Lead isotope compositions of bulk mineral samples (fluorite, orpiment, and realgar) determined using conventional techniques and of ore-stage arsenian pyrite using the Sensitive High Resolution Ion-Microprobe (SHRIMP) in the Getchell and Turquoise Ridge Carlin-type gold deposits (Osgood Mountains) require contribution from two different Pb sources. One Pb source dominates the ore stage. It has a limited Pb isotope range characterized by 208Pb/ 206Pb values of 2.000 to 2.005 and 207Pb/ 206Pb values of 0.8031 to 0.8075, as recorded by 10-μm-diameter spot SHRIMP analyses of ore-stage arsenian pyrite. These values approximately correspond to 206Pb/ 204Pb of 19.3 to 19.6, 207Pb/ 204Pb of 15.65 to 15.75, and 208Pb/ 204Pb of 39.2 to 39.5. This Pb source is isotopically similar to that in average Neoproterozoic and Cambrian elastic rocks but not to any potential magmatic sources. Whether those clastic rocks provided Pb to the ore fluid cannot be unequivocally proven because their Pb isotope compositions over the same range as in ore-stage arsenian pyrite are similar to those of Ordovician to Devonian siliciclastic and calcareous rocks. The Pb source in the calcareous rocks most likely is largely detrital minerals, since that detritus was derived from the same sources as the detritus in the Neoproterozoic and Cambrian clastic rocks. The second Pb source is characterized by a large range of 206Pb/ 204Pb values (18-34) with a limited range of 208Pb/ 204Pb values (38.1-39.5), indicating low but variable Th/U and high and variable U/Pb values. The second Pb source dominates late and postore-stage minerals but is also found in preore sulfide minerals. These Pb isotope characteristics typify Ordovician to Devonian siliciclastic and calcareous rocks around the Carlin trend in northeast Nevada. Petrologically similar rocks host the Getchell and Turquoise Ridge deposits. Lead from the second source was either contributed from the host sedimentary rock sequences or brought into the hydrothermal system by oxidized ground water as the system collapsed. Late ore- and postore-stage sulfide minerals (pyrite, orpiment, and stibnite) from the Betze-Post and Meikle deposits in the Carlin trend and from the Jerritt Canyon mining district have Pb isotope characteristics similar to those determined in Getchell and Turquoise Ridge. This observation suggests that the Pb isotope compositions of their ore fluids may be similar to those at Getchell and Turquoise Ridge. Two models can explain the Pb isotope compositions of the ore-stage arsenian pyrite versus the late ore or postore sulfide minerals. In either model, Pb from the Ordovician to Devonian siliciclastic and calcareous rock source enters the hydrothermal system late in the ore stage but not to any extent during the main stage of ore deposition. In one model, ore-stage Pb was derived from a source with Pb isotope compositions similar to those of the Neoproterozoic and Cambrian clastic sequence, transported as part of the ore fluid and then deposited in the ore-stage arsenian pyrite and fluorite. The second model is based on the observation that the Pb isotope characteristics of the ore-stage minerals also are found in some Ordovician to Devonian calcareous and siliciclastic rocks. Hence, ore-stage Pb could have been derived locally and simply concentrated during the ore stage. Critical to the second model is the removal of all high 206Pb/ 204Pb (>20) material during alteration. It Also requires the retention of only the low 206Pb/ 204Pb component of the Ordovician to Devonian sedimentary rocks. This critical step is possible only if the high 206Pb/ 204Pb values are contained in readily dissolvable mineral phases, whereas the low 206Pb/ 204Pb values are found only in refractory minerals that released Pb during a final alteration stage just prior deposition of auriferous arsenian pyrite. Distinguishing between Pb transported with the ore fluid or inherited from the site of mineral deposition is not straightforward; however, it is simpler to explain the Pb isotope compositions of ore-stage arsenian pyrite and fluorite in two different but spatially related Carlin-type deposits (Getchell and Turquoise Ridge) with different host rocks by input of Pb with the ore fluid. Once the limited Pb in the hydrothermal fluid was exhausted by incorporation in ore-stage arsenian pyrite or other ore-stage minerals, Pb from the second source, the Ordovician to Devonian sedimentary rock sequences, became available for incorporation in some but not all of the late-stage sulfide minerals.
","language":"English","publisher":"Society of Economic Geologists","doi":"10.2113/gsecongeo.98.6.1189","issn":"03610128","usgsCitation":"Tosdal, R., Cline, J.S., Fanning, C., and Wooden, J.L., 2003, Lead in the Getchell-Turquoise ridge Carlin-type gold deposits from the perspective of potential igneous and sedimentary rock sources in Northern Nevada: Implications for fluid and metal sources: Economic Geology, v. 98, no. 6, p. 1189-1211, https://doi.org/10.2113/gsecongeo.98.6.1189.","productDescription":"23 p.","startPage":"1189","endPage":"1211","costCenters":[],"links":[{"id":387489,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"country":"United States","state":"Nevada","otherGeospatial":"northern Nevada","geographicExtents":"{\n \"type\": \"FeatureCollection\",\n \"features\": [\n {\n \"type\": \"Feature\",\n \"properties\": {},\n \"geometry\": {\n \"type\": \"Polygon\",\n \"coordinates\": [\n [\n [\n -119.981689453125,\n 40.91351257612758\n ],\n [\n -114.027099609375,\n 40.91351257612758\n ],\n [\n -114.027099609375,\n 42.00032514831621\n ],\n [\n -119.981689453125,\n 42.00032514831621\n ],\n [\n -119.981689453125,\n 40.91351257612758\n ]\n ]\n ]\n }\n }\n ]\n}","volume":"98","issue":"6","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a45bce4b0c8380cd6749a","contributors":{"authors":[{"text":"Tosdal, R. M.","contributorId":54982,"corporation":false,"usgs":true,"family":"Tosdal","given":"R. M.","affiliations":[],"preferred":false,"id":404293,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Cline, J. S.","contributorId":39541,"corporation":false,"usgs":false,"family":"Cline","given":"J.","email":"","middleInitial":"S.","affiliations":[],"preferred":false,"id":404292,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Fanning, C.M.","contributorId":82434,"corporation":false,"usgs":true,"family":"Fanning","given":"C.M.","email":"","affiliations":[],"preferred":false,"id":404295,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Wooden, J. L.","contributorId":58678,"corporation":false,"usgs":true,"family":"Wooden","given":"J.","email":"","middleInitial":"L.","affiliations":[],"preferred":false,"id":404294,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}} ,{"id":70025228,"text":"70025228 - 2003 - Morphological traits of Pacific Flyway Canada Geese as an aid to subspecies identification and management","interactions":[],"lastModifiedDate":"2018-07-14T13:53:51","indexId":"70025228","displayToPublicDate":"2003-01-01T00:00:00","publicationYear":"2003","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2284,"text":"Journal of Field Ornithology","active":true,"publicationSubtype":{"id":10}},"title":"Morphological traits of Pacific Flyway Canada Geese as an aid to subspecies identification and management","docAbstract":"Subspecies of Canada Geese (Branta canadensis) exhibit wide variation in body size across their range. To monitor harvest levels in the Pacific Flyway, biologists commonly use culmen length and plumage color to differentiate among subspecies on sympatric wintering grounds. Among the four large-bodied Pacific subspecies (B. c. parvipes, B. c. occidentalis, B. c. fulva, and B. c. moffitti), overlap in culmen length and subjectivity of visually assessing color results in misclassification and inaccurate harvest estimates. We examined the morphology of Pacific large-bodied Canada Geese to characterize body size variation among subspecies and provide more discriminatory measures for harvest assessments. We found that culmen length, one of the most commonly used field measures, overlapped widely among subspecies, and it had little support for inclusion in discriminatory models. Morphological measures with greater explanatory power included bill width at nail, bill width at base, head length, and mid wing. If culmen length and plumage color continue to be used to assess winter harvest, we recommend the addition of at least one sex-specific measurement to reduce levels of misclassification among subspecies. If an additional morphological measure is included, further evaluation on the wintering grounds should be conducted as this measure's effectiveness may vary depending upon observer bias, temporal and spatial variation in subspecies abundance, and the proportion of birds accurately sexed by cloacal examination.
","language":"English","publisher":"Wiley","doi":"10.1648/0273-8570-74.4.357","issn":"02738570","usgsCitation":"Pearce, J.M., and Bollinger, K.S., 2003, Morphological traits of Pacific Flyway Canada Geese as an aid to subspecies identification and management: Journal of Field Ornithology, v. 74, no. 4, p. 357-369, https://doi.org/10.1648/0273-8570-74.4.357.","productDescription":"13 p.","startPage":"357","endPage":"369","costCenters":[{"id":114,"text":"Alaska Science Center","active":true,"usgs":true},{"id":117,"text":"Alaska Science Center Biology WTEB","active":true,"usgs":true}],"links":[{"id":235773,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"country":"Canada, United States","otherGeospatial":"Pacific Flyway","volume":"74","issue":"4","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a5e43e4b0c8380cd708f4","contributors":{"authors":[{"text":"Pearce, John M. 0000-0002-8503-5485 jpearce@usgs.gov","orcid":"https://orcid.org/0000-0002-8503-5485","contributorId":181766,"corporation":false,"usgs":true,"family":"Pearce","given":"John","email":"jpearce@usgs.gov","middleInitial":"M.","affiliations":[{"id":114,"text":"Alaska Science Center","active":true,"usgs":true},{"id":117,"text":"Alaska Science Center Biology WTEB","active":true,"usgs":true}],"preferred":true,"id":404315,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Bollinger, Karen S.","contributorId":33842,"corporation":false,"usgs":true,"family":"Bollinger","given":"Karen","email":"","middleInitial":"S.","affiliations":[],"preferred":false,"id":404314,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70025229,"text":"70025229 - 2003 - Structural controls on Carlin-type gold mineralization in the gold bar district, Eureka County, Nevada","interactions":[],"lastModifiedDate":"2021-07-27T18:41:15.89257","indexId":"70025229","displayToPublicDate":"2003-01-01T00:00:00","publicationYear":"2003","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1472,"text":"Economic Geology","active":true,"publicationSubtype":{"id":10}},"title":"Structural controls on Carlin-type gold mineralization in the gold bar district, Eureka County, Nevada","docAbstract":"The Gold Bar district in the southern Roberts Mountains, 48 km northwest of Eureka, Nevada, contains one main deposit (Gold Bar), five satellite deposits, and other resources. Approximately 0.5 Moz of gold have been recovered from a resource of 1,639,000 oz of gold in Carlin-type gold deposits in lower plate, miogeoclinal carbonate rocks below the Roberts Mountains thrust. Host rocks are unit 2 of the Upper Member of the Devonian Denay Formation and the Bartine Member of the McColley Canyon Formation. Spatial and temporal relations between structures and gold mineralization indicate that both pre-Tertiary and Tertiary structures were important controls on gold mineralization. Gold mineralization occurs primarily along high-angle Tertiary normal faults, some of which are reactivated reverse faults of Paleozoic or Mesozoic age. Most deposits are localized at the intersection of northwest- and northeast-striking faults. Alteration includes decalcification, and to a lesser extent, silicification along high-angle faults. Jasperoid (pervasive silicification), which formed along most faults and in some strata-bound zones, accounts for a small portion of the ore in every deposit. In the Gold Canyon deposit, a high-grade jasperoid pipe formed along a Tertiary normal fault which was localized along a zone of overturned fault-propagation folds and thrust faults of Paleozoic or Mesozoic age.
