Fractionation of Cu and Zn isotopes during adsorption onto amorphous ferric oxyhydroxide is examined in experimental mixtures of metal-rich acid rock drainage and relatively pure river water and during batch adsorption experiments using synthetic ferrihydrite. A diverse set of Cu- and Zn-bearing solutions was examined, including natural waters, complex synthetic acid rock drainage, and simple NaNO3 electrolyte. Metal adsorption data are combined with isotopic measurements of dissolved Cu (65Cu/63Cu) and Zn (66Zn/64Zn) in each of the experiments. Fractionation of Cu and Zn isotopes occurs during adsorption of the metal onto amorphous ferric oxyhydroxide. The adsorption data are modeled successfully using the diffuse double layer model in PHREEQC. The isotopic data are best described by a closed system, equilibrium exchange model. The fractionation factors (αsoln–solid) are 0.99927 ± 0.00008 for Cu and 0.99948 ± 0.00004 for Zn or, alternately, the separation factors (Δsoln–solid) are −0.73 ± 0.08‰ for Cu and −0.52 ± 0.04‰ for Zn. These factors indicate that the heavier isotope preferentially adsorbs onto the oxyhydroxide surface, which is consistent with shorter metal–oxygen bonds and lower coordination number for the metal at the surface relative to the aqueous ion. Fractionation of Cu isotopes also is greater than that for Zn isotopes. Limited isotopic data for adsorption of Cu, Fe(II), and Zn onto amorphous ferric oxyhydroxide suggest that isotopic fractionation is related to the intrinsic equilibrium constants that define aqueous metal interactions with oxyhydroxide surface sites. Greater isotopic fractionation occurs with stronger metal binding by the oxyhydroxide with Cu > Zn > Fe(II).
We compute ground motions for the Beroza (1991) and Wald et al. (1991) source models of the 1989 magnitude 6.9 Loma Prieta earthquake using four different wave-propagation codes and recently developed 3D geologic and seismic velocity models. In preparation for modeling the 1906 San Francisco earthquake, we use this well-recorded earthquake to characterize how well our ground-motion simulations reproduce the observed shaking intensities and amplitude and durations of recorded motions throughout the San Francisco Bay Area. All of the simulations generate ground motions consistent with the large-scale spatial variations in shaking associated with rupture directivity and the geologic structure. We attribute the small variations among the synthetics to the minimum shear-wave speed permitted in the simulations and how they accommodate topography. Our long-period simulations, on average, under predict shaking intensities by about one-half modified Mercalli intensity (MMI) units (25%-35% in peak velocity), while our broadband simulations, on average, under predict the shaking intensities by one-fourth MMI units (16% in peak velocity). Discrepancies with observations arise due to errors in the source models and geologic structure. The consistency in the synthetic waveforms across the wave-propagation codes for a given source model suggests the uncertainty in the source parameters tends to exceed the uncertainty in the seismic velocity structure. In agreement with earlier studies, we find that a source model with slip more evenly distributed northwest and southeast of the hypocenter would be preferable to both the Beroza and Wald source models. Although the new 3D seismic velocity model improves upon previous velocity models, we identify two areas needing improvement. Nevertheless, we find that the seismic velocity model and the wave-propagation codes are suitable for modeling the 1906 earthquake and scenario events in the San Francisco Bay Area.
","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Bulletin of the Seismological Society of America","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","publisher":"Seismological Society of America","publisherLocation":"Stanford","doi":"10.1785/0120060409","issn":"00371106","usgsCitation":"Aagaard, B.T., Brocher, T., Dolenc, D., Dreger, D., Graves, R., Harmsen, S., Hartzell, S., Larsen, S., and Zoback, M., 2008, Ground-motion modeling of the 1906 San Francisco earthquake, part I: Validation using the 1989 Loma Prieta earthquake: Bulletin of the Seismological Society of America, v. 98, no. 2, p. 989-1011, https://doi.org/10.1785/0120060409.","productDescription":"23 p.","startPage":"989","endPage":"1011","numberOfPages":"23","onlineOnly":"N","additionalOnlineFiles":"N","costCenters":[],"links":[{"id":239715,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":212255,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1785/0120060409"}],"volume":"98","issue":"2","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a2b6ee4b0c8380cd5b98d","contributors":{"authors":[{"text":"Aagaard, Brad T. 0000-0002-8795-9833 baagaard@usgs.gov","orcid":"https://orcid.org/0000-0002-8795-9833","contributorId":192869,"corporation":false,"usgs":true,"family":"Aagaard","given":"Brad","email":"baagaard@usgs.gov","middleInitial":"T.","affiliations":[{"id":300,"text":"Geologic Hazards Science Center","active":true,"usgs":true},{"id":237,"text":"Earthquake Science Center","active":true,"usgs":true}],"preferred":false,"id":433220,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Brocher, T.M. 0000-0002-9740-839X","orcid":"https://orcid.org/0000-0002-9740-839X","contributorId":69994,"corporation":false,"usgs":true,"family":"Brocher","given":"T.M.","affiliations":[],"preferred":false,"id":433223,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Dolenc, D.","contributorId":64027,"corporation":false,"usgs":true,"family":"Dolenc","given":"D.","affiliations":[],"preferred":false,"id":433222,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Dreger, D.","contributorId":12242,"corporation":false,"usgs":true,"family":"Dreger","given":"D.","affiliations":[],"preferred":false,"id":433217,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Graves, R.W. 0000-0001-9758-453X","orcid":"https://orcid.org/0000-0001-9758-453X","contributorId":77691,"corporation":false,"usgs":true,"family":"Graves","given":"R.W.","affiliations":[],"preferred":false,"id":433224,"contributorType":{"id":1,"text":"Authors"},"rank":5},{"text":"Harmsen, S.","contributorId":79600,"corporation":false,"usgs":true,"family":"Harmsen","given":"S.","affiliations":[],"preferred":false,"id":433225,"contributorType":{"id":1,"text":"Authors"},"rank":6},{"text":"Hartzell, S.","contributorId":12603,"corporation":false,"usgs":true,"family":"Hartzell","given":"S.","email":"","affiliations":[],"preferred":false,"id":433218,"contributorType":{"id":1,"text":"Authors"},"rank":7},{"text":"Larsen, S.","contributorId":37087,"corporation":false,"usgs":true,"family":"Larsen","given":"S.","email":"","affiliations":[],"preferred":false,"id":433221,"contributorType":{"id":1,"text":"Authors"},"rank":8},{"text":"Zoback, M.L.","contributorId":12982,"corporation":false,"usgs":true,"family":"Zoback","given":"M.L.","email":"","affiliations":[],"preferred":false,"id":433219,"contributorType":{"id":1,"text":"Authors"},"rank":9}]}} ,{"id":70032141,"text":"70032141 - 2008 - Validation of the ASTER instrument level 1A scene geometry","interactions":[],"lastModifiedDate":"2012-03-12T17:21:27","indexId":"70032141","displayToPublicDate":"2008-01-01T00:00:00","publicationYear":"2008","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":3052,"text":"Photogrammetric Engineering and Remote Sensing","active":true,"publicationSubtype":{"id":10}},"title":"Validation of the ASTER instrument level 1A scene geometry","docAbstract":"An independent assessment of the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) instrument geometry was undertaken by the U.S. ASTER Team, to confirm the geometric correction parameters developed and applied to Level 1A (radiometrically and geometrically raw with correction parameters appended) ASTER data. The goal was to evaluate the geometric quality of the ASTER system and the stability of the Terra spacecraft. ASTER is a 15-band system containing optical instruments with resolutions from 15- to 90-meters; all geometrically registered products are ultimately tied to the 15-meter Visible and Near Infrared (VNIR) sub-system. Our evaluation process first involved establishing a large database of Ground Control Points (GCP) in the mid-western United States; an area with features of an appropriate size for spacecraft instrument resolutions. We used standard U.S. Geological Survey (USGS) Digital Orthophoto Quads (DOQS) of areas in the mid-west to locate accurate GCPs by systematically identifying road intersections and recording their coordinates. Elevations for these points were derived from USGS Digital Elevation Models (DEMS). Road intersections in a swath of nine contiguous ASTER scenes were then matched to the GCPs, including terrain correction. We found no significant distortion in the images; after a simple image offset to absolute position, the RMS residual of about 200 points per scene was less than one-half a VNIR pixel. Absolute locations were within 80 meters, with a slow drift of about 10 meters over the entire 530-kilometer swath. Using strictly simultaneous observations of scenes 370 kilometers apart, we determined a stereo angle correction of 0.00134 degree with an accuracy of one microradian. The mid-west GCP field and the techniques used here should be widely applicable in assessing other spacecraft instruments having resolutions from 5 to 50-meters. ?? 2008 American Society for Photogrammetry and Remote Sensing.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Photogrammetric Engineering and Remote Sensing","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","issn":"00991112","usgsCitation":"Kieffer, H.H., Mullins, K.F., and MacKinnon, D.J., 2008, Validation of the ASTER instrument level 1A scene geometry: Photogrammetric Engineering and Remote Sensing, v. 74, no. 3, p. 289-301.","startPage":"289","endPage":"301","numberOfPages":"13","costCenters":[],"links":[{"id":242798,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"74","issue":"3","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505bc103e4b08c986b32a40a","contributors":{"authors":[{"text":"Kieffer, H. H.","contributorId":40725,"corporation":false,"usgs":false,"family":"Kieffer","given":"H.","email":"","middleInitial":"H.","affiliations":[],"preferred":false,"id":434704,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Mullins, K. F.","contributorId":104702,"corporation":false,"usgs":true,"family":"Mullins","given":"K.","email":"","middleInitial":"F.","affiliations":[],"preferred":false,"id":434706,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"MacKinnon, D. J.","contributorId":79145,"corporation":false,"usgs":true,"family":"MacKinnon","given":"D.","email":"","middleInitial":"J.","affiliations":[],"preferred":false,"id":434705,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70032129,"text":"70032129 - 2008 - Modeling the effects of potential salinity shifts on the recovery of striped bass in the Savannah River estuary, Georgia-South Carolina, United States","interactions":[],"lastModifiedDate":"2016-11-30T11:19:10","indexId":"70032129","displayToPublicDate":"2008-01-01T00:00:00","publicationYear":"2008","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1547,"text":"Environmental Management","active":true,"publicationSubtype":{"id":10}},"title":"Modeling the effects of potential salinity shifts on the recovery of striped bass in the Savannah River estuary, Georgia-South Carolina, United States","docAbstract":"Increased salinity in spawning and nursery grounds in the Savannah River estuary was cited as the primary cause of a 97% decrease in adult striped bass (Morone saxatilis) and a concomitant 96% decrease in striped bass egg production. Restoration efforts focused on environmental remediation and stock enhancement have resulted in restored salinity patterns and increased egg and adult abundances. However, future water needs or harbor development may preclude further recovery by reducing freshwater inflow or increasing salinity intrusion. To assess the effect of potential changes in the salinity regime, we developed models relating discharge, tidal phase, and salinity to striped bass egg and early larval survival and re-cast these in a quantitative Bayesian belief network. The model indicated that a small upstream shift (???1.67 km) in the salinity regime would have the least impact on striped bass early life history survival, whereas shifts >1.67 km would have progressively larger impacts, with a 8.33-km shift potentially reducing our estimated survival probability by >28%. Such an impact could have cumulative and long-term detrimental effects on the recovery of the Savannah River striped bass population. The available salinity data were collected during average and low flows, so our model represents some typical and some extreme conditions during a striped bass spawning season. Our model is a relatively simplistic, \"first-order\" attempt at evaluating potential effects of changes in the Savannah River estuarine salinity regime and points to areas of concern and potential future research. ?? 2008 Springer Science+Business Media, LLC.