{"pageNumber":"1141","pageRowStart":"28500","pageSize":"25","recordCount":40871,"records":[{"id":70024457,"text":"70024457 - 2002 - Nonlinear and linear site response and basin effects in Seattle for the M 6.8 Nisqually, Washington, earthquake","interactions":[],"lastModifiedDate":"2012-03-12T17:20:11","indexId":"70024457","displayToPublicDate":"2002-01-01T00:00:00","publicationYear":"2002","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":"Nonlinear and linear site response and basin effects in Seattle for the M 6.8 Nisqually, Washington, earthquake","docAbstract":"We used recordings of the M 6.8 Nisqually earthquake and its ML 3.4 aftershock to study site response and basin effects for 35 locations in Seattle, Washington. We determined site amplification from Fourier spectral ratios of the recorded horizontal ground motions, referenced to a soft-rock site. Soft-soil sites (generally National Earthquake Hazard Reduction Program [NEHRP] class E) on artificial fill and young alluvium have the largest 1-Hz amplifications (factors of 3-7) for both the mainshock and aftershock. These amplifications are correlated with areas of higher damage from the mainshock to major buildings and liquefaction. There are several indications of nonlinear response at the soft-soil sites for the mainshock ground motions, despite relatively modest peak accelerations in the S waves of 15%-22%g. First, the mainshock spectral ratios do not show amplification at 2-8 Hz as do the aftershock spectral ratios. Spectral peaks at frequencies below 2 Hz generally occur at lower frequencies for the mainshock spectral ratios than for the aftershock ratios. At one soft-soil site, there is a clear shift of the resonant frequency to a lower frequency for the mainshock compared with the aftershock. The frequency of this resonance increases in the coda of the mainshock record, indicating that the site response during the weaker motions of the coda is more linear than that of the initial S wave. Three of the soft-soil sites display cusped, one-sided mainshock accelerograms after the S wave. These soft-soil sites also show amplification at 10-20 Hz in the S wave, relative to the rock site, that is not observed for the aftershock. The cusped waveforms and 10-20-Hz amplification are symptomatic of nonlinear response at the soft-soil sites. These sites had nearby liquefaction. The largest amplifications for 0.5 Hz occur at soft-soil sites on the southern portion of the Seattle Basin. Stiff-soil sites (NEHRP classes D and C) on Pleistocene-age glacial deposits display similar spectral amplification for the mainshock and aftershock, indicating approximately linear response. The stiff-soil sites generally have moderate amplification (factors of 1.1-2.4) at 0.5 and 1 Hz. Amplifications at 1 and 5 Hz for all sites generally increase with decreasing shear-wave velocity measured in the top 30 m (Vs 30). However, larger amplifications at 0.5 and 1 Hz for sites with similar Vs 30 values are observed for sites in the Seattle Basin, illustrating the amplification from the deeper (>30 m) sediments and the contribution from basin surface waves. Record sections for the mainshock and aftershock show that basin surface waves produce the peak velocities for many of the sites in the Seattle Basin and often dominate the amplitude at 1 Hz and lower frequencies.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Bulletin of the Seismological Society of America","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1785/0120010254","issn":"00371106","usgsCitation":"Frankel, A., Carver, D.L., and Williams, R.A., 2002, Nonlinear and linear site response and basin effects in Seattle for the M 6.8 Nisqually, Washington, earthquake: Bulletin of the Seismological Society of America, v. 92, no. 6, p. 2090-2109, https://doi.org/10.1785/0120010254.","startPage":"2090","endPage":"2109","numberOfPages":"20","costCenters":[],"links":[{"id":207772,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1785/0120010254"},{"id":232974,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"92","issue":"6","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a677fe4b0c8380cd7336b","contributors":{"authors":[{"text":"Frankel, A.D.","contributorId":53828,"corporation":false,"usgs":true,"family":"Frankel","given":"A.D.","email":"","affiliations":[],"preferred":false,"id":401358,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Carver, D. L.","contributorId":55808,"corporation":false,"usgs":true,"family":"Carver","given":"D.","email":"","middleInitial":"L.","affiliations":[],"preferred":false,"id":401359,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Williams, R. A.","contributorId":82323,"corporation":false,"usgs":true,"family":"Williams","given":"R.","email":"","middleInitial":"A.","affiliations":[],"preferred":false,"id":401360,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}}
,{"id":70024398,"text":"70024398 - 2002 - Fasting modifies Aroclor 1254 impact on plasma cortisol, glucose and lactate responses to a handling disturbance in Arctic charr","interactions":[],"lastModifiedDate":"2017-05-06T15:21:59","indexId":"70024398","displayToPublicDate":"2002-01-01T00:00:00","publicationYear":"2002","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1296,"text":"Comparative Biochemistry and Physiology, Part C: Toxicology & Pharmacology","active":true,"publicationSubtype":{"id":10}},"title":"Fasting modifies Aroclor 1254 impact on plasma cortisol, glucose and lactate responses to a handling disturbance in Arctic charr","docAbstract":"<p>Integrated effects of polychlorinated biphenyl (PCB) and nutritional status on responses to handling disturbance were investigated in the Arctic charr (<i>Salvelinus alpinus</i>). The fish were orally contaminated with Aroclor 1254 and held either with or without food for 5 months before they were subjected to a 10-min handling disturbance. Food-deprived fish were given 0, 1, 10 or 100 mg PCB kg<sup>−1</sup> and the fed fish 0 or 100 mg PCB kg<sup>−1</sup>. Plasma cortisol, glucose and lactate levels were measured at 0 (pre-handling), 1, 3, 6 and 23 h after the handling disturbance. Food-deprived control fish had elevated plasma cortisol levels compared with fed fish before handling. These basal cortisol levels were suppressed by PCB in food-deprived fish, and elevated by PCB in fed fish. The immediate cortisol and glucose responses to handling disturbance were suppressed by PCB in a dose-dependent way in food-deprived fish. Although these responses were also lowered by PCB in the fed fish, the effect was much less pronounced than in food-deprived fish. There were only minor effects on plasma lactate responses. Our findings suggest that the stress responses of the Arctic charr are compromised by PCB and that the long-term fasting, typical of high-latitude fish, makes these species particularly sensitive to organochlorines such as PCB.</p>","language":"English","publisher":"Elsevier","doi":"10.1016/S1532-0456(02)00069-8","issn":"15320456","usgsCitation":"Jorgensen, E., Vijayan, M., Aluru, N., and Maule, A., 2002, Fasting modifies Aroclor 1254 impact on plasma cortisol, glucose and lactate responses to a handling disturbance in Arctic charr: Comparative Biochemistry and Physiology, Part C: Toxicology & Pharmacology, v. 132, no. 2, p. 235-245, https://doi.org/10.1016/S1532-0456(02)00069-8.","productDescription":"11 p.","startPage":"235","endPage":"245","onlineOnly":"N","additionalOnlineFiles":"N","costCenters":[{"id":654,"text":"Western Fisheries Research Center","active":true,"usgs":true}],"links":[{"id":232038,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"132","issue":"2","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a0effe4b0c8380cd536f6","contributors":{"authors":[{"text":"Jorgensen, E.H.","contributorId":13782,"corporation":false,"usgs":true,"family":"Jorgensen","given":"E.H.","affiliations":[],"preferred":false,"id":401120,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Vijayan, M.M.","contributorId":33087,"corporation":false,"usgs":true,"family":"Vijayan","given":"M.M.","email":"","affiliations":[],"preferred":false,"id":401121,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Aluru, N.","contributorId":80454,"corporation":false,"usgs":true,"family":"Aluru","given":"N.","email":"","affiliations":[],"preferred":false,"id":401123,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Maule, A.G.","contributorId":45067,"corporation":false,"usgs":true,"family":"Maule","given":"A.G.","email":"","affiliations":[],"preferred":false,"id":401122,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}}
,{"id":70025101,"text":"70025101 - 2002 - Invertebrate biomass: Associations with lesser prairie-chicken habitat use and sand sagebrush density in southwestern Kansas","interactions":[],"lastModifiedDate":"2017-12-27T11:51:04","indexId":"70025101","displayToPublicDate":"2002-01-01T00:00:00","publicationYear":"2002","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":3779,"text":"Wildlife Society Bulletin","onlineIssn":"1938-5463","printIssn":"0091-7648","active":true,"publicationSubtype":{"id":10}},"title":"Invertebrate biomass: Associations with lesser prairie-chicken habitat use and sand sagebrush density in southwestern Kansas","docAbstract":"Invertebrates are important food sources for lesser prairie-chicken (Tympanuchus pallidicinctus) adults and broods. We compared invertebrate biomass in areas used and not used by lesser prairie-chicken adults and broods. We used radiotelemetry to determine use and non-use areas in sand sagebrush (Artemisia filifolia) prairie in southwestern Kansas and sampled invertebrate populations during summer 1998 and 1999. Sweepnet-collected biomass of short-horned grasshoppers (Acrididae) and total invertebrate biomass generally were greater in habitats used by lesser prairie-chickens than in paired non-use areas. We detected no differences in pitfall-collected biomass of Acrididae (P=0.81) or total invertebrate biomass (P=0.93) among sampling areas with sand sagebrush canopy cover of 0 to 10%, 11 to 30%, and >30%. Results of multivariate analysis and regression model selection suggested that forbs were more strongly associated with invertebrate biomass than shrubs, grasses, or bare ground. We could not separate lesser prairie-chicken selection for areas of forb cover from selection of areas with greater invertebrate biomass associated with forb cover. Regardless of whether the effects of forbs were direct or indirect, their importance in sand sagebrush habitat has management implications. Practices that maintain or increase forb cover likely will increase invertebrate biomass and habitat quality in southwestern Kansas.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Wildlife Society Bulletin","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","issn":"00917648","usgsCitation":"Jamison, B., Robel, R., Pontius, J., and Applegate, R., 2002, Invertebrate biomass: Associations with lesser prairie-chicken habitat use and sand sagebrush density in southwestern Kansas: Wildlife Society Bulletin, v. 30, no. 2, p. 517-526.","productDescription":"10 p.","startPage":"517","endPage":"526","costCenters":[{"id":480,"text":"Northern Prairie Wildlife Research Center","active":true,"usgs":true}],"links":[{"id":236136,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"30","issue":"2","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a3e5ae4b0c8380cd63ce2","contributors":{"authors":[{"text":"Jamison, B.E.","contributorId":102831,"corporation":false,"usgs":true,"family":"Jamison","given":"B.E.","email":"","affiliations":[],"preferred":false,"id":403827,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Robel, R.J.","contributorId":20297,"corporation":false,"usgs":true,"family":"Robel","given":"R.J.","email":"","affiliations":[],"preferred":false,"id":403825,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Pontius, J.S.","contributorId":69523,"corporation":false,"usgs":true,"family":"Pontius","given":"J.S.","email":"","affiliations":[],"preferred":false,"id":403826,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Applegate, R.D.","contributorId":15581,"corporation":false,"usgs":true,"family":"Applegate","given":"R.D.","email":"","affiliations":[],"preferred":false,"id":403824,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}}
