"lastModifiedDate":"2024-11-13T17:02:12.156911","indexId":"70018513","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":"Coral ages and island subsidence, Hilo drill hole","docAbstract":"A 25.8-m-thick sedimentary section containing coral fragments occurs directly below a surface lava flow (the ∼1340 year old Panaewa lava flow) at the Hilo drill hole. Ten coral samples from this section dated by accelerator mass spectrometry (AMS) radiocarbon and five by thermal infrared multispectral scanner (TIMS) 230Th/U methods show good agreement. The calcareous unit is 9790 years old at the bottom and 1690 years old at the top and was deposited in a shallow lagoon behind an actively growing reef. This sedimentary unit is underlain by a 34-m-thick lava flow which in turn overlies a thin volcaniclastic silt with coral fragments that yield a single 14C date of 10,340 years. The age-depth relations of the dated samples can be compared with proposed eustatic sea level curves after allowance for island subsidence is taken. Island subsidence averages 2.2 mm/yr for the last 47 years based on measurements from a tide gage near the drill hole or 2.5–2.6 mm/yr for the last 500,000 years based on the ages and depths of a series of drowned coral reefs offshore from west Hawaii. The age-depth measurements of coral fragments are more consistent with eustatic sea levels as determined by coral dating at Barbados and Albrolhos Islands than those based on oxygen isotopic data from deep sea cores. The Panaewa lava flow entered a lagoon underlain by coral debris and covered the drill site with 30.9 m of lava of which 11 m was above sea level. This surface has now subsided to 4.2 m above sea level, but it demonstrates how a modern lava flow entering Hilo Bay would not only change the coastline but could extensively modify the offshore shelf.
","language":"English","publisher":"American Geophysical Union","doi":"10.1029/95JB03215","issn":"01480227","usgsCitation":"Moore, J., Ingram, B., Ludwig, K., and Clague, D., 1996, Coral ages and island subsidence, Hilo drill hole: Journal of Geophysical Research B: Solid Earth, v. 101, no. 5, p. 11599-11605, https://doi.org/10.1029/95JB03215.","productDescription":"7 p.","startPage":"11599","endPage":"11605","costCenters":[{"id":615,"text":"Volcano Hazards Program","active":true,"usgs":true}],"links":[{"id":227428,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"101","issue":"5","noUsgsAuthors":false,"publicationDate":"1996-05-10","publicationStatus":"PW","scienceBaseUri":"5059fc05e4b0c8380cd4e0aa","contributors":{"authors":[{"text":"Moore, J.G.","contributorId":67496,"corporation":false,"usgs":true,"family":"Moore","given":"J.G.","email":"","affiliations":[],"preferred":false,"id":379883,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Ingram, B.L.","contributorId":51731,"corporation":false,"usgs":true,"family":"Ingram","given":"B.L.","email":"","affiliations":[],"preferred":false,"id":379882,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Ludwig, K.R.","contributorId":97112,"corporation":false,"usgs":true,"family":"Ludwig","given":"K.R.","email":"","affiliations":[{"id":218,"text":"Denver Federal Center","active":false,"usgs":true}],"preferred":false,"id":379884,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Clague, D.A.","contributorId":36129,"corporation":false,"usgs":true,"family":"Clague","given":"D.A.","email":"","affiliations":[],"preferred":false,"id":379881,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}} ,{"id":70018512,"text":"70018512 - 1996 - Velocity structure of a bottom simulating reflector offshore Peru: Results from full waveform inversion","interactions":[],"lastModifiedDate":"2018-01-08T12:53:45","indexId":"70018512","displayToPublicDate":"1996-01-01T00:00:00","publicationYear":"1996","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1427,"text":"Earth and Planetary Science Letters","active":true,"publicationSubtype":{"id":10}},"title":"Velocity structure of a bottom simulating reflector offshore Peru: Results from full waveform inversion","docAbstract":"Much of our knowledge of the worldwide distribution of submarine gas hydrates comes from seismic observations of Bottom Simulating Reflectors (BSRs). Full waveform inversion has proven to be a reliable technique for studying the fine structure of BSRs using the compressional wave velocity. We applied a non-linear full waveform inversion technique to a BSR at a location offshore Peru. We first determined the large-scale features of seismic velocity variations using a statistical inversion technique to maximise coherent energy along travel-time curves. These velocities were used for a starting velocity model for the full waveform inversion, which yielded a detailed velocity/depth model in the vicinity of the BSR. We found that the data are best fit by a model in which the BSR consists of a thin, low-velocity layer. The compressional wave velocity drops from 2.15 km/s down to an average of 1.70 km/s in an 18m thick interval, with a minimum velocity of 1.62 km/s in a 6 m interval. The resulting compressional wave velocity was used to estimate gas content in the sediments. Our results suggest that the low velocity layer is a 6-18 m thick zone containing a few percent of free gas in the pore space. The presence of the BSR coincides with a region of vertical uplift. Therefore, we suggest that gas at this BSR is formed by a dissociation of hydrates at the base of the hydrate stability zone due to uplift and subsequently a decrease in pressure.