A new activated-carbon fiber-cloth (ACFC) adsorber coupled with an electrothermal regenerator and a cryogenic condenser was designed and developed to efficiently capture and recover toxic chemical vapors (TCVs) from simulated industrial gas streams. The system was characterized for adsorption by ACFC, electrothermal desorption, and cryogenic condensation to separate acetone and methyl ethyl ketone from gas streams. Adsorption dynamics are numerically modeled to predict system characteristics during scale-up and optimization of the process in the future. The model requires diffusivities of TCVs into an activated-carbon fiber (ACF) as an input. Effective diffusivities of TCVs into ACFs were modeled as a function of temperature, concentration, and pore size distribution. Effective diffusivities for acetone at 65 °C and 30−60 ppmv were measured using a chromatography method. The energy factor for surface diffusion was determined from comparison between the experimental and modeled effective diffusivities. The modeled effective diffusivities were used in a dispersive computational model to predict mass transfer zones of TCVs in fixed beds of ACFC under realistic conditions for industrial applications.
Sediment delivery to the Gulf of Alaska occurs via four areally extensive deepwater fans, sourced from grounded tidewater glaciers. During periods of climatic cooling, glaciers cross a narrow shelf and discharge sediment down the continental slope. Because the coastal terrain is dominated by fjords and a narrow, high-relief Pacific watershed, deposition is dominated by channellized point-source fan accumulations, the volumes of which are primarily a function of climate. The sediment distribution is modified by a long-term tectonic translation of the Pacific plate to the north along the transform margin. As a result, the deep-water fans are gradually moved away from the climatically controlled point sources. Sets of abandoned channels record the effect of translation during the Plio-Pleistocene.
","language":"English","publisher":"Geological Society, London","doi":"10.1144/GSL.SP.1998.129.01.04","issn":"03058719","usgsCitation":"Dobson, M., O'Leary, D., and Veart, M., 1998, Sediment delivery to the Gulf of Alaska: Source mechanisms along a glaciated transform margin: Geological Society Special Publication, v. 129, p. 43-66, https://doi.org/10.1144/GSL.SP.1998.129.01.04.","productDescription":"24 p.","startPage":"43","endPage":"66","numberOfPages":"24","costCenters":[],"links":[{"id":228103,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"129","noUsgsAuthors":false,"publicationDate":"1998-05-15","publicationStatus":"PW","scienceBaseUri":"505b896fe4b08c986b316ddd","contributors":{"authors":[{"text":"Dobson, M.R.","contributorId":100858,"corporation":false,"usgs":true,"family":"Dobson","given":"M.R.","email":"","affiliations":[],"preferred":false,"id":384213,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"O'Leary, D.","contributorId":90487,"corporation":false,"usgs":true,"family":"O'Leary","given":"D.","affiliations":[],"preferred":false,"id":384212,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Veart, M.","contributorId":24506,"corporation":false,"usgs":true,"family":"Veart","given":"M.","email":"","affiliations":[],"preferred":false,"id":384211,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70019856,"text":"70019856 - 1998 - Propagation of seismic waves in tall buildings","interactions":[],"lastModifiedDate":"2012-03-12T17:19:17","indexId":"70019856","displayToPublicDate":"1998-01-01T00:00:00","publicationYear":"1998","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":3482,"text":"Structural Design of Tall Buildings","active":true,"publicationSubtype":{"id":10}},"title":"Propagation of seismic waves in tall buildings","docAbstract":"A discrete-time wave propagation formulation of the seismic response of tall buildings is introduced. The building is modeled as a layered medium, similar to a layered soil medium, and is subjected to vertically propagating seismic shear waves. Soil layers and the bedrock under the foundation are incorporated in the formulation as additional layers. Seismic response is expressed in terms of the wave travel times between the layers, and the wave reflection and transmission coefficients at the layer interfaces. The equations account for the frequency-dependent filtering effects of the foundation and floor masses. The calculation of seismic response is reduced to a pair of simple finite-difference equations for each layer, which can be solved recursively starting from the bedrock. Compared to the commonly used vibration formulation, the wave propagation formulation provides several advantages, including simplified calculations, better representation of damping, ability to account for the effects of the soil layers under the foundation, and better tools for identification and damage detection from seismic records. Examples presented show the versatility of the method. ?? 1998 John Wiley & Sons, Ltd.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Structural Design of Tall Buildings","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","issn":"10628002","usgsCitation":"Safak, E., 1998, Propagation of seismic waves in tall buildings: Structural Design of Tall Buildings, v. 7, no. 4, p. 295-306.","startPage":"295","endPage":"306","numberOfPages":"12","costCenters":[],"links":[{"id":227981,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"7","issue":"4","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a8f10e4b0c8380cd7f572","contributors":{"authors":[{"text":"Safak, E.","contributorId":104070,"corporation":false,"usgs":true,"family":"Safak","given":"E.","email":"","affiliations":[],"preferred":false,"id":384179,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}} ,{"id":70019845,"text":"70019845 - 1998 - Ground-water resource evaluation on Long Island, New York, using flow models and a geographic information system","interactions":[],"lastModifiedDate":"2012-03-12T17:19:17","indexId":"70019845","displayToPublicDate":"1998-01-01T00:00:00","publicationYear":"1998","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2897,"text":"Northeastern Geology and Environmental Sciences","active":true,"publicationSubtype":{"id":10}},"title":"Ground-water resource evaluation on Long Island, New York, using flow models and a geographic information system","docAbstract":"[No abstract available]","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Northeastern Geology and Environmental Sciences","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","issn":"01941453","usgsCitation":"Schubert, C., Buxton, H., and Monti, J., 1998, Ground-water resource evaluation on Long Island, New York, using flow models and a geographic information system: Northeastern Geology and Environmental Sciences, v. 20, no. 4, p. 