,{"id":70024345,"text":"70024345 - 2002 - Using simple environmental variables to estimate below-ground productivity in grasslands","interactions":[],"lastModifiedDate":"2017-04-10T10:19:05","indexId":"70024345","displayToPublicDate":"2002-01-01T00:00:00","publicationYear":"2002","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1839,"text":"Global Ecology and Biogeography","active":true,"publicationSubtype":{"id":10}},"title":"Using simple environmental variables to estimate below-ground productivity in grasslands","docAbstract":"In many temperate and annual grasslands, above-ground net primary productivity (NPP) can be estimated by measuring peak above-ground biomass. Estimates of below-ground net primary productivity and, consequently, total net primary productivity, are more difficult. We addressed one of the three main objectives of the Global Primary Productivity Data Initiative for grassland systems to develop simple models or algorithms to estimate missing components of total system NPP. Any estimate of below-ground NPP (BNPP) requires an accounting of total root biomass, the percentage of living biomass and annual turnover of live roots. We derived a relationship using above-ground peak biomass and mean annual temperature as predictors of below-ground biomass (r2 = 0.54; P = 0.01). The percentage of live material was 0.6, based on published values. We used three different functions to describe root turnover: constant, a direct function of above-ground biomass, or as a positive exponential relationship with mean annual temperature. We tested the various models against a large database of global grassland NPP and the constant turnover and direct function models were approximately equally descriptive (r2 = 0.31 and 0.37), while the exponential function had a stronger correlation with the measured values (r2 = 0.40) and had a better fit than the other two models at the productive end of the BNPP gradient. When applied to extensive data we assembled from two grassland sites with reliable estimates of total NPP, the direct function was most effective, especially at lower productivity sites. We provide some caveats for its use in systems that lie at the extremes of the grassland gradient and stress that there are large uncertainties associated with measured and modelled estimates of BNPP.","language":"English","publisher":"Wiley","doi":"10.1046/j.1466-822X.2001.00267.x","issn":"1466822X","usgsCitation":"Gill, R., Kelly, R., Parton, W., Day, K., Jackson, R., Morgan, J., Scurlock, J., Tieszen, L., Castle, J., Ojima, D., and Zhang, X., 2002, Using simple environmental variables to estimate below-ground productivity in grasslands: Global Ecology and Biogeography, v. 11, no. 1, p. 79-86, https://doi.org/10.1046/j.1466-822X.2001.00267.x.","productDescription":"8 p.","startPage":"79","endPage":"86","numberOfPages":"8","costCenters":[{"id":222,"text":"Earth Resources Observation and Science (EROS) Center","active":true,"usgs":true}],"links":[{"id":231663,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":207071,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1046/j.1466-822X.2001.00267.x"}],"volume":"11","issue":"1","noUsgsAuthors":false,"publicationDate":"2002-02-20","publicationStatus":"PW","scienceBaseUri":"505bc09fe4b08c986b32a223","contributors":{"authors":[{"text":"Gill, R.A.","contributorId":60409,"corporation":false,"usgs":true,"family":"Gill","given":"R.A.","email":"","affiliations":[],"preferred":false,"id":400929,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Kelly, R.H.","contributorId":95231,"corporation":false,"usgs":true,"family":"Kelly","given":"R.H.","email":"","affiliations":[],"preferred":false,"id":400934,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Parton, W.J.","contributorId":89685,"corporation":false,"usgs":true,"family":"Parton","given":"W.J.","email":"","affiliations":[],"preferred":false,"id":400933,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Day, K.A.","contributorId":23307,"corporation":false,"usgs":true,"family":"Day","given":"K.A.","email":"","affiliations":[],"preferred":false,"id":400924,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Jackson, R.B.","contributorId":42174,"corporation":false,"usgs":true,"family":"Jackson","given":"R.B.","email":"","affiliations":[],"preferred":false,"id":400927,"contributorType":{"id":1,"text":"Authors"},"rank":5},{"text":"Morgan, J.A.","contributorId":74162,"corporation":false,"usgs":true,"family":"Morgan","given":"J.A.","email":"","affiliations":[],"preferred":false,"id":400931,"contributorType":{"id":1,"text":"Authors"},"rank":6},{"text":"Scurlock, J.M.O.","contributorId":76905,"corporation":false,"usgs":true,"family":"Scurlock","given":"J.M.O.","email":"","affiliations":[],"preferred":false,"id":400932,"contributorType":{"id":1,"text":"Authors"},"rank":7},{"text":"Tieszen, L.L.","contributorId":24046,"corporation":false,"usgs":true,"family":"Tieszen","given":"L.L.","email":"","affiliations":[],"preferred":false,"id":400925,"contributorType":{"id":1,"text":"Authors"},"rank":8},{"text":"Castle, J.V.","contributorId":65249,"corporation":false,"usgs":true,"family":"Castle","given":"J.V.","email":"","affiliations":[],"preferred":false,"id":400930,"contributorType":{"id":1,"text":"Authors"},"rank":9},{"text":"Ojima, D.S.","contributorId":49549,"corporation":false,"usgs":true,"family":"Ojima","given":"D.S.","email":"","affiliations":[],"preferred":false,"id":400928,"contributorType":{"id":1,"text":"Authors"},"rank":10},{"text":"Zhang, X.S.","contributorId":26848,"corporation":false,"usgs":true,"family":"Zhang","given":"X.S.","email":"","affiliations":[],"preferred":false,"id":400926,"contributorType":{"id":1,"text":"Authors"},"rank":11}]}}
,{"id":70024396,"text":"70024396 - 2002 - Consistency of patterns in concentration‐discharge plots","interactions":[],"lastModifiedDate":"2018-11-06T13:49:42","indexId":"70024396","displayToPublicDate":"2002-01-01T00:00:00","publicationYear":"2002","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":"Consistency of patterns in concentration‐discharge plots","docAbstract":"<div class=\"article-section__content n/a main\"><p>Concentration‐discharge (c‐Q) plots have been used to infer how flow components such as event water, soil water, and groundwater mix to produce the observed episodic hydrochemical response of small catchments. Because c‐Q plots are based only on observed streamflow and solute concentration, their interpretation requires assumptions about the relative volume, hydrograph timing, and solute concentration of the streamflow end‐members.<span>&nbsp;</span><span><i>Evans and Davies</i>&nbsp;[1998]</span><span>&nbsp;</span>present a taxonomy of c‐Q loops resulting from three‐component conservative mixing. Their analysis, based on a fixed template of end‐member hydrograph volume, timing, and concentration, suggests a unique relationship between c‐Q loop form and the rank order of end‐member concentrations. Many catchments exhibit variability in component contributions to storm flow in response to antecedent conditions or rainfall characteristics, but the effects of such variation on c‐Q relationships have not been studied systematically. Starting with a “baseline” condition similar to that assumed by<span>&nbsp;</span><span><i>Evans and Davies</i>&nbsp;[1998]</span>, we use a simple computer model to characterize the variability in c‐Q plot patterns resulting from variation in end‐member volume, timing, and solute concentration. Variability in these three factors can result in more than one c‐Q loop shape for a given rank order of end‐member solute concentrations. The number of resulting hysteresis patterns and their relative frequency depends on the rank order of solute concentrations and on their separation in absolute value. In ambiguous cases the c‐Q loop shape is determined by the relative “prominence” of the event water versus soil water components. This “prominence” is broadly defined as a capacity to influence the total streamflow concentration and may result from a combination of end‐member volume, timing, or concentration. The modeling results indicate that plausible hydrological variability in field situations can confound the interpretation of c‐Q plots, even when fundamental end‐member mixing assumptions are satisfied.</p></div>","language":"English","publisher":"American Geophysical Union","doi":"10.1029/2001WR000971","usgsCitation":"Chanat, J.G., Rice, K.C., and Hornberger, G., 2002, Consistency of patterns in concentration‐discharge plots: Water Resources Research, v. 38, no. 8, p. 22-1-22-10, https://doi.org/10.1029/2001WR000971.","productDescription":"Article 1147; 10 p.","startPage":"22-1","endPage":"22-10","costCenters":[{"id":614,"text":"Virginia Water Science Center","active":true,"usgs":true},{"id":37280,"text":"Virginia and West Virginia Water Science Center ","active":true,"usgs":true}],"links":[{"id":232001,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"38","issue":"8","noUsgsAuthors":false,"publicationDate":"2002-08-17","publicationStatus":"PW","scienceBaseUri":"5059fa00e4b0c8380cd4d880","contributors":{"authors":[{"text":"Chanat, Jeffrey G. 0000-0002-3629-7307 jchanat@usgs.gov","orcid":"https://orcid.org/0000-0002-3629-7307","contributorId":5062,"corporation":false,"usgs":true,"family":"Chanat","given":"Jeffrey","email":"jchanat@usgs.gov","middleInitial":"G.","affiliations":[{"id":614,"text":"Virginia Water Science Center","active":true,"usgs":true}],"preferred":true,"id":401111,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Rice, Karen C. 0000-0002-9356-5443 kcrice@usgs.gov","orcid":"https://orcid.org/0000-0002-9356-5443","contributorId":1998,"corporation":false,"usgs":true,"family":"Rice","given":"Karen","email":"kcrice@usgs.gov","middleInitial":"C.","affiliations":[{"id":614,"text":"Virginia Water Science Center","active":true,"usgs":true}],"preferred":false,"id":401113,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Hornberger, George M.","contributorId":63894,"corporation":false,"usgs":true,"family":"Hornberger","given":"George M.","affiliations":[],"preferred":false,"id":401112,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}}
,{"id":70024583,"text":"70024583 - 2002 - Prediction of the fate of p,p'-DDE in sediment on the Palos Verdes shelf, California, USA","interactions":[],"lastModifiedDate":"2017-09-14T14:25:50","indexId":"70024583","displayToPublicDate":"2002-01-01T00:00:00","publicationYear":"2002","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1333,"text":"Continental Shelf Research","active":true,"publicationSubtype":{"id":10}},"title":"Prediction of the fate of p,p'-DDE in sediment on the Palos Verdes shelf, California, USA","docAbstract":"Long-term (60-yr) predictions of vertical profiles of p,p???-DDE concentrations in contaminated bottom sediments on the Palos Verdes shelf were calculated for three locations along the 60-m isobath using a numerical solution of the one-dimensional advection-diffusion equation. The calculations incorporated the following processes: sediment deposition (or erosion), depth-dependent solid-phase biodiffusive mixing, in situ diagenetic transformation, and loss of p,p???-DDE across the sediment-water interface by two mechanisms (resuspension of sediments by wave action and subsequent loss of p,p???-DDE to the water column by desorption, and desorption from sediments to porewater and subsequent molecular diffusion to the water column). A combination of field measurements, laboratory analyses, and calculations with supporting models was used to set parameters for the model. The model explains significant features observed in measurements made every 2 years from 1981 to 1997 by the County Sanitation Districts of Los Angeles (LACSD). Analyses of available data suggest that two sites northwest of the Whites Point sewage outfalls will remain depositional, even as particulate supply from the sewage-treatment plant and nearby Portuguese Bend Landslide decreases. At these sites, model predictions for 1991-2050 indicate that most of the existing inventory of p,p???-DDE will remain buried and that surface concentrations will gradually decrease. Analyses of data southeast of the outfalls suggest that erosion is likely to occur somewhere on the southeast edge of the existing effluent-affected deposit, and model predictions for such a site showed that erosion and biodiffusion will reintroduce the p,p???-DDE to the upper layer of sediments, with subsequent increases in surface concentrations and loss to the overlying water column.","language":"English","publisher":"Elsevier","doi":"10.1016/S0278-4343(01)00118-2","issn":"02784343","usgsCitation":"Sherwood, C.R., Drake, D., Wiberg, P., and Wheatcroft, R.A., 2002, Prediction of the fate of p,p'-DDE in sediment on the Palos Verdes shelf, California, USA: Continental Shelf Research, v. 22, no. 6-7, p. 1025-1058, https://doi.org/10.1016/S0278-4343(01)00118-2.","productDescription":"34 p.","startPage":"1025","endPage":"1058","costCenters":[{"id":678,"text":"Woods Hole Coastal and Marine Science Center","active":true,"usgs":true}],"links":[{"id":233269,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"country":"United States","state":"California","otherGeospatial":"Palos Verdes shelf","geographicExtents":"{\n  \"type\": \"FeatureCollection\",\n  \"features\": [\n    {\n      \"type\": \"Feature\",\n      \"properties\": {},\n      \"geometry\": {\n        \"type\": \"Polygon\",\n        \"coordinates\": [\n          [\n            [\n              -118.46557617187499,\n              33.764307046898494\n            ],\n            [\n              -118.48205566406251,\n              33.696922692957685\n            ],\n            [\n              -118.46694946289064,\n              33.66149615643826\n            ],\n            [\n              -118.45321655273438,\n              33.637489243170826\n            ],\n            [\n              -118.40927124023438,\n              33.62948545097293\n            ],\n            [\n              -118.38043212890625,\n              33.592887216626245\n            ],\n            [\n              -118.30764770507811,\n              33.57687060377715\n            ],\n            [\n              -118.28842163085938,\n              33.62605502663528\n            ],\n            [\n              -118.25546264648438,\n              33.65349459599047\n            ],\n            [\n              -118.28567504882812,\n              33.6912097228257\n            ],\n            [\n              -118.32000732421875,\n              33.70263528325575\n            ],\n            [\n              -118.36257934570312,\n              33.716343950060214\n            ],\n            [\n              -118.42437744140625,\n              33.714059324224124\n            ],\n            [\n              -118.46557617187499,\n              33.764307046898494\n            ]\n          ]\n        ]\n      }\n    }\n  ]\n}","volume":"22","issue":"6-7","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a81f6e4b0c8380cd7b81a","contributors":{"authors":[{"text":"Sherwood, C. R.","contributorId":48235,"corporation":false,"usgs":true,"family":"Sherwood","given":"C.","email":"","middleInitial":"R.","affiliations":[],"preferred":false,"id":401789,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Drake, D.E.","contributorId":48150,"corporation":false,"usgs":true,"family":"Drake","given":"D.E.","email":"","affiliations":[],"preferred":false,"id":401788,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Wiberg, P.L.","contributorId":33827,"corporation":false,"usgs":true,"family":"Wiberg","given":"P.L.","email":"","affiliations":[],"preferred":false,"id":401787,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Wheatcroft, R. A.","contributorId":76503,"corporation":false,"usgs":false,"family":"Wheatcroft","given":"R.","email":"","middleInitial":"A.","affiliations":[],"preferred":false,"id":401790,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}}