","language":"English","publisher":"Society of Economic Geologists","doi":"10.2113/gsecongeo.98.6.1173","issn":"03610128","usgsCitation":"Yigit, O., Nelson, E., Hitzman, M., and Hofstra, A., 2003, Structural controls on Carlin-type gold mineralization in the gold bar district, Eureka County, Nevada: Economic Geology, v. 98, no. 6, p. 1173-1188, https://doi.org/10.2113/gsecongeo.98.6.1173.","productDescription":"16 p.","startPage":"1173","endPage":"1188","costCenters":[],"links":[{"id":235809,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"country":"United States","state":"Nevada","city":"Eureka","geographicExtents":"{\n \"type\": \"FeatureCollection\",\n \"features\": [\n {\n \"type\": \"Feature\",\n \"properties\": {},\n \"geometry\": {\n \"type\": \"Polygon\",\n \"coordinates\": [\n [\n [\n -116.3177490234375,\n 39.232253141714885\n ],\n [\n -115.697021484375,\n 39.232253141714885\n ],\n [\n -115.697021484375,\n 39.787433886224406\n ],\n [\n -116.3177490234375,\n 39.787433886224406\n ],\n [\n -116.3177490234375,\n 39.232253141714885\n ]\n ]\n ]\n }\n }\n ]\n}","volume":"98","issue":"6","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505b9bdce4b08c986b31d121","contributors":{"authors":[{"text":"Yigit, O.","contributorId":54383,"corporation":false,"usgs":true,"family":"Yigit","given":"O.","email":"","affiliations":[],"preferred":false,"id":404318,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Nelson, E.P.","contributorId":53577,"corporation":false,"usgs":true,"family":"Nelson","given":"E.P.","email":"","affiliations":[],"preferred":false,"id":404317,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Hitzman, M.W.","contributorId":107906,"corporation":false,"usgs":true,"family":"Hitzman","given":"M.W.","affiliations":[],"preferred":false,"id":404319,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Hofstra, A. H. 0000-0002-2450-1593","orcid":"https://orcid.org/0000-0002-2450-1593","contributorId":41426,"corporation":false,"usgs":true,"family":"Hofstra","given":"A. H.","affiliations":[],"preferred":false,"id":404316,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}} ,{"id":70025233,"text":"70025233 - 2003 - Numerical modeling of coupled nitrification-denitrification in sediment perfusion cores from the hyporheic zone of the Shingobee River, MN","interactions":[],"lastModifiedDate":"2018-11-19T09:45:02","indexId":"70025233","displayToPublicDate":"2003-01-01T00:00:00","publicationYear":"2003","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":"Numerical modeling of coupled nitrification-denitrification in sediment perfusion cores from the hyporheic zone of the Shingobee River, MN","docAbstract":"Nitrification and denitrification kinetics in sediment perfusion cores were numerically modeled and compared to experiments on cores from the Shingobee River MN, USA. The experimental design incorporated mixing groundwater discharge with stream water penetration into the cores, which provided a well-defined, one-dimensional simulation of in situ hydrologic conditions. Ammonium (NH4+) and nitrate (NO3−) concentration gradients suggested the upper region of the cores supported coupled nitrification–denitrification, where groundwater-derived NH4+ was first oxidized to NO3− then subsequently reduced via denitrification to N2. Nitrification and denitrification were modeled using a Crank–Nicolson finite difference approximation to a one-dimensional advection–dispersion equation. Both processes were modeled using first-order reaction kinetics because substrate concentrations (NH4+ and NO3−) were much smaller than published Michaelis constants. Rate coefficients for nitrification and denitrification ranged from 0.2 to 15.8 h−1 and 0.02 to 8.0 h−1, respectively. The rate constants followed an Arrhenius relationship between 7.5 and 22 °C. Activation energies for nitrification and denitrification were 162 and 97.3 kJ/mol, respectively. Seasonal NH4+ concentration patterns in the Shingobee River were accurately simulated from the relationship between perfusion core temperature and NH4+ flux to the overlying water. The simulations suggest that NH4+ in groundwater discharge is controlled by sediment nitrification that, consistent with its activation energy, is strongly temperature dependent.
The 1994 Double Spring Flat earthquake (Mw 5.8) occurred within a densely faulted step-over between the Genoa and Antelope Valley faults, two principal normal faults of the transition zone between the Basin and Range Province and the northern Sierra Nevada. The earthquake created zones of ground cracks from 0.1 to 2.8 km long along at least five northwest- to north-northwest-striking faults in the epicentral area. Individual cracks had extensional openings generally from 1 to 10 mm wide. No cracks displayed obvious vertical separation, and only one zone showed permissive evidence of right-lateral separation. Over the 8 days following the mainshock (the period over which the cracks were found), aftershocks formed a dominant northeast trend suggesting the earthquake occurred along a northeast-striking structure. However, no ground breakage was found along faults striking parallel to this northeast aftershock alignment, and subsequent aftershocks formed a conjugate northwest trend. Based on the location and character of the five zones, the observed cracks are attributed to secondary fault slip and shaking effects. The earthquake also created ground cracks along at least two faults 15-25 km from the epicenter. In both of these cases, the faults had documented histories of prior ground cracking, indicating that they are particularly susceptible to such triggered deformation.
","language":"English","publisher":"Seismological Society of America","doi":"10.1785/0120020177","issn":"00371106","usgsCitation":"Ramelli, A., DePolo, C., and Yount, J.C., 2003, Ground cracks associated with the 1994 double spring flat earthquake, west-central Nevada: Bulletin of the Seismological Society of America, v. 93, no. 6, p. 2762-2768, https://doi.org/10.1785/0120020177.","productDescription":"7 p.","startPage":"2762","endPage":"2768","costCenters":[],"links":[{"id":387426,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"93","issue":"6","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a2a8fe4b0c8380cd5b290","contributors":{"authors":[{"text":"Ramelli, A. R.","contributorId":100564,"corporation":false,"usgs":true,"family":"Ramelli","given":"A. R.","affiliations":[],"preferred":false,"id":404519,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"DePolo, C.M.","contributorId":74533,"corporation":false,"usgs":true,"family":"DePolo","given":"C.M.","email":"","affiliations":[],"preferred":false,"id":404518,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Yount, J. C.","contributorId":69553,"corporation":false,"usgs":true,"family":"Yount","given":"J.","middleInitial":"C.","affiliations":[],"preferred":false,"id":404517,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70025285,"text":"70025285 - 2003 - Extensive deposits on the Pacific plate from Late Pleistocene North American glacial lake outbursts","interactions":[],"lastModifiedDate":"2021-08-16T23:08:12.729574","indexId":"70025285","displayToPublicDate":"2003-01-01T00:00:00","publicationYear":"2003","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2309,"text":"Journal of Geology","active":true,"publicationSubtype":{"id":10}},"title":"Extensive deposits on the Pacific plate from Late Pleistocene North American glacial lake outbursts","docAbstract":"One of the major unresolved issues of the Late Pleistocene catastrophic-flood events in the northwestern United States (e.g., from glacial Lake Missoula) has been what happened when the flood discharge reached the ocean. This study compiles available 3.5-kHz high-resolution and airgun seismic reflection data, long-range sidescan sonar images, and sediment core data to define the distribution of flood sediment in deepwater areas of the Pacific Ocean. Upon reaching the ocean at the mouth of the Columbia River near the present-day upper continental slope, sediment from the catastrophic floods continued flowing downslope as hyperpycnally generated turbidity currents. The turbidity currents resulting from the Lake Missoula and other latest Pleistocene floods followed the Cascadia Channel into and through the Blanco Fracture Zone and then flowed west to the Tufts Abyssal Plain. A small part of the flood sediment, which was stripped off the main flow at a bend in the Cascadia Channel at its exit point from the Blanco Fracture Zone, continued flowing more than 400 km to the south and reached the Escanaba Trough, a rift valley of the southern Gorda Ridge. Understanding the development of the pathway for the Late Pleistocene flood sediment reaching Escanaba Trough provides insight for understanding the extent of catastrophic flood deposits on the Pacific plate.