308-313.","startPage":"308","endPage":"313","numberOfPages":"6","costCenters":[],"links":[{"id":227814,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"20","issue":"4","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a2cf0e4b0c8380cd5bdca","contributors":{"authors":[{"text":"Schubert, C.E.","contributorId":87576,"corporation":false,"usgs":true,"family":"Schubert","given":"C.E.","email":"","affiliations":[],"preferred":false,"id":384145,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Buxton, H. T.","contributorId":67873,"corporation":false,"usgs":true,"family":"Buxton","given":"H. T.","affiliations":[],"preferred":false,"id":384144,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Monti, J. Jr.","contributorId":39956,"corporation":false,"usgs":true,"family":"Monti","given":"J.","suffix":"Jr.","email":"","affiliations":[],"preferred":false,"id":384143,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70019843,"text":"70019843 - 1998 - Regression models of herbicide concentrations in outflow from reservoirs in the midwestern USA, 1992-1993","interactions":[],"lastModifiedDate":"2019-02-04T10:28:04","indexId":"70019843","displayToPublicDate":"1998-01-01T00:00:00","publicationYear":"1998","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2529,"text":"Journal of the American Water Resources Association","active":true,"publicationSubtype":{"id":10}},"title":"Regression models of herbicide concentrations in outflow from reservoirs in the midwestern USA, 1992-1993","docAbstract":"Reservoirs are used to store water for public water supply, flood control, irrigation, recreation, hydropower, and wildlife habitat, but also often store undesirable substances such as herbicides. The outflow from 76 reservoirs in the midwestern USA, was sampled four times in 1992 and four times in 1993. At least one herbicide was detected in 82.6 percent of all samples, and atrazine was detected in 82.1 percent of all samples. Herbicide properties; topography, land use, herbicide use, and soil type in the contributing drainage area; residence time of water in reservoirs; and timing of inflow, release, and rainfall all can affect the concentration of herbicides in reservoirs. A GIS was used to quantify characteristics of land use, agricultural chemical use, climatic conditions, topographic character, and soil type by reservoir drainage basins. Multiple linear and logistic regression equations were used to model mean herbicide concentrations in reservoir outflow as a function of these characteristics. Results demonstrate a strong association between mean herbicide concentrations in reservoir outflow and herbicide use rates within associated drainage basins. Results also demonstrate the importance of including soils and basin hydrologic characteristics in models used to estimate mean herbicide concentrations.","language":"English","publisher":"Wiley","doi":"10.1111/j.1752-1688.1998.tb05438.x","issn":"1093474X","usgsCitation":"Battaglin, W., and Goolsby, D.A., 1998, Regression models of herbicide concentrations in outflow from reservoirs in the midwestern USA, 1992-1993: Journal of the American Water Resources Association, v. 34, no. 6, p. 1369-1390, https://doi.org/10.1111/j.1752-1688.1998.tb05438.x.","productDescription":"22 p.","startPage":"1369","endPage":"1390","costCenters":[{"id":589,"text":"Toxic Substances Hydrology Program","active":true,"usgs":true}],"links":[{"id":227812,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"34","issue":"6","noUsgsAuthors":false,"publicationDate":"2007-06-08","publicationStatus":"PW","scienceBaseUri":"50e4a5d2e4b0e8fec6cdc016","contributors":{"authors":[{"text":"Battaglin, W.A.","contributorId":16376,"corporation":false,"usgs":true,"family":"Battaglin","given":"W.A.","email":"","affiliations":[],"preferred":false,"id":384137,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Goolsby, D. A.","contributorId":50508,"corporation":false,"usgs":true,"family":"Goolsby","given":"D.","email":"","middleInitial":"A.","affiliations":[],"preferred":false,"id":384138,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70019833,"text":"70019833 - 1998 - Nd isotopic composition of cratonic rocks in the southern Death Valley region: Evidence for a substantial Archean source component in Mojavia","interactions":[],"lastModifiedDate":"2024-01-17T00:53:23.969887","indexId":"70019833","displayToPublicDate":"1998-01-01T00:00:00","publicationYear":"1998","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1796,"text":"Geology","active":true,"publicationSubtype":{"id":10}},"title":"Nd isotopic composition of cratonic rocks in the southern Death Valley region: Evidence for a substantial Archean source component in Mojavia","docAbstract":"Thirty Early Proterozoic intermediate to silicic metasedimentary and metaigneous rocks in the southern Death Valley region and vicinity show ϵNd values of −1.6 to −6.3 at 1.7 Ga and Nd model ages of 2.1 to 2.6 Ga. These cratonic rocks thus reveal an older signature than so far reported for Nd province 1 of the western United States; as much as 30%–40% of their mass may be Archean crustal material. The Archean component was introduced in the form of sedimentary detritus that was probably subducted and mixed with juvenile material at a convergent margin. Three younger Precambrian rocks associated with the cratonic rocks also have a Nd isotopic composition of province 1 type.
Down-hole geochemical anomalies encountered in active accretionary systems can be used to constrain the timing, rates, and localization of fluid flow. Here we combine a coupled flow and solute transport model with a kinetic model for smectite dehydration to better understand and quantify fluid flow in the Nankai accretionary complex offshore of Japan. Compaction of sediments and clay dehydration provide fluid sources which drive the model flow system. We explicitly include the consolidation rate of underthrust sediments in our calculations to evaluate the impact that variations in this unknown quantity have on pressure and chloride distribution. Sensitivity analysis of steady state pressure solutions constrains bulk and flow conduit permeabilities. Steady state simulations with 30% smectite in the incoming sedimentary sequence result in minimum chloride concentrations at site 808 of 550 mM, but measured chlorinity is as low as 447 mM. We simulate the transient effects of hydrofracture or a strain event by assuming an instantaneous permeability increase of 3–4 orders of magnitude along a flow conduit (in this case the décollement), using steady state results as initial conditions. Transient results with an increase in décollement permeability from 10−16 m2 to 10−13 m2 and 20% smectite reproduce the observed chloride profile at site 808 after 80–160 kyr. Modeled chloride concentrations are highly sensitive to the consolidation rate of underthrust sediments, such that rapid compaction of underthrust material leads to increased freshening. Pressures within the décollement during transient simulations rise rapidly to a significant fraction of lithostatic and remain high for at least 160 kyr, providing a mechanism for maintaining high permeability. Flow rates at the deformation front for transient simulations are in good agreement with direct measurements, but steady state flow rates are 2–3 orders of magnitude smaller than observed. Fluid budget calculations indicate that nearly 71% of the incoming water in the sediments leaves the accretionary wedge via diffuse flow out the seafloor, 0–5% escapes by focused flow along the décollement, and roughly 1% is subducted.