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Earth and Planetary Science Letters","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1016/0012-821X(95)00242-5","issn":"0012821X","usgsCitation":"Pecher, I., Minshull, T., Singh, S., and von Huene, R.E., 1996, Velocity structure of a bottom simulating reflector offshore Peru: Results from full waveform inversion: Earth and Planetary Science Letters, v. 139, no. 3-4, p. 459-469, https://doi.org/10.1016/0012-821X(95)00242-5.","startPage":"459","endPage":"469","numberOfPages":"11","costCenters":[],"links":[{"id":227388,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":205907,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/0012-821X(95)00242-5"}],"volume":"139","issue":"3-4","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505bc1fce4b08c986b32a87c","contributors":{"authors":[{"text":"Pecher, I.A.","contributorId":14011,"corporation":false,"usgs":true,"family":"Pecher","given":"I.A.","email":"","affiliations":[],"preferred":false,"id":379877,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Minshull, T.A.","contributorId":75815,"corporation":false,"usgs":true,"family":"Minshull","given":"T.A.","email":"","affiliations":[],"preferred":false,"id":379879,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Singh, S.C.","contributorId":106380,"corporation":false,"usgs":true,"family":"Singh","given":"S.C.","email":"","affiliations":[],"preferred":false,"id":379880,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"von Huene, Roland E. 0000-0003-1301-3866 rvonhuene@usgs.gov","orcid":"https://orcid.org/0000-0003-1301-3866","contributorId":191070,"corporation":false,"usgs":true,"family":"von Huene","given":"Roland","email":"rvonhuene@usgs.gov","middleInitial":"E.","affiliations":[{"id":237,"text":"Earthquake Science Center","active":true,"usgs":true},{"id":7065,"text":"USGS emeritus","active":true,"usgs":false}],"preferred":false,"id":379878,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}} ,{"id":70018569,"text":"70018569 - 1996 - Late Quaternary variations in relative sea level due to glacial cycle polar wander","interactions":[],"lastModifiedDate":"2024-02-12T12:06:01.178724","indexId":"70018569","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":"Late Quaternary variations in relative sea level due to glacial cycle polar wander","docAbstract":"Growth and decay of continental ice sheets can excite significant motion of the Earth's rotation pole and cause a complex spatio-temporal pattern of changes in relative sea level. These two effects have generally been considered separately, but may interact in important ways. In particular, a simple model of the melting of the Laurentide ice sheet causes a uniform eustatic sea level rise of 55 m, and also induces a motion of the rotation pole by 0.1 to 1 degree, depending on viscosity structure in the mantle. This motion produces a secular pole tide, which is a spherical harmonic degree 2, order 1 component of the relative sea level pattern, with peak-to-peak amplitude of 20 to 40 m. The maximum effect is along the great circle passing through the path of the pole and at latitudes of ±45°. This secular pole tide has been ignored in most previous attempts to estimate ice sheet loading history and mantle viscosity from global patterns of relative sea level change. It has a large influence along the East coast of North America and the West coast of South America, and significantly contributes to present day rates of relative sea level change.
Numerical simulations of multiphase fluid and heat transport through a porous medium define combinations of rock properties and boundary conditions which lead to geyser‐like periodic discharge. Within the rather narrow range of conditions that allow geyser‐like behavior, eruption frequency and discharge are highly sensitive to the intrinsic permeabilities of the geyser conduit and the surrounding rock matrix, to the relative permeability functions assumed, and to pressure gradients in the matrix. In theory, heat pipes (concomitant upward flow of steam and downward flow of liquid) can exist under similar conditions, but our simulations suggest that the periodic solution is more stable. Simulated time series of geyser discharge are chaotic, but integrated quantities such as eruption frequency and mass discharge per eruption are free of chaos. These results may explain the observed sensitivity of natural geysers to small strains such as those caused by remote earthquakes, if ground motion is sufficient to induce permeability changes. Changes in geyser behavior caused by minor preseismic deformation, periodic surface loading, and Earth tides are more difficult to explain in the context of our current model.
","language":"English","publisher":"AGU","doi":"10.1029/96JB02285","issn":"01480227","usgsCitation":"Ingebritsen, S.E., and Rojstaczer, S., 1996, Geyser periodicity and the response of geysers to deformation: Journal of Geophysical Research B: Solid Earth, v. 101, no. B10, p. 21891-21905, https://doi.org/10.1029/96JB02285.","productDescription":"15 p.","startPage":"21891","endPage":"21905","costCenters":[{"id":615,"text":"Volcano Hazards Program","active":true,"usgs":true}],"links":[{"id":479133,"rank":1,"type":{"id":41,"text":"Open Access External Repository Page"},"url":"http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.601.9222","text":"External Repository"},{"id":227440,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"101","issue":"B10","noUsgsAuthors":false,"publicationDate":"1996-10-10","publicationStatus":"PW","scienceBaseUri":"505a28e7e4b0c8380cd5a509","contributors":{"authors":[{"text":"Ingebritsen, S. E.","contributorId":8078,"corporation":false,"usgs":true,"family":"Ingebritsen","given":"S.","email":"","middleInitial":"E.","affiliations":[],"preferred":false,"id":380449,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Rojstaczer, S.A.","contributorId":54620,"corporation":false,"usgs":true,"family":"Rojstaczer","given":"S.A.","email":"","affiliations":[],"preferred":false,"id":380450,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ]}