The Morro Velho gold deposit, Quadrilátero Ferrífero region, Minas Gerais, Brazil, is hosted by rocks at the base of the Archean Rio das Velhas greenstone belt. The deposit occurs within a thick carbonaceous phyllite package, containing intercalations of felsic and intermediate volcaniclastic rocks and dolomites. Considering the temporal and spatial association of the deposit with the Rio das Velhas orogeny, and location in close proximity to a major NNW-trending fault zone, it can be classified as an orogenic gold deposit. Hydrothermal activity was characterized by intense enrichment in alteration zones of carbonates, sulfides, chlorite, white mica±biotite, albite and quartz, as described in other Archean lode-type gold ores. Two types of ore occur in the deposit: dark gray quartz veins and sulfide-rich gold orebodies. The sulfide-rich orebodies range from disseminated concentrations of sulfide minerals to massive sulfide bodies. The sulfide assemblage comprises (by volume), on average, 74% pyrrhotite, 17% arsenopyrite, 8% pyrite and 1% chalcopyrite. The orebodies have a long axis parallel to the local stretching lineation, with continuity down the plunge of fold axis for at least 4.8 km. The group of rocks hosting the Morro Velho gold mineralization is locally referred to as lapa seca. These were isoclinally folded and metamorphosed prior to gold mineralization. The lapa seca and the orebodies it hosts are distributed in five main tight folds related to F1 (the best examples are the X, Main and South orebodies, in level 25), which are disrupted by NE- to E-striking shear zones. Textural features indicate that the sulfide mineralization postdated regional peak metamorphism, and that the massive sulfide ore has subsequently been neither metamorphosed nor deformed. Lead isotope ratios indicate a model age of 2.82 ± 0.05 Ga for both sulfide and gold mineralization. The lapa seca are interpreted as the results of a pre-gold alteration process and may be divided into carbonatic, micaceous and quartzose types. The carbonatic lapa seca is subdivided into gray and brown subtypes. Non-mineralized, gray carbonatic lapa seca forms the hanging wall to the orebodies, and is interpreted as the product of extreme CO2 metasomatism during hydrothermal alteration. This dolomitic lapa seca ranges in composition from relatively pure limestone and dolomite to silty limestone and dolomite. The brown carbonatic and micaceous lapa secas are the host rocks to gold. These units are interpreted to correspond to the sheared and hydrothermal products of metamorphosed volcaniclastic and/or volcanic rocks of varying composition from dacitic to andesitic, forming various types of schists and phyllites. The high-grade, massive sulfide orebodies occur at the base of the gray carbonatic lapa seca. Both disseminated mineralization and quartz veins are hosted by micaceous lapa seca. The data are consistent with a model of epigenetic mineralization for the lapa seca, from a hydrothermal fluid derived in part from the Archean basement or older crust material.
","language":"English","publisher":"Elsevier","doi":"10.1016/j.oregeorev.2004.12.008","issn":"01691368","usgsCitation":"Vial, D.S., DeWitt, E., Lobato, L.M., and Thorman, C.H., 2007, The geology of the Morro Velho gold deposit in the Archean Rio das Velhas greenstone belt, Quadrilátero Ferrífero, Brazil: Ore Geology Reviews, v. 32, no. 3-4, p. 511-542, https://doi.org/10.1016/j.oregeorev.2004.12.008.","productDescription":"32 p.","startPage":"511","endPage":"542","onlineOnly":"N","additionalOnlineFiles":"N","costCenters":[],"links":[{"id":240585,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":213005,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/j.oregeorev.2004.12.008"}],"volume":"32","issue":"3-4","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505bac79e4b08c986b323500","contributors":{"authors":[{"text":"Vial, Diogenes Scipioni","contributorId":25366,"corporation":false,"usgs":true,"family":"Vial","given":"Diogenes","email":"","middleInitial":"Scipioni","affiliations":[],"preferred":false,"id":424743,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"DeWitt, Ed edewitt@usgs.gov","contributorId":725,"corporation":false,"usgs":true,"family":"DeWitt","given":"Ed","email":"edewitt@usgs.gov","affiliations":[{"id":171,"text":"Central Mineral and Environmental Resources Science Center","active":true,"usgs":true}],"preferred":false,"id":424746,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Lobato, Lydia Maria","contributorId":78941,"corporation":false,"usgs":true,"family":"Lobato","given":"Lydia","email":"","middleInitial":"Maria","affiliations":[],"preferred":false,"id":424745,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Thorman, Charles H. cthorman@usgs.gov","contributorId":254,"corporation":false,"usgs":false,"family":"Thorman","given":"Charles","email":"cthorman@usgs.gov","middleInitial":"H.","affiliations":[{"id":7065,"text":"USGS emeritus","active":true,"usgs":false}],"preferred":false,"id":424744,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}} ,{"id":70029890,"text":"70029890 - 2007 - Probabilistic seismic demand analysis using advanced ground motion intensity