","language":"English","publisher":"American Geophysical Union","doi":"10.1029/98JB01983","issn":"01480227","usgsCitation":"Saffer, D., and Bekins, B., 1998, Episodic fluid flow in the Nankai accretionary complex: Timescale, geochemistry, flow rates, and fluid budget: Journal of Geophysical Research B: Solid Earth, v. 103, no. B12, p. 30351-30370, https://doi.org/10.1029/98JB01983.","productDescription":"20 p.","startPage":"30351","endPage":"30370","numberOfPages":"20","costCenters":[],"links":[{"id":479855,"rank":2,"type":{"id":40,"text":"Open Access Publisher Index Page"},"url":"https://doi.org/10.1029/98jb01983","text":"Publisher Index Page"},{"id":228138,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"103","issue":"B12","noUsgsAuthors":false,"publicationDate":"1998-12-10","publicationStatus":"PW","scienceBaseUri":"505a0a10e4b0c8380cd521a7","contributors":{"authors":[{"text":"Saffer, D.M.","contributorId":72945,"corporation":false,"usgs":true,"family":"Saffer","given":"D.M.","email":"","affiliations":[],"preferred":false,"id":384041,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Bekins, B.A.","contributorId":98309,"corporation":false,"usgs":true,"family":"Bekins","given":"B.A.","email":"","affiliations":[],"preferred":false,"id":384042,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70020275,"text":"70020275 - 1998 - Major occurrences and reservoir concepts of marine clathrate hydrates: Implications of field evidence","interactions":[],"lastModifiedDate":"2018-03-13T17:00:58","indexId":"70020275","displayToPublicDate":"1998-01-01T00:00:00","publicationYear":"1998","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1785,"text":"Geological Society Special Publication","active":true,"publicationSubtype":{"id":10}},"title":"Major occurrences and reservoir concepts of marine clathrate hydrates: Implications of field evidence","docAbstract":"This paper is part of the special publication Gas hydrates: relevance to world margin stability and climatic change (eds J.P. Henriet and J. Mienert). Questions concerning clathrate hydrate as an energy resource, as a factor in modifying global climate and as a triggering mechanism for mass movements invite consideration of what factors promote hydrate concentration, and what the quintessential hydrate-rich sediment may be. Gas hydrate field data, although limited, provide a starting point for identifying the environments and processes that lead to more massive concentrations. Gas hydrate zones are up to 30 m thick and the vertical range of occurrence at a site may exceed 200 m. Zones typically occur more than 100m above the phase boundary. Thicker zones are overwhelmingly associated with structural features and tectonism, and often contain sand. It is unclear whether an apparent association between zone thickness and porosity represents a cause-and-effect relationship. The primary control on the thickness of a potential gas hydrate reservoir is the geological setting. Deep water and low geothermal gradients foster thick gas hydrate stability zones (GHSZs). The presence of faults, fractures, etc. can favour migration of gas-rich fluids. Geological processes, such as eustacy or subsidence, may alter the thickness of the GHSZ or affect hydrate concentratiion. Tectonic forces may promote injection of gas into the GHSZ. More porous and permeable sediment, as host sediment properties, increase storage capacity and fluid conductivity, and thus also enhance reservoir potential.","largerWorkTitle":"Geological Society Special Publication","language":"English","doi":"10.1144/GSL.SP.1998.137.01.08","issn":"03058719","usgsCitation":"Booth, J., Winters, W., Dillon, W.P., Clennell, M.B., and Rowe, M., 1998, Major occurrences and reservoir concepts of marine clathrate hydrates: Implications of field evidence: Geological Society Special Publication, v. 137, p. 113-127, https://doi.org/10.1144/GSL.SP.1998.137.01.08.","productDescription":"15 p.","startPage":"113","endPage":"127","costCenters":[{"id":678,"text":"Woods Hole Coastal and Marine Science Center","active":true,"usgs":true}],"links":[{"id":231288,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"137","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a4c18e4b0c8380cd699dd","contributors":{"authors":[{"text":"Booth, J.S.","contributorId":13619,"corporation":false,"usgs":true,"family":"Booth","given":"J.S.","email":"","affiliations":[],"preferred":false,"id":385604,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Winters, W.J.","contributorId":49796,"corporation":false,"usgs":true,"family":"Winters","given":"W.J.","email":"","affiliations":[],"preferred":false,"id":385605,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Dillon, William P. bdillon@usgs.gov","contributorId":79820,"corporation":false,"usgs":true,"family":"Dillon","given":"William","email":"bdillon@usgs.gov","middleInitial":"P.","affiliations":[{"id":678,"text":"Woods Hole Coastal and Marine Science Center","active":true,"usgs":true}],"preferred":false,"id":385607,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Clennell, M. B.","contributorId":95221,"corporation":false,"usgs":true,"family":"Clennell","given":"M.","email":"","middleInitial":"B.","affiliations":[],"preferred":false,"id":385608,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Rowe, M.M.","contributorId":56412,"corporation":false,"usgs":true,"family":"Rowe","given":"M.M.","email":"","affiliations":[],"preferred":false,"id":385606,"contributorType":{"id":1,"text":"Authors"},"rank":5}]}} ,{"id":70020693,"text":"70020693 - 1998 - A comparison of zero-order, first-order, and monod biotransformation models","interactions":[],"lastModifiedDate":"2018-12-21T07:43:38","indexId":"70020693","displayToPublicDate":"1998-01-01T00:00:00","publicationYear":"1998","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1861,"text":"Ground Water","active":true,"publicationSubtype":{"id":10}},"title":"A comparison of zero-order, first-order, and monod biotransformation models","docAbstract":"Under some conditions, a first-order kinetic model is a poor representation of biodegradation in contaminated aquifers. Although it is well known that the assumption of first-order kinetics is valid only when substrate concentration, S, is much less than the half-saturation constant, K(s), this assumption is often made without verification of this condition. We present a formal error analysis showing that the relative error in the first-order approximation is S/K(S) and in the zero-order approximation the error is K(s)/S. We then examine the problems that arise when the first-order approximation is used outside the range for which it is valid. A series of numerical simulations comparing results of first- and zero-order rate approximations to Monod kinetics for a real data set illustrates that if concentrations observed in the field are higher than K(s), it may better to model degradation using a zero-order rate expression. Compared with Monod kinetics, extrapolation of a first-order rate to lower concentrations under-predicts the biotransformation potential, while extrapolation to higher concentrations may grossly over-predict the transformation