,{"id":70025100,"text":"70025100 - 2002 - Interferometric synthetic aperture radar studies of Alaska volcanoes","interactions":[],"lastModifiedDate":"2022-05-06T16:33:42.063288","indexId":"70025100","displayToPublicDate":"2002-01-01T00:00:00","publicationYear":"2002","noYear":false,"publicationType":{"id":24,"text":"Conference Paper"},"publicationSubtype":{"id":19,"text":"Conference Paper"},"title":"Interferometric synthetic aperture radar studies of Alaska volcanoes","docAbstract":"<p><span>Interferometric synthetic aperture radar (InSAR) imaging is a recently developed geodetic technique capable of measuring ground-surface deformation with centimeter to subcentimeter vertical precision and spatial resolution of tens-of-meter over a relatively large region (/spl sim/10/sup 4/ km/sup 2/). The spatial distribution of surface deformation data, derived from InSAR images, enables the construction of detailed mechanical models to enhance the study of magmatic and tectonic processes associated with volcanoes. This paper summarizes our recent InSAR studies of several Alaska volcanoes, which include Okmok, Akutan, Kiska, Augustine, Westdahl, and Peulik volcanoes.</span></p>","largerWorkType":{"id":4,"text":"Book"},"largerWorkTitle":"IEEE International Geoscience and Remote Sensing Symposium","largerWorkSubtype":{"id":12,"text":"Conference publication"},"conferenceTitle":"2002 IEEE International Geoscience and Remote Sensing Symposium (IGARSS 2002)","conferenceDate":"Jun 24-28, 2002","conferenceLocation":"Toronto, Ontario, Canada","language":"English","publisher":"IEEE","doi":"10.1109/IGARSS.2002.1024984","usgsCitation":"Lu, Z., Wicks, C., Power, J., Dzurisin, D., Thatcher, W., and Masterlark, T., 2002, Interferometric synthetic aperture radar studies of Alaska volcanoes, <i>in</i> IEEE International Geoscience and Remote Sensing Symposium, v. 1, Toronto, Ontario, Canada, Jun 24-28, 2002, p. 191-194, https://doi.org/10.1109/IGARSS.2002.1024984.","productDescription":"4 p.","startPage":"191","endPage":"194","numberOfPages":"4","onlineOnly":"N","additionalOnlineFiles":"N","costCenters":[{"id":222,"text":"Earth Resources Observation and Science (EROS) Center","active":true,"usgs":true}],"links":[{"id":236135,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"country":"United States","state":"Alaska","geographicExtents":"{\n  \"type\": \"FeatureCollection\",\n  \"features\": [\n    {\n      \"type\": \"Feature\",\n      \"properties\": {},\n      \"geometry\": {\n        \"type\": \"Polygon\",\n        \"coordinates\": [\n          [\n            [\n              -177.18749999999997,\n              50.62507306341435\n            ],\n            [\n              -157.32421875,\n              55.47885346331034\n            ],\n            [\n              -150.82031249999997,\n              57.79794388498275\n            ],\n            [\n              -146.95312499999997,\n              60.23981116999893\n            ],\n            [\n              -137.63671875,\n              57.89149735271034\n            ],\n            [\n              -133.76953125,\n              55.52863052257191\n            ],\n            [\n              -133.9453125,\n              59.17592824927136\n            ],\n            [\n              -140.44921875,\n              60.54377524118842\n            ],\n            [\n              -141.50390625,\n              62.59334083012024\n            ],\n            [\n              -157.58789062499997,\n              61.64816245852389\n            ],\n            [\n              -182.724609375,\n              52.74959372674114\n            ],\n            [\n              -182.8125,\n              50.3454604086048\n            ],\n            [\n              -177.18749999999997,\n              50.62507306341435\n            ]\n          ]\n        ]\n      }\n    }\n  ]\n}","volume":"1","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a3d00e4b0c8380cd63200","contributors":{"authors":[{"text":"Lu, Z.","contributorId":106241,"corporation":false,"usgs":true,"family":"Lu","given":"Z.","affiliations":[],"preferred":false,"id":403823,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Wicks, C. Jr.","contributorId":87681,"corporation":false,"usgs":true,"family":"Wicks","given":"C.","suffix":"Jr.","email":"","affiliations":[],"preferred":false,"id":403821,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Power, J.","contributorId":48699,"corporation":false,"usgs":true,"family":"Power","given":"J.","email":"","affiliations":[],"preferred":false,"id":403819,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Dzurisin, D.","contributorId":76067,"corporation":false,"usgs":true,"family":"Dzurisin","given":"D.","email":"","affiliations":[],"preferred":false,"id":403820,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Thatcher, W.","contributorId":32669,"corporation":false,"usgs":true,"family":"Thatcher","given":"W.","email":"","affiliations":[],"preferred":false,"id":403818,"contributorType":{"id":1,"text":"Authors"},"rank":5},{"text":"Masterlark, Timothy","contributorId":92829,"corporation":false,"usgs":false,"family":"Masterlark","given":"Timothy","email":"","affiliations":[{"id":35607,"text":"South Dakota School of Mines","active":true,"usgs":false}],"preferred":false,"id":403822,"contributorType":{"id":1,"text":"Authors"},"rank":6}]}}
,{"id":70024461,"text":"70024461 - 2002 - Comparison of two probability distributions used to model sizes of undiscovered oil and gas accumulations: Does the tail wag the assessment?","interactions":[],"lastModifiedDate":"2019-10-16T15:16:42","indexId":"70024461","displayToPublicDate":"2002-01-01T00:00:00","publicationYear":"2002","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2700,"text":"Mathematical Geology","active":true,"publicationSubtype":{"id":10}},"title":"Comparison of two probability distributions used to model sizes of undiscovered oil and gas accumulations: Does the tail wag the assessment?","docAbstract":"Undiscovered oil and gas assessments are commonly reported as aggregate estimates of hydrocarbon volumes. Potential commercial value and discovery costs are, however, determined by accumulation size, so engineers, economists, decision makers, and sometimes policy analysts are most interested in projected discovery sizes. The lognormal and Pareto distributions have been used to model exploration target sizes. This note contrasts the outcomes of applying these alternative distributions to the play level assessments of the U.S. Geological Survey's 1995 National Oil and Gas Assessment. Using the same numbers of undiscovered accumulations and the same minimum, medium, and maximum size estimates, substitution of the shifted truncated lognormal distribution for the shifted truncated Pareto distribution reduced assessed undiscovered oil by 16% and gas by 15%. Nearly all of the volume differences resulted because the lognormal had fewer larger fields relative to the Pareto. The lognormal also resulted in a smaller number of small fields relative to the Pareto. For the Permian Basin case study presented here, reserve addition costs were 20% higher with the lognormal size assumption. ?? 2002 International Association for Mathematical Geology.","language":"English","publisher":"Springer","doi":"10.1023/A:1019809410934","issn":"08828121","usgsCitation":"Attanasi, E.D., and Charpentier, R., 2002, Comparison of two probability distributions used to model sizes of undiscovered oil and gas accumulations: Does the tail wag the assessment?: Mathematical Geology, v. 34, no. 6, p. 767-777, https://doi.org/10.1023/A:1019809410934.","productDescription":"11 p.","startPage":"767","endPage":"777","numberOfPages":"11","costCenters":[{"id":241,"text":"Eastern Energy Resources Science Center","active":true,"usgs":true}],"links":[{"id":233013,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"34","issue":"6","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"5059f8bae4b0c8380cd4d266","contributors":{"authors":[{"text":"Attanasi, E. D. 0000-0001-6845-7160","orcid":"https://orcid.org/0000-0001-6845-7160","contributorId":107672,"corporation":false,"usgs":true,"family":"Attanasi","given":"E.","middleInitial":"D.","affiliations":[],"preferred":false,"id":401372,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Charpentier, Ronald R.","contributorId":33674,"corporation":false,"usgs":true,"family":"Charpentier","given":"Ronald R.","affiliations":[],"preferred":false,"id":401371,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}}
,{"id":70024394,"text":"70024394 - 2002 - Isotope variations in a Sierra Nevada snowpack and their relation to meltwater","interactions":[],"lastModifiedDate":"2018-09-27T11:30:25","indexId":"70024394","displayToPublicDate":"2002-01-01T00:00:00","publicationYear":"2002","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2342,"text":"Journal of Hydrology","active":true,"publicationSubtype":{"id":10}},"title":"Isotope variations in a Sierra Nevada snowpack and their relation to meltwater","docAbstract":"<p><span>Isotopic variations in melting snow are poorly understood. We made weekly measurements at the Central Sierra Snow Laboratory, California, of snow temperature, density, water equivalent and liquid water volume to examine how physical changes within the&nbsp;snowpackgovern&nbsp;meltwater&nbsp;</span><i>δ</i><sup>18</sup><span>O. Snowpack samples were extracted at 0.1</span><span>&nbsp;</span><span>m intervals from ground level to the top of the snowpack profile between December 1991 and April 1992. Approximately 800</span><span>&nbsp;</span><span>mm of precipitation fell during the study period with&nbsp;</span><i>δ</i><sup>18</sup><span>O values between −21.35 and −4.25‰. Corresponding snowpack&nbsp;</span><i>δ</i><sup>18</sup><span>O ranged from −22.25 to −6.25‰. The coefficient of variation of&nbsp;</span><i>δ</i><sup>18</sup><span>O in snowpack levels decreased from −0.37 to −0.07 from winter to spring, indicating isotopic snowpack homogenization. Meltwater&nbsp;</span><i>δ</i><sup>18</sup><span>O ranged from −15.30 to −8.05‰, with variations of up to 2.95‰ observed within a single&nbsp;snowmeltepisode, highlighting the need for frequent sampling. Early snowmelt originated in the lower snowpack with higher&nbsp;</span><i>δ</i><sup>18</sup><span>O through ground&nbsp;heat flux&nbsp;and rainfall. After the snowpack became isothermal, infiltrating snowmelt displaced the higher&nbsp;</span><i>δ</i><sup>18</sup><span>O liquid in the lower snowpack through a piston flow process.&nbsp;Fractionation&nbsp;analysis using a two-component mixing model on the isothermal snowpack indicated that&nbsp;</span><i>δ</i><sup>18</sup><span>O in the initial and final half of major snowmelt was 1.30‰ lower and 1.45‰ higher, respectively, than the value from simple mixing. Mean snowpack&nbsp;</span><i>δ</i><sup>18</sup><span>O on individual profiling days showed a steady increase from −15.15 to −12.05‰ due to removal of lower&nbsp;</span><i>δ</i><sup>18</sup><span>O snowmelt and addition of higher&nbsp;</span><i>δ</i><sup>18</sup><span>O rainfall. Results suggest that direct sampling of snowmelt and snow cores should be undertaken to quantify tracer input compositions adequately. The snowmelt sequence also suggests that regimes of early lower&nbsp;</span><i>δ</i><sup>18</sup><span>O and later higher&nbsp;</span><i>δ</i><sup>18</sup><span>O melt may be modeled and used in catchment tracing studies.</span></p>","language":"English","publisher":"Elsevier","doi":"10.1016/S0022-1694(01)00596-0","issn":"00221694","usgsCitation":"Unnikrishna, P., McDonnell, J.J., and Kendall, C., 2002, Isotope variations in a Sierra Nevada snowpack and their relation to meltwater: Journal of Hydrology, v. 260, no. 1-4, p. 38-57, https://doi.org/10.1016/S0022-1694(01)00596-0.","productDescription":"20 p.","startPage":"38","endPage":"57","costCenters":[{"id":154,"text":"California Water Science Center","active":true,"usgs":true}],"links":[{"id":207212,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/S0022-1694(01)00596-0"},{"id":231967,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"260","issue":"1-4","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a3f8de4b0c8380cd645f0","contributors":{"authors":[{"text":"Unnikrishna, P.V.","contributorId":69327,"corporation":false,"usgs":true,"family":"Unnikrishna","given":"P.V.","email":"","affiliations":[],"preferred":false,"id":401107,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"McDonnell, Jeffery J. 0000-0002-3880-3162","orcid":"https://orcid.org/0000-0002-3880-3162","contributorId":62723,"corporation":false,"usgs":false,"family":"McDonnell","given":"Jeffery","email":"","middleInitial":"J.","affiliations":[],"preferred":false,"id":401106,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Kendall, C. 0000-0002-0247-3405","orcid":"https://orcid.org/0000-0002-0247-3405","contributorId":35050,"corporation":false,"usgs":true,"family":"Kendall","given":"C.","affiliations":[],"preferred":false,"id":401105,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}}