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Environmental Management","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1007/s00267-008-9082-x","issn":"0364152X","usgsCitation":"Reinert, T., and Peterson, J., 2008, Modeling the effects of potential salinity shifts on the recovery of striped bass in the Savannah River estuary, Georgia-South Carolina, United States: Environmental Management, v. 41, no. 5, p. 753-765, https://doi.org/10.1007/s00267-008-9082-x.","startPage":"753","endPage":"765","numberOfPages":"13","costCenters":[{"id":13634,"text":"South Atlantic Water Science Center","active":true,"usgs":true}],"links":[{"id":242606,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":214853,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1007/s00267-008-9082-x"}],"country":"United States","geographicExtents":"{\n \"type\": \"FeatureCollection\",\n \"features\": [\n {\n \"type\": \"Feature\",\n \"properties\": {},\n \"geometry\": {\n \"type\": \"Polygon\",\n \"coordinates\": [\n [\n [\n -81.2164306640625,\n 31.64519805333295\n ],\n [\n -81.2164306640625,\n 32.2801666335657\n ],\n [\n -80.66574096679688,\n 32.2801666335657\n ],\n [\n -80.66574096679688,\n 31.64519805333295\n ],\n [\n -81.2164306640625,\n 31.64519805333295\n ]\n ]\n ]\n }\n }\n ]\n}","volume":"41","issue":"5","noUsgsAuthors":false,"publicationDate":"2008-02-22","publicationStatus":"PW","scienceBaseUri":"505a5c42e4b0c8380cd6fb4d","contributors":{"authors":[{"text":"Reinert, T.R.","contributorId":28043,"corporation":false,"usgs":true,"family":"Reinert","given":"T.R.","email":"","affiliations":[],"preferred":false,"id":434649,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Peterson, J.T.","contributorId":30170,"corporation":false,"usgs":true,"family":"Peterson","given":"J.T.","email":"","affiliations":[],"preferred":false,"id":434650,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70032124,"text":"70032124 - 2008 - Dispersal leads to spatial autocorrelation in species distributions: A simulation model","interactions":[],"lastModifiedDate":"2012-03-12T17:21:29","indexId":"70032124","displayToPublicDate":"2008-01-01T00:00:00","publicationYear":"2008","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1458,"text":"Ecological Modelling","active":true,"publicationSubtype":{"id":10}},"title":"Dispersal leads to spatial autocorrelation in species distributions: A simulation model","docAbstract":"Compared to population growth regulated by local conditions, dispersal has been underappreciated as a central process shaping the spatial distribution of populations. This paper asks: (a) which conditions increase the importance of dispersers relative to local recruits in determining population sizes? and (b) how does dispersal influence the spatial distribution patterns of abundances among connected populations? We approached these questions with a simulation model of populations on a coupled lattice with cells of continuously varying habitat quality expressed as carrying capacities. Each cell contained a population with the basic dynamics of density-regulated growth, and was connected to other populations by immigration and emigration. The degree to which dispersal influenced the distribution of population sizes depended most strongly on the absolute amount of dispersal, and then on the potential population growth rate. Dispersal decaying in intensity with distance left close neighbours more alike in population size than distant populations, leading to an increase in spatial autocorrelation. The spatial distribution of species with low potential growth rates is more dependent on dispersal than that of species with high growth rates; therefore, distribution modelling for species with low growth rates requires particular attention to autocorrelation, and conservation management of these species requires attention to factors curtailing dispersal, such as fragmentation and dispersal barriers. ?? 2007 Elsevier B.V. All rights reserved.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Ecological Modelling","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1016/j.ecolmodel.2007.12.005","issn":"03043800","usgsCitation":"Bahn, V., Krohn, W., and O’Connor, R., 2008, Dispersal leads to spatial autocorrelation in species distributions: A simulation model: Ecological Modelling, v. 213, no. 3-4, p. 285-292, https://doi.org/10.1016/j.ecolmodel.2007.12.005.","startPage":"285","endPage":"292","numberOfPages":"8","costCenters":[],"links":[{"id":214753,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/j.ecolmodel.2007.12.005"},{"id":242503,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"213","issue":"3-4","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a0219e4b0c8380cd4fea6","contributors":{"authors":[{"text":"Bahn, V.","contributorId":23741,"corporation":false,"usgs":true,"family":"Bahn","given":"V.","email":"","affiliations":[],"preferred":false,"id":434629,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Krohn, W.B.","contributorId":64355,"corporation":false,"usgs":true,"family":"Krohn","given":"W.B.","email":"","affiliations":[],"preferred":false,"id":434631,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"O’Connor, R.J.","contributorId":37861,"corporation":false,"usgs":true,"family":"O’Connor","given":"R.J.","email":"","affiliations":[],"preferred":false,"id":434630,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70033612,"text":"70033612 - 2008 - Rain‐induced subsurface airflow and Lisse effect","interactions":[],"lastModifiedDate":"2018-04-03T11:48:56","indexId":"70033612","displayToPublicDate":"2008-01-01T00:00:00","publicationYear":"2008","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":"Rain‐induced subsurface airflow and Lisse effect","docAbstract":"Water‐level increase after rainfall is usually indicative of rainfall recharge to groundwater. This, however, may not be true if the Lisse effect occurs. This effect represents the water‐level increase in a well driven by airflow induced by an advancing wetting front during highly intensive rains. The rainwater, which may behave like a low‐permeability lid, seals the ground surface so that the air pressure beneath the wetting front is increased because of air compression due to downward movement of the wetting front. A rapid and substantial rise of the water level in the well screened below water table, which bears no relationship to groundwater recharge, can be induced when various factors such as soil properties and the rain‐runoff condition combine favorably. A transient, three‐dimensional and variably saturated flow model was employed to study the air and groundwater flows in the soil under rain conditions. The objectives of this paper are two‐fold: to evaluate the reliability of the theory of the Lisse effect presented by Weeks to predict its magnitude in modeled situations that mimic the physical complexity of real aquifers, and to conduct parametric studies on the sensitivity of the water‐level rise in the well to soil properties and the rain event. The simulation results reveal that the magnitude of the Lisse effect increases with the ponding depth. Soil permeability plays a key role in generating the Lisse effect. The water‐level rise in the well is delayed relative to the air‐pressure rise in the unsaturated zone when the soil permeability is low, and the maximum water‐level rise is less than the maximum air pressure induced by rain infiltration. The simulation also explores the sensitivity of the Lisse effect to the van Genuchten parameters and the water table depth.
","language":"English","publisher":"American Geophysical Union","doi":"10.1029/2007WR006294","usgsCitation":"Guo, H., Jiao, J.J., and Weeks, E.P., 2008, Rain‐induced subsurface airflow and Lisse effect: Water Resources Research, v. 44, no. 7, Article W07409; 9 p., https://doi.org/10.1029/2007WR006294.","productDescription":"Article W07409; 9 p.","costCenters":[],"links":[{"id":242090,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"44","issue":"7","noUsgsAuthors":false,"publicationDate":"2008-07-18","publicationStatus":"PW","scienceBaseUri":"505a944ae4b0c8380cd81301","contributors":{"authors":[{"text":"Guo, Haipeng","contributorId":152547,"corporation":false,"usgs":false,"family":"Guo","given":"Haipeng","email":"","affiliations":[],"preferred":false,"id":441670,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Jiao, Jiu J.","contributorId":80132,"corporation":false,"usgs":false,"family":"Jiao","given":"Jiu","email":"","middleInitial":"J.","affiliations":[],"preferred":false,"id":441672,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Weeks, Edwin P. epweeks@usgs.gov","contributorId":2576,"corporation":false,"usgs":true,"family":"Weeks","given":"Edwin","email":"epweeks@usgs.gov","middleInitial":"P.","affiliations":[],"preferred":true,"id":441671,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70033598,"text":"70033598 - 2008 - High resolution shallow geologic characterization of a late Pleistocene eolian environment using ground penetrating radar and optically stimulated luminescence techniques: North Carolina, USA","interactions":[],"lastModifiedDate":"2012-03-12T17:21:30","indexId":"70033598","displayToPublicDate":"2008-01-01T00:00:00","publicationYear":"2008","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":3443,"text":"Southeastern Geology","active":true,"publicationSubtype":{"id":10}},"title":"High resolution shallow geologic characterization of a late Pleistocene eolian environment using ground penetrating radar and optically stimulated luminescence techniques: North Carolina, USA","docAbstract":"Geophysical surveys, sedimentology, and optically-stimulated luminescence age analyses were used to assess the geologic development of a coastal system near Swansboro, NC. This area is a significant Woodland Period Native American habitation and is designated the \"Broad Reach\" archaeological site. 2-d and 3-d subsurface geophysical surveys were performed using a ground penetrating radar system to define the stratigraphic framework and depositional facies. Sediment samples were collected and analyzed for grain-size to determine depositional environments. Samples were acquired and analyzed using optically stimulated luminescence techniques to derive the depositional age of the various features. The data support a low eolian to shallow subtidal coastal depositional setting for this area. Li-DAR data reveal ridge and swale topography, most likely related to beach ridges, and eolian features including low-relief, low-angle transverse and parabolic dunes, blowouts, and a low-relief eolian sand sheet. Geophysical data reveal dominantly seaward dipping units, and low-angle mounded features. Sedimentological data reveal mostly moderately-well to well-sorted fine-grained symmetrical to coarse skewed sands, suggesting initial aqueous transport and deposition, followed by eolian reworking and bioturbation. OSL data indicate initial coastal deposition prior to ca. 45,000 yBP, followed by eolian reworking and low dune stabilization at ca. 13,000 to 11,500 yBP, and again at ca. 10,000 yBP (during, and slightly after the Younger Dryas chronozone).","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Southeastern Geology","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","issn":"00383678","usgsCitation":"Mallinson, D., Mahan, S., and Moore, C., 2008, High resolution shallow geologic characterization of a late Pleistocene eolian environment using ground penetrating radar and optically stimulated luminescence techniques: North Carolina, USA: Southeastern Geology, v. 45, no. 3, p. 161-177.","startPage":"161","endPage":"177","numberOfPages":"17","costCenters":[],"links":[{"id":241892,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"45","issue":"3","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a30d1e4b0c8380cd5d991","contributors":{"authors":[{"text":"Mallinson, D.","contributorId":93686,"corporation":false,"usgs":true,"family":"Mallinson","given":"D.","affiliations":[],"preferred":false,"id":441607,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Mahan, S.","contributorId":98894,"corporation":false,"usgs":true,"family":"Mahan","given":"S.","email":"","affiliations":[],"preferred":false,"id":441608,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Moore, Christine","contributorId":21774,"corporation":false,"usgs":true,"family":"Moore","given":"Christine","email":"","affiliations":[],"preferred":false,"id":441606,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70033587,"text":"70033587 - 2008 - Collaboration tools and techniques for large model datasets","interactions":[],"lastModifiedDate":"2017-08-23T12:24:46","indexId":"70033587","displayToPublicDate":"2008-01-01T00:00:00","publicationYear":"2008","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2381,"text":"Journal of Marine Systems","active":true,"publicationSubtype":{"id":10}},"title":"Collaboration tools and techniques for large model datasets","docAbstract":"In MREA and many other marine applications, it is common to have multiple models running with different grids, run by different institutions. Techniques and tools are described for low-bandwidth delivery of data from large multidimensional datasets, such as those from meteorological and oceanographic models, directly into generic analysis and visualization tools. Output is stored using the NetCDF CF Metadata Conventions, and then delivered to collaborators over the web via OPeNDAP. OPeNDAP datasets served by different institutions are then organized via THREDDS catalogs. Tools and procedures are then used which enable scientists to explore data on the original model grids using tools they are familiar with. It is also low-bandwidth, enabling users to extract just the data they require, an important feature for access from ship or remote areas. The entire implementation is simple enough to be handled by modelers working with their webmasters - no advanced programming support is necessary. ?? 2007 Elsevier B.V. All rights reserved.