rate. A summary of solubilities and Monod parameters for aerobic benzene, toluene, and xylene (BTX) degradation shows that the a priori assumption of first-order degradation kinetics at sites contaminated with these compounds is not valid. In particular, out of six published values of KS for toluene, only one is greater than 2 mg/L, indicating that when toluene is present in concentrations greater than about a part per million, the assumption of first-order kinetics may be invalid. Finally, we apply an existing analytical solution for steady-state one-dimensional advective transport with Monod degradation kinetics to a field data set.A formal error analysis is presented showing that the relative error in the first-order approximation is S/KS and in the zero-order approximation the error is KS/S where S is the substrate concentration and KS is the half-saturation constant. The problems that arise when the first-order approximation is used outside the range for which it is valid are examined. A series of numerical simulations comparing results of first- and zero-order rate approximations to Monod kinetics for a real data set illustrates that if concentrations observed in the field are higher than KS, it may be better to model degradation using a zero-order rate expression.","language":"English","publisher":"Wiley","doi":"10.1111/j.1745-6584.1998.tb01091.x","issn":"0017467X","usgsCitation":"Bekins, B., Warren, E., and Godsy, E., 1998, A comparison of zero-order, first-order, and monod biotransformation models: Ground Water, v. 36, no. 2, p. 261-268, https://doi.org/10.1111/j.1745-6584.1998.tb01091.x.","productDescription":"8 p.","startPage":"261","endPage":"268","costCenters":[{"id":589,"text":"Toxic Substances Hydrology Program","active":true,"usgs":true}],"links":[{"id":231235,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"36","issue":"2","noUsgsAuthors":false,"publicationDate":"2005-08-04","publicationStatus":"PW","scienceBaseUri":"5059e37ce4b0c8380cd46075","contributors":{"authors":[{"text":"Bekins, B.A.","contributorId":98309,"corporation":false,"usgs":true,"family":"Bekins","given":"B.A.","email":"","affiliations":[],"preferred":false,"id":387165,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Warren, E.","contributorId":15360,"corporation":false,"usgs":true,"family":"Warren","given":"E.","email":"","affiliations":[],"preferred":false,"id":387163,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Godsy, E.M.","contributorId":56685,"corporation":false,"usgs":true,"family":"Godsy","given":"E.M.","email":"","affiliations":[],"preferred":false,"id":387164,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70020692,"text":"70020692 - 1998 - Caledonian eclogite-facies metamorphism of early Proterozoic protoliths from the North-East Greenland Eclogite Province","interactions":[],"lastModifiedDate":"2012-03-12T17:20:19","indexId":"70020692","displayToPublicDate":"1998-01-01T00:00:00","publicationYear":"1998","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1336,"text":"Contributions to Mineralogy and Petrology","active":true,"publicationSubtype":{"id":10}},"title":"Caledonian eclogite-facies metamorphism of early Proterozoic protoliths from the North-East Greenland Eclogite Province","docAbstract":"High-pressure metamorphic assemblages occur in mafic, ultramafic and a few intermediate rocks in a gneiss complex that covers an area of approximately 400 ?? 100 km in the North-East Greenland Caledonides. Detailed petrologic and geochronologic studies were carried out on three samples in order to clarify the P-T-t evolution of this eclogite province. Geothermobarometry yields temperature estimates of 700-800 ??C and pressure estimates of at least 1.5 GPa from an ecologite senu stricto and a high as 2.35 GPa for a garnet websterite. The eclogite defines a garnet-clinopyroxene-amphibole-whole rock Sm-Nd isochron age of 405 ?? 24 Ma (MSWSD 0.9). Isofacial garnet websterites define garnet-clinopyroxene-orthopyroxene-amphibole-whole rock-(biotite) ages of 439 ?? 8 Ma (MSWD = 2.1) for a coarse=grained sample and 370 ?? 12 Ma (MSWD = 0.6) for a finer-grained variety. Overgrowths on zircons from the fine-grained pyroxenite and the eclogite give a pooled 206Pb/238U SHRIMP age of 377 ?? 7 Ma (n = 4). Significantly younger Rb-Sr biotite ages of 357 ?? 8, 330 ?? 6 and 326 ?? 6 agree withyoung Rb-Sr, K-Ar and 40Ar/39Ar mineral ages from the gneiss complex and indicate slow cooling of the eclogitic rocks. High-pressure metamorphism may have been at least 439 Ma old (Siluro-Ordovician) with cooling through amphibolite-facies conditions in the Devonian and continued crustal thinning and exhumation well into the Carboniferous. Sm-Nd whole rock model ages indicate the eclogite protoliths are Early Proterozoic in age, while 207Pb/206Pb SHRIMP ages of 1889 ?? 8 from an-hedral zircon cores probably reflect Proterozoic metasomatism. The samples have negative ??Nd values (-5 to -16) and elevated 87Sr/86Sr ratios (0.708-0.715), consistent with field evidence that the eclogite protoliths were an integral part of the continental crust long before Caledonian metamorphism. The presence of a large Caledonian eclogite terrane in Greenland requires modification of current tectonic models that postulate subduction of Baltica beneath Laurentia during the Caledonian orogeny.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Contributions to Mineralogy and Petrology","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1007/s004100050353","issn":"00107999","usgsCitation":"Brueckner, H., Gilotti, J.A., and Nutman, A., 1998, Caledonian eclogite-facies metamorphism of early Proterozoic protoliths from the North-East Greenland Eclogite Province: Contributions to Mineralogy and Petrology, v. 130, no. 2, p. 103-120, https://doi.org/10.1007/s004100050353.","startPage":"103","endPage":"120","numberOfPages":"18","costCenters":[],"links":[{"id":206917,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1007/s004100050353"},{"id":231234,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"130","issue":"2","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"5059f30be4b0c8380cd4b57d","contributors":{"authors":[{"text":"Brueckner, H.K.","contributorId":75719,"corporation":false,"usgs":true,"family":"Brueckner","given":"H.K.","email":"","affiliations":[],"preferred":false,"id":387162,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Gilotti, J. A.","contributorId":15776,"corporation":false,"usgs":true,"family":"Gilotti","given":"J.","middleInitial":"A.","affiliations":[],"preferred":false,"id":387160,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Nutman, A.P.","contributorId":16177,"corporation":false,"usgs":true,"family":"Nutman","given":"A.P.","affiliations":[],"preferred":false,"id":387161,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70020683,"text":"70020683 - 1998 - Effects of slip, slip rate, and shear heating on the friction of granite","interactions":[],"lastModifiedDate":"2024-07-19T14:16:32.73282","indexId":"70020683","displayToPublicDate":"1998-01-01T00:00:00","publicationYear":"1998","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":"Effects of slip, slip