,{"id":70024453,"text":"70024453 - 2002 - Impacts of climate change on the global forest sector","interactions":[],"lastModifiedDate":"2012-03-12T17:20:17","indexId":"70024453","displayToPublicDate":"2002-01-01T00:00:00","publicationYear":"2002","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1252,"text":"Climatic Change","active":true,"publicationSubtype":{"id":10}},"title":"Impacts of climate change on the global forest sector","docAbstract":"The path and magnitude of future anthropogenic emissions of carbon dioxide will likely influence changes in climate that may impact the global forest sector. These responses in the global forest sector may have implications for international efforts to stabilize the atmospheric concentration of carbon dioxide. This study takes a step toward including the role of global forest sector in integrated assessments of the global carbon cycle by linking global models of climate dynamics, ecosystem processes and forest economics to assess the potential responses of the global forest sector to different levels of greenhouse gas emissions. We utilize three climate scenarios and two economic scenarios to represent a range of greenhouse gas emissions and economic behavior. At the end of the analysis period (2040), the potential responses in regional forest growing stock simulated by the global ecosystem model range from decreases and increases for the low emissions climate scenario to increases in all regions for the high emissions climate scenario. The changes in vegetation are used to adjust timber supply in the softwood and hardwood sectors of the economic model. In general, the global changes in welfare are positive, but small across all scenarios. At the regional level, the changes in welfare can be large and either negative or positive. Markets and trade in forest products play important roles in whether a region realizes any gains associated with climate change. In general, regions with the lowest wood fiber production cost are able to expand harvests. Trade in forest products leads to lower prices elsewhere. The low-cost regions expand market shares and force higher-cost regions to decrease their harvests. Trade produces different economic gains and losses across the globe even though, globally, economic welfare increases. The results of this study indicate that assumptions within alternative climate scenarios and about trade in forest products are important factors that strongly influence the effects of climate change on the global forest sector.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Climatic Change","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1023/A:1016124517309","issn":"01650009","usgsCitation":"Perez-Garcia, J., Joyce, L., McGuire, A., and Xiao, X., 2002, Impacts of climate change on the global forest sector: Climatic Change, v. 54, no. 4, p. 439-461, https://doi.org/10.1023/A:1016124517309.","startPage":"439","endPage":"461","numberOfPages":"23","costCenters":[],"links":[{"id":207065,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1023/A:1016124517309"},{"id":231656,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"54","issue":"4","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a38e6e4b0c8380cd6171d","contributors":{"authors":[{"text":"Perez-Garcia, J.","contributorId":100151,"corporation":false,"usgs":true,"family":"Perez-Garcia","given":"J.","email":"","affiliations":[],"preferred":false,"id":401341,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Joyce, L.A.","contributorId":36321,"corporation":false,"usgs":true,"family":"Joyce","given":"L.A.","email":"","affiliations":[],"preferred":false,"id":401339,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"McGuire, A. D.","contributorId":16552,"corporation":false,"usgs":true,"family":"McGuire","given":"A. D.","affiliations":[],"preferred":false,"id":401338,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Xiao, X.","contributorId":82869,"corporation":false,"usgs":true,"family":"Xiao","given":"X.","email":"","affiliations":[],"preferred":false,"id":401340,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}}
,{"id":70025099,"text":"70025099 - 2002 - SHE analysis for biozonation of benthic foraminiferal assemblages from western arctic ocean","interactions":[],"lastModifiedDate":"2022-08-15T16:36:33.114112","indexId":"70025099","displayToPublicDate":"2002-01-01T00:00:00","publicationYear":"2002","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":3000,"text":"Palaios","active":true,"publicationSubtype":{"id":10}},"title":"SHE analysis for biozonation of benthic foraminiferal assemblages from western arctic ocean","docAbstract":"<p>Benthic foraminiferal species abundance in samples from three Mendeleyev Ridge box cores were analyzed by cluster analysis and the newer method of SHE analysis. Previously, the latter technique only has been used on foraminiferal data from depth transects of modern surface sediment samples. Unlike most methods, which initially compare all possible pairs of samples, the SHE procedure results in a linear pattern if a sequence of samples are from the same statistical distribution. A change in slope indicates a statistical change in community structure and/or a change in species composition.</p><p>The research reported herein is the first application of SHE for the purpose of identifying biozones in sediment core samples for the purpose of stratigraphic correlation. Both cluster analysis and the SHE method provided zonation within cores. However, the cluster method often produced clusters that were difficult to identify and also contained a mixture of samples without stratigraphic continuity. In contrast, SHE resulted in easily identifiable biozones and ensured temporal continuity within them. In general, the cluster analysis produced more zones than the SHE analysis. About 87% of the cluster zones and 64% of the SHE zones were correlated across more than one core. The average age range for correlated biozone boundaries among the three cores, based on radiocarbon dates, was 821 years using cluster analysis and 296 years using SHE. The sequential nature of the analysis, ease in choosing boundaries, and correlation of these boundaries across cores makes SHE the preferred technique.</p>","language":"English","publisher":"SEPM Society for Sedimentary Geology","doi":"10.1669/0883-1351(2002)017%3C0297:SAFBOB%3E2.0.CO;2","usgsCitation":"Osterman, L.E., Buzas, M.A., and Hayek, L.C., 2002, SHE analysis for biozonation of benthic foraminiferal assemblages from western arctic ocean: Palaios, v. 17, no. 3, p. 297-303, https://doi.org/10.1669/0883-1351(2002)017%3C0297:SAFBOB%3E2.0.CO;2.","productDescription":"7 p.","startPage":"297","endPage":"303","numberOfPages":"7","costCenters":[{"id":574,"text":"St. Petersburg Coastal and Marine Science Center","active":true,"usgs":true}],"links":[{"id":236134,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"17","issue":"3","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505aaf3ee4b0c8380cd87487","contributors":{"authors":[{"text":"Osterman, Lisa E. osterman@usgs.gov","contributorId":3058,"corporation":false,"usgs":true,"family":"Osterman","given":"Lisa","email":"osterman@usgs.gov","middleInitial":"E.","affiliations":[{"id":574,"text":"St. Petersburg Coastal and Marine Science Center","active":true,"usgs":true}],"preferred":true,"id":403815,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Buzas, Martin A","contributorId":261663,"corporation":false,"usgs":false,"family":"Buzas","given":"Martin","email":"","middleInitial":"A","affiliations":[{"id":36606,"text":"Smithsonian Institution","active":true,"usgs":false}],"preferred":false,"id":403816,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Hayek, Lee-Ann C.","contributorId":16730,"corporation":false,"usgs":true,"family":"Hayek","given":"Lee-Ann","email":"","middleInitial":"C.","affiliations":[],"preferred":false,"id":403817,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}}
,{"id":70024611,"text":"70024611 - 2002 - Lunar prospector epithermal neutrons from impact craters and landing sites: Implications for surface maturity and hydrogen distribution","interactions":[],"lastModifiedDate":"2022-08-02T22:50:53.505412","indexId":"70024611","displayToPublicDate":"2002-01-01T00:00:00","publicationYear":"2002","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2317,"text":"Journal of Geophysical Research E: Planets","active":true,"publicationSubtype":{"id":10}},"title":"Lunar prospector epithermal neutrons from impact craters and landing sites: Implications for surface maturity and hydrogen distribution","docAbstract":"<p><span class=\"paraNumber\"><span>&nbsp;</span></span><span>Initial studies of neutron spectrometer data returned by Lunar Prospector concentrated on the discovery of enhanced hydrogen abundances near both lunar poles. However, the nonpolar data exhibit intriguing patterns that appear spatially correlated with surface features such as young impact craters (e.g., Tycho). Such immature crater materials may have low hydrogen contents because of their relative lack of exposure to solar wind-implanted volatiles. We tested this hypothesis by comparing epithermal* neutron counts (i.e., epithermal −0.057 × thermal neutrons) for Copernican-age craters classified as relatively young, intermediate, and old (as determined by previous studies of Clementine optical maturity variations). The epithermal* counts of the crater and continuous ejecta regions suggest that the youngest impact materials are relatively devoid of hydrogen in the upper 1 m of regolith. We also show that the mean hydrogen contents measured in Apollo and Luna landing site samples are only moderately well correlated to the epithermal* neutron counts at the landing sites, likely owing to the effects of rare earth elements. These results suggest that further work is required to define better how hydrogen distribution can be revealed by epithermal neutrons in order to understand more fully the nature and sources (e.g., solar wind, meteorite impacts) of volatiles in the lunar regolith.</span></p>","language":"English","publisher":"American Geophysical Union","doi":"10.1029/2000JE001430","usgsCitation":"Johnson, J.R., Feldman, W.C., Lawrence, D.J., Maurice, S., Swindle, T.D., and Lucey, P.G., 2002, Lunar prospector epithermal neutrons from impact craters and landing sites: Implications for surface maturity and hydrogen distribution: Journal of Geophysical Research E: Planets, v. 107, no. E2, p. 3-1-3-8, https://doi.org/10.1029/2000JE001430.","productDescription":"8 p.","startPage":"3-1","endPage":"3-8","costCenters":[],"links":[{"id":233198,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"otherGeospatial":"Moon","volume":"107","issue":"E2","noUsgsAuthors":false,"publicationDate":"2002-02-28","publicationStatus":"PW","scienceBaseUri":"505a4a95e4b0c8380cd68e9c","contributors":{"authors":[{"text":"Johnson, J. R.","contributorId":69278,"corporation":false,"usgs":true,"family":"Johnson","given":"J.","email":"","middleInitial":"R.","affiliations":[],"preferred":false,"id":401901,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Feldman, W. C.","contributorId":40767,"corporation":false,"usgs":false,"family":"Feldman","given":"W.","email":"","middleInitial":"C.","affiliations":[],"preferred":false,"id":401899,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Lawrence, D. J.","contributorId":84952,"corporation":false,"usgs":false,"family":"Lawrence","given":"D.","email":"","middleInitial":"J.","affiliations":[],"preferred":false,"id":401903,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Maurice, S.","contributorId":18144,"corporation":false,"usgs":true,"family":"Maurice","given":"S.","email":"","affiliations":[],"preferred":false,"id":401898,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Swindle, T. D.","contributorId":68042,"corporation":false,"usgs":false,"family":"Swindle","given":"T.","email":"","middleInitial":"D.","affiliations":[],"preferred":false,"id":401900,"contributorType":{"id":1,"text":"Authors"},"rank":5},{"text":"Lucey, P. G.","contributorId":72532,"corporation":false,"usgs":false,"family":"Lucey","given":"P.","email":"","middleInitial":"G.","affiliations":[],"preferred":false,"id":401902,"contributorType":{"id":1,"text":"Authors"},"rank":6}]}}