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Journal of Marine Systems","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1016/j.jmarsys.2007.02.013","issn":"09247963","usgsCitation":"Signell, R.P., Carniel, S., Chiggiato, J., Janekovic, I., Pullen, J., and Sherwood, C.R., 2008, Collaboration tools and techniques for large model datasets: Journal of Marine Systems, v. 69, no. 1-2, p. 154-161, https://doi.org/10.1016/j.jmarsys.2007.02.013.","productDescription":"8 p.","startPage":"154","endPage":"161","costCenters":[{"id":678,"text":"Woods Hole Coastal and Marine Science Center","active":true,"usgs":true}],"links":[{"id":476753,"rank":1,"type":{"id":41,"text":"Open Access External Repository Page"},"url":"https://hdl.handle.net/1912/2050","text":"External Repository"},{"id":242220,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"69","issue":"1-2","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"5059f7abe4b0c8380cd4cc3d","contributors":{"authors":[{"text":"Signell, R. P.","contributorId":89147,"corporation":false,"usgs":true,"family":"Signell","given":"R.","email":"","middleInitial":"P.","affiliations":[],"preferred":false,"id":441567,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Carniel, S.","contributorId":47504,"corporation":false,"usgs":true,"family":"Carniel","given":"S.","email":"","affiliations":[],"preferred":false,"id":441564,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Chiggiato, J.","contributorId":47065,"corporation":false,"usgs":true,"family":"Chiggiato","given":"J.","affiliations":[],"preferred":false,"id":441563,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Janekovic, I.","contributorId":69796,"corporation":false,"usgs":true,"family":"Janekovic","given":"I.","email":"","affiliations":[],"preferred":false,"id":441566,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Pullen, J.","contributorId":34339,"corporation":false,"usgs":true,"family":"Pullen","given":"J.","email":"","affiliations":[],"preferred":false,"id":441562,"contributorType":{"id":1,"text":"Authors"},"rank":5},{"text":"Sherwood, C. R.","contributorId":48235,"corporation":false,"usgs":true,"family":"Sherwood","given":"C.","email":"","middleInitial":"R.","affiliations":[],"preferred":false,"id":441565,"contributorType":{"id":1,"text":"Authors"},"rank":6}]}} ,{"id":70033585,"text":"70033585 - 2008 - A close look at Saturn's rings with Cassini VIMS","interactions":[],"lastModifiedDate":"2012-03-12T17:21:33","indexId":"70033585","displayToPublicDate":"2008-01-01T00:00:00","publicationYear":"2008","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1963,"text":"Icarus","active":true,"publicationSubtype":{"id":10}},"title":"A close look at Saturn's rings with Cassini VIMS","docAbstract":"Soon after the Cassini-Huygens spacecraft entered orbit about Saturn on 1 July 2004, its Visual and Infrared Mapping Spectrometer obtained two continuous spectral scans across the rings, covering the wavelength range 0.35-5.1 ??m, at a spatial resolution of 15-25 km. The first scan covers the outer C and inner B rings, while the second covers the Cassini Division and the entire A ring. Comparisons of the VIMS radial reflectance profile at 1.08 ??m with similar profiles at a wavelength of 0.45 ??m assembled from Voyager images show very little change in ring structure over the intervening 24 years, with the exception of a few features already known to be noncircular. A model for single-scattering by a classical, many-particle-thick slab of material with normal optical depths derived from the Voyager photopolarimeter stellar occultation is found to provide an excellent fit to the observed VIMS reflectance profiles for the C ring and Cassini Division, and an acceptable fit for the inner B ring. The A ring deviates significantly from such a model, consistent with previous suggestions that this region may be closer to a monolayer. An additional complication here is the azimuthally-variable average optical depth associated with \"self-gravity wakes\" in this region and the fact that much of the A ring may be a mixture of almost opaque wakes and relatively transparent interwake zones. Consistently with previous studies, we find that the near-infrared spectra of all main ring regions are dominated by water ice, with a typical regolith grain radius of 5-20 ??m, while the steep decrease in visual reflectance shortward of 0.6 ??m is suggestive of an organic contaminant, perhaps tholin-like. Although no materials other than H2O ice have been identified with any certainty in the VIMS spectra of the rings, significant radial variations are seen in the strength of the water-ice absorption bands. Across the boundary between the C and B rings, over a radial range of ???7000 km, the near-IR band depths strengthen considerably. A very similar pattern is seen across the outer half of the Cassini Division and into the inner A ring, accompanied by a steepening of the red slope in the visible spectrum shortward of 0.55 ??m. We attribute these trends-as well as smaller-scale variations associated with strong density waves in the A ring-to differing grain sizes in the tholin-contaminated icy regolith that covers the surfaces of the decimeter-to-meter sized ring particles. On the largest scale, the spectral variations seen by VIMS suggest that the rings may be divided into two larger 'ring complexes,' with similar internal variations in structure, optical depth, particle size, regolith texture and composition. The inner complex comprises the C and B rings, while the outer comprises the Cassini Division and A ring. ?? 2007 Elsevier Inc. All rights reserved.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Icarus","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1016/j.icarus.2007.08.036","issn":"00191035","usgsCitation":"Nicholson, P.D., Hedman, M., Clark, R.N., Showalter, M., Cruikshank, D.P., Cuzzi, J., Filacchione, G., Capaccioni, F., Cerroni, P., Hansen, G.B., Sicardy, B., Drossart, P., Brown, R.H., Buratti, B.J., Baines, K.H., and Coradini, A., 2008, A close look at Saturn's rings with Cassini VIMS: Icarus, v. 193, no. 1, p. 182-212, https://doi.org/10.1016/j.icarus.2007.08.036.","startPage":"182","endPage":"212","numberOfPages":"31","costCenters":[],"links":[{"id":214461,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/j.icarus.2007.08.036"},{"id":242189,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"193","issue":"1","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"5059e345e4b0c8380cd45f17","contributors":{"authors":[{"text":"Nicholson, P. D.","contributorId":54330,"corporation":false,"usgs":false,"family":"Nicholson","given":"P.","email":"","middleInitial":"D.","affiliations":[],"preferred":false,"id":441549,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Hedman, M.M.","contributorId":91694,"corporation":false,"usgs":true,"family":"Hedman","given":"M.M.","email":"","affiliations":[],"preferred":false,"id":441553,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Clark, R. N.","contributorId":6568,"corporation":false,"usgs":true,"family":"Clark","given":"R.","email":"","middleInitial":"N.","affiliations":[],"preferred":false,"id":441539,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Showalter, M.R.","contributorId":24992,"corporation":false,"usgs":true,"family":"Showalter","given":"M.R.","email":"","affiliations":[],"preferred":false,"id":441542,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Cruikshank, D. P.","contributorId":51434,"corporation":false,"usgs":false,"family":"Cruikshank","given":"D.","email":"","middleInitial":"P.","affiliations":[],"preferred":false,"id":441547,"contributorType":{"id":1,"text":"Authors"},"rank":5},{"text":"Cuzzi, J.N.","contributorId":53962,"corporation":false,"usgs":true,"family":"Cuzzi","given":"J.N.","email":"","affiliations":[],"preferred":false,"id":441548,"contributorType":{"id":1,"text":"Authors"},"rank":6},{"text":"Filacchione, G.","contributorId":48740,"corporation":false,"usgs":true,"family":"Filacchione","given":"G.","affiliations":[],"preferred":false,"id":441546,"contributorType":{"id":1,"text":"Authors"},"rank":7},{"text":"Capaccioni, F.","contributorId":90900,"corporation":false,"usgs":true,"family":"Capaccioni","given":"F.","email":"","affiliations":[],"preferred":false,"id":441552,"contributorType":{"id":1,"text":"Authors"},"rank":8},{"text":"Cerroni, P.","contributorId":7869,"corporation":false,"usgs":true,"family":"Cerroni","given":"P.","affiliations":[],"preferred":false,"id":441540,"contributorType":{"id":1,"text":"Authors"},"rank":9},{"text":"Hansen, G. B.","contributorId":98478,"corporation":false,"usgs":false,"family":"Hansen","given":"G.","email":"","middleInitial":"B.","affiliations":[],"preferred":false,"id":441554,"contributorType":{"id":1,"text":"Authors"},"rank":10},{"text":"Sicardy, B.","contributorId":57622,"corporation":false,"usgs":true,"family":"Sicardy","given":"B.","affiliations":[],"preferred":false,"id":441550,"contributorType":{"id":1,"text":"Authors"},"rank":11},{"text":"Drossart, P.","contributorId":29574,"corporation":false,"usgs":true,"family":"Drossart","given":"P.","affiliations":[],"preferred":false,"id":441543,"contributorType":{"id":1,"text":"Authors"},"rank":12},{"text":"Brown, R. H.","contributorId":19931,"corporation":false,"usgs":false,"family":"Brown","given":"R.","email":"","middleInitial":"H.","affiliations":[],"preferred":false,"id":441541,"contributorType":{"id":1,"text":"Authors"},"rank":13},{"text":"Buratti, B. J.","contributorId":69280,"corporation":false,"usgs":false,"family":"Buratti","given":"B.","email":"","middleInitial":"J.","affiliations":[],"preferred":false,"id":441551,"contributorType":{"id":1,"text":"Authors"},"rank":14},{"text":"Baines, K. H.","contributorId":37868,"corporation":false,"usgs":false,"family":"Baines","given":"K.","email":"","middleInitial":"H.","affiliations":[],"preferred":false,"id":441545,"contributorType":{"id":1,"text":"Authors"},"rank":15},{"text":"Coradini, A.","contributorId":34679,"corporation":false,"usgs":true,"family":"Coradini","given":"A.","affiliations":[],"preferred":false,"id":441544,"contributorType":{"id":1,"text":"Authors"},"rank":16}]}} ,{"id":70032116,"text":"70032116 - 2008 - Use of tolerance values to diagnose water-quality stressors to aquatic biota in New England streams","interactions":[],"lastModifiedDate":"2012-03-12T17:21:29","indexId":"70032116","displayToPublicDate":"2008-01-01T00:00:00","publicationYear":"2008","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1456,"text":"Ecological Indicators","active":true,"publicationSubtype":{"id":10}},"title":"Use of tolerance values to diagnose water-quality stressors to aquatic biota in New England streams","docAbstract":"Identification of stressors related to biological impairment is critical to biological assessments. We applied nationally derived tolerance indicator values for four water-quality variables to fish and benthic macroinvertebrate assemblages at 29 sites along an urban gradient in New England. Tolerance indicator values (TIVs), as biologically based predictors of water-quality variables, were determined for dissolved oxygen, nitrite plus nitrate (nitrate), total phosphorus, and water temperature for each site based on observed biological assemblages (TIVO), and for expected assemblages (TIVE). The quotient method, based on a ratio of the TIVs for observed and expected assemblages (tolerance units), was used to diagnose potential water-quality stressors. In addition, the ratio of measured water-quality values to water-quality criteria (water-quality units) was calculated for each water-quality variable to assess measured water-quality stressors. Results from a RIVPACS predictive model for benthic macroinvertebrates and Bray-Curtis dissimilarity for fish were used to classify sites into categories of good or impaired ecological condition. Significant differences were detected between good and impaired sites for all biological tolerance units (fish and benthic macroinvertebrate assemblages averaged) except for nitrate (P = 0.480), and for all water-quality units except for nitrate (P = 0.183). Diagnosis of water-quality stressors at selected sites was, in general, consistent with State-reported causes of impairment. Tolerance units for benthic macroinvertebrate and fish assemblages were significantly correlated for water temperature (P = 0.001, r = 0.63), dissolved oxygen (P = 0.001, r = 0.61), and total phosphorus (P = 0.001, r = 0.61), but not for nitrate (P = 0.059, r = -0.35). Differences between the two assemblages in site-specific diagnosis of water-quality stressors may be the result of differences in nitrate tolerance.