rate, and shear heating on the friction of granite","docAbstract":"The stability of fault slip is sensitive to the way in which frictional strength responds to changes in slip rate and in particular to the effective velocity dependence of steady state friction Δμss/Δ ln V. This quantity can vary substantially with displacement, temperature and slip rate. To investigate the physical basis for this behavior and the possible influence of shear heating, we slid initially bare granite surfaces in unconfined rotary shear to displacements of hundreds of millimeters at normal stresses, σn of 10 and 25 MPa and at room temperature. We imposed step changes in slip rate within the range 10−2 to 103.5 μm/s and also monitored frictional heating with thermistors embedded in the granite. The transient response of μ to slip rate steps was fit to a rate- and state-dependent friction law using two state variables to estimate the values of several parameters in the constitutive law. The first 20 mm of slip shows rising friction and falling Δμss/Δ ln V; further slip shows roughly constant friction, Δμss/Δ ln V and parameter values, suggesting that a steady state condition is reached on the fault surface. At V ≤ 10 μm/s, Δμss/Δ ln V = −0.004 ± 0.001. At higher rates the response is sensitive to normal stress: At σn = 25 MPa granite shows a transition to effective velocity strengthening (Δμss/Δ ln V = 0.008 ± 0.004) at the highest slip rates tested. At 10 MPa granite shows a less dramatic change to Δμss/Δ ln V ≈ 0 at the highest rates. The maximum temperature measured in the granite is ∼60°C at 25 MPa and 103.5 μm/s. Temperatures are in general agreement with a numerical model of heat conduction which assumes spatially homogeneous frictional heating over the sliding surface. The simplest interpretation of our measurements of Δμss/Δ ln V is that the granite is inherently velocity weakening (∂μss/∂ ln V < 0) and temperature strengthening (∂μss/∂T−1 < 0) at all velocities. At high slip rates the response of μ to changes in temperature from shear heating may outweigh the response to changing velocity, such that the net effect Δμss/Δ ln V > 0 mimics velocity strengthening. These results have implications for the frictional behavior of faults during earthquakes. High slip rates may cause a switch to effective velocity strengthening which could limit peak coseismic slip rate and stress drop. For fluid-saturated faults, strengthening by this mechanism may be partly or fully offset by weakening due to thermal pressurization of a poorly drained pore fluid.
","language":"English","publisher":"American Geophysical Union","doi":"10.1029/97JB02480","issn":"01480227","usgsCitation":"Blanpied, M., Tullis, T., and Weeks, J., 1998, Effects of slip, slip rate, and shear heating on the friction of granite: Journal of Geophysical Research B: Solid Earth, v. 103, no. 1, p. 489-511, https://doi.org/10.1029/97JB02480.","productDescription":"23 p.","startPage":"489","endPage":"511","numberOfPages":"23","costCenters":[],"links":[{"id":231076,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"103","issue":"1","noUsgsAuthors":false,"publicationDate":"1998-01-10","publicationStatus":"PW","scienceBaseUri":"505a07cee4b0c8380cd51847","contributors":{"authors":[{"text":"Blanpied, M.L.","contributorId":61961,"corporation":false,"usgs":true,"family":"Blanpied","given":"M.L.","email":"","affiliations":[],"preferred":false,"id":387110,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Tullis, T.E.","contributorId":91252,"corporation":false,"usgs":true,"family":"Tullis","given":"T.E.","email":"","affiliations":[],"preferred":false,"id":387111,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Weeks, J.D.","contributorId":51034,"corporation":false,"usgs":true,"family":"Weeks","given":"J.D.","email":"","affiliations":[],"preferred":false,"id":387109,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70020679,"text":"70020679 - 1998 - Sulphur-radical control on petroleum formation rates","interactions":[],"lastModifiedDate":"2012-03-12T17:19:42","indexId":"70020679","displayToPublicDate":"1998-01-01T00:00:00","publicationYear":"1998","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2840,"text":"Nature","active":true,"publicationSubtype":{"id":10}},"title":"Sulphur-radical control on petroleum formation rates","docAbstract":"Most petroleum is formed through the partial decomposition of kerogen (an insoluble sedimentary organic material) in response to thermal stress during subsurface burial in a sedimentary basin. Knowing the mechanisms and kinetics of this process allows the determination of the extent and timing of petroleum formation, which, in turn, are critical for evaluating the potential for petroleum occurrences within a sedimentary basin. Kinetic models of petroleum generation are derived mainly from pyrolysis experiments, in which it is usually assumed that formation rates are controlled by the strength of the bonds within the precursor compounds: this agrees with the observation that petroleum formation rates increase with increasing sulphur content of thermally immature kerogen, C-S bonds being weaker than C-C bonds. However, this explanation fails to account for the overall composition of petroleum. Here I argue, on the basis of pyrolysis experiments, that it is the presence of sulphur radicals, rather than the relative weakness of C-S bonds, that controls petroleum formation rates. My findings suggest that the rate of petroleum formation depends critically on the concentration of sulphur radicals generated during the initial stages of thermal maturation. The proposed mechanism appears to provide a realistic explanation for both the overall composition of petroleum and the observed variation in formation rates.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Nature","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1038/34391","issn":"00280836","usgsCitation":"Lewan, M.D., 1998, Sulphur-radical control on petroleum formation rates: Nature, v. 391, no. 6663, p. 164-166, https://doi.org/10.1038/34391.","startPage":"164","endPage":"166","numberOfPages":"3","costCenters":[],"links":[{"id":206861,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1038/34391"},{"id":230996,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"391","issue":"6663","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505b9dece4b08c986b31dba1","contributors":{"authors":[{"text":"Lewan, M. D.","contributorId":46540,"corporation":false,"usgs":true,"family":"Lewan","given":"M.","email":"","middleInitial":"D.","affiliations":[],"preferred":false,"id":387098,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}} ,{"id":70020678,"text":"70020678 - 1998 - Late Pleistocene C4 plant dominance and summer rainfall in the southwestern United States from isotopic study of herbivore teeth","interactions":[],"lastModifiedDate":"2012-03-12T17:19:42","indexId":"70020678","displayToPublicDate":"1998-01-01T00:00:00","publicationYear":"1998","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":3218,"text":"Quaternary Research","active":true,"publicationSubtype":{"id":10}},"title":"Late Pleistocene C4 plant dominance and summer