,{"id":70025046,"text":"70025046 - 2002 - Stable carbon and nitrogen isotope composition of aquatic and terrestrial plants of the San Francisco Bay estuarine system","interactions":[],"lastModifiedDate":"2021-04-02T15:11:42.988316","indexId":"70025046","displayToPublicDate":"2002-01-01T00:00:00","publicationYear":"2002","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2620,"text":"Limnology and Oceanography","active":true,"publicationSubtype":{"id":10}},"title":"Stable carbon and nitrogen isotope composition of aquatic and terrestrial plants of the San Francisco Bay estuarine system","docAbstract":"<div class=\"article-section__content en main\"><p>We report measurements of seasonal variability in the C‐N stable isotope ratios of plants collected across the habitat mosaic of San Francisco Bay, its marshes, and its tributary river system. Analyses of 868 plant samples were binned into 10 groups (e.g., terrestrial riparian, freshwater phytoplankton, salt marsh) to determine whether C‐N isotopes can be used as biomarkers for tracing the origins of organic matter in this river‐marsh‐estuary complex. Variability of δ<sup>13</sup>C and δ<sup>15</sup>N was high (~5–10‰) within each plant group, and we identified three modes of variability: (1) between species and their microhabitats, (2) over annual cycles of plant growth and senescence, and (3) between living and decomposing biomass. These modes of within‐group variability obscure any source specific isotopic signatures, confounding the application of C‐N isotopes for identifying the origins of organic matter. A second confounding factor was large dissimilarity between the δ<sup>13</sup>C‐δ<sup>15</sup>N of primary producers and the organic matter pools in the seston and sediments. Both confounding factors impede the application of C‐N isotopes to reveal the food supply to primary consumers in ecosystems supporting diverse autotrophs and where the isotopic composition of organic matter has been transformed and become distinct from that of its parent plant sources. Our results support the advice of others: variability of C‐N stable isotopes within all organic‐matter pools is high and must be considered in applications of these isotopes to trace trophic linkages from primary producers to primary consumers. Isotope‐based approaches are perhaps most powerful when used to complement other tools, such as molecular biomarkers, bioassays, direct measures of production, and compilations of organic‐matter budgets.</p></div>","language":"English","publisher":"ASLO","doi":"10.4319/lo.2002.47.3.0713","usgsCitation":"Cloern, J., Canuel, E.A., and Harris, D., 2002, Stable carbon and nitrogen isotope composition of aquatic and terrestrial plants of the San Francisco Bay estuarine system: Limnology and Oceanography, v. 47, no. 3, p. 713-729, https://doi.org/10.4319/lo.2002.47.3.0713.","productDescription":"17 p.","startPage":"713","endPage":"729","onlineOnly":"N","additionalOnlineFiles":"N","costCenters":[{"id":154,"text":"California Water Science Center","active":true,"usgs":true},{"id":552,"text":"San Francisco Bay-Delta","active":false,"usgs":true},{"id":589,"text":"Toxic Substances Hydrology Program","active":true,"usgs":true},{"id":5079,"text":"Pacific Regional Director's Office","active":true,"usgs":true},{"id":13634,"text":"South Atlantic Water Science Center","active":true,"usgs":true}],"links":[{"id":478701,"rank":2,"type":{"id":40,"text":"Open Access Publisher Index Page"},"url":"https://doi.org/10.4319/lo.2002.47.3.0713","text":"Publisher Index Page"},{"id":438882,"rank":1,"type":{"id":30,"text":"Data Release"},"url":"https://doi.org/10.5066/P98ZSO0X","text":"USGS data release","linkHelpText":"Stable isotope analysis of San Francisco Bay-Delta primary producers (1990-2000)"},{"id":235946,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"country":"United States","state":"California","otherGeospatial":"San Francisco Bay","geographicExtents":"{\n  \"type\": \"FeatureCollection\",\n  \"features\": [\n    {\n      \"type\": \"Feature\",\n      \"properties\": {},\n      \"geometry\": {\n        \"type\": \"Polygon\",\n        \"coordinates\": [\n          [\n            [\n              -122.64862060546875,\n              37.391981943533544\n            ],\n            [\n              -121.74362182617188,\n              37.391981943533544\n            ],\n            [\n              -121.74362182617188,\n              38.238180119798635\n            ],\n            [\n              -122.64862060546875,\n              38.238180119798635\n            ],\n            [\n              -122.64862060546875,\n              37.391981943533544\n            ]\n          ]\n        ]\n      }\n    }\n  ]\n}","volume":"47","issue":"3","noUsgsAuthors":false,"publicationDate":"2002-05-07","publicationStatus":"PW","scienceBaseUri":"505b9660e4b08c986b31b487","contributors":{"authors":[{"text":"Cloern, J. E.","contributorId":59453,"corporation":false,"usgs":true,"family":"Cloern","given":"J. E.","affiliations":[],"preferred":false,"id":403572,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Canuel, E. A.","contributorId":52206,"corporation":false,"usgs":false,"family":"Canuel","given":"E.","email":"","middleInitial":"A.","affiliations":[],"preferred":false,"id":403571,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Harris, D.","contributorId":78520,"corporation":false,"usgs":false,"family":"Harris","given":"D.","affiliations":[],"preferred":false,"id":403573,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}}
,{"id":70024443,"text":"70024443 - 2002 - A Brownian model for recurrent earthquakes","interactions":[],"lastModifiedDate":"2012-03-12T17:20:01","indexId":"70024443","displayToPublicDate":"2002-01-01T00:00:00","publicationYear":"2002","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":"A Brownian model for recurrent earthquakes","docAbstract":"We construct a probability model for rupture times on a recurrent earthquake source. Adding Brownian perturbations to steady tectonic loading produces a stochastic load-state process. Rupture is assumed to occur when this process reaches a critical-failure threshold. An earthquake relaxes the load state to a characteristic ground level and begins a new failure cycle. The load-state process is a Brownian relaxation oscillator. Intervals between events have a Brownian passage-time distribution that may serve as a temporal model for time-dependent, long-term seismic forecasting. This distribution has the following noteworthy properties: (1) the probability of immediate rerupture is zero; (2) the hazard rate increases steadily from zero at t = 0 to a finite maximum near the mean recurrence time and then decreases asymptotically to a quasi-stationary level, in which the conditional probability of an event becomes time independent; and (3) the quasi-stationary failure rate is greater than, equal to, or less than the mean failure rate because the coefficient of variation is less than, equal to, or greater than 1/???2 ??? 0.707. In addition, the model provides expressions for the hazard rate and probability of rupture on faults for which only a bound can be placed on the time of the last rupture. The Brownian relaxation oscillator provides a connection between observable event times and a formal state variable that reflects the macromechanics of stress and strain accumulation. Analysis of this process reveals that the quasi-stationary distance to failure has a gamma distribution, and residual life has a related exponential distribution. It also enables calculation of \"interaction\" effects due to external perturbations to the state, such as stress-transfer effects from earthquakes outside the target source. The influence of interaction effects on recurrence times is transient and strongly dependent on when in the loading cycle step pertubations occur. Transient effects may be much stronger than would be predicted by the \"clock change\" method and characteristically decay inversely with elapsed time after the perturbation.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Bulletin of the Seismological Society of America","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1785/0120010267","issn":"00371106","usgsCitation":"Matthews, M., Ellsworth, W., and Reasenberg, P., 2002, A Brownian model for recurrent earthquakes: Bulletin of the Seismological Society of America, v. 92, no. 6, p. 2233-2250, https://doi.org/10.1785/0120010267.","startPage":"2233","endPage":"2250","numberOfPages":"18","costCenters":[],"links":[{"id":207088,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1785/0120010267"},{"id":231696,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"92","issue":"6","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"5059e2cbe4b0c8380cd45c5d","contributors":{"authors":[{"text":"Matthews, M.V.","contributorId":70920,"corporation":false,"usgs":true,"family":"Matthews","given":"M.V.","email":"","affiliations":[],"preferred":false,"id":401305,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Ellsworth, W.L.","contributorId":48541,"corporation":false,"usgs":true,"family":"Ellsworth","given":"W.L.","email":"","affiliations":[],"preferred":false,"id":401304,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Reasenberg, P.A.","contributorId":19959,"corporation":false,"usgs":true,"family":"Reasenberg","given":"P.A.","email":"","affiliations":[],"preferred":false,"id":401303,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}}
,{"id":70024521,"text":"70024521 - 2002 - Partial entrainment of gravel bars during floods","interactions":[],"lastModifiedDate":"2018-04-02T11:36:09","indexId":"70024521","displayToPublicDate":"2002-01-01T00:00:00","publicationYear":"2002","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":"Partial entrainment of gravel bars during floods","docAbstract":"<p><span>Spatial patterns of bed material entrainment by floods were documented at seven gravel bars using arrays of metal washers (bed tags) placed in the streambed. The observed patterns were used to test a general stochastic model that bed material entrainment is a spatially independent, random process where the probability of entrainment is uniform over a gravel bar and a function of the peak dimensionless shear stress τ</span><sub>0</sub><span>* of the flood. The fraction of tags missing from a gravel bar during a flood, or partial entrainment, had an approximately normal distribution with respect to τ</span><sub>0</sub><span>* with a mean value (50% of the tags entrained) of 0.085 and standard deviation of 0.022 (root‐mean‐square error of 0.09). Variation in partial entrainment for a given τ</span><sub>0</sub><span>* demonstrated the effects of flow conditioning on bed strength, with lower values of partial entrainment after intermediate magnitude floods (0.065 &lt; τ</span><sub>0</sub><span>*&lt; 0.08) than after higher magnitude floods. Although the probability of bed material entrainment was approximately uniform over a gravel bar during individual floods and independent from flood to flood, regions of preferential stability and instability emerged at some bars over the course of a wet season. Deviations from spatially uniform and independent bed material entrainment were most pronounced for reaches with varied flow and in consecutive floods with small to intermediate magnitudes.</span></p>","language":"English","publisher":"American Geophysical Union","doi":"10.1029/2001WR000828","usgsCitation":"Konrad, C.P., Booth, D.B., Burges, S.J., and Montgomery, D.R., 2002, Partial entrainment of gravel bars during floods: Water Resources Research, v. 38, no. 7, p. 9-1-9-16, https://doi.org/10.1029/2001WR000828.","productDescription":"Article 1104; 16 p.","startPage":"9-1","endPage":"9-16","onlineOnly":"N","additionalOnlineFiles":"N","costCenters":[{"id":622,"text":"Washington Water Science Center","active":true,"usgs":true}],"links":[{"id":232842,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"38","issue":"7","noUsgsAuthors":false,"publicationDate":"2002-07-11","publicationStatus":"PW","scienceBaseUri":"505a7523e4b0c8380cd779ec","contributors":{"authors":[{"text":"Konrad, Christopher P. 0000-0002-7354-547X cpkonrad@usgs.gov","orcid":"https://orcid.org/0000-0002-7354-547X","contributorId":1716,"corporation":false,"usgs":true,"family":"Konrad","given":"Christopher","email":"cpkonrad@usgs.gov","middleInitial":"P.","affiliations":[{"id":622,"text":"Washington Water Science Center","active":true,"usgs":true}],"preferred":true,"id":401563,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Booth, Derek B.","contributorId":100873,"corporation":false,"usgs":false,"family":"Booth","given":"Derek","email":"","middleInitial":"B.","affiliations":[{"id":6934,"text":"University of Washington","active":true,"usgs":false}],"preferred":false,"id":401565,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Burges, Stephen J.","contributorId":8567,"corporation":false,"usgs":false,"family":"Burges","given":"Stephen","email":"","middleInitial":"J.","affiliations":[],"preferred":false,"id":401566,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Montgomery, David R.","contributorId":67389,"corporation":false,"usgs":true,"family":"Montgomery","given":"David","email":"","middleInitial":"R.","affiliations":[],"preferred":false,"id":401564,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}}
,{"id":70024527,"text":"70024527 - 2002 - Recovery of severely compacted soils in the Mojave Desert, California, USA","interactions":[],"lastModifiedDate":"2012-03-12T17:20:12","indexId":"70024527","displayToPublicDate":"2002-01-01T00:00:00","publicationYear":"2002","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":904,"text":"Arid Land Research and Management","active":true,"publicationSubtype":{"id":10}},"title":"Recovery of severely compacted soils in the Mojave Desert, California, USA","docAbstract":"Often as a result of large-scale military maneuvers in the past, many soils in the Mojave Desert are highly vulnerable to soil compaction, particularly when wet. Previous studies indicate that natural recovery of severely compacted desert soils is extremely slow, and some researchers have suggested that subsurface compaction may not recover. Poorly sorted soils, particularly those with a loamy sand texture, are most vulnerable to soil compaction, and these soils are the most common in alluvial fans of the Mojave Desert. Recovery of compacted soil is expected to vary as a function of precipitation amounts, wetting-and-drying cycles, freeze-thaw cycles, and bioturbation, particularly root growth. Compaction recovery, as estimated using penetration depth and bulk density, was measured at 19 sites with 32 site-time combinations, including the former World War II Army sites of Camps Ibis, Granite, Iron Mountain, Clipper, and Essex. Although compaction at these sites was caused by a wide variety of forces, ranging from human trampling to tank traffic, the data do not allow segregation of differences in recovery rates for different compaction forces. The recovery rate appears to be logarithmic, with the highest rate of change occurring in the first few decades following abandonment. Some higher-elevation sites have completely recovered from soil compaction after 70 years. Using a linear model of recovery, the full recovery time ranges from 92 to 100 years; using a logarithmic model, which asymptotically approaches full recovery, the time required for 85% recovery ranges from 105-124 years.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Arid Land Research and Management","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1080/153249802760284829","issn":"15324982","usgsCitation":"Webb, R.H., 2002, Recovery of severely compacted soils in the Mojave Desert, California, USA: Arid Land Research and Management, v. 16, no. 3, p. 291-305, https://doi.org/10.1080/153249802760284829.","startPage":"291","endPage":"305","numberOfPages":"15","costCenters":[],"links":[{"id":207757,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1080/153249802760284829"},{"id":232946,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"16","issue":"3","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"50e4a33de4b0e8fec6cdb7d6","contributors":{"authors":[{"text":"Webb, R. H.","contributorId":13648,"corporation":false,"usgs":true,"family":"Webb","given":"R.","email":"","middleInitial":"H.","affiliations":[],"preferred":false,"id":401583,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}}