measures","interactions":[],"lastModifiedDate":"2012-03-12T17:21:06","indexId":"70029890","displayToPublicDate":"2007-01-01T00:00:00","publicationYear":"2007","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1434,"text":"Earthquake Engineering and Structural Dynamics","active":true,"publicationSubtype":{"id":10}},"title":"Probabilistic seismic demand analysis using advanced ground motion intensity measures","docAbstract":"One of the objectives in performance-based earthquake engineering is to quantify the seismic reliability of a structure at a site. For that purpose, probabilistic seismic demand analysis (PSDA) is used as a tool to estimate the mean annual frequency of exceeding a specified value of a structural demand parameter (e.g. interstorey drift). This paper compares and contrasts the use, in PSDA, of certain advanced scalar versus vector and conventional scalar ground motion intensity measures (IMs). One of the benefits of using a well-chosen IM is that more accurate evaluations of seismic performance are achieved without the need to perform detailed ground motion record selection for the nonlinear dynamic structural analyses involved in PSDA (e.g. record selection with respect to seismic parameters such as earthquake magnitude, source-to-site distance, and ground motion epsilon). For structural demands that are dominated by a first mode of vibration, using inelastic spectral displacement (Sdi) can be advantageous relative to the conventionally used elastic spectral acceleration (Sa) and the vector IM consisting of Sa and epsilon (??). This paper demonstrates that this is true for ordinary and for near-source pulse-like earthquake records. The latter ground motions cannot be adequately characterized by either Sa alone or the vector of Sa and ??. For structural demands with significant higher-mode contributions (under either of the two types of ground motions), even Sdi (alone) is not sufficient, so an advanced scalar IM that additionally incorporates higher modes is used.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Earthquake Engineering and Structural Dynamics","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1002/eqe.696","issn":"00988847","usgsCitation":"Tothong, P., and Luco, N., 2007, Probabilistic seismic demand analysis using advanced ground motion intensity measures: Earthquake Engineering and Structural Dynamics, v. 36, no. 13, p. 1837-1860, https://doi.org/10.1002/eqe.696.","startPage":"1837","endPage":"1860","numberOfPages":"24","costCenters":[],"links":[{"id":213038,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1002/eqe.696"},{"id":240618,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"36","issue":"13","noUsgsAuthors":false,"publicationDate":"2007-06-11","publicationStatus":"PW","scienceBaseUri":"505a8c98e4b0c8380cd7e796","contributors":{"authors":[{"text":"Tothong, P.","contributorId":107503,"corporation":false,"usgs":true,"family":"Tothong","given":"P.","email":"","affiliations":[],"preferred":false,"id":424748,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Luco, N.","contributorId":34240,"corporation":false,"usgs":true,"family":"Luco","given":"N.","email":"","affiliations":[],"preferred":false,"id":424747,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70029892,"text":"70029892 - 2007 - Free zinc ion and dissolved orthophosphate effects on phytoplankton from Coeur d'Alene Lake, Idaho","interactions":[],"lastModifiedDate":"2023-08-25T12:07:25.166789","indexId":"70029892","displayToPublicDate":"2007-01-01T00:00:00","publicationYear":"2007","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1565,"text":"Environmental Science & Technology","onlineIssn":"1520-5851","printIssn":"0013-936X","active":true,"publicationSubtype":{"id":10}},"title":"Free zinc ion and dissolved orthophosphate effects on phytoplankton from Coeur d'Alene Lake, Idaho","docAbstract":"Coeur d'Alene Lake in northern Idaho is fed by two major rivers: the Coeur d'Alene River from the east and the St. Joe River from the south, with the Spokane River as its outlet to the north. This phosphorus-limited lake has been subjected to decades of mining (primarily for zinc and silver) and other anthropogenic inputs. A 32 full-factorial experimental design was used to examine the interactive effects of free (uncomplexed) zinc ion and dissolved-orthophosphate concentrations on phytoplankton that were isolated from two sites along a longitudinal zinc-concentration gradient in Coeur d'Alene Lake. The two sites displayed different dominant taxa. Chlorella minutissima, a dominant species near the southern St. Joe River inlet, exhibited greater sensitivity to free Zn ions than Asterionella formosa, collected nearer the Coeur d'Alene River mouth with elevated dissolved-zinc concentrations. Empirical phytoplankton-response models were generated to describe phytoplankton growth in response to remediation strategies in the surrounding watershed. If dissolved Zn can be reduced in the water column from >500 nM (i.e., current concentrations near and down stream of the Coeur d'Alene River plume) to <3 nM (i.e., concentrations near the southern St. Joe River inlet) such that the lake is truly phosphorus limited, management of phosphorus inputs by surrounding communities will ultimately determine the limnologic state of the lake.