","language":"English","publisher":"University of Chicago Press","doi":"10.1086/378334","issn":"00221376","usgsCitation":"Normark, W.R., and Reid, J., 2003, Extensive deposits on the Pacific plate from Late Pleistocene North American glacial lake outbursts: Journal of Geology, v. 111, no. 6, p. 617-637, https://doi.org/10.1086/378334.","productDescription":"21 p.","startPage":"617","endPage":"637","costCenters":[],"links":[{"id":387964,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"111","issue":"6","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a0e46e4b0c8380cd5339e","contributors":{"authors":[{"text":"Normark, W. R.","contributorId":87137,"corporation":false,"usgs":true,"family":"Normark","given":"W.","email":"","middleInitial":"R.","affiliations":[],"preferred":false,"id":404610,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Reid, J.A.","contributorId":90907,"corporation":false,"usgs":true,"family":"Reid","given":"J.A.","email":"","affiliations":[],"preferred":false,"id":404611,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70025294,"text":"70025294 - 2003 - Effect of isolated fractures on accelerated flow in unsaturated porous rock","interactions":[],"lastModifiedDate":"2018-11-16T10:11:08","indexId":"70025294","displayToPublicDate":"2003-01-01T00:00:00","publicationYear":"2003","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":"Effect of isolated fractures on accelerated flow in unsaturated porous rock","docAbstract":"Fractures that begin and end in the unsaturated zone, or isolated fractures, have been ignored in previous studies because they were generally assumed to behave as capillary barriers and remain nonconductive. We conducted a series of experiments using Berea sandstone samples to examine the physical mechanisms controlling flow in a rock containing a single isolated fracture. The input fluxes and fracture orientation were varied in these experiments. Visualization experiments using dyed water in a thin vertical slab of rock were conducted to identify flow mechanisms occurring due to the presence of the isolated fracture. Two mechanisms occurred: (1) localized flow through the rock matrix in the vicinity of the isolated fracture and (2) pooling of water at the bottom of the fracture, indicating the occurrence of film flow along the isolated fracture wall. These mechanisms were observed at fracture angles of 20 and 60 degrees from the horizontal, but not at 90 degrees. Pooling along the bottom of the fracture was observed over a wider range of input fluxes for low‐angled isolated fractures compared to high‐angled ones. Measurements of matrix water pressures in the samples with the 20 and 60 degree fractures also demonstrated that preferential flow occurred through the matrix in the fracture vicinity, where higher pressures occurred in the regions where faster flow was observed in the visualization experiments. The pooling length at the terminus of a 20 degree isolated fracture was measured as a function of input flux. Calculations of the film flow rate along the fracture were made using these measurements and indicated that up to 22% of the flow occurred as film flow. These experiments, apparently the first to consider isolated fractures, demonstrate that such features can accelerate flow through the unsaturated zone and should be considered when developing conceptual models.
","language":"English","publisher":"American Geophysical Union","doi":"10.1029/2002WR001691","usgsCitation":"Su, G.W., Nimmo, J.R., and Dragila, M.I., 2003, Effect of isolated fractures on accelerated flow in unsaturated porous rock: Water Resources Research, v. 39, no. 12, p. 1-1-1-5, https://doi.org/10.1029/2002WR001691.","productDescription":"Article 1326; 5 p.","startPage":"1-1","endPage":"1-5","costCenters":[{"id":589,"text":"Toxic Substances Hydrology Program","active":true,"usgs":true}],"links":[{"id":478538,"rank":1,"type":{"id":40,"text":"Open Access Publisher Index Page"},"url":"https://doi.org/10.1029/2002wr001691","text":"Publisher Index Page"},{"id":235693,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"39","issue":"12","noUsgsAuthors":false,"publicationDate":"2003-12-02","publicationStatus":"PW","scienceBaseUri":"505a05f0e4b0c8380cd51033","contributors":{"authors":[{"text":"Su, Grace W.","contributorId":145734,"corporation":false,"usgs":false,"family":"Su","given":"Grace","email":"","middleInitial":"W.","affiliations":[{"id":595,"text":"U.S. Geological Survey","active":false,"usgs":true}],"preferred":false,"id":404652,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Nimmo, John R. 0000-0001-8191-1727 jrnimmo@usgs.gov","orcid":"https://orcid.org/0000-0001-8191-1727","contributorId":757,"corporation":false,"usgs":true,"family":"Nimmo","given":"John","email":"jrnimmo@usgs.gov","middleInitial":"R.","affiliations":[{"id":438,"text":"National Research Program - Western Branch","active":true,"usgs":true},{"id":37277,"text":"WMA - Earth System Processes Division","active":true,"usgs":true}],"preferred":true,"id":404653,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Dragila, Maria I.","contributorId":8657,"corporation":false,"usgs":false,"family":"Dragila","given":"Maria","email":"","middleInitial":"I.","affiliations":[],"preferred":false,"id":404651,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70025303,"text":"70025303 - 2003 - Conceptual model for transferring information between small watersheds","interactions":[],"lastModifiedDate":"2012-03-12T17:20:29","indexId":"70025303","displayToPublicDate":"2003-01-01T00:00:00","publicationYear":"2003","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1539,"text":"Environmental Geology","active":true,"publicationSubtype":{"id":10}},"title":"Conceptual model for transferring information between small watersheds","docAbstract":"Stream and watershed management and restoration can be greatly facilitated through use of physiographic landform classification to organize and communicate natural resource, hazard, and environmental information at a broad scale (1:250,000) as illustrated by the Piedmont and Coastal Plain Provinces in Maryland, or at a small scale (1:24,000) as illustrated using divisions and zones combined with a conceptual model. The conceptual model brings together geology, surficial processes, landforms and land use change information at the small watershed scale and facilitates transfer of information from one small watershed to another with similar geology and landforms. Stream flow, sediment erosion, and water quality illustrate the use of the model.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Environmental Geology","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1007/s00254-003-0872-4","issn":"09430105","usgsCitation":"Cleaves, E., 2003, Conceptual model for transferring information between small watersheds: Environmental Geology, v. 45, no. 2, p. 190-197, https://doi.org/10.1007/s00254-003-0872-4.","startPage":"190","endPage":"197","numberOfPages":"8","costCenters":[],"links":[{"id":209406,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1007/s00254-003-0872-4"},{"id":235814,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"45","issue":"2","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"5059f9a9e4b0c8380cd4d6f9","contributors":{"authors":[{"text":"Cleaves, E.T.","contributorId":41148,"corporation":false,"usgs":true,"family":"Cleaves","given":"E.T.","email":"","affiliations":[],"preferred":false,"id":404688,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}} ,{"id":70025304,"text":"70025304 - 2003 - Effects of ammonia on juvenile unionid mussels (Lampsilis cardium) in laboratory sediment toxicity tests","interactions":[],"lastModifiedDate":"2012-12-18T15:19:26","indexId":"70025304","displayToPublicDate":"2003-01-01T00:00:00","publicationYear":"2003","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1571,"text":"Environmental Toxicology and Chemistry","active":true,"publicationSubtype":{"id":10}},"title":"Effects of ammonia on juvenile unionid mussels (Lampsilis cardium) in laboratory sediment toxicity tests","docAbstract":"Ammonia is a relatively toxic compound generated in water and sediments by heterotrophic bacteria and accumulates in sediments and pore water. Recent data suggest that unionid mussels are sensitive to un-ionized ammonia (NH3) relative to other organisms. Existing sediment exposure systems are not suitable for ammonia toxicity studies with juvenile unionids; thus, we modified a system to expose juveniles to ammonia that was continuously infused into sediments. This system maintained consistent concentrations of ammonia in pore water up to 10 d. Juvenile Lampsilis cardium mussels were exposed to NH3 in pore water in replicate 96-h and 10-d sediment toxicity tests. The 96-h median lethal concentrations (LC50s) were 127 and 165 μg NH3-N/L, and the 10-d LC50s were 93 and 140 μg NH3-N/L. The median effective concentrations (EC50s) (based on the proportion affected, including dead and inactive mussels) were 73 and 119 μg NH3-N/L in the 96-h tests and 71 and 99 μg NH3-N/L in the 10-d tests. Growth rate was substantially reduced at concentrations between 31 and 76 μg NH3-N/L. The lethality results (when expressed as total ammonia) are about one-half the acute national water quality criteria for total ammonia, suggesting that existing criteria may not protect juvenile unionids.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Environmental Toxicology and Chemistry","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","publisher":"Wiley","publisherLocation":"Hoboken, NJ","doi":"10.1897/02-342","issn":"07307268","usgsCitation":"Newton, T., Allran, J.W., O’Donnell, J.A., Bartsch, M., and Richardson, W.B., 2003, Effects of ammonia on juvenile unionid mussels (Lampsilis cardium) in laboratory sediment toxicity tests: Environmental Toxicology and Chemistry, v. 22, no. 11, p. 2554-2560, https://doi.org/10.1897/02-342.","productDescription":"7 p.","startPage":"2554","endPage":"2560","numberOfPages":"7","costCenters":[{"id":606,"text":"Upper Midwest Environmental Sciences Center","active":true,"usgs":true}],"links":[{"id":209423,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1897/02-342"},{"id":235850,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"country":"United States","volume":"22","issue":"11","noUsgsAuthors":false,"publicationDate":"2003-11-01","publicationStatus":"PW","scienceBaseUri":"505a0686e4b0c8380cd512ac","contributors":{"authors":[{"text":"Newton, Teresa J. 0000-0001-9351-5852","orcid":"https://orcid.org/0000-0001-9351-5852","contributorId":78696,"corporation":false,"usgs":true,"family":"Newton","given":"Teresa J.","affiliations":[{"id":606,"text":"Upper Midwest Environmental Sciences Center","active":true,"usgs":true}],"preferred":true,"id":404691,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Allran, John W.","contributorId":97297,"corporation":false,"usgs":true,"family":"Allran","given":"John","email":"","middleInitial":"W.","affiliations":[],"preferred":false,"id":404693,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"O’Donnell, Jonathan A.","contributorId":84138,"corporation":false,"usgs":true,"family":"O’Donnell","given":"Jonathan","email":"","middleInitial":"A.","affiliations":[],"preferred":false,"id":404692,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Bartsch, Michelle 0000-0002-9571-5564 mbartsch@usgs.gov","orcid":"https://orcid.org/0000-0002-9571-5564","contributorId":3165,"corporation":false,"usgs":true,"family":"Bartsch","given":"Michelle","email":"mbartsch@usgs.gov","affiliations":[{"id":606,"text":"Upper Midwest Environmental Sciences Center","active":true,"usgs":true}],"preferred":true,"id":404689,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Richardson, William B. 0000-0002-7471-4394 wrichardson@usgs.gov","orcid":"https://orcid.org/0000-0002-7471-4394","contributorId":3277,"corporation":false,"usgs":true,"family":"Richardson","given":"William","email":"wrichardson@usgs.gov","middleInitial":"B.","affiliations":[{"id":606,"text":"Upper Midwest Environmental Sciences Center","active":true,"usgs":true}],"preferred":true,"id":404690,"contributorType":{"id":1,"text":"Authors"},"rank":5}]}} ,{"id":70025326,"text":"70025326 - 2003 - A new pterosaur tracksite from the Jurassic Summerville formation, near Ferron, Utah","interactions":[],"lastModifiedDate":"2018-03-06T15:27:20","indexId":"70025326","displayToPublicDate":"2003-01-01T00:00:00","publicationYear":"2003","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1965,"text":"Ichnos: An International Journal for Plant and Animal Traces","onlineIssn":"1563-5236","printIssn":"1042-0940","active":true,"publicationSubtype":{"id":10}},"title":"A new pterosaur tracksite from the Jurassic Summerville formation, near Ferron, Utah","docAbstract":"Pterosaur tracks (cf. Pteraichnus) from the Summerville Formation of the Ferron area of central Utah add to the growing record of Pteraichnus tracksites in the Late Jurassic Summerville Formation and time-equivalent, or near time-equivalent, deposits. The site is typical in revealing high pterosaur track densities, but low ichnodiversity suggesting congregations or “flocks” of many individuals. Footprint length varies from 2.0 to 7.0 cms. The ratio of well-preserved pes:manus tracks is about 1:3.4. This reflects a bias in favor of preservation of manus tracks due to the greater weight-bearing role of the front limbs, as noted in other pterosaur track assemblages. The sample also reveals a number of well-preserved trackways including one suggestive of pes-only progression that might be associated with take off or landing, and another that shows pronounced lengthening of stride indicating acceleration.