,{"id":70024464,"text":"70024464 - 2002 - Mapping apparent stress and energy radiation over fault zones of major earthquakes","interactions":[],"lastModifiedDate":"2012-03-12T17:20:05","indexId":"70024464","displayToPublicDate":"2002-01-01T00:00:00","publicationYear":"2002","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":"Mapping apparent stress and energy radiation over fault zones of major earthquakes","docAbstract":"Using published slip models for five major earthquakes, 1979 Imperial Valley, 1989 Loma Prieta, 1992 Landers, 1994 Northridge, and 1995 Kobe, we produce maps of apparent stress and radiated seismic energy over their fault surfaces. The slip models, obtained by inverting seismic and geodetic data, entail the division of the fault surfaces into many subfaults for which the time histories of seismic slip are determined. To estimate the seismic energy radiated by each subfault, we measure the near-fault seismic-energy flux from the time-dependent slip there and then multiply by a function of rupture velocity to obtain the corresponding energy that propagates into the far-field. This function, the ratio of far-field to near-fault energy, is typically less than 1/3, inasmuch as most of the near-fault energy remains near the fault and is associated with permanent earthquake deformation. Adding the energy contributions from all of the subfaults yields an estimate of the total seismic energy, which can be compared with independent energy estimates based on seismic-energy flux measured in the far-field, often at teleseismic distances. Estimates of seismic energy based on slip models are robust, in that different models, for a given earthquake, yield energy estimates that are in close agreement. Moreover, the slip-model estimates of energy are generally in good accord with independent estimates by others, based on regional or teleseismic data. Apparent stress is estimated for each subfault by dividing the corresponding seismic moment into the radiated energy. Distributions of apparent stress over an earthquake fault zone show considerable heterogeneity, with peak values that are typically about double the whole-earthquake values (based on the ratio of seismic energy to seismic moment). The range of apparent stresses estimated for subfaults of the events studied here is similar to the range of apparent stresses for earthquakes in continental settings, with peak values of about 8 MPa in each case. For earthquakes in compressional tectonic settings, peak apparent stresses at a given depth are substantially greater than corresponding peak values from events in extensional settings; this suggests that crustal strength, inferred from laboratory measurements, may be a limiting factor. Lower bounds on shear stresses inferred from the apparent stress distribution of the 1995 Kobe earthquake are consistent with tectonic-stress estimates reported by Spudich et al. (1998), based partly on slip-vector rake changes.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Bulletin of the Seismological Society of America","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1785/0120010129","issn":"00371106","usgsCitation":"McGarr, A., and Fletcher, J.B., 2002, Mapping apparent stress and energy radiation over fault zones of major earthquakes: Bulletin of the Seismological Society of America, v. 92, no. 5, p. 1633-1646, https://doi.org/10.1785/0120010129.","startPage":"1633","endPage":"1646","numberOfPages":"14","costCenters":[],"links":[{"id":207842,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1785/0120010129"},{"id":233082,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"92","issue":"5","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a5051e4b0c8380cd6b5e1","contributors":{"authors":[{"text":"McGarr, Art 0000-0001-9769-4093","orcid":"https://orcid.org/0000-0001-9769-4093","contributorId":43491,"corporation":false,"usgs":true,"family":"McGarr","given":"Art","affiliations":[],"preferred":false,"id":401382,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Fletcher, Joe B.","contributorId":8850,"corporation":false,"usgs":true,"family":"Fletcher","given":"Joe","email":"","middleInitial":"B.","affiliations":[],"preferred":false,"id":401381,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}}
,{"id":70024467,"text":"70024467 - 2002 - An upwelling model for the Phosphoria sea: A Permian, ocean-margin sea in the northwest United States","interactions":[],"lastModifiedDate":"2021-12-03T17:06:25.246185","indexId":"70024467","displayToPublicDate":"2002-01-01T00:00:00","publicationYear":"2002","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":701,"text":"American Association of Petroleum Geologists Bulletin","active":true,"publicationSubtype":{"id":10}},"title":"An upwelling model for the Phosphoria sea: A Permian, ocean-margin sea in the northwest United States","docAbstract":"The Permian Phosphoria Formation, a petroleum source rock and world-class phosphate deposit, was deposited in an epicratonic successor basin on the western margin of North America. We calculate the seawater circulation in the basin during deposition of the lower ore zone in the Meade Peak Member from the accumulation rates of carbonate fluorapatite and trace elements. The model gives the exchange rate of water between the Phosphoria sea and the open ocean to the west in terms of an upwelling rate (84 m yr-1) and residence time (4.2 yr) of seawater in the basin. These hydrographic properties supported a mean rate of primary productivity of 0.87 g m-2 d-1 of carbon in the uppermost few tens of meters of the water column (the photic zone) and denitrifying redox conditions in the bottom water (below approximately 150 m depth). High rain rates, onto the sea floor, of the organic matter that hosted the phosphate and several trace elements contributed to the accumulation of phosphorite, chert, and black shales and mudstones. Evaporation in the Goose Egg basin to the east of the Phosphoria basin ensured the import of surface seawater from the Phosphoria sea. Budgets of water, salt, phosphate, and oxygen, plus the minor accumulation of the biomarker gammacerane, show that exchange of water between the two basins was limited, possibly by the shallow carbonate platform that separated the two basins.","language":"English","publisher":"AAPG","doi":"10.1306/61EEDC60-173E-11D7-8645000102C1865D","usgsCitation":"Piper, D., and Link, P.K., 2002, An upwelling model for the Phosphoria sea: A Permian, ocean-margin sea in the northwest United States: American Association of Petroleum Geologists Bulletin, v. 86, no. 7, p. 1217-1235, https://doi.org/10.1306/61EEDC60-173E-11D7-8645000102C1865D.","productDescription":"19 p.","startPage":"1217","endPage":"1235","costCenters":[{"id":312,"text":"Geology, Minerals, Energy, and Geophysics Science Center","active":true,"usgs":true}],"links":[{"id":233119,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"country":"United States","state":"Idaho, Montana, Utah, Wyoming","geographicExtents":"{\n  \"type\": \"FeatureCollection\",\n  \"features\": [\n    {\n      \"type\": \"Feature\",\n      \"properties\": {},\n      \"geometry\": {\n        \"type\": \"Polygon\",\n        \"coordinates\": [\n          [\n            [\n              -111.796875,\n              41.31082388091818\n            ],\n            [\n              -109.3359375,\n              42.391008609205045\n            ],\n            [\n              -110.61035156249999,\n              44.08758502824516\n            ],\n            [\n              -111.181640625,\n              45.213003555993964\n            ],\n            [\n              -111.46728515624999,\n              45.75219336063106\n            ],\n            [\n              -112.52197265625,\n              45.72152152227954\n            ],\n            [\n              -111.796875,\n              41.31082388091818\n            ]\n          ]\n        ]\n      }\n    }\n  ]\n}","volume":"86","issue":"7","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"5059eab6e4b0c8380cd48a21","contributors":{"authors":[{"text":"Piper, D.Z.","contributorId":34154,"corporation":false,"usgs":false,"family":"Piper","given":"D.Z.","email":"","affiliations":[],"preferred":false,"id":401385,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Link, P. K.","contributorId":34973,"corporation":false,"usgs":true,"family":"Link","given":"P.","email":"","middleInitial":"K.","affiliations":[],"preferred":false,"id":401386,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}}
,{"id":70024470,"text":"70024470 - 2002 - The oligocene Lund Tuff, Great Basin, USA: A very large volume monotonous intermediate","interactions":[],"lastModifiedDate":"2012-03-12T17:20:05","indexId":"70024470","displayToPublicDate":"2002-01-01T00:00:00","publicationYear":"2002","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2499,"text":"Journal of Volcanology and Geothermal Research","active":true,"publicationSubtype":{"id":10}},"title":"The oligocene Lund Tuff, Great Basin, USA: A very large volume monotonous intermediate","docAbstract":"Unusual monotonous intermediate ignimbrites consist of phenocryst-rich dacite that occurs as very large volume (> 1000 km3) deposits that lack systematic compositional zonation, comagmatic rhyolite precursors, and underlying plinian beds. They are distinct from countless, usually smaller volume, zoned rhyolite-dacite-andesite deposits that are conventionally believed to have erupted from magma chambers in which thermal and compositional gradients were established because of sidewall crystallization and associated convective fractionation. Despite their great volume, or because of it, monotonous intermediates have received little attention. Documentation of the stratigraphy, composition, and geologic setting of the Lund Tuff - one of four monotonous intermediate tuffs in the middle-Tertiary Great Basin ignimbrite province - provides insight into its unusual origin and, by implication, the origin of other similar monotonous intermediates. The Lund Tuff is a single cooling unit with normal magnetic polarity whose volume likely exceeded 3000 km3. It was emplaced 29.02 ?? 0.04 Ma in and around the coeval White Rock caldera which has an unextended north-south diameter of about 50 km. The tuff is monotonous in that its phenocryst assemblage is virtually uniform throughout the deposit: plagioclase > quartz ??? hornblende > biotite > Fe-Ti oxides ??? sanidine > titanite, zircon, and apatite. However, ratios of phenocrysts vary by as much as an order of magnitude in a manner consistent with progressive crystallization in the pre-eruption chamber. A significant range in whole-rock chemical composition (e.g., 63-71 wt% SiO2) is poorly correlated with phenocryst abundance. These compositional attributes cannot have been caused wholly by winnowing of glass from phenocrysts during eruption, as has been suggested for the monotonous intermediate Fish Canyon Tuff. Pumice fragments are also crystal-rich, and chemically and mineralogically indistinguishable from bulk tuff. We postulate that convective mixing in a sill-like magma chamber precluded development of a zoned chamber with a rhyolitic top or of a zoned pyroclastic deposit. Chemical variations in the Lund Tuff are consistent with equilibrium crystallization of a parental dacitic magma followed by eruptive mixing of compositionally diverse crystals and high-silica rhyolite vitroclasts during evacuation and emplacement. This model contrasts with the more systematic withdrawal from a bottle-shaped chamber in which sidewall crystallization creates a marked vertical compositional gradient and a substantial volume of capping-evolved rhyolite magma. Eruption at exceptionally high discharge rates precluded development of an underlying plinian deposit. The generation of the monotonous intermediate Lund magma and others like it in the middle Tertiary of the western USA reflects an unusually high flux of mantle-derived mafic magma into unusually thick and warm crust above a subducting slab of oceanic lithosphere. ?? 2002 Elsevier Science B.V. All rights reserved.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Journal of Volcanology and Geothermal Research","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1016/S0377-0273(01)00256-6","issn":"03770273","usgsCitation":"Maughan, L., Christiansen, E.H., Best, M.G., Grommé, C., Deino, A., and Tingey, D., 2002, The oligocene Lund Tuff, Great Basin, USA: A very large volume monotonous intermediate: Journal of Volcanology and Geothermal Research, v. 113, no. 1-2, p. 129-157, https://doi.org/10.1016/S0377-0273(01)00256-6.","startPage":"129","endPage":"157","numberOfPages":"29","costCenters":[],"links":[{"id":207882,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/S0377-0273(01)00256-6"},{"id":233155,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"113","issue":"1-2","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505bae51e4b08c986b323feb","contributors":{"authors":[{"text":"Maughan, L.L.","contributorId":72981,"corporation":false,"usgs":true,"family":"Maughan","given":"L.L.","email":"","affiliations":[],"preferred":false,"id":401396,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Christiansen, E. H.","contributorId":65077,"corporation":false,"usgs":true,"family":"Christiansen","given":"E.","email":"","middleInitial":"H.","affiliations":[],"preferred":false,"id":401395,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Best, M. G.","contributorId":57843,"corporation":false,"usgs":true,"family":"Best","given":"M.","email":"","middleInitial":"G.","affiliations":[],"preferred":false,"id":401393,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Grommé, C. S.","contributorId":38558,"corporation":false,"usgs":true,"family":"Grommé","given":"C. S.","affiliations":[],"preferred":false,"id":401392,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Deino, A.L.","contributorId":61153,"corporation":false,"usgs":true,"family":"Deino","given":"A.L.","email":"","affiliations":[],"preferred":false,"id":401394,"contributorType":{"id":1,"text":"Authors"},"rank":5},{"text":"Tingey, D.G.","contributorId":102145,"corporation":false,"usgs":true,"family":"Tingey","given":"D.G.","email":"","affiliations":[],"preferred":false,"id":401397,"contributorType":{"id":1,"text":"Authors"},"rank":6}]}}