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Ecological Indicators","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1016/j.ecolind.2008.01.002","issn":"1470160X","usgsCitation":"Meador, M.R., Carlisle, D., and Coles, J., 2008, Use of tolerance values to diagnose water-quality stressors to aquatic biota in New England streams: Ecological Indicators, v. 8, no. 5, p. 718-728, https://doi.org/10.1016/j.ecolind.2008.01.002.","startPage":"718","endPage":"728","numberOfPages":"11","costCenters":[],"links":[{"id":242400,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":214656,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/j.ecolind.2008.01.002"}],"volume":"8","issue":"5","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505bbfa4e4b08c986b329ca1","contributors":{"authors":[{"text":"Meador, M. R.","contributorId":74400,"corporation":false,"usgs":true,"family":"Meador","given":"M.","email":"","middleInitial":"R.","affiliations":[],"preferred":false,"id":434600,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Carlisle, D.M.","contributorId":81059,"corporation":false,"usgs":true,"family":"Carlisle","given":"D.M.","email":"","affiliations":[],"preferred":false,"id":434602,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Coles, J.F.","contributorId":80257,"corporation":false,"usgs":true,"family":"Coles","given":"J.F.","affiliations":[],"preferred":false,"id":434601,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70033575,"text":"70033575 - 2008 - Pathogen and chemical transport in the karst limestone of the Biscayne aquifer: 1. Revised conceptualization of groundwater flow","interactions":[],"lastModifiedDate":"2018-10-22T08:41:54","indexId":"70033575","displayToPublicDate":"2008-01-01T00:00:00","publicationYear":"2008","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":"Pathogen and chemical transport in the karst limestone of the Biscayne aquifer: 1. Revised conceptualization of groundwater flow","docAbstract":"The Biscayne aquifer is a highly transmissive karst limestone that serves as the sole source of drinking water to over two million residents in south Florida. The aquifer is characterized by eogenetic karst, where the most transmissive void space can be an interconnected, touching‐vug, biogenically influenced porosity of biogenic origin. Public supply wells in the aquifer are in close proximity to lakes established by surface mining. The mining of the limestone has occurred to the same depths as the production wells, which has raised concerns about pathogen and chemical transport from these surface water bodies. Hydraulic and forced gradient tracer tests were conducted to augment geologic and geophysical studies and to develop a hydrogeologic conceptual model of groundwater flow and chemical transport in the Biscayne aquifer. Geologic and geophysical data indicate multiple, areally extensive subhorizontal preferential flow zones of vuggy limestone separated by rock with a matrix pore system. The hydraulic response from an aquifer test suggests that the Biscayne aquifer behaves as a dual‐porosity medium; however, the results of the tracer test showed rapid transport similar to other types of karst. The tracer test and concurrent temperature logging revealed that only one of the touching‐vug flow zones dominates transport near the production wells. On the basis of the rising limb of the breakthrough curve, the dispersivity is estimated to be less than 3% of the tracer travel distance, which suggests that the fastest flow paths in the formation are likely to yield limited dilution of chemical constituents.
","language":"English","publisher":"American Geophysical Union","doi":"10.1029/2007WR006058","usgsCitation":"Renken, R.A., Cunningham, K.J., Shapiro, A.M., Harvey, R.W., Zygnerski, M.R., Metge, D.W., and Wacker, M.A., 2008, Pathogen and chemical transport in the karst limestone of the Biscayne aquifer: 1. Revised conceptualization of groundwater flow: Water Resources Research, v. 44, no. 8, W08429; 16 p., https://doi.org/10.1029/2007WR006058.","productDescription":"W08429; 16 p.","costCenters":[{"id":589,"text":"Toxic Substances Hydrology Program","active":true,"usgs":true}],"links":[{"id":476744,"rank":1,"type":{"id":40,"text":"Open Access Publisher Index Page"},"url":"https://doi.org/10.1029/2007wr006058","text":"Publisher Index Page"},{"id":242021,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"44","issue":"8","noUsgsAuthors":false,"publicationDate":"2008-08-23","publicationStatus":"PW","scienceBaseUri":"505a7595e4b0c8380cd77c14","contributors":{"authors":[{"text":"Renken, Robert A. rarenken@usgs.gov","contributorId":269,"corporation":false,"usgs":true,"family":"Renken","given":"Robert","email":"rarenken@usgs.gov","middleInitial":"A.","affiliations":[],"preferred":true,"id":441504,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Cunningham, Kevin J. 0000-0002-2179-8686 kcunning@usgs.gov","orcid":"https://orcid.org/0000-0002-2179-8686","contributorId":1689,"corporation":false,"usgs":true,"family":"Cunningham","given":"Kevin","email":"kcunning@usgs.gov","middleInitial":"J.","affiliations":[{"id":269,"text":"FLWSC-Ft. Lauderdale","active":true,"usgs":true}],"preferred":true,"id":441499,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Shapiro, Allen M. 0000-0002-6425-9607 ashapiro@usgs.gov","orcid":"https://orcid.org/0000-0002-6425-9607","contributorId":2164,"corporation":false,"usgs":true,"family":"Shapiro","given":"Allen","email":"ashapiro@usgs.gov","middleInitial":"M.","affiliations":[{"id":436,"text":"National Research Program - Eastern Branch","active":true,"usgs":true},{"id":37277,"text":"WMA - Earth System Processes Division","active":true,"usgs":true}],"preferred":true,"id":441502,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Harvey, Ronald W. 0000-0002-2791-8503 rwharvey@usgs.gov","orcid":"https://orcid.org/0000-0002-2791-8503","contributorId":564,"corporation":false,"usgs":true,"family":"Harvey","given":"Ronald","email":"rwharvey@usgs.gov","middleInitial":"W.","affiliations":[{"id":5044,"text":"National Research Program - Central Branch","active":true,"usgs":true}],"preferred":true,"id":441498,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Zygnerski, Michael R.","contributorId":25469,"corporation":false,"usgs":true,"family":"Zygnerski","given":"Michael","email":"","middleInitial":"R.","affiliations":[],"preferred":false,"id":441500,"contributorType":{"id":1,"text":"Authors"},"rank":5},{"text":"Metge, David W. dwmetge@usgs.gov","contributorId":663,"corporation":false,"usgs":true,"family":"Metge","given":"David","email":"dwmetge@usgs.gov","middleInitial":"W.","affiliations":[{"id":5044,"text":"National Research Program - Central Branch","active":true,"usgs":true}],"preferred":true,"id":441501,"contributorType":{"id":1,"text":"Authors"},"rank":6},{"text":"Wacker, Michael A. mwacker@usgs.gov","contributorId":2162,"corporation":false,"usgs":true,"family":"Wacker","given":"Michael","email":"mwacker@usgs.gov","middleInitial":"A.","affiliations":[{"id":269,"text":"FLWSC-Ft. Lauderdale","active":true,"usgs":true}],"preferred":true,"id":441503,"contributorType":{"id":1,"text":"Authors"},"rank":7}]}} ,{"id":70033434,"text":"70033434 - 2008 - Regulating continent growth and composition by chemical weathering","interactions":[],"lastModifiedDate":"2012-03-12T17:21:32","indexId":"70033434","displayToPublicDate":"2008-01-01T00:00:00","publicationYear":"2008","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":3165,"text":"Proceedings of the National Academy of Sciences of the United States of America","active":true,"publicationSubtype":{"id":10}},"title":"Regulating continent growth and composition by chemical weathering","docAbstract":"Continents ride high above the ocean floor because they are underlain by thick, low-density, Si-rich, and Mg-poor crust. However, the parental magmas of continents were basaltic, which means they must have lost Mg relative to Si during their maturation into continents. Igneous differentiation followed by lower crustal delamination and chemical weathering followed by subduction recycling are possible solutions, but the relative magnitudes of each process have never been quantitatively constrained because of the lack of appropriate data. Here, we show that the relative contributions of these processes can be obtained by simultaneous examination of Mg and Li (an analog for Mg) on the regional and global scales in arcs, delaminated lower crust, and river waters. At least 20% of Mg is lost from continents by weathering, which translates into >20% of continental mass lost by weathering (40% by delamination). Chemical weathering leaves behind a more Si-rich and Mg-poor crust, which is less dense and hence decreases the probability of crustal recycling by subduction. Net continental growth is thus modulated by chemical weathering and likely influenced by secular changes in weathering mechanisms. ?? 2008 by The National Academy of Sciences of the USA.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Proceedings of the National Academy of Sciences of the United States of America","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1073/pnas.0711143105","issn":"00278424","usgsCitation":"Lee, C., Morton, D.M., Little, M., Kistler, R., Horodyskyj, U., Leeman, W., and Agranier, A., 2008, Regulating continent growth and composition by chemical weathering: Proceedings of the National Academy of Sciences of the United States of America, v. 105, no. 13, p. 4981-4986, https://doi.org/10.1073/pnas.0711143105.","startPage":"4981","endPage":"4986","numberOfPages":"6","costCenters":[],"links":[{"id":487732,"rank":10000,"type":{"id":41,"text":"Open Access External Repository Page"},"url":"https://insu.hal.science/insu-00305310","text":"External Repository"},{"id":214329,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1073/pnas.0711143105"},{"id":242046,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"105","issue":"13","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"50e4a5d5e4b0e8fec6cdc027","contributors":{"authors":[{"text":"Lee, C.-T.A.","contributorId":20549,"corporation":false,"usgs":true,"family":"Lee","given":"C.-T.A.","email":"","affiliations":[],"preferred":false,"id":440854,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Morton, D. M.","contributorId":54608,"corporation":false,"usgs":true,"family":"Morton","given":"D.","email":"","middleInitial":"M.","affiliations":[],"preferred":false,"id":440858,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Little, M.G.","contributorId":31998,"corporation":false,"usgs":true,"family":"Little","given":"M.G.","email":"","affiliations":[],"preferred":false,"id":440855,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Kistler, R.","contributorId":92878,"corporation":false,"usgs":true,"family":"Kistler","given":"R.","affiliations":[],"preferred":false,"id":440859,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Horodyskyj, U.N.","contributorId":45130,"corporation":false,"usgs":true,"family":"Horodyskyj","given":"U.N.","affiliations":[],"preferred":false,"id":440857,"contributorType":{"id":1,"text":"Authors"},"rank":5},{"text":"Leeman, W.P.","contributorId":7841,"corporation":false,"usgs":true,"family":"Leeman","given":"W.P.","affiliations":[],"preferred":false,"id":440853,"contributorType":{"id":1,"text":"Authors"},"rank":6},{"text":"Agranier, A.","contributorId":35136,"corporation":false,"usgs":true,"family":"Agranier","given":"A.","email":"","affiliations":[],"preferred":false,"id":440856,"contributorType":{"id":1,"text":"Authors"},"rank":7}]}} ,{"id":70032101,"text":"70032101 - 2008 - Translocation and early post-release demography of endangered Laysan teal","interactions":[],"lastModifiedDate":"2012-03-12T17:21:27","indexId":"70032101","displayToPublicDate":"2008-01-01T00:00:00","publicationYear":"2008","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":774,"text":"Animal Conservation","active":true,"publicationSubtype":{"id":10}},"title":"Translocation and early post-release demography of endangered Laysan teal","docAbstract":"In an attempt to reduce the high extinction risk inherent to small island populations, we translocated wild Laysan teal Anas laysanensis to a portion of its presumed prehistoric range. Most avian translocations lack the strategic post-release monitoring needed to assess early population establishment or failure. Therefore, we monitored the survival and reproduction of all founders, and their first-generation offspring using radio telemetry for 2 years after the first release. Forty-two Laysan teal were sourced directly from the only extant population on Laysan Island and transported 2 days by ship to Midway Atoll. All birds survived the translocation with nutritional and veterinary support, and spent between 4 and 14 days in captivity. Post-release survival of 42 founders was 0.857 (95% CI 0.86-0.99) during 2004-2006 or annualized 0.92 (95% CI 0.83-0.98). Seventeen of 18 founding hens attempted nesting in the first two breeding seasons. Fledgling success was 0.57 (95% CI 0.55-0.60) in 2005 and 0.63 (95% CI 0.62-0.64) in 2006. The effective founding female population (Ne) was 13. We applied these initial demographic rates to model population growth. The nascent population size increased to >100 after only 2 years post-release (?? = 1.73). If this growth rate continues, the size of the Midway population could surpass the source population before 2010. ?? 2008 The Authors. Journal compilation ?? 2008 The Zoological Society of London.