One well-preserved medium-sized theropod trackway (Therangospodus) and other larger theropod track casts (cf. Megalosauripus) are associated with what otherwise appears to be a nearly monospecific pterosaur track assemblage. However, traces of a fifth pes digit suggest some tracks are of rhamphorynchoid rather than pterodactyloid origin, as usually inferred for Pteraichnus. The tracks occur at several horizons in a thin stratigraphic interval of ripple marked sandstones and siltstones. Overall the assemblage is similar to others found in the same time interval in the Western Interior from central and eastern Utah through central and southern Wyoming, Colorado, northeastern Arizona, and western Oklahoma. This vast “Pteraichnusichnofacies,” with associated saurischian tracks, remains the only ichnological evidence of pre-Cretaceous pterosaurs in North America and sheds important light on the vertebrate ecology of the Summerville Formation and contiguous deposits.
","language":"English","publisher":"Taylor & Francis","doi":"10.1080/10420940490445437","usgsCitation":"Mickelson, D.L., Lockley, M.G., Bishop, J., and Kirkland, J.I., 2003, A new pterosaur tracksite from the Jurassic Summerville formation, near Ferron, Utah: Ichnos: An International Journal for Plant and Animal Traces, v. 11, no. 1-2, p. 125-142, https://doi.org/10.1080/10420940490445437.","productDescription":"18 p.","startPage":"125","endPage":"142","costCenters":[],"links":[{"id":236185,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"country":"United States","state":"Utah","city":"Ferron","volume":"11","issue":"1-2","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"5059e4aee4b0c8380cd46835","contributors":{"authors":[{"text":"Mickelson, Debra L.","contributorId":29987,"corporation":false,"usgs":false,"family":"Mickelson","given":"Debra","email":"","middleInitial":"L.","affiliations":[{"id":6713,"text":"University of Colorado, Boulder CO","active":true,"usgs":false}],"preferred":false,"id":404767,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Lockley, Martin G.","contributorId":22428,"corporation":false,"usgs":false,"family":"Lockley","given":"Martin","email":"","middleInitial":"G.","affiliations":[],"preferred":false,"id":404768,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Bishop, John","contributorId":146771,"corporation":false,"usgs":false,"family":"Bishop","given":"John","email":"","affiliations":[],"preferred":false,"id":404770,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Kirkland, James I.","contributorId":173915,"corporation":false,"usgs":false,"family":"Kirkland","given":"James","email":"","middleInitial":"I.","affiliations":[{"id":17626,"text":"Utah Geological Survey","active":true,"usgs":false}],"preferred":false,"id":404769,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}} ,{"id":70025408,"text":"70025408 - 2003 - Binding of mercury(II) to aquatic humic substances: Influence of pH and source of humic substances","interactions":[],"lastModifiedDate":"2018-11-19T08:30:27","indexId":"70025408","displayToPublicDate":"2003-01-01T00:00:00","publicationYear":"2003","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":"Binding of mercury(II) to aquatic humic substances: Influence of pH and source of humic substances","docAbstract":"Conditional distribution coefficients (KDOM‘) for Hg(II) binding to seven dissolved organic matter (DOM) isolates were measured at environmentally relevant ratios of Hg(II) to DOM. The results show that KDOM‘ values for different types of samples (humic acids, fulvic acids, hydrophobic acids) isolated from diverse aquatic environments were all within 1 order of magnitude (1022.5±1.0−1023.5±1.0 L kg-1), suggesting similar Hg(II) binding environments, presumably involving thiol groups, for the different isolates. KDOM‘ values decreased at low pHs (4) compared to values at pH 7, indicating proton competition for the strong Hg(II) binding sites. Chemical modeling of Hg(II)−DOM binding at different pH values was consistent with bidentate binding of Hg(II) by one thiol group (pKa = 10.3) and one other group (pKa = 6.3) in the DOM, which is in agreement with recent results on the structure of Hg(II)−DOM bonds obtained by extended X-ray absorption fine structure spectroscopy (EXAFS).
High-quality seismic reflection profiles fill a major gap in geophysical data along the south Florida shelf, allowing updated interpretations of the history of the Quaternary coral reef system. Incorporation of the new and existing data sets provides the basis for detailed color maps of the Pleistocene surface and thickness of overlying Holocene accretions. The maps cover the Florida Keys to a margin-wide upper-slope terrace (30 to 40 m deep) and extend from The Elbow Reef (north Key Largo) to Rebecca Shoal (Gulf of Mexico). The data indicate that Pleistocene bedrock is several meters deeper to the southwest than to the northeast, yet in general, Holocene sediments are ~3 to 4 m thick shelf-wide. The Pleistocene map demonstrates the significance of a westward-dipping bedrock surface to Holocene flooding history and coral reef evolution. Seismic facies show evidence for two possible Holocene stillstands. Aerial photographs provide information on the seabed surface, much of which is below seismic resolution. The photographs define a prominent, regional nearshore rock ledge that extends ~2.5 km seaward from the keys' shoreline. They show that bands of rock ridges exist along the outer shelf and on the upper-slope terrace. The photographs also reveal four tracts of outlier reefs on the terrace, one more than had been documented seismically. Seismic and photographic data indicate the tracts are >200 km long, nearly four times longer than previously thought. New interpretations provide insights into a youngest possible terrace age (ca. 175 ka?) and the likelihood that precise ages of oxygen isotope substage 5e ooid tidal-bar and coral reef components may differ. The tidal-bar/reef complex forms the Florida Keys.