,{"id":70024350,"text":"70024350 - 2002 - Horseshoe crab (Limulus polyphemus) reproductive activity on Delaware Bay beaches: Interactions with beach characteristics","interactions":[],"lastModifiedDate":"2012-03-12T17:20:00","indexId":"70024350","displayToPublicDate":"2002-01-01T00:00:00","publicationYear":"2002","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2220,"text":"Journal of Coastal Research","active":true,"publicationSubtype":{"id":10}},"title":"Horseshoe crab (Limulus polyphemus) reproductive activity on Delaware Bay beaches: Interactions with beach characteristics","docAbstract":"We used results from a survey of horseshoe crab reproductive activity that was conducted in 1999 throughout Delaware Bay to examine the relationship between estimates of spawning females and egg deposition and analyze how that relationship varies with geography, time within a spawning season, beach morphology, and wave energy. We found that beach morphology and wave energy interacted with density of spawning females to explain variation in the density and distribution of eggs and larvae. For example, the quantity of eggs in surface sediment (i.e., eggs that are potentially available to foraging shorebirds) was associated with the density of spawning females, beach morphology, and wave energy. The association between beach morphology and live eggs in surface sediment was strong especially in late May (Percent Reduction in Error = 86% from regression tree model) where egg density was an order of magnitude higher on beaches <15 m wide (3.38*105 m-2; 90% CI: 2.29*105, 4.47*105) compared to wider beaches (1.49*104 m-2; 90% CI: 4.47*103, 2.53*104). Results also indicate that, among bay-front beaches, horseshoe crabs prefer to spawn on narrow beaches, possibly because of reduced wave energy. At peak periods of spawning activity, density of spawning females was inversely related to foreshore width on mid-latitude beaches within Delaware Bay (t = -2.68, 7 df, p = 0.03). Because the distribution of eggs across the foreshore varied with beach morphology and widened as the spawning season progressed, methods used to sample eggs need to be robust to variation in beach morphology and applicable regardless of when the samples are taken. Because beach morphology and wave energy were associated with the quantity of eggs in surface sediment, certain beach types may be critical to the conservation of shorebird foraging habitat.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Journal of Coastal Research","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","issn":"07490208","usgsCitation":"Smith, D., Pooler, P., Loveland, R., Botton, M., Michels, S., Weber, R., and Carter, D.B., 2002, Horseshoe crab (Limulus polyphemus) reproductive activity on Delaware Bay beaches: Interactions with beach characteristics: Journal of Coastal Research, v. 18, no. 4, p. 730-740.","startPage":"730","endPage":"740","numberOfPages":"11","costCenters":[],"links":[{"id":231776,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"18","issue":"4","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a322ae4b0c8380cd5e594","contributors":{"authors":[{"text":"Smith, D. R. 0000-0001-6074-9257","orcid":"https://orcid.org/0000-0001-6074-9257","contributorId":44108,"corporation":false,"usgs":true,"family":"Smith","given":"D. R.","affiliations":[{"id":365,"text":"Leetown Science Center","active":true,"usgs":true}],"preferred":false,"id":400951,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Pooler, P.S.","contributorId":78686,"corporation":false,"usgs":true,"family":"Pooler","given":"P.S.","affiliations":[],"preferred":false,"id":400953,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Loveland, R.E.","contributorId":49158,"corporation":false,"usgs":true,"family":"Loveland","given":"R.E.","email":"","affiliations":[],"preferred":false,"id":400952,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Botton, M.L.","contributorId":104682,"corporation":false,"usgs":true,"family":"Botton","given":"M.L.","email":"","affiliations":[],"preferred":false,"id":400954,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Michels, S.F.","contributorId":34867,"corporation":false,"usgs":true,"family":"Michels","given":"S.F.","email":"","affiliations":[],"preferred":false,"id":400949,"contributorType":{"id":1,"text":"Authors"},"rank":5},{"text":"Weber, R.G.","contributorId":38686,"corporation":false,"usgs":true,"family":"Weber","given":"R.G.","affiliations":[],"preferred":false,"id":400950,"contributorType":{"id":1,"text":"Authors"},"rank":6},{"text":"Carter, Daniel B.","contributorId":18880,"corporation":false,"usgs":true,"family":"Carter","given":"Daniel","email":"","middleInitial":"B.","affiliations":[],"preferred":false,"id":400948,"contributorType":{"id":1,"text":"Authors"},"rank":7}]}}
,{"id":70024367,"text":"70024367 - 2002 - Key Largo Limestone revisited: Pleistocene shelf-edge facies, Florida Keys, USA","interactions":[],"lastModifiedDate":"2019-06-05T09:57:38","indexId":"70024367","displayToPublicDate":"2002-01-01T00:00:00","publicationYear":"2002","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1622,"text":"Facies","active":true,"publicationSubtype":{"id":10}},"title":"Key Largo Limestone revisited: Pleistocene shelf-edge facies, Florida Keys, USA","docAbstract":"<p>New dates and analysis of 12 deep and 57 shallow cores allow a more detailed interpretation of the Pleistocene shelf edge of the Florida Platform as found in various facies of the Key Largo Limestone beneath the Florida Keys. In this study a three-phase evolution of the Quaternary units (Q1-Q5) of the Key Largo is presented with new subdivision of the Q5. (1) In the first phase, the Q1 and Q2 (perhaps deposited during oxygen-isotope stage 11) deep-water quartz-rich environment evolved into a shallow carbonate phase. (2) Subsequently, a Q3 (presumably corresponding to oxygen-isotope stage 9) flourishing reef and productive high-platform sediment phase developed. (3) Finally, a Q4 and Q5 (corresponding to oxygen-isotope stages 7 and 5) stabilization phase occurred with reefs and leeward productive lagoons, followed by lower sea levels presenting a sequence of younger (isotope substages 5c, 5a) shelf-margin wedges, sediment veneers and outlier reefs. The Key Largo Limestone provides an accessible model of a carbonate shelf edge with fluctuating water depth, bordering a deep seaward basin for a period of at least 300 ka. During this time, at least four onlaps/offlaps, often separated by periods of karst development with associated diagenetic alterations, took place. The story presented by this limestone not only allows a better understanding of the history of south Florida but also aids in the interpretation of similar persistent shelf-edge sites bordering deep basins in other areas.</p>","language":"English","publisher":"Springer","doi":"10.1007/BF02668083","issn":"01729179","usgsCitation":"Gray, M.H., Gischler, E., Lundberg, J., Simmons, K.R., and Shinn, E., 2002, Key Largo Limestone revisited: Pleistocene shelf-edge facies, Florida Keys, USA: Facies, no. 46, p. 229-272, https://doi.org/10.1007/BF02668083.","productDescription":"44 p.","startPage":"229","endPage":"272","numberOfPages":"44","costCenters":[],"links":[{"id":231817,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"country":"United States","state":"Florida","otherGeospatial":"Florida Keys","geographicExtents":"{\n  \"type\": \"FeatureCollection\",\n  \"features\": [\n    {\n      \"type\": \"Feature\",\n      \"properties\": {},\n      \"geometry\": {\n        \"type\": \"Polygon\",\n        \"coordinates\": [\n          [\n            [\n              -82.694091796875,\n              24.387127324604496\n            ],\n            [\n              -79.991455078125,\n              24.387127324604496\n            ],\n            [\n              -79.991455078125,\n              25.45319497952487\n            ],\n            [\n              -82.694091796875,\n              25.45319497952487\n            ],\n            [\n              -82.694091796875,\n              24.387127324604496\n            ]\n          ]\n        ]\n      }\n    }\n  ]\n}","issue":"46","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a4078e4b0c8380cd64db8","contributors":{"authors":[{"text":"Gray, Multer H.","contributorId":91274,"corporation":false,"usgs":true,"family":"Gray","given":"Multer","email":"","middleInitial":"H.","affiliations":[],"preferred":false,"id":401020,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Gischler, E.","contributorId":43944,"corporation":false,"usgs":true,"family":"Gischler","given":"E.","affiliations":[],"preferred":false,"id":401017,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Lundberg, J.","contributorId":78908,"corporation":false,"usgs":true,"family":"Lundberg","given":"J.","email":"","affiliations":[],"preferred":false,"id":401019,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Simmons, K. R.","contributorId":68771,"corporation":false,"usgs":true,"family":"Simmons","given":"K.","email":"","middleInitial":"R.","affiliations":[],"preferred":false,"id":401018,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Shinn, E.A.","contributorId":38610,"corporation":false,"usgs":true,"family":"Shinn","given":"E.A.","email":"","affiliations":[],"preferred":false,"id":401016,"contributorType":{"id":1,"text":"Authors"},"rank":5}]}}
,{"id":70024618,"text":"70024618 - 2002 - Parasite (Ribeiroia ondatrae) infection linked to amphibian malformations in the western United States","interactions":[],"lastModifiedDate":"2018-11-28T08:41:07","indexId":"70024618","displayToPublicDate":"2002-01-01T00:00:00","publicationYear":"2002","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1459,"text":"Ecological Monographs","active":true,"publicationSubtype":{"id":10}},"title":"Parasite (Ribeiroia ondatrae) infection linked to amphibian malformations in the western United States","docAbstract":"<p>Parasites and pathogens can influence the survivorship, behavior, and very structure of their host species. For example, experimental studies have shown that trematode parasites can cause high frequencies of severe limb malformations in amphibians. In a broad-scale field survey covering parts of California, Oregon, Washington, Idaho, and Montana, we examined relationships between the frequency and types of morphological abnormalities in amphibians and the abundance of trematode parasite infection, pH, concentrations of 61 pesticides, and levels of orthophosphate and total nitrate. We recorded severe malformations at frequencies ranging from 1% to 90% in nine amphibian species from 53 aquatic systems. Infection of larvae by the trematode Ribeiroia ondatrae was associated with, and functionally related to, higher frequencies of amphibian limb malformations than found in uninfected populations (≤5%). Parasites were concentrated around the basal tissue of hind limbs in infected anurans, and malformations associated with infection included skin webbings, supernumerary limbs and digits, and missing or malformed hind limbs. In the absence of Ribeiroia, amphibian populations exhibited low (0-5%) frequencies of abnormalities involving missing digits or distal portions of a hind limb. Species were affected differentially by the parasite, and Ambystoma macrodactylum, Hyla regilla, Rand aurora, R. luteiventris, and Taricha torosa typically exhibited the highest frequencies of abnormalities. None of the water-quality variables measured was associated with malformed amphibians, but aquatic snail hosts (Planorbella spp.) were significant predictors of the presence and abundance of Ribeiroia infection. Morphological comparisons of adult specimens of Ribeiroia collected from different sites and raised in experimental definitive hosts suggested that all samples represented the same species - R. ondatrae. These field results, coupled with experimental research on the effects of Ribeiroia on amphibians, demonstrate that Ribeiroia infection is an important and widespread cause of amphibian limb malformations in the western United States. The relevance of trematode infection to declines of amphibian populations and the influence of habitat modification on the pathology and life cycle of Ribeiroia are emphasized as areas requiring further research.