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Animal Conservation","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1111/j.1469-1795.2008.00166.x","issn":"13679430","usgsCitation":"Reynolds, M., Seavy, N., Vekasy, M., Klavitter, J., and Laniawe, L., 2008, Translocation and early post-release demography of endangered Laysan teal: Animal Conservation, v. 11, no. 2, p. 160-168, https://doi.org/10.1111/j.1469-1795.2008.00166.x.","startPage":"160","endPage":"168","numberOfPages":"9","costCenters":[],"links":[{"id":476886,"rank":10000,"type":{"id":40,"text":"Open Access Publisher Index Page"},"url":"https://doi.org/10.1111/j.1469-1795.2008.00166.x","text":"Publisher Index Page"},{"id":242730,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":214968,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1111/j.1469-1795.2008.00166.x"}],"volume":"11","issue":"2","noUsgsAuthors":false,"publicationDate":"2008-03-27","publicationStatus":"PW","scienceBaseUri":"505bb71ce4b08c986b327073","contributors":{"authors":[{"text":"Reynolds, M.H. 0000-0001-7253-8158","orcid":"https://orcid.org/0000-0001-7253-8158","contributorId":64214,"corporation":false,"usgs":true,"family":"Reynolds","given":"M.H.","affiliations":[],"preferred":false,"id":434556,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Seavy, N.E.","contributorId":26403,"corporation":false,"usgs":true,"family":"Seavy","given":"N.E.","affiliations":[],"preferred":false,"id":434555,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Vekasy, M.S.","contributorId":70345,"corporation":false,"usgs":true,"family":"Vekasy","given":"M.S.","email":"","affiliations":[],"preferred":false,"id":434557,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Klavitter, J.L.","contributorId":8677,"corporation":false,"usgs":true,"family":"Klavitter","given":"J.L.","affiliations":[],"preferred":false,"id":434553,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Laniawe, L.P.","contributorId":15420,"corporation":false,"usgs":true,"family":"Laniawe","given":"L.P.","affiliations":[],"preferred":false,"id":434554,"contributorType":{"id":1,"text":"Authors"},"rank":5}]}} ,{"id":70032099,"text":"70032099 - 2008 - Effective mitigation of debris flows at Lemon Dam, La Plata County, Colorado","interactions":[],"lastModifiedDate":"2012-03-12T17:21:27","indexId":"70032099","displayToPublicDate":"2008-01-01T00:00:00","publicationYear":"2008","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1801,"text":"Geomorphology","active":true,"publicationSubtype":{"id":10}},"title":"Effective mitigation of debris flows at Lemon Dam, La Plata County, Colorado","docAbstract":"To reduce the hazards from debris flows in drainage basins burned by wildfire, erosion control measures such as construction of check dams, installation of log erosion barriers (LEBs), and spreading of straw mulch and seed are common practice. After the 2002 Missionary Ridge Fire in southwest Colorado, these measures were implemented at Knight Canyon above Lemon Dam to protect the intake structures of the dam from being filled with sediment. Hillslope erosion protection measures included LEBs at concentrations of 220-620/ha (200-600% of typical densities), straw mulch was hand spread at concentrations up to 5.6??metric tons/hectare (125% of typical densities), and seeds were hand spread at 67-84??kg/ha (150% of typical values). The mulch was carefully crimped into the soil to keep it in place. In addition, 13 check dams and 3 debris racks were installed in the main drainage channel of the basin. The technical literature shows that each mitigation method working alone, or improperly constructed or applied, was inconsistent in its ability to reduce erosion and sedimentation. At Lemon Dam, however, these methods were effective in virtually eliminating sedimentation into the reservoir, which can be attributed to a number of factors: the density of application of each mitigation method, the enhancement of methods working in concert, the quality of installation, and rehabilitation of mitigation features to extend their useful life. The check dams effectively trapped the sediment mobilized during rainstorms, and only a few cubic meters of debris traveled downchannel, where it was intercepted by debris racks. Using a debris volume-prediction model developed for use in burned basins in the Western U.S., recorded rainfall events following the Missionary Ridge Fire should have produced a debris flow of approximately 10,000??m3 at Knight Canyon. The mitigation measures, therefore, reduced the debris volume by several orders of magnitude. For comparison, rainstorm-induced debris flows occurred in two adjacent canyons at volumes within the range predicted by the model. ?? 2007 Elsevier B.V. All rights reserved.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Geomorphology","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1016/j.geomorph.2007.04.008","issn":"0169555X","usgsCitation":"deWolfe, V., Santi, P., Ey, J., and Gartner, J., 2008, Effective mitigation of debris flows at Lemon Dam, La Plata County, Colorado: Geomorphology, v. 96, no. 3-4, p. 366-377, https://doi.org/10.1016/j.geomorph.2007.04.008.","startPage":"366","endPage":"377","numberOfPages":"12","costCenters":[],"links":[{"id":214935,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/j.geomorph.2007.04.008"},{"id":242696,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"96","issue":"3-4","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a0633e4b0c8380cd51150","contributors":{"authors":[{"text":"deWolfe, V.G.","contributorId":97722,"corporation":false,"usgs":true,"family":"deWolfe","given":"V.G.","affiliations":[],"preferred":false,"id":434549,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Santi, P.M.","contributorId":82927,"corporation":false,"usgs":true,"family":"Santi","given":"P.M.","email":"","affiliations":[],"preferred":false,"id":434548,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Ey, J.","contributorId":54422,"corporation":false,"usgs":true,"family":"Ey","given":"J.","affiliations":[],"preferred":false,"id":434546,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Gartner, J.E.","contributorId":80098,"corporation":false,"usgs":true,"family":"Gartner","given":"J.E.","email":"","affiliations":[],"preferred":false,"id":434547,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}} ,{"id":70031784,"text":"70031784 - 2008 - A review of the endemic Hawaiian Drosophilidae and their host plants","interactions":[],"lastModifiedDate":"2012-03-12T17:21:13","indexId":"70031784","displayToPublicDate":"2008-01-01T00:00:00","publicationYear":"2008","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":3814,"text":"Zootaxa","onlineIssn":"1175-5334","printIssn":"1175-5326","active":true,"publicationSubtype":{"id":10}},"title":"A review of the endemic Hawaiian Drosophilidae and their host plants","docAbstract":"The Hawaiian Drosophilidae is one of the best examples of rapid speciation in nature. Nearly 1,000 species of endemic drosophilids have evolved in situ in Hawaii since a single colonist arrived over 25 million years ago. A number of mechanisms, including ecological adaptation, sexual selection, and geographic isolation, have been proposed to explain the evolution of this hyperdiverse group of species. Here, we examine the known ecological associations of 326 species of endemic Hawaiian Drosophilidae in light of the phylogenetic relationships of these species. Our analysis suggests that the long-accepted belief of strict ecological specialization in this group does not hold for all taxa. While many species have a primary host plant family, females will also oviposit on non-preferred host plant taxa. Host shifting is fairly common in some groups, especially the grimshawi and modified mouthparts species groups of Drosophila, and the Scaptomyza subgenus Elmomyza. Associations with types of substrates (bark, leaves, flowers) are more evolutionarily conserved than associations with host plant families. These data not only give us insight into the role ecology has played in the evolution of this large group, but can help in making decisions about the management of rare and endangered host plants and the insects that rely upon them for survival. Copyright ?? 2008 Magnolia Press.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Zootaxa","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","issn":"11755326","usgsCitation":"Magnacca, K., Foote, D., and O’Grady, P.M., 2008, A review of the endemic Hawaiian Drosophilidae and their host plants: Zootaxa, no. 1728, p. 1-58.","startPage":"1","endPage":"58","numberOfPages":"58","costCenters":[],"links":[{"id":239879,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"issue":"1728","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"5059e559e4b0c8380cd46cdb","contributors":{"authors":[{"text":"Magnacca, K.N.","contributorId":103872,"corporation":false,"usgs":true,"family":"Magnacca","given":"K.N.","affiliations":[],"preferred":false,"id":433107,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Foote, D.","contributorId":94823,"corporation":false,"usgs":true,"family":"Foote","given":"D.","affiliations":[],"preferred":false,"id":433106,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"O’Grady, P. M.","contributorId":53601,"corporation":false,"usgs":true,"family":"O’Grady","given":"P.","email":"","middleInitial":"M.","affiliations":[],"preferred":false,"id":433105,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70033433,"text":"70033433 - 2008 - A laboratory study of particle ploughing and pore-pressure feedback: A velocity-weakening mechanism for soft glacier beds","interactions":[],"lastModifiedDate":"2012-03-12T17:21:33","indexId":"70033433","displayToPublicDate":"2008-01-01T00:00:00","publicationYear":"2008","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2328,"text":"Journal of Glaciology","active":true,"publicationSubtype":{"id":10}},"title":"A laboratory study of particle ploughing and pore-pressure feedback: A velocity-weakening mechanism for soft glacier beds","docAbstract":"If basal-water discharge and pressure are sufficiently high, a soft-bedded glacier will slip over its bed by ploughing, the process in which particles that span the ice-bed interface are dragged across the bed surface. Results of laboratory experiments indicate that resistance to ploughing can decrease with increasing ploughing velocity (velocity weakening). During ploughing at various velocities (15-400 ma-1), till was compacted in front of idealized particles, causing pore pressures there that were orders of magnitude higher than the ambient value. This excess pore pressure locally weakened the till in shear, thereby decreasing ploughing resistance by a factor of 3.0-6.6 with a six-fold increase in ploughing velocity. Characteristic timescales of pore-pressure diffusion and compaction down-glacier from ploughing particles depend on till diffusivity, ploughing velocity and sizes of ploughing particles. These timescales accurately predict the ranges of these variables over which excess pore pressure and velocity weakening occurred. Existing ploughing models do not account for velocity weakening. A new ploughing model with no adjustable parameters predicts ploughing resistance to no worse than 38% but requires that excess pore pressures be measured. Velocity weakening by this mechanism may affect fast glacier flow, sediment transport by bed deformation and basal seismicity.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Journal of Glaciology","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.3189/002214308784409008","issn":"00221430","usgsCitation":"Thomason, J., and Iverson, N., 2008, A laboratory study of particle ploughing and pore-pressure feedback: A velocity-weakening mechanism for soft glacier beds: Journal of Glaciology, v. 54, no. 184, p. 169-181, https://doi.org/10.3189/002214308784409008.","startPage":"169","endPage":"181","numberOfPages":"13","costCenters":[],"links":[{"id":476763,"rank":10000,"type":{"id":40,"text":"Open Access Publisher Index Page"},"url":"https://doi.org/10.3189/002214308784409008","text":"Publisher Index Page"},{"id":214303,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.3189/002214308784409008"},{"id":242012,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"54","issue":"184","noUsgsAuthors":false,"publicationDate":"2017-09-08","publicationStatus":"PW","scienceBaseUri":"5059e42ee4b0c8380cd4648d","contributors":{"authors":[{"text":"Thomason, J.F.","contributorId":11745,"corporation":false,"usgs":true,"family":"Thomason","given":"J.F.","email":"","affiliations":[],"preferred":false,"id":440851,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Iverson, N.R.","contributorId":19682,"corporation":false,"usgs":true,"family":"Iverson","given":"N.R.","email":"","affiliations":[],"preferred":false,"id":440852,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70033422,"text":"70033422 - 2008 - Determining an age for the Inararo Tuff eruption of Mt. Pinatubo, based on correlation with a distal ash layer in core MD97-2142, South China Sea","interactions":[],"lastModifiedDate":"2012-03-12T17:21:37","indexId":"70033422","displayToPublicDate":"2008-01-01T00:00:00","publicationYear":"2008","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":3217,"text":"Quaternary International","active":true,"publicationSubtype":{"id":10}},"title":"Determining an age for the Inararo Tuff eruption of Mt. Pinatubo, based on correlation with a distal ash layer in core MD97-2142, South China Sea","docAbstract":"The largest known eruption of Mt. Pinatubo in the late Quaternary was the Inararo Tuff Formation (ITF) eruption, roughly estimated as five times larger than the 1991 eruption. The precise age of the ITF eruption has been uncertain. Here, a correlative of the ITF eruption, Layer D, is identified in marine sediments, and an age obtained. Tephras were identified in core MD97-2142 of Leg II of the IMAGES III cruise in northern offshore of Palawan, southeastern South China Sea (12??41.33???N, 119??27.90???E). On the basis of the geochemical and isotopic fingerprints, Layer D can be correlated with the ITF eruption of the modern Pinatubo-eruption sequence. By means of the MD97-2142 SPECMAP chronology, Layer D was dated at around 81??2 ka. This estimated age of the ITF eruption and tephra Layer D coincides with an anomalously high SO4-2 spike occurring within the 5 millennia from 79 to 84 ka in the GISP2 ice core record. ?? 2007.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Quaternary International","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1016/j.quaint.2007.02.025","issn":"10406182","usgsCitation":"Ku, Y., Chen, C., Newhall, C.G., Song, S., Yang, T., Iizuka, Y., and McGeehin, J., 2008, Determining an age for the Inararo Tuff eruption of Mt. Pinatubo, based on correlation with a distal ash layer in core MD97-2142, South China Sea: Quaternary International, v. 178, no. 1, p. 138-145, https://doi.org/10.1016/j.quaint.2007.02.025.","startPage":"138","endPage":"145","numberOfPages":"8","costCenters":[],"links":[{"id":240801,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":213198,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/j.quaint.2007.02.025"}],"volume":"178","issue":"1","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"5059ffebe4b0c8380cd4f48d","contributors":{"authors":[{"text":"Ku, Y.