","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Geological Society of America Bulletin","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1130/0016-7606(2003)115<0845:RQSGIT>2.0.CO;2","issn":"00167606","usgsCitation":"Lidz, B.H., Reich, C., and Shinn, E., 2003, Regional quaternary submarine geomorphology in the Florida Keys: Geological Society of America Bulletin, v. 115, no. 7, p. 845-866, https://doi.org/10.1130/0016-7606(2003)115<0845:RQSGIT>2.0.CO;2.","startPage":"845","endPage":"866","numberOfPages":"22","costCenters":[],"links":[{"id":235666,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":209342,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1130/0016-7606(2003)115<0845:RQSGIT>2.0.CO;2"}],"volume":"115","issue":"7","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"50e4a54be4b0e8fec6cdbddd","contributors":{"authors":[{"text":"Lidz, B. H.","contributorId":30651,"corporation":false,"usgs":true,"family":"Lidz","given":"B.","email":"","middleInitial":"H.","affiliations":[],"preferred":false,"id":405067,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Reich, C. D. 0000-0002-2534-1456","orcid":"https://orcid.org/0000-0002-2534-1456","contributorId":36978,"corporation":false,"usgs":true,"family":"Reich","given":"C. D.","affiliations":[],"preferred":false,"id":405068,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Shinn, E.A.","contributorId":38610,"corporation":false,"usgs":true,"family":"Shinn","given":"E.A.","email":"","affiliations":[],"preferred":false,"id":405069,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70025420,"text":"70025420 - 2003 - Analysis of aquifer mineralization by paleodrainage channels","interactions":[],"lastModifiedDate":"2012-03-12T17:20:30","indexId":"70025420","displayToPublicDate":"2003-01-01T00:00:00","publicationYear":"2003","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":"Analysis of aquifer mineralization by paleodrainage channels","docAbstract":"Mineralization of groundwater resources is a problem in south-central Kansas, due to the penetration of saline water from Permian bedrock formations into the overlying alluvial aquifer. One of the mechanisms involved in the mineralization involves small bedrock features of high permeability located in places occupied by streams and rivers in past geological eras. These geological features are termed 'paleodrainage channels'. The permeability of the overlying aquifer can be significantly smaller than that of the channel fill material. The comparatively fast migration of saline water through these channels of high permeability is associated with the transfer of minerals into the overlying freshwater aquifer. This study applies a set of boundary layer approaches to quantify the process of mineral transfer from the channels into the aquifer. The methods used in the present study provide quick estimation and evaluation of the dilution of the channel flow, as well as mineral concentration profile changes in the mineralized zone created in the overlying aquifer. More generally, the method can also be useful for the analysis and evaluation of various types of groundwater contamination in heterogeneous aquifers. The application of the method is exemplified by a complete set of calculations characterizing the possible mineralization process at a specific channel in south central Kansas. Sensitivity analyses are performed and provide information about the importance of the various parameters that affect the mineralization process. Some possible scenarios for the aquifer mineralization phenomena are described and evaluated. It is shown that the channel mineralization may create either several stream tubes of the aquifer with high mineral concentration, or many stream tubes mineralized to a lesser extent. Characteristics of these two patterns of aquifer mineralization are quantified and discussed. ?? 2003 Published by Elsevier Science B.V.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Journal of Hydrology","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1016/S0022-1694(03)00123-9","issn":"00221694","usgsCitation":"Rubin, H., and Buddemeier, R., 2003, Analysis of aquifer mineralization by paleodrainage channels: Journal of Hydrology, v. 277, no. 3-4, p. 280-304, https://doi.org/10.1016/S0022-1694(03)00123-9.","startPage":"280","endPage":"304","numberOfPages":"25","costCenters":[],"links":[{"id":209408,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/S0022-1694(03)00123-9"},{"id":235821,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"277","issue":"3-4","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"5059eb06e4b0c8380cd48b78","contributors":{"authors":[{"text":"Rubin, H.","contributorId":54358,"corporation":false,"usgs":true,"family":"Rubin","given":"H.","email":"","affiliations":[],"preferred":false,"id":405103,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Buddemeier, R. W.","contributorId":86492,"corporation":false,"usgs":true,"family":"Buddemeier","given":"R. W.","affiliations":[],"preferred":false,"id":405104,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70025431,"text":"70025431 - 2003 - Metabolic and structural response of hyporheic microbial communities to variations in supply of dissolved organic matter","interactions":[],"lastModifiedDate":"2021-08-21T19:25:15.039165","indexId":"70025431","displayToPublicDate":"2003-01-01T00:00:00","publicationYear":"2003","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":"Metabolic and structural response of hyporheic microbial communities to variations in supply of dissolved organic matter","docAbstract":"Hyporheic sediment bacterial communities were exposed to dissolved organic matter (DOM) from a variety of sources to assess the interdependence of bacterial metabolism and community composition. Experiments ranged from small-scale core perfusions with defined compounds (glucose, bovine serum albumin) to mesocosms receiving natural leaf leachate or water from different streams. Response variables included bacterial production, oxygen consumption, extracellular enzyme activity, and community similarity as manifest by changes in banding patterns of randomly amplified polymorphic DNA (RAPD). All DOM manipulations generated responses in at least one metabolic variable. Additions of both labile and recalcitrant materials increased either oxygen consumption, production, or both depending on background DOM. Enzyme activities were affected by both types of carbon addition with largest effects from the labile mixture. Cluster analysis of RAPD data showed strong divergence of communities exposed to labile versus recalcitrant DOM. Additions of leaf leachate to mesocosms representing hyporheic flow-paths caused increases in oxygen consumption and some enzyme activities with weaker effects on production. Community structure yeas strongly affected; samples from the leachate-amended mesocosms clustered separately from the control samples. In mesocosms receiving water from streams ranging in DOC (0.5-4.5 mg L-1), there were significant differences in bacterial growth, oxygen consumption, and enzyme activities. RAPD analysis showed strongest clustering of samples by stream type with more subtle effects of position along the flowpaths. Responses in community metabolism were always accompanied by shifts in community composition, suggesting carbon supply affects both functional and structural attributes of hyporheic bacterial communities.
","language":"English","publisher":"Association for the Sciences of Limnology and Oceanography","doi":"10.4319/lo.2003.48.4.1608","issn":"00243590","usgsCitation":"Findlay, S., Sinsabaugh, R.L., Sobczak, W.V., and Hoostal, M., 2003, Metabolic and structural response of hyporheic microbial communities to variations in supply of dissolved organic matter: Limnology and Oceanography, v. 48, no. 4, p. 1608-1617, https://doi.org/10.4319/lo.2003.48.4.1608.","productDescription":"10 p.","startPage":"1608","endPage":"1617","costCenters":[],"links":[{"id":478453,"rank":0,"type":{"id":40,"text":"Open Access Publisher Index Page"},"url":"https://doi.org/10.4319/lo.2003.48.4.1608","text":"Publisher Index Page"},{"id":388310,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"48","issue":"4","noUsgsAuthors":false,"publicationDate":"2003-07-16","publicationStatus":"PW","scienceBaseUri":"505a545ee4b0c8380cd6cf6f","contributors":{"authors":[{"text":"Findlay, S.E.G.","contributorId":10531,"corporation":false,"usgs":true,"family":"Findlay","given":"S.E.G.","email":"","affiliations":[],"preferred":false,"id":405141,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Sinsabaugh, R. L.","contributorId":30784,"corporation":false,"usgs":false,"family":"Sinsabaugh","given":"R.","email":"","middleInitial":"L.","affiliations":[{"id":7164,"text":"Department of Biology, University of New Mexico, Albuquerque, NM 87131 USA","active":true,"usgs":false}],"preferred":false,"id":405143,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Sobczak, W. V.","contributorId":41983,"corporation":false,"usgs":true,"family":"Sobczak","given":"W.","email":"","middleInitial":"V.","affiliations":[],"preferred":false,"id":405144,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Hoostal, M.","contributorId":18555,"corporation":false,"usgs":true,"family":"Hoostal","given":"M.","email":"","affiliations":[],"preferred":false,"id":405142,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}} ,{"id":70025434,"text":"70025434 - 2003 - Long-term, high-frequency current and temperature measurements along central California: Insights into upwelling/relaxation and internal waves on the inner shelf","interactions":[],"lastModifiedDate":"2012-03-12T17:20:59","indexId":"70025434","displayToPublicDate":"2003-01-01T00:00:00","publicationYear":"2003","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":"Long-term, high-frequency current and temperature measurements along central California: Insights into upwelling/relaxation and internal waves on the inner shelf","docAbstract":"Thermistor chains and acoustic Doppler current profilers were deployed at the northern and southern ends of Monterey Bay to examine the thermal and hydrodynamic structure of the inner (h ??? 20 m) shelf of central California. These instruments sampled temperature and current velocity at 2-min intervals over a 13-month period from June 2000 to July 2001. Time series of these data, in conjunction with SST imagery and CODAR sea surface current maps, helped to establish the basic hydrography for Monterey Bay. Analysis of time series data revealed that depth integrated flow at both sites was shore parallel (northwest-southeast) with net flows out of the Bay (northwest). The current and temperature records were dominated by semi-diurnal and diurnal tidal signals that lagged the surface tides by 3 h on average. Over the course of an internal tidal cycle these flows were asymmetric, with the flow during the flooding internal tide to the southeast typically lasting only one-third as long as the flow to the northwest during the ebbing internal tide. The transitions from ebb to flood were rapid and bore-like in nature; they were also marked by rapid increases in temperature and high shear. During the spring and summer, when thermal stratification was high, we observed almost 2000 high-frequency (Tp ??? 4-20 min) internal waves in packets of 8-10 following the heads of these bore-like features. Previous studies along the West Coast of the US have concluded that warm water bores and high-frequency internal waves may play a significant role in the onshore transport of larvae.