rainfall in the southwestern United States from isotopic study of herbivore teeth","docAbstract":"Patterns of climate and C4 plant abundance in the southwestern United States during the last glaciation were evaluated from isotopic study of herbivore tooth enamel. Enamel ??13C values revealed a substantial eastward increase in C4 plant consumption for Mammuthus spp., Bison spp., Equus spp., and Camelops spp. The ??13C values were greatest in Bison spp. (-6.9 to + 1.7???) and Mammuthus spp. (-9.0 to +0.3???), and in some locales indicated C4-dominated grazing. The ??13C values of Antilocaprids were lowest among taxa (-12.5 to -7.9???) and indicated C3 feeding at all sites. On the basis of modern correlations between climate and C4 grass abundance, the enamel data imply significant summer rain in parts of southern Arizona and New Mexico throughout the last glaciation. Enamel ??18O values range from +19.0 to +31.0??? and generally increase to the east. This pattern could point to a tropical or subtropical source of summer rainfall. At a synoptic scale, the isotope data indicate that interactions of seasonal moisture, temperature, and lowered atmospheric pCO2 determined glacial-age C4 abundance patterns.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Quaternary Research","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1006/qres.1998.1986","issn":"00335894","usgsCitation":"Connin, S., Betancourt, J., and Quade, J., 1998, Late Pleistocene C4 plant dominance and summer rainfall in the southwestern United States from isotopic study of herbivore teeth: Quaternary Research, v. 50, no. 2, p. 179-193, https://doi.org/10.1006/qres.1998.1986.","startPage":"179","endPage":"193","numberOfPages":"15","costCenters":[],"links":[{"id":206849,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1006/qres.1998.1986"},{"id":230957,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"50","issue":"2","noUsgsAuthors":false,"publicationDate":"2017-01-20","publicationStatus":"PW","scienceBaseUri":"505a4506e4b0c8380cd66f89","contributors":{"authors":[{"text":"Connin, S.L.","contributorId":90497,"corporation":false,"usgs":true,"family":"Connin","given":"S.L.","email":"","affiliations":[],"preferred":false,"id":387097,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Betancourt, J.","contributorId":63768,"corporation":false,"usgs":true,"family":"Betancourt","given":"J.","affiliations":[],"preferred":false,"id":387096,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Quade, Jay","contributorId":22108,"corporation":false,"usgs":false,"family":"Quade","given":"Jay","affiliations":[{"id":7042,"text":"University of Arizona","active":true,"usgs":false}],"preferred":false,"id":387095,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70020676,"text":"70020676 - 1998 - Verification of the Rhea-orographic-precipitation model","interactions":[],"lastModifiedDate":"2024-05-29T00:08:39.272232","indexId":"70020676","displayToPublicDate":"1998-01-01T00:00:00","publicationYear":"1998","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2529,"text":"Journal of the American Water Resources Association","active":true,"publicationSubtype":{"id":10}},"title":"Verification of the Rhea-orographic-precipitation model","docAbstract":"ABSTRACT: Observed April 1 snowpack accumulations within and near the Gunnison River basin in southwestern Colorado are compared with simulations from the Rhea-orographic-precipitation model to determine if the model simulates reliable magnitudes and temporal and spatial variability in winter precipitation for the basin. Twenty simulations of the Rhea model were performed using‘optimal’parameter sets determined for 10-kilometer (km) grids (10-km by 10-km grid cells) through stochastic calibration. Comparisons of Rhea-model simulations of winter precipitation with April 1 snowpack accumulations at 32 snowcourse stations were performed for the years 1972–1990. For most stations and most years the Rhea model reliably simulates the temporal and spatial variability in April 1 snowpack accumulations. However, in general, the Rhea-model underestimates April 1 snowpack accumulations in the Gunnison River basin area, and the underestimation is greatest for locations that receive the largest amount of snow. A significant portion of the error in Rhea-model simulations is due to the calibration of the Rhea model using gauge-catch precipitation measurements which can be as much as 50 percent below actual snowfall accumulations. Additional error in the Rhea-model simulations is a result of the comparison of gridded precipitation values to observed values measured at points.
We present a new global model for the Earth's crust based on seismic refraction data published in the period 1948-1995 and a detailed compilation of ice and sediment thickness. An extensive compilation of seismic refraction measurements has been used to determine the crustal structure on continents and their margins. Oceanic crust is modeled with both a standard model for normal oceanic crust, and variants for nonstandard regions, such as oceanic plateaus. Our model (CRUST 5.1) consists of 2592 5° × 5° tiles in which the crust and uppermost mantle are described by eight layers: (1) ice, (2) water, (3) soft sediments, (4) hard sediments, (5) crystalline upper, (6) middle, (7) lower crust, and (8) uppermost mantle. Topography and bathymetry are adopted from a Mandard database (ETOPO-5). Compressional wave velocity in each layer is based on field measurements, and shear wave velocity and density are estimated using recently published empirical Vp-Vs and Vp -density relationships. The crustal model differs from previous models in that (1) the thickness and seismic/density structure of sedimentary basins is accounted for more completely, (2) the velocity structure of unmeasured regions is estimated using statistical averages that are based on a significantly larger database of crustal structure, (3) the compressional wave, shear wave, and density structure have been explicitly specified using newly available constraints from field and laboratory studies. Thus - this global crustal model is based on substantially more data than previous models and differs from them in many important respects. A new map of the thickness of the Earth's crust is presented, and we illustrate the application of this model by using it to provide the crustal correction for surface wave phase velocity maps. Love waves at 40 s are dominantly sensitive to crustal structure, and there is a very close correspondence between observed phase velocities at this period and those predicted by CRUST 5.1. We find that the application of crustal corrections to long-period (167 s) Rayleigh waves significantly increases the variance in the phase velocity maps and strengthens the upper mantle , velocity anomalies beneath stable continental regions. A simple calculation of crustal isostacy indicates significant lateral variations in upper mantle density. The model CRUST 5.1 provides a complete description of the physical properties of the Earth's crust at a scale of 5° × 5° and can be used for a wide range of seismological and nonseismological problems.