-P.","contributorId":47169,"corporation":false,"usgs":true,"family":"Ku","given":"Y.-P.","email":"","affiliations":[],"preferred":false,"id":440806,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Chen, C.-H.","contributorId":62029,"corporation":false,"usgs":true,"family":"Chen","given":"C.-H.","email":"","affiliations":[],"preferred":false,"id":440809,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Newhall, C. G.","contributorId":93056,"corporation":false,"usgs":true,"family":"Newhall","given":"C.","email":"","middleInitial":"G.","affiliations":[],"preferred":false,"id":440812,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Song, S.-R.","contributorId":71004,"corporation":false,"usgs":true,"family":"Song","given":"S.-R.","email":"","affiliations":[],"preferred":false,"id":440810,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Yang, T.F.","contributorId":60861,"corporation":false,"usgs":true,"family":"Yang","given":"T.F.","email":"","affiliations":[],"preferred":false,"id":440808,"contributorType":{"id":1,"text":"Authors"},"rank":5},{"text":"Iizuka, Y.","contributorId":76949,"corporation":false,"usgs":true,"family":"Iizuka","given":"Y.","affiliations":[],"preferred":false,"id":440811,"contributorType":{"id":1,"text":"Authors"},"rank":6},{"text":"McGeehin, J.","contributorId":49554,"corporation":false,"usgs":true,"family":"McGeehin","given":"J.","email":"","affiliations":[],"preferred":false,"id":440807,"contributorType":{"id":1,"text":"Authors"},"rank":7}]}} ,{"id":70032135,"text":"70032135 - 2008 - Development and evaluation of geochemical methods for the sourcing of archaeological maize","interactions":[],"lastModifiedDate":"2018-02-15T12:58:12","indexId":"70032135","displayToPublicDate":"2008-01-01T00:00:00","publicationYear":"2008","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2182,"text":"Journal of Archaeological Science","active":true,"publicationSubtype":{"id":10}},"title":"Development and evaluation of geochemical methods for the sourcing of archaeological maize","docAbstract":"Strontium (Sr)-isotope values on bone from deer mice pairs from 12 field sites in the Chaco Canyon area, New Mexico, were compared with isotope values of synthetic soil waters from the same fields. The data indicate that mice obtain Sr from near-surface sources and that soil samples collected at depths ranging from 25 to 95 cm contain Sr that is more accessible to the deep roots of maize; thus, synthetic soil solutions provide better data for the sourcing of archaeological maize. However, the Sr-isotope composition of mice may be more valuable in sourcing archaeological remains of animals such as rabbit, turkey, and deer. In a separate study, five Native American maize (Zea mays L. ssp. mays) accessions grown out at New Mexico State University Agricultural Science Center, Farmington, New Mexico were used to determine if soil-water metal pairs partition systematically into cobs and kernels. The sampled maize included landraces from three Native American groups (Acoma, Hopi, Zuni) that still occupy the Four Corners area. Two cobs each were picked from 10 plants of each landrace. Partitioning of the Ba/Mn, Ba/Sr, Ca/Sr, and K/Rb metal pairs from the soil water to the cob appears to behave in a systematic fashion. In addition, 51 rare earth element (REE) pairs also appear to systematically partition from the soil water into cobs; however, the ratios of the REE dissolved in the soil waters are relatively invariant; therefore, the distribution coefficients that describe the partitioning of REE from the soil water to the cob may not apply to archeological cobs grown under chemically heterogeneous conditions. Partitioning of Ba/Rb, Ba/Sr, Mg/P, and Mn/P metal pairs from the soil water to kernels also behaves in a systematic fashion. Given that modern Native American landraces were grown under optimal environmental conditions that may not have been duplicated by prehistoric Native Americans, the distribution coefficients obtained in this study should be used with caution. ?? 2007 Elsevier Ltd. All rights reserved.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Journal of Archaeological Science","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1016/j.jas.2007.06.018","issn":"03054403","usgsCitation":"Benson, L.V., Taylor, H.E., Peterson, K., Shattuck, B., Ramotnik, C., and Stein, J., 2008, Development and evaluation of geochemical methods for the sourcing of archaeological maize: Journal of Archaeological Science, v. 35, no. 4, p. 912-921, https://doi.org/10.1016/j.jas.2007.06.018.","startPage":"912","endPage":"921","numberOfPages":"10","costCenters":[],"links":[{"id":214937,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/j.jas.2007.06.018"},{"id":242698,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"35","issue":"4","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a0022e4b0c8380cd4f5e3","contributors":{"authors":[{"text":"Benson, L. V.","contributorId":50159,"corporation":false,"usgs":true,"family":"Benson","given":"L.","email":"","middleInitial":"V.","affiliations":[],"preferred":false,"id":434673,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Taylor, Howard E. hetaylor@usgs.gov","contributorId":1551,"corporation":false,"usgs":true,"family":"Taylor","given":"Howard","email":"hetaylor@usgs.gov","middleInitial":"E.","affiliations":[{"id":5044,"text":"National Research Program - Central Branch","active":true,"usgs":true}],"preferred":true,"id":434672,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Peterson, K.A.","contributorId":65344,"corporation":false,"usgs":true,"family":"Peterson","given":"K.A.","email":"","affiliations":[],"preferred":false,"id":434675,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Shattuck, B.D.","contributorId":20226,"corporation":false,"usgs":true,"family":"Shattuck","given":"B.D.","email":"","affiliations":[],"preferred":false,"id":434670,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Ramotnik, C.A.","contributorId":23896,"corporation":false,"usgs":true,"family":"Ramotnik","given":"C.A.","email":"","affiliations":[],"preferred":false,"id":434671,"contributorType":{"id":1,"text":"Authors"},"rank":5},{"text":"Stein, J.R.","contributorId":60029,"corporation":false,"usgs":true,"family":"Stein","given":"J.R.","email":"","affiliations":[],"preferred":false,"id":434674,"contributorType":{"id":1,"text":"Authors"},"rank":6}]}} ,{"id":70033775,"text":"70033775 - 2008 - Range-wide patterns of greater sage-grouse persistence","interactions":[],"lastModifiedDate":"2017-12-27T15:10:43","indexId":"70033775","displayToPublicDate":"2008-01-01T00:00:00","publicationYear":"2008","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1399,"text":"Diversity and Distributions","active":true,"publicationSubtype":{"id":10}},"title":"Range-wide patterns of greater sage-grouse persistence","docAbstract":"Aim: Greater sage-grouse (Centrocercus urophasianus), a shrub-steppe obligate species of western North America, currently occupies only half its historical range. Here we examine how broad-scale, long-term trends in landscape condition have affected range contraction. Location: Sagebrush biome of the western USA. Methods: Logistic regression was used to assess persistence and extirpation of greater sage-grouse range based on landscape conditions measured by human population (density and population change), vegetation (percentage of sagebrush habitat), roads (density of and distance to roads), agriculture (cropland, farmland and cattle density), climate (number of severe and extreme droughts) and range periphery. Model predictions were used to identify areas where future extirpations can be expected, while also explaining possible causes of past extirpations. Results: Greater sage-grouse persistence and extirpation were significantly related to sagebrush habitat, cultivated cropland, human population density in 1950, prevalence of severe droughts and historical range periphery. Extirpation of sage-grouse was most likely in areas having at least four persons per square kilometre in 1950, 25% cultivated cropland in 2002 or the presence of three or more severe droughts per decade. In contrast, persistence of sage-grouse was expected when at least 30 km from historical range edge and in habitats containing at least 25% sagebrush cover within 30 km. Extirpation was most often explained (35%) by the combined effects of peripherality (within 30 km of range edge) and lack of sagebrush cover (less than 25% within 30 km). Based on patterns of prior extirpation and model predictions, we predict that 29% of remaining range may be at risk. Main Conclusions: Spatial patterns in greater sage-grouse range contraction can be explained by widely available landscape variables that describe patterns of remaining sagebrush habitat and loss due to cultivation, climatic trends, human population growth and peripherality of populations. However, future range loss may relate less to historical mechanisms and more to recent changes in land use and habitat condition, including energy developments and invasions by non-native species such as cheatgrass (Bromus tectorum) and West Nile virus. In conjunction with local measures of population performance, landscape-scale predictions of future range loss may be useful for prioritizing management and protection. Our results suggest that initial conservation efforts should focus on maintaining large expanses of sagebrush habitat, enhancing quality of existing habitats, and increasing habitat connectivity.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Diversity and Distributions","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1111/j.1472-4642.2008.00502.x","issn":"13669","usgsCitation":"Aldridge, C.L., Nielsen, S.E., Beyer, H.L., Boyce, M.S., Connelly, J., Knick, S.T., and Schroeder, M.A., 2008, Range-wide patterns of greater sage-grouse persistence: Diversity and Distributions, v. 14, no. 6, p. 983-994, https://doi.org/10.1111/j.1472-4642.2008.00502.x.","startPage":"983","endPage":"994","numberOfPages":"12","costCenters":[{"id":290,"text":"Forest and Rangeland Ecosystem Science Center","active":false,"usgs":true}],"links":[{"id":242098,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":214375,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1111/j.1472-4642.2008.00502.x"}],"volume":"14","issue":"6","noUsgsAuthors":false,"publicationDate":"2008-10-15","publicationStatus":"PW","scienceBaseUri":"505a94a7e4b0c8380cd8152f","contributors":{"authors":[{"text":"Aldridge, Cameron L. 0000-0003-3926-6941 aldridgec@usgs.gov","orcid":"https://orcid.org/0000-0003-3926-6941","contributorId":191773,"corporation":false,"usgs":true,"family":"Aldridge","given":"Cameron","email":"aldridgec@usgs.gov","middleInitial":"L.","affiliations":[{"id":291,"text":"Fort Collins Science Center","active":true,"usgs":true}],"preferred":false,"id":442397,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Nielsen, Scott E.","contributorId":65190,"corporation":false,"usgs":true,"family":"Nielsen","given":"Scott","email":"","middleInitial":"E.","affiliations":[],"preferred":false,"id":442395,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Beyer, Hawthorne L.","contributorId":99871,"corporation":false,"usgs":true,"family":"Beyer","given":"Hawthorne","email":"","middleInitial":"L.","affiliations":[],"preferred":false,"id":442396,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Boyce, Mark S.","contributorId":113205,"corporation":false,"usgs":false,"family":"Boyce","given":"Mark","email":"","middleInitial":"S.","affiliations":[{"id":12980,"text":"Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada","active":true,"usgs":false}],"preferred":false,"id":442393,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Connelly, John W.","contributorId":32391,"corporation":false,"usgs":true,"family":"Connelly","given":"John W.","affiliations":[],"preferred":false,"id":442394,"contributorType":{"id":1,"text":"Authors"},"rank":5},{"text":"Knick, Steven T. 0000-0003-4025-1704 steve_knick@usgs.gov","orcid":"https://orcid.org/0000-0003-4025-1704","contributorId":159,"corporation":false,"usgs":true,"family":"Knick","given":"Steven","email":"steve_knick@usgs.gov","middleInitial":"T.","affiliations":[{"id":289,"text":"Forest and Rangeland Ecosys Science Center","active":true,"usgs":true},{"id":290,"text":"Forest and Rangeland Ecosystem Science Center","active":false,"usgs":true}],"preferred":true,"id":442398,"contributorType":{"id":1,"text":"Authors"},"rank":6},{"text":"Schroeder, Michael A.","contributorId":26053,"corporation":false,"usgs":true,"family":"Schroeder","given":"Michael","email":"","middleInitial":"A.","affiliations":[],"preferred":false,"id":442399,"contributorType":{"id":1,"text":"Authors"},"rank":7}]}} ,{"id":70033531,"text":"70033531 - 2008 - A simulation model for projecting changes in salinity concentrations and species dominance in the coastal margin habitats of the Everglades","interactions":[],"lastModifiedDate":"2012-03-12T17:21:29","indexId":"70033531","displayToPublicDate":"2008-01-01T00:00:00","publicationYear":"2008","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1458,"text":"Ecological Modelling","active":true,"publicationSubtype":{"id":10}},"title":"A simulation model for projecting changes in salinity concentrations and species dominance in the coastal margin habitats of the Everglades","docAbstract":"Sharp boundaries typically separate the salinity tolerant mangroves from the salinity intolerant hardwood hammock species, which occupy the similar geographical areas of southern Florida. Evidence of strong feedback between tree community-type and the salinity of the unsaturated (vadose) zone of the soil suggests that a severe disturbance that significantly tilts the salinity in the vadose zone might cause a shift from one vegetation type to the other. In this study, a model based upon the feedback dynamics between vegetation and salinity of the vadose zone of the soil was used to take account of storm surge events to investigate the mechanisms that by which this large-scale disturbance could affect the spatial pattern of hardwood hammocks and mangroves. Model simulation results indicated that a heavy storm surge that completely saturated the vadose zone at 30 ppt for 1 day could lead to a regime shift in which there is domination by mangroves of areas previously dominated by hardwood hammocks. Lighter storm surges that saturated the vadose zone at less than 7 ppt did not cause vegetation shifts. Investigations of model sensitivity analysis indicated that the thickness of the vadose zone, coupled with precipitation, influenced the residence time of high salinity in the vadose zone and therefore determined the rate of mangrove domination. The model was developed for a southern Florida coastal ecosystem, but its applicability may be much broader. ?? 