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Continental Shelf Research","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1016/S0278-4343(03)00045-1","issn":"02784343","usgsCitation":"Storlazzi, C., McManus, M., and Figurski, J., 2003, Long-term, high-frequency current and temperature measurements along central California: Insights into upwelling/relaxation and internal waves on the inner shelf: Continental Shelf Research, v. 23, no. 9, p. 901-918, https://doi.org/10.1016/S0278-4343(03)00045-1.","startPage":"901","endPage":"918","numberOfPages":"18","costCenters":[],"links":[{"id":209507,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/S0278-4343(03)00045-1"},{"id":236044,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"23","issue":"9","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a49b4e4b0c8380cd6880b","contributors":{"authors":[{"text":"Storlazzi, C. D. 0000-0001-8057-4490","orcid":"https://orcid.org/0000-0001-8057-4490","contributorId":98905,"corporation":false,"usgs":true,"family":"Storlazzi","given":"C. D.","affiliations":[],"preferred":false,"id":405153,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"McManus, M.A.","contributorId":73390,"corporation":false,"usgs":true,"family":"McManus","given":"M.A.","email":"","affiliations":[],"preferred":false,"id":405151,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Figurski, J.D.","contributorId":80853,"corporation":false,"usgs":true,"family":"Figurski","given":"J.D.","affiliations":[],"preferred":false,"id":405152,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70025462,"text":"70025462 - 2003 - Local extinction and turnover rates at the edge and interior of species' ranges","interactions":[],"lastModifiedDate":"2012-03-12T17:20:30","indexId":"70025462","displayToPublicDate":"2003-01-01T00:00:00","publicationYear":"2003","noYear":false,"publicationType":{"id":24,"text":"Conference Paper"},"publicationSubtype":{"id":19,"text":"Conference Paper"},"title":"Local extinction and turnover rates at the edge and interior of species' ranges","docAbstract":"One hypothesis for the maintenance of the edge of a species' range suggests that more central (and abundant) populations are relatively stable and edge populations are less stable with increased local extinction and turnover rates. To date, estimates of such metrics are equivocal due to design and analysis flaws. Apparent increased estimates of extinction and turnover rates at the edge of range, versus the interior, could be a function of decreased detection probabilities alone, and not of a biological process. We estimated extinction and turnover rates for species at the interiors and edges of their ranges using an approach which incorporates potential heterogeneity in species detection probabilities. Extinction rates were higher at the edges (0.17 ?? 0.03 []) than in the interiors (0.04 ?? 0.01), as was turnover. Without taking the probability of detection into account these differences would be artificially magnified. Knowledge of extinction and turnover rates is essential in furthering our understanding of range dynamics, and in directing conservation efforts. This study further illustrates the practical application of methods proposed recently for estimating extinction rates and other community dynamic parameters.","largerWorkTitle":"Annales Zoologici Fennici","language":"English","issn":"0003455X","usgsCitation":"Doherty, P., Boulinier, T., and James., D.N., 2003, Local extinction and turnover rates at the edge and interior of species' ranges, in Annales Zoologici Fennici, v. 40, no. 2, p. 145-153.","startPage":"145","endPage":"153","numberOfPages":"9","costCenters":[],"links":[{"id":235862,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"40","issue":"2","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a48dbe4b0c8380cd6819b","contributors":{"authors":[{"text":"Doherty, P.F. Jr.","contributorId":74096,"corporation":false,"usgs":true,"family":"Doherty","given":"P.F.","suffix":"Jr.","email":"","affiliations":[],"preferred":false,"id":405286,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Boulinier, T.","contributorId":37845,"corporation":false,"usgs":true,"family":"Boulinier","given":"T.","email":"","affiliations":[],"preferred":false,"id":405285,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"James., D. Nichols Nichols","contributorId":36818,"corporation":false,"usgs":true,"family":"James.","given":"D.","suffix":"Nichols","email":"","middleInitial":"Nichols","affiliations":[],"preferred":false,"id":405284,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70025480,"text":"70025480 - 2003 - Uptake of elements from seawater by ferromanganese crusts: Solid-phase associations and seawater speciation","interactions":[],"lastModifiedDate":"2012-03-12T17:20:59","indexId":"70025480","displayToPublicDate":"2003-01-01T00:00:00","publicationYear":"2003","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2667,"text":"Marine Geology","active":true,"publicationSubtype":{"id":10}},"title":"Uptake of elements from seawater by ferromanganese crusts: Solid-phase associations and seawater speciation","docAbstract":"Marine Fe-Mn oxyhydroxide crusts form by precipitation of dissolved components from seawater. Three hydrogenetic crust samples (one phosphatized) and two hydrothermal Mn-oxide samples were subjected to a sequential-leaching procedure in order to determine the host phases of 40 elements. Those host-phase associations are discussed with respect to element speciation in seawater. The partitioning of elements between the two major phases, Mn oxide and Fe oxyhydroxide, can in a first-order approximation be explained by a simple sorption model related to the inorganic speciation of the elements in seawater, as has been proposed in earlier models. Free and weakly complexed cations, such as alkali and alkaline earth metals, Mn, Co, Ni, Zn, T1(I), and partly Y, are sorbed preferentially on the negatively charged surface of the MnO2 in hydrogenetic crusts. The driving force is a strong coulombic interaction. All neutral or negatively charged chloro (Cd, Hg, T1), carbonate (Cu, Y, Pb, and U), and hydroxide (Be, Sc, Ti, Fe, Zr, Nb, In, Sn, Sb, Te, Hf, Ta, Bi, Th, and T1(III)) complexes and oxyanions (V, Cr, As, Se, Mo, and W) bind to the slightly positively charged surface of the amorphous FeOOH phase. While coulombic interaction can explain the sorption of the negatively charged species, the binding of neutral species is based on specific chemical interaction. Organic complexation of elements in deep-ocean water seems to be at most of minor importance. Surface oxidation can explain some strong metal associations, e.g. of Co and T1 with the MnO2 and Te with the FeOOH. Sorption reactions initially driven by coulombic forces are often followed by the formation of specific bonds between the adsorbate and the atoms of the oxide surface. Differences in the associations of some metals between the non-phosphatized and phosphatized hydrogenetic crusts and between the hydrogenetic and the hydrothermal samples reflect the different physico-chemical environments of formation and speciations in oxic seawater vs. less-oxic fluids, especially for the redox-sensitive metals such as Mo and V. These environmental-related differences indicate that the methodology of chemical speciation used here in combination with spectroscopic methods may allow for the detection of changes in paleoceanographic conditions recorded during the several tens of millions of years of crust growth. ?? 2003 Elsevier Science B.V. All rights reserved.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Marine Geology","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1016/S0025-3227(03)00122-1","issn":"00253227","usgsCitation":"Koschinsky, A., and Hein, J., 2003, Uptake of elements from seawater by ferromanganese crusts: Solid-phase associations and seawater speciation: Marine Geology, v. 198, no. 3-4, p. 331-351, https://doi.org/10.1016/S0025-3227(03)00122-1.","startPage":"331","endPage":"351","numberOfPages":"21","costCenters":[],"links":[{"id":209562,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/S0025-3227(03)00122-1"},{"id":236160,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"198","issue":"3-4","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505bbd76e4b08c986b329041","contributors":{"authors":[{"text":"Koschinsky, A.","contributorId":42724,"corporation":false,"usgs":true,"family":"Koschinsky","given":"A.","affiliations":[],"preferred":false,"id":405364,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Hein, J.R. 0000-0002-5321-899X","orcid":"https://orcid.org/0000-0002-5321-899X","contributorId":61429,"corporation":false,"usgs":true,"family":"Hein","given":"J.R.","affiliations":[],"preferred":false,"id":405365,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70025484,"text":"70025484 - 2003 - Variable near-surface deformation along the Commerce segment of the Commerce geophysical lineament, southeast Missouri to southern Illinois, USA","interactions":[],"lastModifiedDate":"2012-03-12T17:20:59","indexId":"70025484","displayToPublicDate":"2003-01-01T00:00:00","publicationYear":"2003","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":3525,"text":"Tectonophysics","active":true,"publicationSubtype":{"id":10}},"title":"Variable near-surface deformation along the Commerce segment of the Commerce geophysical lineament, southeast Missouri to southern Illinois, USA","docAbstract":"Recent studies have demonstrated a plausible link between surface and near-surface tectonic features and the vertical projection of the Commerce geophysical lineament (CGL). The CGL is a 5- to 10-km-wide zone of basement magnetic and gravity anomalies traceable for more than 600 km, extending from Arkansas through southeast Missouri and southern Illinois and into Indiana. Twelve kilometers of high-resolution seismic reflection data, collected at four sites along a 175-km segment of the CGL projection, are interpreted to show varying amounts of deformation involving Tertiary and some Quaternary sediments. Some of the locally anomalous geomorphic features in the northern Mississippi embayment region (i.e., paleoliquefaction features, anomalous directional changes in stream channels, and areas of linear bluff escarpments) overlying the CGL can be correlated with specific faults and/or narrow zones of deformed (faulted and folded) strata that are imaged on high-resolution seismic reflection data. There is an observable change in near-surface deformation style and complexity progressing from the southwest to the northeast along the trace of the CGL. The seismic reflection data collaborate mapping evidence which suggests that this region has undergone a complex history of deformation, some of which is documented to be as young as Quaternary, during multiple episodes of reactivation under varying stress fields. This work, along with that of other studies presented in this volume, points to the existence of at least one major crustal feature outside the currently defined zone of seismic activity (New Madrid Seismic Zone) that should be considered as a significant potential source zone for seismogenic activity within the midcontinent region of the United States. ?? 2003 Elsevier B.V. All rights reserved.