","language":"English","publisher":"AGU Publications","doi":"10.1029/97JB02122","issn":"01480227","usgsCitation":"Mooney, W.D., Laske, G., and Masters, T.G., 1998, CRUST 5.1: A global crustal model at 5° x 5°: Journal of Geophysical Research B: Solid Earth, v. 103, no. 1, p. 727-747, https://doi.org/10.1029/97JB02122.","productDescription":"21 p.","startPage":"727","endPage":"747","onlineOnly":"N","additionalOnlineFiles":"N","costCenters":[{"id":237,"text":"Earthquake Science Center","active":true,"usgs":true}],"links":[{"id":231382,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"103","issue":"1","noUsgsAuthors":false,"publicationDate":"1998-01-10","publicationStatus":"PW","scienceBaseUri":"5059f2e6e4b0c8380cd4b484","contributors":{"authors":[{"text":"Mooney, Walter D. 0000-0002-5310-3631 mooney@usgs.gov","orcid":"https://orcid.org/0000-0002-5310-3631","contributorId":3194,"corporation":false,"usgs":true,"family":"Mooney","given":"Walter","email":"mooney@usgs.gov","middleInitial":"D.","affiliations":[{"id":237,"text":"Earthquake Science Center","active":true,"usgs":true}],"preferred":true,"id":387050,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Laske, Gabi","contributorId":69324,"corporation":false,"usgs":true,"family":"Laske","given":"Gabi","email":"","affiliations":[],"preferred":false,"id":387049,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Masters, T. Guy","contributorId":93191,"corporation":false,"usgs":true,"family":"Masters","given":"T.","email":"","middleInitial":"Guy","affiliations":[],"preferred":false,"id":387051,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70020659,"text":"70020659 - 1998 - Comparison of rangeland vegetation sampling techniques in the Central Grasslands","interactions":[],"lastModifiedDate":"2024-05-13T15:27:30.382068","indexId":"70020659","displayToPublicDate":"1998-01-01T00:00:00","publicationYear":"1998","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2441,"text":"Journal of Range Management","active":true,"publicationSubtype":{"id":10}},"title":"Comparison of rangeland vegetation sampling techniques in the Central Grasslands","docAbstract":"Maintaining native plant diversity, detecting exotic species, and monitoring rare species are becoming important objectives in rangeland conservation. Four rangeland vegetation sampling techniques were compared to see how well they captured local pant diversity. The methods tested included the commonly used Parker transects, Daubenmire transects as modified by the USDA Forest Service, a new transect and 'large quadrat' design proposed by the USDA Agricultural Research Service, and the Modified-Whittaker multi-scale vegetation plot. The 4 methods were superimposed in shortgrass steppe, mixed grass prairie, northern mixed prairie, and tallgrass prairie in the Central Grasslands of the United States with 4 replicates in each prairie type. Analysis of variance tests showed significant method effects and prairie type effects, but no significant method X type interactions for total species richness, the number of native species, the number of species with less than 1 % cover, and the time required for sampling. The methods behaved similarly in each prairie type under a wide variety of grazing regimens. The Parker, large quadrat, and Daubenmire transects significantly underestimated the total species richness and the number of native species in each prairie type, and the number of species with less than 1 % cover in all but the tallgrass prairie type. The transect techniques also consistently missed half the exotic species, including noxious weeds, in each prairie type. The Modified-Whittaker method, which included an exhaustive search for plant species in a 20 x 50 m plot, served as the baseline for species richeness comparisons. For all prairie types, the Modified-Whittaker plot captured an average of 42. (± 2.4; 1 S.E.) plant species per site compared to 15.9 (± 1.3), 18.9 (± 1.2), and 22.8 (± 1.6) plant species per site using the Parker, large quadrat, and Daubenmire transect methods, respectively. The 4 methods captured most of the dominant species at each site and thus produced similar results for total foliar cover and soil cover. The detection and measurement of exotic plant species were greatly enhanced by using ten 1 m2 subplots in a multi-scale sampling design and searching a larger area (1,000 m2) at each site. Even with 4 replicate sites, the transect methods usually captured, and thus would monitor, 36 to 66 % of the plant species at each site. To evaluate the status and trends of common, rare, and exotic plant species at local, regional, and national scales, innovative, multi-scale methods must replace the commonly used transect methods to the past.
","language":"English","publisher":"Allen Press","doi":"10.2307/4003202","issn":"0022409X","usgsCitation":"Stohlgren, T., Bull, K., and Otsuki, Y., 1998, Comparison of rangeland vegetation sampling techniques in the Central Grasslands: Journal of Range Management, v. 51, no. 2, p. 164-172, https://doi.org/10.2307/4003202.","productDescription":"9 p.","startPage":"164","endPage":"172","numberOfPages":"9","costCenters":[],"links":[{"id":479805,"rank":2,"type":{"id":41,"text":"Open Access External Repository Page"},"url":"http://hdl.handle.net/10150/644068","text":"External Repository"},{"id":231274,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"51","issue":"2","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"5059f886e4b0c8380cd4d173","contributors":{"authors":[{"text":"Stohlgren, T.J.","contributorId":7217,"corporation":false,"usgs":true,"family":"Stohlgren","given":"T.J.","email":"","affiliations":[],"preferred":false,"id":387036,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Bull, K.A.","contributorId":60166,"corporation":false,"usgs":true,"family":"Bull","given":"K.A.","email":"","affiliations":[],"preferred":false,"id":387038,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Otsuki, Yuka","contributorId":23107,"corporation":false,"usgs":false,"family":"Otsuki","given":"Yuka","email":"","affiliations":[],"preferred":false,"id":387037,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70020656,"text":"70020656 - 1998 - Review of magnetic field monitoring near active faults and volcanic calderas in California: 1974-1995","interactions":[],"lastModifiedDate":"2013-01-22T15:36:53","indexId":"70020656","displayToPublicDate":"1998-01-01T00:00:00","publicationYear":"1998","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":"Review of magnetic field monitoring near active faults and volcanic calderas in California: 1974-1995","docAbstract":"Differential magnetic fields have been monitored along the San Andreas fault and the Long Valley caldera since 1974. At each monitoring location, proton precession magnetometers sample total magnetic field intensity at a resolution of 0.1 nT or 0.25 nT. Every 10 min, data samples are transmitted via satellite telemetry to Menlo Park, CA for processing and