2008 Elsevier B.V. All rights reserved.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Ecological Modelling","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1016/j.ecolmodel.2007.12.007","issn":"03043800","usgsCitation":"Teh, S., DeAngelis, D., Sternberg, L., Miralles-Wilhelm, F.R., Smith, T., and Koh, H.L., 2008, A simulation model for projecting changes in salinity concentrations and species dominance in the coastal margin habitats of the Everglades: Ecological Modelling, v. 213, no. 2, p. 245-256, https://doi.org/10.1016/j.ecolmodel.2007.12.007.","startPage":"245","endPage":"256","numberOfPages":"12","costCenters":[],"links":[{"id":241920,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":214221,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/j.ecolmodel.2007.12.007"}],"volume":"213","issue":"2","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"5059e595e4b0c8380cd46e4e","contributors":{"authors":[{"text":"Teh, S.Y.","contributorId":22969,"corporation":false,"usgs":true,"family":"Teh","given":"S.Y.","email":"","affiliations":[],"preferred":false,"id":441287,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"DeAngelis, D.L. 0000-0002-1570-4057","orcid":"https://orcid.org/0000-0002-1570-4057","contributorId":32470,"corporation":false,"usgs":true,"family":"DeAngelis","given":"D.L.","affiliations":[],"preferred":false,"id":441288,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Sternberg, L.D.S.L.","contributorId":41223,"corporation":false,"usgs":true,"family":"Sternberg","given":"L.D.S.L.","email":"","affiliations":[],"preferred":false,"id":441289,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Miralles-Wilhelm, F. R.","contributorId":56458,"corporation":false,"usgs":true,"family":"Miralles-Wilhelm","given":"F.","email":"","middleInitial":"R.","affiliations":[],"preferred":false,"id":441292,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Smith, T.J.","contributorId":45034,"corporation":false,"usgs":true,"family":"Smith","given":"T.J.","email":"","affiliations":[],"preferred":false,"id":441291,"contributorType":{"id":1,"text":"Authors"},"rank":5},{"text":"Koh, H. L.","contributorId":44362,"corporation":false,"usgs":true,"family":"Koh","given":"H.","email":"","middleInitial":"L.","affiliations":[],"preferred":false,"id":441290,"contributorType":{"id":1,"text":"Authors"},"rank":6}]}} ,{"id":70032397,"text":"70032397 - 2008 - Mineralogical and compositional characteristics of Late Permian coals from an area of high lung cancer rate in Xuan Wei, Yunnan, China: Occurrence and origin of quartz and chamosite","interactions":[],"lastModifiedDate":"2012-03-12T17:21:20","indexId":"70032397","displayToPublicDate":"2008-01-01T00:00:00","publicationYear":"2008","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2033,"text":"International Journal of Coal Geology","active":true,"publicationSubtype":{"id":10}},"title":"Mineralogical and compositional characteristics of Late Permian coals from an area of high lung cancer rate in Xuan Wei, Yunnan, China: Occurrence and origin of quartz and chamosite","docAbstract":"Some townships in Xuan Wei County, Yunnan Province, have one of the highest lung cancer mortality rates in China and the epidemic disease in the area has generally been attributed to the polycyclic aromatic hydrocarbons (PAHs) released from domestic coal burning. However, the cancer-causing culprit is not settled as Tian [Tian, L., 2005. Coal Combustion Emissions and Lung Cancer in Xuan Wei, China. Ph.D. thesis, University of California, Berkeley.] found nanometer quartz in these coals, soot emissions, and lung cancer tissues. We have conducted mineralogical and geochemical studies of the coals from Xuan Wei for the purpose of shedding light on the minerals which may be related to the epidemic lung cancer. In this paper, abundances, modes of occurrence, and origins of minerals and elements in the coals from two mines in Xuan Wei have been studied using optical microscope, low-temperature ashing, X-ray diffraction analysis, scanning electron microscope equipped with energy-dispersive X-ray spectrometer, and inductively-coupled plasma mass spectrometry. The minerals in the coals are mainly composed of quartz, chamosite, kaolinite, and calcite. The particle size of quartz is rather small, mostly less than 20????m and it is of authigenic origin. Chamosite occurs mainly as cell-fillings. The occurrence of quartz and chamosite indicates that they were derived from the hydrothermal fluids. Epigenetic calcite is derived from calcic fluids. Kaolinite is derived mainly from sediment source region of Kangdian Oldland to the west of coal basin. The composition of Xuan Wei coal is high in SiO2, Fe2O3, TiO2, CaO, MnO, V, Co, Ni, Cu, and Zn. The high SiO2 content is attributed to quartz, and the Fe2O3 content to chamosite. The high Mn and low Mg contents in the coal indicate the inputs of hydrothermal fluids. CaO occurs mainly in epigenetic calcite. Elements Ti, Co, Ni, Cu, Zn, and rare earth elements were derived from the basaltic rocks at sediment source region. ?? 2008 Elsevier B.V. All rights reserved.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"International Journal of Coal Geology","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1016/j.coal.2008.09.001","issn":"01665","usgsCitation":"Dai, S., Tian, L., Chou, C.L., Zhou, Y., Zhang, M., Zhao, L., Wang, J., Yang, Z., Cao, H., and Ren, D., 2008, Mineralogical and compositional characteristics of Late Permian coals from an area of high lung cancer rate in Xuan Wei, Yunnan, China: Occurrence and origin of quartz and chamosite: International Journal of Coal Geology, v. 76, no. 4, p. 318-327, https://doi.org/10.1016/j.coal.2008.09.001.","startPage":"318","endPage":"327","numberOfPages":"10","costCenters":[],"links":[{"id":241613,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":213938,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/j.coal.2008.09.001"}],"volume":"76","issue":"4","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a5a91e4b0c8380cd6ef87","contributors":{"authors":[{"text":"Dai, S.","contributorId":9757,"corporation":false,"usgs":true,"family":"Dai","given":"S.","email":"","affiliations":[],"preferred":false,"id":435950,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Tian, L.","contributorId":86541,"corporation":false,"usgs":true,"family":"Tian","given":"L.","email":"","affiliations":[],"preferred":false,"id":435958,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Chou, C. L.","contributorId":32655,"corporation":false,"usgs":false,"family":"Chou","given":"C.","email":"","middleInitial":"L.","affiliations":[],"preferred":false,"id":435953,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Zhou, Y.","contributorId":70526,"corporation":false,"usgs":true,"family":"Zhou","given":"Y.","email":"","affiliations":[],"preferred":false,"id":435956,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Zhang, M.","contributorId":39161,"corporation":false,"usgs":true,"family":"Zhang","given":"M.","email":"","affiliations":[],"preferred":false,"id":435954,"contributorType":{"id":1,"text":"Authors"},"rank":5},{"text":"Zhao, L.","contributorId":57196,"corporation":false,"usgs":true,"family":"Zhao","given":"L.","email":"","affiliations":[],"preferred":false,"id":435955,"contributorType":{"id":1,"text":"Authors"},"rank":6},{"text":"Wang, Jingyuan","contributorId":10771,"corporation":false,"usgs":false,"family":"Wang","given":"Jingyuan","email":"","affiliations":[],"preferred":false,"id":435951,"contributorType":{"id":1,"text":"Authors"},"rank":7},{"text":"Yang, Z.","contributorId":97709,"corporation":false,"usgs":true,"family":"Yang","given":"Z.","affiliations":[],"preferred":false,"id":435959,"contributorType":{"id":1,"text":"Authors"},"rank":8},{"text":"Cao, H.","contributorId":28026,"corporation":false,"usgs":true,"family":"Cao","given":"H.","email":"","affiliations":[],"preferred":false,"id":435952,"contributorType":{"id":1,"text":"Authors"},"rank":9},{"text":"Ren, D.","contributorId":79212,"corporation":false,"usgs":true,"family":"Ren","given":"D.","email":"","affiliations":[],"preferred":false,"id":435957,"contributorType":{"id":1,"text":"Authors"},"rank":10}]}} ,{"id":70032422,"text":"70032422 - 2008 - The use of groundwater age as a calibration target","interactions":[],"lastModifiedDate":"2018-02-21T15:26:53","indexId":"70032422","displayToPublicDate":"2008-01-01T00:00:00","publicationYear":"2008","noYear":false,"publicationType":{"id":24,"text":"Conference Paper"},"publicationSubtype":{"id":19,"text":"Conference Paper"},"title":"The use of groundwater age as a calibration target","docAbstract":"Groundwater age (or residence time), as estimated on the basis of concentrations of one or more environmental tracers, can provide a useful and independent calibration target for groundwater models. However, concentrations of environmental tracers are affected by the complexities and mixing inherent in groundwater flow through heterogeneous media, especially in the presence of pumping wells. An analysis of flow and age distribution in the Madison aquifer in South Dakota, USA, illustrates the additional benefits and difficulties of using age as a calibration target. Alternative numerical approaches to estimating travel time and age with backward particle tracking are assessed, and the resulting estimates are used to refine estimates of effective porosity and to help assess the adequacy and credibility of the flow model.","largerWorkTitle":"IAHS-AISH Publication","conferenceTitle":"International Conference on Calibration and Reliability in Groundwater Modelling: Credibility of Modelling, M","conferenceDate":"9 September 2007 through 13 September 2007","conferenceLocation":"Copenhagen","language":"English","issn":"01447","isbn":"9781901502497","usgsCitation":"Konikow, L.F., Hornberger, G., Putnam, L., Shapiro, A., and Zinn, B., 2008, The use of groundwater age as a calibration target, in IAHS-AISH Publication, no. 320, Copenhagen, 9 September 2007 through 13 September 2007, p. 250-256.","startPage":"250","endPage":"256","numberOfPages":"7","costCenters":[],"links":[{"id":241509,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"issue":"320","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505bb188e4b08c986b325320","contributors":{"authors":[{"text":"Konikow, Leonard F. 0000-0002-0940-3856 lkonikow@usgs.gov","orcid":"https://orcid.org/0000-0002-0940-3856","contributorId":158,"corporation":false,"usgs":true,"family":"Konikow","given":"Leonard","email":"lkonikow@usgs.gov","middleInitial":"F.","affiliations":[{"id":436,"text":"National Research Program - Eastern Branch","active":true,"usgs":true}],"preferred":true,"id":436087,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Hornberger, G.Z.","contributorId":71582,"corporation":false,"usgs":true,"family":"Hornberger","given":"G.Z.","email":"","affiliations":[],"preferred":false,"id":436089,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Putnam, L.D.","contributorId":47417,"corporation":false,"usgs":true,"family":"Putnam","given":"L.D.","email":"","affiliations":[],"preferred":false,"id":436088,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Shapiro, A.M. 0000-0002-6425-9607","orcid":"https://orcid.org/0000-0002-6425-9607","contributorId":88384,"corporation":false,"usgs":true,"family":"Shapiro","given":"A.M.","affiliations":[],"preferred":true,"id":436091,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Zinn, B.A.","contributorId":78153,"corporation":false,"usgs":true,"family":"Zinn","given":"B.A.","email":"","affiliations":[],"preferred":false,"id":436090,"contributorType":{"id":1,"text":"Authors"},"rank":5}]}} ,{"id":70033475,"text":"70033475 - 2008 - Diffuse flow hydrothermal manganese mineralization along the active Mariana and southern Izu-Bonin arc system, western Pacific","interactions":[],"lastModifiedDate":"2012-03-12T17:21:32","indexId":"70033475","displayToPublicDate":"2008-01-01T00:00:00","publicationYear":"2008","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":"Diffuse flow hydrothermal manganese mineralization along the active Mariana and southern Izu-Bonin arc system, western Pacific","docAbstract":"Abundant ferromanganese oxides were collected along 1200 km of the active Izu-Bonin-Mariana arc system. Chemical compositions and mineralogy show that samples were collected from two deposit types: Fe-Mn crusts of mixed