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Tectonophysics","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1016/S0040-1951(03)00156-2","issn":"00401951","usgsCitation":"Odum, J.K., Stephenson, W.J., and Williams, R.A., 2003, Variable near-surface deformation along the Commerce segment of the Commerce geophysical lineament, southeast Missouri to southern Illinois, USA: Tectonophysics, v. 368, no. 1-4, p. 155-170, https://doi.org/10.1016/S0040-1951(03)00156-2.","startPage":"155","endPage":"170","numberOfPages":"16","costCenters":[],"links":[{"id":209593,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/S0040-1951(03)00156-2"},{"id":236233,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"368","issue":"1-4","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505bc143e4b08c986b32a4df","contributors":{"authors":[{"text":"Odum, J. K.","contributorId":105705,"corporation":false,"usgs":true,"family":"Odum","given":"J.","email":"","middleInitial":"K.","affiliations":[],"preferred":false,"id":405378,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Stephenson, W. J.","contributorId":87982,"corporation":false,"usgs":true,"family":"Stephenson","given":"W.","email":"","middleInitial":"J.","affiliations":[],"preferred":false,"id":405377,"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":405376,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70025493,"text":"70025493 - 2003 - Characterization of the time-dependent strain field at seismogenic depths using first-motion focal mechanisms: Observations of large-scale decadal variations in stress along the San Andrea fault system","interactions":[],"lastModifiedDate":"2012-03-12T17:20:30","indexId":"70025493","displayToPublicDate":"2003-01-01T00:00:00","publicationYear":"2003","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2314,"text":"Journal of Geophysical Research B: Solid Earth","active":true,"publicationSubtype":{"id":10}},"title":"Characterization of the time-dependent strain field at seismogenic depths using first-motion focal mechanisms: Observations of large-scale decadal variations in stress along the San Andrea fault system","docAbstract":"We present a method for summing moment tensors derived from first-motion focal mechanisms to study temporal dependence in features of the subsurface regional strain field. Time-dependent processes are inferred by comparing mechanisms summed over differing time periods. We apply this methodology to seismogenic zones in central and southern California using focal mechanisms produced by the Northern and Southern California Seismograph Networks for events during 1980-1999. We find a consistent pattern in both the style of deformation (strike-slip versus compressional) and seismicity rate across the entire region. If these temporal variations are causally related, it suggests a temporal change in the regional-scale stress field. One change consistent with the observations is a rotation in the regional maximum horizontal compressive stress direction, followed by a reversal to the original direction. Depending upon the dominant style of deformation locally, this change in orientation of the regional stress will tend to either enhance or hinder deformation. The mode of enhanced deformation can range from increased microseismicity and creep to major earthquakes. We hypothesize that these temporal changes in the regional stress field are the result of subtle changes in apparent relative plate motion between the Pacific and North American plates, perhaps due to long-range postseismic stress diffusion. Others have hypothesized that small changes in plate motion over thousands of years, and/or over decades, are responsible for changes in the style of deformation in southern California. We propose that such changes, over the course of just a few years, also affect the style of deformation.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Journal of Geophysical Research B: Solid Earth","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","issn":"01480227","usgsCitation":"Sipkin, S., and Silver, P., 2003, Characterization of the time-dependent strain field at seismogenic depths using first-motion focal mechanisms: Observations of large-scale decadal variations in stress along the San Andrea fault system: Journal of Geophysical Research B: Solid Earth, v. 108, no. 7.","costCenters":[],"links":[{"id":235790,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"108","issue":"7","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"5059f4e7e4b0c8380cd4bfc5","contributors":{"authors":[{"text":"Sipkin, S.A.","contributorId":9399,"corporation":false,"usgs":true,"family":"Sipkin","given":"S.A.","email":"","affiliations":[],"preferred":false,"id":405407,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Silver, P.G.","contributorId":31642,"corporation":false,"usgs":true,"family":"Silver","given":"P.G.","email":"","affiliations":[],"preferred":false,"id":405408,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70025496,"text":"70025496 - 2003 - Observations of large-amplitude cross-shore internal bores near the shelf break, Santa Monica Bay, CA","interactions":[],"lastModifiedDate":"2012-03-12T17:20:25","indexId":"70025496","displayToPublicDate":"2003-01-01T00:00:00","publicationYear":"2003","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2664,"text":"Marine Environmental Research","active":true,"publicationSubtype":{"id":10}},"title":"Observations of large-amplitude cross-shore internal bores near the shelf break, Santa Monica Bay, CA","docAbstract":"Two sets of moorings were deployed along a cross-shelf transect in central Santa Monica bay for four months in the winter of 1998-1999. Both sites had an array of instruments attached to tripods set on the seafloor to monitor currents over the entire water column, surface waves, near-bed temperature, water clarity and suspended sediment. A companion mooring had temperature sensors spaced approximately 10 m apart to measure temperature profiles between the surface and the seafloor. One array was deployed in 70 m of water at a site adjacent to the shelf break, just northwest of a major ocean outfall. The other was deployed on the mid shelf in 35 m of water approximately 6 km from the shelf break site. The subtidal currents in the region flowed parallel to the isobaths with fluctuating time scales around 10 days, a typical coastal-ocean pattern. However, during the falling phase of the barotropic spring tide, sets of large-amplitude, sheared cross-shore current pulses with a duration of 2-5 h were observed at the shelf break site. Currents in these pulses flowed exclusively offshore in a thin layer near the bed with amplitudes reaching 30-40 cm/s. Simultaneously, currents with amplitudes around 15-20 cm/s flowed exclusively onshore in the thicker layer between the offshore flow layer and the sea surface. The net offshore transport was about half the onshore transport. Near-surface isotherms were depressed 30-40 m. These pulses were likely internal bores generated by tidal currents. Bed stresses associated with these events exceeded 3 dynes/cm2. These amplitudes are large enough to resuspend and transport not only fine-grained material, but also medium to coarse sands from the shelf toward the slope. Consequently, the seafloor over the shelf break was swept clear of fine sediments. The data suggest that the internal bores dissipate and are reduced in amplitude as they propagate across this relatively narrow shelf. There is evidence that they reach the 35 m site, but other coastal ocean processes obscure their distinctive characteristics.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Marine Environmental Research","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1016/S0141-1136(02)00328-8","issn":"01411136","usgsCitation":"Noble, M., and Xu, J.P., 2003, Observations of large-amplitude cross-shore internal bores near the shelf break, Santa Monica Bay, CA: Marine Environmental Research, v. 56, no. 1-2, p. 127-149, https://doi.org/10.1016/S0141-1136(02)00328-8.","startPage":"127","endPage":"149","numberOfPages":"23","costCenters":[],"links":[{"id":209429,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/S0141-1136(02)00328-8"},{"id":235863,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"56","issue":"1-2","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a6a96e4b0c8380cd74262","contributors":{"authors":[{"text":"Noble, M.A.","contributorId":93513,"corporation":false,"usgs":true,"family":"Noble","given":"M.A.","email":"","affiliations":[],"preferred":false,"id":405418,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Xu, J. P.","contributorId":74528,"corporation":false,"usgs":true,"family":"Xu","given":"J.","email":"","middleInitial":"P.","affiliations":[],"preferred":false,"id":405417,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70025523,"text":"70025523 - 2003 - Possible Juventae Chasma subice volcanic eruptions and Maja Valles ice outburst floods on Mars: Implications of Mars Global surveyor crater densities, geomorphology, and topography","interactions":[],"lastModifiedDate":"2012-03-12T17:20:26","indexId":"70025523","displayToPublicDate":"2003-01-01T00:00:00","publicationYear":"2003","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":"Possible Juventae Chasma subice volcanic eruptions and Maja Valles ice outburst floods on Mars: Implications of Mars Global surveyor crater densities, geomorphology, and topography","docAbstract":"This article discusses image, topographic, and spectral data from the Mars Global Surveyor (MGS) mission that provide new information concerning the surface age, geomorphology, and topography of the Juventae Chasma/Maja Valles system. Our study utilizes data from two instruments on board MGS: images from the Mars Orbiter Camera (MOC) and topography from the Mars Orbiter Laser Altimeter (MOLA). Within Maja Valles we can now observe depositional bars with megaripples that unequivocally show catastrophic floods occurred in the channel. Viking impact crater densities indicated the chasma and channel floor areas were all one age (late Hesperian to Amazonian); however, MOC data indicate a marked difference in densities of small craters between Juventae Chasma, Maja Valles, and the channel debouchment area in Chryse Planitia basin. Although other processes may contribute to crater variability, young resurfacing events in the chasma and episodes of recent erosion at Maja Valles channel head may possibly account for the disparate crater densities along the chasma/channel system. Relatively young volcanic eruptions may have contributed to resurfacing; as in Juventae Chasma, a small possible volcanic cone of young dark material is observed. MOC data also indicate previously unknown interior layered deposit mounds in the chasma that indicate at least two periods of mound formation. Finally, MOLA topography shows that the entire floor of the chasma lies at the same elevation as the channel debouchment area in Chryse basin, resulting in a 3-km-high barrier to water flow out of the chasma. Blocked ponded water would rapidly freeze in the current (and likely past) climate of Mars. For catastrophic flow to occur in Maja Valles, some process is required to melt ice and induce floods out of the chasma. We suggest subice volcanic eruption and calculate estimates of water discharges and volumes that these eruptions might have produced.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Journal of Geophysical Research E: Planets","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","issn":"01480227","usgsCitation":"Chapman, M.G., Gudmundsson, M., Russell, A., and Hare, T., 2003, Possible Juventae Chasma subice volcanic eruptions and Maja Valles ice outburst floods on Mars: Implications of Mars Global surveyor crater densities, geomorphology, and topography: Journal of Geophysical Research E: Planets, v. 108, no. 10, p. 2-1.","startPage":"2","endPage":"1","numberOfPages":"0","costCenters":[],"links":[{"id":235674,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"108","issue":"10","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a7e0ee4b0c8380cd7a2f3","contributors":{"authors":[{"text":"Chapman, M. G.","contributorId":105737,"corporation":false,"usgs":true,"family":"Chapman","given":"M.","email":"","middleInitial":"G.","affiliations":[],"preferred":false,"id":405508,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Gudmundsson, M.T.","contributorId":46281,"corporation":false,"usgs":true,"family":"Gudmundsson","given":"M.T.","affiliations":[],"preferred":false,"id":405506,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Russell, A.J.","contributorId":98516,"corporation":false,"usgs":true,"family":"Russell","given":"A.J.","email":"","affiliations":[],"preferred":false,"id":405507,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Hare, T.M. 0000-0001-8842-389X","orcid":"https://orcid.org/0000-0001-8842-389X","contributorId":43828,"corporation":false,"usgs":true,"family":"Hare","given":"T.M.","affiliations":[],"preferred":false,"id":405505,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}} ,{"id":70025535,"text":"70025535 - 2003 - Nesting behavior of Palila, as assessed from video recordings","interactions":[],"lastModifiedDate":"2012-03-12T17:20:26","indexId":"70025535","displayToPublicDate":"2003-01-01T00:00:00","publicationYear":"2003","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2990,"text":"Pacific Science","active":true,"publicationSubtype":{"id":10}},"title":"Nesting behavior of Palila, as assessed from video recordings","docAbstract":"We quantified nesting behavior of Palila (Loxiodes bailleui), an endangered Hawaiian honeycreeper, by recording at nests during three breeding seasons using a black-and-white video camera connected to a Videocassette recorder. A total of seven nests was observed. We measured the following factors for daylight hours: percentage of time the female was on the nest (attendance), length of attendance bouts by the female, length of nest recesses, and adult provisioning rates. Comparisons were made between three stages of the 40-day nesting cycle: incubation (day 1-day 16), early nestling stage (day 17-day 30 [i.e., nestlings ??? 