analysis. The number of active magnetometer sites has varied during the past 21 years from 6 to 25, with 12 sites currently operational. We use this network to identify magnetic field changes generated by earthquake and volcanic processes. During the two decades of monitoring, five moderate earthquakes (M5.9 to M7.3) have occurred within 20 km of magnetometer sites located along the San Andreas fault and only one preseismic signal of 1.5 nT has been observed. During moderate earthquakes, coseismic magnetic signals, with amplitudes from 0.7 nT to 1.3 nT, have been identified for 3 of the 5 events. These observations are generally consistent with those calculated from simple seismomagnetic models of these earthquakes and near-fault coseismic magnetic field disturbances rarely exceed one nanotesla. These data are consistent with the concept of low shear stress and relatively uniform displacement of the San Andreas fault system as expected due to high pore fluid pressure on the fault. A systematic decrease of 0.8-1 nT/year in magnetic field has occurred in the Long Valley caldera since 1989. These magnetic field data are similar in form to observed geodetically measured displacements from inflation of the resurgent dome. A simple volcanomagnetic model involving pressure increase of 50 MPa/a at a depth of 7 km under the resurgent dome can replicate these magnetic field observations. This model is derived from the intrusion model that best fits the surface deformation data. ?? 1998 Elsevier Science B.V.","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/S0031-9201(97)00086-1","issn":"00319201","usgsCitation":"Mueller, R., and Johnston, M., 1998, Review of magnetic field monitoring near active faults and volcanic calderas in California: 1974-1995: Physics of the Earth and Planetary Interiors, v. 105, no. 3-4, p. 131-144, https://doi.org/10.1016/S0031-9201(97)00086-1.","startPage":"131","endPage":"144","numberOfPages":"14","costCenters":[],"links":[{"id":231232,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":266260,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/S0031-9201(97)00086-1"}],"volume":"105","issue":"3-4","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505aac76e4b0c8380cd86d46","contributors":{"authors":[{"text":"Mueller, R.J.","contributorId":77135,"corporation":false,"usgs":true,"family":"Mueller","given":"R.J.","email":"","affiliations":[],"preferred":false,"id":387028,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Johnston, M.J.S. 0000-0003-4326-8368","orcid":"https://orcid.org/0000-0003-4326-8368","contributorId":104889,"corporation":false,"usgs":true,"family":"Johnston","given":"M.J.S.","affiliations":[],"preferred":false,"id":387029,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70020655,"text":"70020655 - 1998 - Determination of Δσ and κ0 from response spectra of large earthquakes in Greece","interactions":[],"lastModifiedDate":"2023-10-19T00:00:30.501457","indexId":"70020655","displayToPublicDate":"1998-01-01T00:00:00","publicationYear":"1998","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1135,"text":"Bulletin of the Seismological Society of America","onlineIssn":"1943-3573","printIssn":"0037-1106","active":true,"publicationSubtype":{"id":10}},"title":"Determination of Δσ and κ0 from response spectra of large earthquakes in Greece","docAbstract":"We fit an ω−2 model to response spectra from eight recent Greek earthquakes ranging in size from M = 5.8 to M = 6.9. The diminution parameter κ0 was determined for each site, with a value near 0.06 for a typical soil site. The stress parameter (Δσ) showed little variation from earthquake to earthquake and had a mean value of 56 bars over all earthquakes. Predictions of peak velocity, peak acceleration, rupture duration, and fault length using the derived stress parameters are consistent with observations. Frequency-dependent site amplifications were included in all estimates; the combined effect of amplification and attenuation had a maximum value close to a factor of 2.5 for a typical soil site, relative to the motions at the surface of a perfectly elastic uniform half-space composed of materials near the source. The results form the foundation for predictions of strong motions in Greece for distances and magnitudes other than those for which data are available.
The origin of cratonic sheet sandstones of Proterozoic and early Paleozoic age has been a long-standing problem for sedimentologists. Lower Paleozoic strata in the Upper Mississippi Valley are best known for several such sandstone bodies, the regional depositional histories of which are poorly understood. We have combined outcrop and subsurface data from six states to place the Upper Cambrian Wonewoc (Ironton and Galesville) Sandstone in a well-constrained stratigraphic framework across thousands of square kilometers. This framework makes it possible for the first time to construct a regional-scale depositional model that explains the origin of this and other cratonic sheet sandstones.
","language":"English","publisher":"Geological Society of America","doi":"10.1130/0016-7606(1998)110<0188:OOACCS>2.3.CO;2","issn":"00167606","usgsCitation":"Runkel, A.C., McKay, R., and Palmer, A.R., 1998, Origin of a classic cratonic sheet sandstone: Stratigraphy across the Sauk II-Sauk III boundary in the Upper Mississippi Valley: Geological Society of America Bulletin, v. 110, no. 2, p. 188-210, https://doi.org/10.1130/0016-7606(1998)110<0188:OOACCS>2.3.CO;2.","productDescription":"23 p.","startPage":"188","endPage":"210","numberOfPages":"23","costCenters":[],"links":[{"id":231151,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"country":"United States","geographicExtents":"{\n \"type\": \"FeatureCollection\",\n \"features\": [\n {\n \"type\": \"Feature\",\n \"properties\": {},\n \"geometry\": {\n \"coordinates\": [\n [\n [\n -98.24927107442258,\n 50.84930949962455\n ],\n [\n -98.24927107442258,\n 36.74108819977258\n ],\n [\n -85.2414585744225,\n 36.74108819977258\n ],\n [\n -85.2414585744225,\n 50.84930949962455\n ],\n [\n -98.24927107442258,\n 50.84930949962455\n ]\n ]\n ],\n \"type\": \"Polygon\"\n }\n }\n ]\n}","volume":"110","issue":"2","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a70c4e4b0c8380cd76225","contributors":{"authors":[{"text":"Runkel, Anthony C.","contributorId":63186,"corporation":false,"usgs":true,"family":"Runkel","given":"Anthony","email":"","middleInitial":"C.","affiliations":[],"preferred":false,"id":387020,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"McKay, R.M.","contributorId":91238,"corporation":false,"usgs":true,"family":"McKay","given":"R.M.","email":"","affiliations":[],"preferred":false,"id":387021,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Palmer, A. R.","contributorId":41819,"corporation":false,"usgs":true,"family":"Palmer","given":"A.","email":"","middleInitial":"R.","affiliations":[],"preferred":false,"id":387019,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ]}