hydrogenetic/hydrothermal origin and hydrothermal Mn oxide deposits; this paper addresses only the second type. Mn oxides cement volcaniclastic and biogenic sandstone and breccia layers (Mn sandstone) and form discrete dense stratabound layers along bedding planes and within beds (stratabound Mn). The Mn oxide was deposited within coarse-grained sediments from diffuse flow systems where precipitation occurred below the seafloor. Deposits were exposed at the seabed by faulting, mass wasting, and erosion. Scanning electron microscopy and microprobe analyses indicate the presence of both amorphous and crystalline 10 ?? and 7 ?? manganate minerals, the fundamental chemical difference being high water contents in the amorphous Mn oxides. Alternation of amorphous and crystalline laminae occurs in many samples, which likely resulted from initial rapid precipitation of amorphous Mn oxides from waxing pulses of hydrothermal fluids followed by precipitation of slow forming crystallites during waning stages. The chemical composition is characteristic of a hydrothermal origin including strong fractionation between Fe (mean 0.9 wt %) and Mn (mean 48 wt %) for the stratabound Mn, generally low trace metal contents, and very low rare earth element and platinum group element contents. However, Mo, Cd, Zn, Cu, Ni, and Co occur in high concentrations in some samples and may be good indicator elements for proximity to the heat source or to massive sulfide deposits. For the Mn sandstones, Fe (mean-8.4%) and Mn (12.4%) are not significantly fractionated because of high Fe contents in the volcaniclastic material. However, the proportion of hydrothermal Fe (nondetrital Fe) to total Fe is remarkably constant (49-58%) for all the sample groups, regardless of the degree of Mn mineralization. Factor analyses indicate various mixtures of two dominant components: hydrothermal Mn oxide for the stratabound Mn and detrital aluminosilicate for the Mn-cemented sandstone; and two minor components, hydrothermal Fe oxyhydroxide and biocarbonate/biosilica. Our conceptual model shows that Mn mineralization was produced by hydrothermal convection cells within arc volcanoes and sedimentary prisms that occur along, the flanks and within calderas. The main source of hydrothermal fluid was seawater that penetrated through fractures, faults, and permeable volcanic edifices. The fluids were heated by magma, enriched in metals by leaching of basement rocks and sediments, and mixed with magmatic fluids and gases. Dikes and sills may have been another source of heat that drove small-scale circulation within sedimentary prisms. Copyright 2008 by the American Geophysical Union.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Journal of Geophysical Research B: Solid Earth","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1029/2007JB005432","issn":"01480","usgsCitation":"Hein, J., Schulz, M.S., Dunham, R., Stern, R.J., and Bloomer, S., 2008, Diffuse flow hydrothermal manganese mineralization along the active Mariana and southern Izu-Bonin arc system, western Pacific: Journal of Geophysical Research B: Solid Earth, v. 113, no. 8, https://doi.org/10.1029/2007JB005432.","costCenters":[],"links":[{"id":476705,"rank":10000,"type":{"id":40,"text":"Open Access Publisher Index Page"},"url":"https://doi.org/10.1029/2007jb005432","text":"Publisher Index Page"},{"id":214453,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1029/2007JB005432"},{"id":242181,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"113","issue":"8","noUsgsAuthors":false,"publicationDate":"2008-06-25","publicationStatus":"PW","scienceBaseUri":"505a010de4b0c8380cd4fa92","contributors":{"authors":[{"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":441021,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Schulz, M. S.","contributorId":7299,"corporation":false,"usgs":true,"family":"Schulz","given":"M.","email":"","middleInitial":"S.","affiliations":[],"preferred":false,"id":441018,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Dunham, R.E.","contributorId":8297,"corporation":false,"usgs":true,"family":"Dunham","given":"R.E.","email":"","affiliations":[],"preferred":false,"id":441019,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Stern, R. J.","contributorId":8616,"corporation":false,"usgs":true,"family":"Stern","given":"R.","middleInitial":"J.","affiliations":[],"preferred":false,"id":441020,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Bloomer, S.H.","contributorId":82545,"corporation":false,"usgs":true,"family":"Bloomer","given":"S.H.","email":"","affiliations":[],"preferred":false,"id":441022,"contributorType":{"id":1,"text":"Authors"},"rank":5}]}} ,{"id":70030447,"text":"70030447 - 2008 - Hydrochemical characterization of groundwater in the Akyem area, Ghana","interactions":[],"lastModifiedDate":"2012-03-12T17:21:04","indexId":"70030447","displayToPublicDate":"2008-01-01T00:00:00","publicationYear":"2008","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2257,"text":"Journal of Environmental Hydrology","active":true,"publicationSubtype":{"id":10}},"title":"Hydrochemical characterization of groundwater in the Akyem area, Ghana","docAbstract":"The Akyem area is a small farming community located in southeastern Ghana. Groundwater samples from wells in the area were analyzed for concentrations of the major ions, silica, electrical conductivity and pH. The objective was to determine the main controls on the hydrochemistry of ground-water. Mass balance modeling was used together with multivariate R-mode hierarchical cluster analysis to determine the significant sources of variation in the hydrochemistry. Two water types exist in this area. The first is influenced most by the weathering of silicate minerals from the underlying geology, and is thus rich in silica, sodium, calcium, bicarbonate, and magnesium ions. The second is water that has been influenced by the effects of fertilizers and other anthropogenic activities in the area. Mineral speciation and silicate mineral stability diagrams suggest that montmorillonite, probably derived from the incongruent dissolution of feldspars and micas, is the most stable silicate phase in the groundwaters. The apparent incongruent weathering of silicate minerals in the groundwater system has led to the enrichment of sodium, calcium, magnesium and bicarbonate ions as well as silica, leading to the supersaturation of calcite, aragonite, dolomite and quartz. Stability in the montmorillonite field suggests restricted flow conditions and a long groundwater residence time, leading to greater exposure of the rock to weathering. Cation exchange processes appear to play minor roles in the hydrochemistry of groundwater.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Journal of Environmental Hydrology","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","issn":"10583","usgsCitation":"Banoeng-Yakubo, B., Yidana, S., Anku, Y., Akabzaa, T., and Asiedu, D., 2008, Hydrochemical characterization of groundwater in the Akyem area, Ghana: Journal of Environmental Hydrology, v. 16, p. 1-12.","startPage":"1","endPage":"12","numberOfPages":"12","costCenters":[],"links":[{"id":239172,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"16","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a332ce4b0c8380cd5edbf","contributors":{"authors":[{"text":"Banoeng-Yakubo, B.","contributorId":75332,"corporation":false,"usgs":true,"family":"Banoeng-Yakubo","given":"B.","email":"","affiliations":[],"preferred":false,"id":427190,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Yidana, S.M.","contributorId":59554,"corporation":false,"usgs":true,"family":"Yidana","given":"S.M.","email":"","affiliations":[],"preferred":false,"id":427189,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Anku, Y.","contributorId":96083,"corporation":false,"usgs":true,"family":"Anku","given":"Y.","affiliations":[],"preferred":false,"id":427192,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Akabzaa, T.","contributorId":39580,"corporation":false,"usgs":true,"family":"Akabzaa","given":"T.","email":"","affiliations":[],"preferred":false,"id":427188,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Asiedu, D.","contributorId":76131,"corporation":false,"usgs":true,"family":"Asiedu","given":"D.","affiliations":[],"preferred":false,"id":427191,"contributorType":{"id":1,"text":"Authors"},"rank":5}]}} ,{"id":70032009,"text":"70032009 - 2008 - Thermal history of the unsaturated zone at Yucca Mountain, Nevada, USA","interactions":[],"lastModifiedDate":"2012-03-12T17:21:28","indexId":"70032009","displayToPublicDate":"2008-01-01T00:00:00","publicationYear":"2008","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":835,"text":"Applied Geochemistry","active":true,"publicationSubtype":{"id":10}},"title":"Thermal history of the unsaturated zone at Yucca Mountain, Nevada, USA","docAbstract":"Secondary calcite, silica and minor amounts of fluorite deposited in fractures and cavities record the chemistry, temperatures, and timing of past fluid movement in the unsaturated zone at Yucca Mountain, Nevada, the proposed site of a high-level radioactive waste repository. The distribution and geochemistry of these deposits are consistent with low-temperature precipitation from meteoric waters that infiltrated at the surface and percolated down through the unsaturated zone. However, the discovery of fluid inclusions in calcite with homogenization temperatures (Th) up to ???80 ??C was construed by some scientists as strong evidence for hydrothermal deposition. This paper reports the results of investigations to test the hypothesis of hydrothermal deposition and to determine the temperature and timing of secondary mineral deposition. Mineral precipitation temperatures in the unsaturated zone are estimated from calcite- and fluorite-hosted fluid inclusions and calcite ??18O values, and depositional timing is constrained by the 207Pb/235U ages of chalcedony or opal in the deposits. Fluid inclusion Th from 50 samples of calcite and four samples of fluorite range from ???35 to ???90 ??C. Calcite ??18O values range from ???0 to ???22??? (SMOW) but most fall between 12 and 20???. The highest Th and the lowest ??18O values are found in the older calcite. Calcite Th and ??18O values indicate that most calcite precipitated from water with ??18O values between -13 and -7???, similar to modern meteoric waters. Twenty-two 207Pb/235U ages of chalcedony or opal that generally postdate elevated depositional temperatures range from ???9.5 to 1.9 Ma. New and published 207Pb/235U and 230Th/Uages coupled with the Th values and estimates of temperature from calcite ??18O values indicate that maximum unsaturated zone temperatures probably predate ???10 Ma and that the unsaturated zone had cooled to near-present-day temperatures (24-26 ??C at a depth of 250 m) by 2-4 Ma. The evidence of elevated temperatures persisting in ash flow tuffs adjacent to parent calderas for as much as ???8 Ma is a new finding, but consistent with thermal modeling. Simulations using the HEAT code demonstrate that prolonged cooling of the unsaturated zone is consistent with magmatic heat inputs and deep-seated (sub-water table) hydrothermal activity generated by the large magma body ???8 km to the north that produced the 15-11 Ma ash flows and ash falls that make up Yucca Mountain. The evidence discussed in this and preceding papers strongly supports unsaturated zone deposition of the secondary minerals from descending meteoric waters. Although depositional temperatures reflect conductive (and possibly vapor-phase convective) heating of the unsaturated zone related to regional magmatic sources until perhaps 6 Ma, depositional conditions similar to the present-day unsaturated zone have prevailed for at least the past 2-4 Ma.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Applied Geochemistry","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1016/j.apgeochem.2007.08.009","issn":"08832927","usgsCitation":"Whelan, J.F., Neymark, L., Moscati, R., Marshall, B., and Roedder, E., 2008, Thermal history of the unsaturated zone at Yucca Mountain, Nevada, USA: Applied Geochemistry, v. 23, no. 5, p. 1041-1075, https://doi.org/10.1016/j.apgeochem.2007.08.009.","startPage":"1041","endPage":"1075","numberOfPages":"35","costCenters":[],"links":[{"id":214588,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/j.apgeochem.2007.08.009"},{"id":242327,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"23","issue":"5","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505bb226e4b08c986b32561e","contributors":{"authors":[{"text":"Whelan, J. F.","contributorId":45328,"corporation":false,"usgs":true,"family":"Whelan","given":"J.","email":"","middleInitial":"F.","affiliations":[],"preferred":false,"id":434125,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Neymark, L.A. 0000-0003-4190-0278","orcid":"https://orcid.org/0000-0003-4190-0278","contributorId":56673,"corporation":false,"usgs":true,"family":"Neymark","given":"L.A.","affiliations":[],"preferred":false,"id":434126,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Moscati, R.J.","contributorId":27882,"corporation":false,"usgs":true,"family":"Moscati","given":"R.J.","affiliations":[],"preferred":false,"id":434124,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Marshall, B.D.","contributorId":19581,"corporation":false,"usgs":true,"family":"Marshall","given":"B.D.","email":"","affiliations":[],"preferred":false,"id":434123,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Roedder, E.","contributorId":100986,"corporation":false,"usgs":true,"family":"Roedder","given":"E.","affiliations":[],"preferred":false,"id":434127,"contributorType":{"id":1,"text":"Authors"},"rank":5}]}} ]}