14 days old]), and late nestling stage (day 31-day 40 [i.e., nestlings > 14 days old]). Of seven nests observed, four fledged at least one nestling and three failed. One of these failed nests was filmed being depredated by a feral cat (Felis catus). Female nest attendance was near 82% during the incubation stage and decreased to 21% as nestlings aged. We did not detect a difference in attendance bout length between stages of the nesting cycle. Mean length of nest recesses increased from 4.5 min during the incubation stage to over 45 min during the late nestling stage. Mean number of nest recesses per hour ranged from 1.6 to 2.0. Food was delivered to nestlings by adults an average of 1.8 times per hour for the early nestling stage and 1.5 times per hour during the late nestling stage and did not change over time. Characterization of parental behavior by video had similarities to but also key differences from findings taken from blind observations. Results from this study will facilitate greater understanding of Palila reproductive strategies.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Pacific Science","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","issn":"00308870","usgsCitation":"Laut, M., Banko, P., and Gray, E., 2003, Nesting behavior of Palila, as assessed from video recordings: Pacific Science, v. 57, no. 4, p. 385-392.","startPage":"385","endPage":"392","numberOfPages":"8","costCenters":[],"links":[{"id":235867,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"57","issue":"4","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a64b1e4b0c8380cd72a2f","contributors":{"authors":[{"text":"Laut, M.E.","contributorId":53141,"corporation":false,"usgs":true,"family":"Laut","given":"M.E.","affiliations":[],"preferred":false,"id":405551,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Banko, P.C. 0000-0002-6035-9803","orcid":"https://orcid.org/0000-0002-6035-9803","contributorId":99531,"corporation":false,"usgs":true,"family":"Banko","given":"P.C.","affiliations":[],"preferred":false,"id":405553,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Gray, E.M.","contributorId":62781,"corporation":false,"usgs":true,"family":"Gray","given":"E.M.","email":"","affiliations":[],"preferred":false,"id":405552,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70025536,"text":"70025536 - 2003 - Structure and mechanics of the Hayward-Rodgers Creek Fault step-over, San Francisco Bay, California","interactions":[],"lastModifiedDate":"2021-07-26T14:15:06.716598","indexId":"70025536","displayToPublicDate":"2003-01-01T00:00:00","publicationYear":"2003","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":"Structure and mechanics of the Hayward-Rodgers Creek Fault step-over, San Francisco Bay, California","docAbstract":"A dilatational step-over between the right-lateral Hayward and Rodgers Creek faults lies beneath San Pablo Bay in the San Francisco Bay area. A key seismic hazard issue is whether an earthquake on one of the faults could rupture through the step-over, enhancing its maximum possible magnitude. If ruptures are terminated at the step-over, then another important issue is how strain transfers through the step. We developed a combined seismic reflection and refraction cross section across south San Pablo Bay and found that the Hayward and Rodgers Creek faults converge to within 4 km of one another near the surface, about 2 km closer than previously thought. Interpretation of potential field data from San Pablo Bay indicated a low likelihood of strike-slip transfer faults connecting the Hayward and Rodgers Creek faults. Numerical simulations suggest that it is possible for a rupture to jump across a 4-km fault gap, although special stressing conditions are probably required (e.g., Harris and Day, 1993, 1999). Slip on the Hayward and Rodgers Creek faults is building an extensional pull-apart basin that could contain hazardous normal faults. We investigated strain in the pull-apart using a finite-element model and calculated a ∼0.02-MPa/yr differential stressing rate in the step-over on a least-principal-stress orientation nearly parallel to the strike-slip faults where they overlap. A 1- to 10-MPa stress-drop extensional earthquake is expected on normal faults oriented perpendicular to the strike-slip faults every 50-500 years. The last such earthquake might have been the 1898 M 6.0-6.5 shock in San Pablo Bay that apparently produced a small tsunami. Historical hydrographic surveys gathered before and after 1898 indicate abnormal subsidence of the bay floor within the step-over, possibly related to the earthquake. We used a hydrodynamic model to show that a dip-slip mechanism in north San Pablo Bay is the most likely 1898 rupture scenario to have caused the tsunami. While we find no strike-slip transfer fault between the Hayward and Rodgers Creek faults, a normal-fault link could enable through-going segmented rupture of both strike-slip faults and may pose an independent hazard of M ∼6 earthquakes like the 1898 event.
","language":"English","publisher":"Seismological Society of America","doi":"10.1785/0120020228","issn":"00371106","usgsCitation":"Parsons, T., Sliter, R., Geist, E., Jachens, R., Jaffe, B.E., Foxgrover, A., Hart, P., and McCarthy, J., 2003, Structure and mechanics of the Hayward-Rodgers Creek Fault step-over, San Francisco Bay, California: Bulletin of the Seismological Society of America, v. 93, no. 5, p. 2187-2200, https://doi.org/10.1785/0120020228.","productDescription":"14 p.","startPage":"2187","endPage":"2200","onlineOnly":"N","additionalOnlineFiles":"N","costCenters":[{"id":552,"text":"San Francisco Bay-Delta","active":false,"usgs":true},{"id":5079,"text":"Pacific Regional Director's Office","active":true,"usgs":true}],"links":[{"id":387417,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"country":"United States","state":"California","city":"San Francisco","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 -123.11279296875001,\n 37.10776507118514\n ],\n [\n -121.77246093750001,\n 37.10776507118514\n ],\n [\n -121.77246093750001,\n 38.58252615935333\n ],\n [\n -123.11279296875001,\n 38.58252615935333\n ],\n [\n -123.11279296875001,\n 37.10776507118514\n ]\n ]\n ]\n }\n }\n ]\n}","volume":"93","issue":"5","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505b9c14e4b08c986b31d27a","contributors":{"authors":[{"text":"Parsons, T.","contributorId":48288,"corporation":false,"usgs":true,"family":"Parsons","given":"T.","email":"","affiliations":[],"preferred":false,"id":405555,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Sliter, R.","contributorId":66311,"corporation":false,"usgs":true,"family":"Sliter","given":"R.","affiliations":[],"preferred":false,"id":405558,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Geist, E.L. 0000-0003-0611-1150","orcid":"https://orcid.org/0000-0003-0611-1150","contributorId":71993,"corporation":false,"usgs":true,"family":"Geist","given":"E.L.","affiliations":[],"preferred":false,"id":405559,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Jachens, R.C.","contributorId":55433,"corporation":false,"usgs":true,"family":"Jachens","given":"R.C.","email":"","affiliations":[],"preferred":false,"id":405557,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Jaffe, B. E.","contributorId":88327,"corporation":false,"usgs":true,"family":"Jaffe","given":"B.","email":"","middleInitial":"E.","affiliations":[],"preferred":false,"id":405561,"contributorType":{"id":1,"text":"Authors"},"rank":5},{"text":"Foxgrover, A.","contributorId":80477,"corporation":false,"usgs":true,"family":"Foxgrover","given":"A.","email":"","affiliations":[],"preferred":false,"id":405560,"contributorType":{"id":1,"text":"Authors"},"rank":6},{"text":"Hart, P. E.","contributorId":10773,"corporation":false,"usgs":true,"family":"Hart","given":"P. E.","affiliations":[],"preferred":false,"id":405554,"contributorType":{"id":1,"text":"Authors"},"rank":7},{"text":"McCarthy, J.","contributorId":50290,"corporation":false,"usgs":true,"family":"McCarthy","given":"J.","affiliations":[],"preferred":false,"id":405556,"contributorType":{"id":1,"text":"Authors"},"rank":8}]}} ,{"id":70025547,"text":"70025547 - 2003 - Atlantic coast feeding habits of striped bass: A synthesis supporting a coast-wide understanding of trophic biology","interactions":[],"lastModifiedDate":"2012-03-12T17:21:00","indexId":"70025547","displayToPublicDate":"2003-01-01T00:00:00","publicationYear":"2003","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1659,"text":"Fisheries Management and Ecology","active":true,"publicationSubtype":{"id":10}},"title":"Atlantic coast feeding habits of striped bass: A synthesis supporting a coast-wide understanding of trophic biology","docAbstract":"The recent increase in the Atlantic coast population of striped bass, Morone saxatilis (Walbaum), prompted managers to re-evaluate their predatory impact. Published and unpublished diet data for striped bass on the Atlantic Coast of North America were examined for geographical, ontogenetic and seasonal patterns in the diet and to assess diet for this species. Diets of young-of-the-year (YOY) striped bass were similar across the Upper Atlantic (UPATL), Chesapeake and Delaware Bays (CBDEL) and North Carolina (NCARO) areas of the Atlantic coast where either fish or mysid shrimp dominate the diet. For age one and older striped bass, cluster analysis partitioned diets based on predominance of either Atlantic menhaden, Brevoortia tyrannus (Latrobe), characteristic of striped bass from the CBDEL and NCARO regions, or non-menhaden fishes or invertebrates, characteristic of fish from the UPATL, in the diet. The predominance of invertebrates in the diets of striped bass in the UPATL region can be attributed to the absence of several important species groups in Northern waters, particularly sciaenid fishes, and to the sporadic occurrences of Atlantic menhaden to UPATL waters. In all regions, across most seasons and in most size classes of striped bass, the clupeiod fishes; menhaden, anchovies (Anchoa spp.) and river herrings (Alosa spp,) and Atlantic herring, Clupea harengus L., dominated the diets of striped bass above the first year of life.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Fisheries Management and Ecology","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1046/j.1365-2400.2003.00373.x","issn":"0969997X","usgsCitation":"Walter, J.F., Overton, A., Ferry, K., and Mather, M.E., 2003, Atlantic coast feeding habits of striped bass: A synthesis supporting a coast-wide understanding of trophic biology: Fisheries Management and Ecology, v. 10, no. 5, p. 349-360, https://doi.org/10.1046/j.1365-2400.2003.00373.x.","startPage":"349","endPage":"360","numberOfPages":"12","costCenters":[],"links":[{"id":209528,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1046/j.1365-2400.2003.00373.x"},{"id":236085,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"10","issue":"5","noUsgsAuthors":false,"publicationDate":"2003-11-07","publicationStatus":"PW","scienceBaseUri":"5059eea6e4b0c8380cd49ea8","contributors":{"authors":[{"text":"Walter, J. F. III","contributorId":107908,"corporation":false,"usgs":true,"family":"Walter","given":"J.","suffix":"III","email":"","middleInitial":"F.","affiliations":[],"preferred":false,"id":405605,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Overton, A.S.","contributorId":105897,"corporation":false,"usgs":true,"family":"Overton","given":"A.S.","email":"","affiliations":[],"preferred":false,"id":405604,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Ferry, K.H.","contributorId":70166,"corporation":false,"usgs":true,"family":"Ferry","given":"K.H.","email":"","affiliations":[],"preferred":false,"id":405602,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Mather, M. E.","contributorId":71708,"corporation":false,"usgs":true,"family":"Mather","given":"M.","email":"","middleInitial":"E.","affiliations":[],"preferred":false,"id":405603,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}} ]}