</p>","language":"English","publisher":"ESA","doi":"10.1890/0012-9615(2002)072[0151:PROILT]2.0.CO;2","issn":"00129615","usgsCitation":"Johnson, P., Lunde, K., Thurman, E., Ritchie, E., Wray, S., Sutherland, D., Kapfer, J., Frest, T., Bowerman, J., and Blaustein, A., 2002, Parasite (Ribeiroia ondatrae) infection linked to amphibian malformations in the western United States: Ecological Monographs, v. 72, no. 2, p. 151-168, https://doi.org/10.1890/0012-9615(2002)072[0151:PROILT]2.0.CO;2.","productDescription":"18 p.","startPage":"151","endPage":"168","costCenters":[{"id":589,"text":"Toxic Substances Hydrology Program","active":true,"usgs":true}],"links":[{"id":502602,"rank":1,"type":{"id":41,"text":"Open Access External Repository Page"},"url":"https://figshare.com/articles/journal_contribution/Parasite_Ribeiroia_ondatrae_infection_linked_to_amphibian_malformations_in_the_western_United_States/20877172","text":"External Repository"},{"id":233308,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"country":"United States","volume":"72","issue":"2","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a74d6e4b0c8380cd77867","contributors":{"authors":[{"text":"Johnson, P.T.J.","contributorId":104255,"corporation":false,"usgs":true,"family":"Johnson","given":"P.T.J.","email":"","affiliations":[],"preferred":false,"id":401934,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Lunde, K.B.","contributorId":10200,"corporation":false,"usgs":true,"family":"Lunde","given":"K.B.","email":"","affiliations":[],"preferred":false,"id":401925,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Thurman, E.M.","contributorId":102864,"corporation":false,"usgs":true,"family":"Thurman","given":"E.M.","affiliations":[],"preferred":false,"id":401933,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Ritchie, E.G.","contributorId":97285,"corporation":false,"usgs":true,"family":"Ritchie","given":"E.G.","email":"","affiliations":[],"preferred":false,"id":401932,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Wray, S.N.","contributorId":90505,"corporation":false,"usgs":true,"family":"Wray","given":"S.N.","email":"","affiliations":[],"preferred":false,"id":401930,"contributorType":{"id":1,"text":"Authors"},"rank":5},{"text":"Sutherland, D.R.","contributorId":15376,"corporation":false,"usgs":true,"family":"Sutherland","given":"D.R.","email":"","affiliations":[],"preferred":false,"id":401926,"contributorType":{"id":1,"text":"Authors"},"rank":6},{"text":"Kapfer, J.M.","contributorId":68505,"corporation":false,"usgs":true,"family":"Kapfer","given":"J.M.","email":"","affiliations":[],"preferred":false,"id":401928,"contributorType":{"id":1,"text":"Authors"},"rank":7},{"text":"Frest, T.J.","contributorId":70964,"corporation":false,"usgs":true,"family":"Frest","given":"T.J.","email":"","affiliations":[],"preferred":false,"id":401929,"contributorType":{"id":1,"text":"Authors"},"rank":8},{"text":"Bowerman, J.","contributorId":94824,"corporation":false,"usgs":true,"family":"Bowerman","given":"J.","email":"","affiliations":[],"preferred":false,"id":401931,"contributorType":{"id":1,"text":"Authors"},"rank":9},{"text":"Blaustein, A.R.","contributorId":40325,"corporation":false,"usgs":true,"family":"Blaustein","given":"A.R.","affiliations":[],"preferred":false,"id":401927,"contributorType":{"id":1,"text":"Authors"},"rank":10}]}}
,{"id":70024619,"text":"70024619 - 2002 - Development and evaluation of a local grid refinement method for block-centered finite-difference groundwater models using shared nodes","interactions":[],"lastModifiedDate":"2012-03-12T17:20:05","indexId":"70024619","displayToPublicDate":"2002-01-01T00:00:00","publicationYear":"2002","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":664,"text":"Advances in Water Resources","active":true,"publicationSubtype":{"id":10}},"title":"Development and evaluation of a local grid refinement method for block-centered finite-difference groundwater models using shared nodes","docAbstract":"A new method of local grid refinement for two-dimensional block-centered finite-difference meshes is presented in the context of steady-state groundwater-flow modeling. The method uses an iteration-based feedback with shared nodes to couple two separate grids. The new method is evaluated by comparison with results using a uniform fine mesh, a variably spaced mesh, and a traditional method of local grid refinement without a feedback. Results indicate: (1) The new method exhibits quadratic convergence for homogeneous systems and convergence equivalent to uniform-grid refinement for heterogeneous systems. (2) Coupling the coarse grid with the refined grid in a numerically rigorous way allowed for improvement in the coarse-grid results. (3) For heterogeneous systems, commonly used linear interpolation of heads from the large model onto the boundary of the refined model produced heads that are inconsistent with the physics of the flow field. (4) The traditional method works well in situations where the better resolution of the locally refined grid has little influence on the overall flow-system dynamics, but if this is not true, lack of a feedback mechanism produced errors in head up to 3.6% and errors in cell-to-cell flows up to 25%. ?? 2002 Elsevier Science Ltd. All rights reserved.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Advances in Water Resources","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1016/S0309-1708(02)00021-0","issn":"03091708","usgsCitation":"Mehl, S., and Hill, M.C., 2002, Development and evaluation of a local grid refinement method for block-centered finite-difference groundwater models using shared nodes: Advances in Water Resources, v. 25, no. 5, p. 497-511, https://doi.org/10.1016/S0309-1708(02)00021-0.","startPage":"497","endPage":"511","numberOfPages":"15","costCenters":[],"links":[{"id":207977,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/S0309-1708(02)00021-0"},{"id":233309,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"25","issue":"5","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a0020e4b0c8380cd4f5d7","contributors":{"authors":[{"text":"Mehl, S.","contributorId":20114,"corporation":false,"usgs":true,"family":"Mehl","given":"S.","affiliations":[],"preferred":false,"id":401935,"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":401936,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}}
,{"id":70024368,"text":"70024368 - 2002 - Relationship of gas hydrate concentration to porosity and reflection amplitude in a research well, Mackenzie Delta, Canada","interactions":[],"lastModifiedDate":"2012-03-12T17:20:01","indexId":"70024368","displayToPublicDate":"2002-01-01T00:00:00","publicationYear":"2002","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2682,"text":"Marine and Petroleum Geology","active":true,"publicationSubtype":{"id":10}},"title":"Relationship of gas hydrate concentration to porosity and reflection amplitude in a research well, Mackenzie Delta, Canada","docAbstract":"Well logs acquired at the Mallik 2L-38 gas hydrate research well. Mackenzie Delta, Canada, reveal a distinct trend showing that the resistivity of gas-hydrate-bearing sediments increases with increases in density porosities. This trend, opposite to the general trend of decrease in resistivity with porosity, implies that gas hydrates are more concentrated in the higher porosity. Using the Mallik 2L-38 well data, a proportional gas hydrate concentration (PGHC) model, which states that the gas hydrate concentration in the sediment's pore space is linearly proportional to porosity, is proposed for the general habitat of gas hydrate in sediments. Anomalous data (less than 6% of the total data) outside the dominant observed trend can be explained by local geological characteristics. The anomalous data analysis indicates that highly concentrated gas-hydrate-bearing layers would be expected where sediments have high proportions of gravel and coarse sand. Using the parameters in the PGHC model determined from resistivity-porosity logs, it is possible to qualitatively predict the degree of reflection amplitude variations in seismic profiles. Moderate-to-strong reflections are expected for the Mallik 2L-38 well. ?? 2002 Elsevier Science Ltd. All rights reserved.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Marine and Petroleum Geology","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1016/S0264-8172(02)00011-9","issn":"02648172","usgsCitation":"Jin, Y., Lee, M.W., and Collett, T.S., 2002, Relationship of gas hydrate concentration to porosity and reflection amplitude in a research well, Mackenzie Delta, Canada: Marine and Petroleum Geology, v. 19, no. 4, p. 407-415, https://doi.org/10.1016/S0264-8172(02)00011-9.","startPage":"407","endPage":"415","numberOfPages":"9","costCenters":[],"links":[{"id":207143,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/S0264-8172(02)00011-9"},{"id":231818,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"19","issue":"4","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"50e4a76de4b0e8fec6cdc464","contributors":{"authors":[{"text":"Jin, Y.K.","contributorId":60810,"corporation":false,"usgs":true,"family":"Jin","given":"Y.K.","email":"","affiliations":[],"preferred":false,"id":401021,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Lee, Myung W.","contributorId":84358,"corporation":false,"usgs":true,"family":"Lee","given":"Myung","middleInitial":"W.","affiliations":[],"preferred":false,"id":401022,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Collett, T. S. 0000-0002-7598-4708","orcid":"https://orcid.org/0000-0002-7598-4708","contributorId":86342,"corporation":false,"usgs":true,"family":"Collett","given":"T.","email":"","middleInitial":"S.","affiliations":[],"preferred":false,"id":401023,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}}
,{"id":70024834,"text":"70024834 - 2002 - Evaluating remedial alternatives for an acid mine drainage stream: Application of a reactive transport model","interactions":[],"lastModifiedDate":"2018-11-28T09:24:57","indexId":"70024834","displayToPublicDate":"2002-01-01T00:00:00","publicationYear":"2002","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":"Evaluating remedial alternatives for an acid mine drainage stream: Application of a reactive transport model","docAbstract":"<div class=\"hlFld-Abstract\"><div id=\"abstractBox\"><p class=\"articleBody_abstractText\">A reactive transport model based on one-dimensional transport and equilibrium chemistry is applied to synoptic data from an acid mine drainage stream. Model inputs include streamflow estimates based on tracer dilution, inflow chemistry based on synoptic sampling, and equilibrium constants describing acid/base, complexation, precipitation/dissolution, and sorption reactions. The dominant features of observed spatial profiles in pH and metal concentration are reproduced along the 3.5-km study reach by simulating the precipitation of Fe(III) and Al solid phases and the sorption of Cu, As, and Pb onto freshly precipitated iron(III) oxides. Given this quantitative description of existing conditions, additional simulations are conducted to estimate the streamwater quality that could result from two hypothetical remediation plans. Both remediation plans involve the addition of CaCO<sub>3</sub><span>&nbsp;</span>to raise the pH of a small, acidic inflow from ∼2.4 to ∼7.0. This pH increase results in a reduced metal load that is routed downstream by the reactive transport model, thereby providing an estimate of post-remediation water quality. The first remediation plan assumes a closed system wherein inflow Fe(II) is not oxidized by the treatment system; under the second remediation plan, an open system is assumed, and Fe(II) is oxidized within the treatment system. Both plans increase instream pH and substantially reduce total and dissolved concentrations of Al, As, Cu, and Fe(II+III) at the terminus of the study reach. Dissolved Pb concentrations are reduced by ∼18% under the first remediation plan due to sorption onto iron(III) oxides within the treatment system and stream channel. In contrast, iron(III) oxides are limiting under the second remediation plan, and removal of dissolved Pb occurs primarily within the treatment system. This limitation results in an increase in dissolved Pb concentrations over existing conditions as additional downstream sources of Pb are not attenuated by sorption.</p></div></div><div class=\"hlFld-Fulltext\"><br data-mce-bogus=\"1\"></div>","language":"English","publisher":"ACS","doi":"10.1021/es0109794","issn":"0013936X","usgsCitation":"Runkel, R., and Kimball, B.A., 2002, Evaluating remedial alternatives for an acid mine drainage stream: Application of a reactive transport model: Environmental Science & Technology, v. 36, no. 5, p. 1093-1101, https://doi.org/10.1021/es0109794.","productDescription":"9 p.","startPage":"1093","endPage":"1101","costCenters":[{"id":589,"text":"Toxic Substances Hydrology Program","active":true,"usgs":true}],"links":[{"id":233284,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":207961,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1021/es0109794"}],"volume":"36","issue":"5","noUsgsAuthors":false,"publicationDate":"2002-01-19","publicationStatus":"PW","scienceBaseUri":"505a0bf1e4b0c8380cd5295e","contributors":{"authors":[{"text":"Runkel, R.L.","contributorId":97529,"corporation":false,"usgs":true,"family":"Runkel","given":"R.L.","affiliations":[],"preferred":false,"id":402795,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Kimball, B. A.","contributorId":87583,"corporation":false,"usgs":false,"family":"Kimball","given":"B.","email":"","middleInitial":"A.","affiliations":[],"preferred":false,"id":402794,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}}
]}