","language":"English","publisher":"American Chemical Society","doi":"10.1021/es062923l","issn":"0013936X","usgsCitation":"Kuwabara, J.S., Topping, B.R., Woods, P.F., and Carter, J.L., 2007, Free zinc ion and dissolved orthophosphate effects on phytoplankton from Coeur d'Alene Lake, Idaho: Environmental Science & Technology, v. 41, no. 8, p. 2811-2817, https://doi.org/10.1021/es062923l.","productDescription":"7 p.","startPage":"2811","endPage":"2817","numberOfPages":"7","costCenters":[{"id":589,"text":"Toxic Substances Hydrology Program","active":true,"usgs":true}],"links":[{"id":240650,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"country":"United States","state":"Idaho","otherGeospatial":"Coeur d'Alene Lake","geographicExtents":"{\n \"type\": \"FeatureCollection\",\n \"features\": [\n {\n \"type\": \"Feature\",\n \"properties\": {},\n \"geometry\": {\n \"type\": \"Polygon\",\n \"coordinates\": [\n [\n [\n -116.81625366210938,\n 47.68018294648414\n ],\n [\n -116.707763671875,\n 47.66538735632654\n ],\n [\n -116.64596557617188,\n 47.635783590864854\n ],\n [\n -116.64321899414062,\n 47.61079236060622\n ],\n [\n -116.7572021484375,\n 47.61264397257417\n ],\n [\n -116.7681884765625,\n 47.57652571374621\n ],\n [\n -116.75170898437501,\n 47.54038252373696\n ],\n [\n -116.8231201171875,\n 47.484728927366504\n ],\n [\n -116.77780151367186,\n 47.4828727909934\n ],\n [\n -116.75857543945312,\n 47.4828727909934\n ],\n [\n -116.75445556640625,\n 47.45223707184017\n ],\n [\n -116.70639038085938,\n 47.40764414848437\n ],\n [\n -116.67892456054688,\n 47.35836223484991\n ],\n [\n -116.69540405273438,\n 47.33789206010502\n ],\n [\n -116.77230834960938,\n 47.34905859411952\n ],\n [\n -116.78741455078125,\n 47.37975438400816\n ],\n [\n -116.79153442382812,\n 47.41322033016902\n ],\n [\n -116.88079833984375,\n 47.462450962249356\n ],\n [\n -116.94671630859375,\n 47.45687999525879\n ],\n [\n -116.94259643554688,\n 47.47823216312885\n ],\n [\n -116.90826416015625,\n 47.51349065484327\n ],\n [\n -116.87667846679689,\n 47.516273211681984\n ],\n [\n -116.82861328125001,\n 47.58486290927609\n ],\n [\n -116.8780517578125,\n 47.592272635166125\n ],\n [\n -116.8780517578125,\n 47.61264397257417\n ],\n [\n -116.83135986328125,\n 47.61819841513311\n ],\n [\n -116.80938720703124,\n 47.62190104905555\n ],\n [\n -116.82861328125001,\n 47.65613798222679\n ],\n [\n -116.83959960937499,\n 47.67186094318796\n ],\n [\n -116.81625366210938,\n 47.68018294648414\n ]\n ]\n ]\n }\n }\n ]\n}","volume":"41","issue":"8","noUsgsAuthors":false,"publicationDate":"2007-03-09","publicationStatus":"PW","scienceBaseUri":"505a13c1e4b0c8380cd54782","contributors":{"authors":[{"text":"Kuwabara, James S. 0000-0003-2502-1601 kuwabara@usgs.gov","orcid":"https://orcid.org/0000-0003-2502-1601","contributorId":3374,"corporation":false,"usgs":true,"family":"Kuwabara","given":"James","email":"kuwabara@usgs.gov","middleInitial":"S.","affiliations":[{"id":651,"text":"Western Ecological Research Center","active":true,"usgs":true}],"preferred":true,"id":424758,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Topping, Brent R. 0000-0002-7887-4221 btopping@usgs.gov","orcid":"https://orcid.org/0000-0002-7887-4221","contributorId":1484,"corporation":false,"usgs":true,"family":"Topping","given":"Brent","email":"btopping@usgs.gov","middleInitial":"R.","affiliations":[{"id":438,"text":"National Research Program - Western Branch","active":true,"usgs":true}],"preferred":true,"id":424760,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Woods, Paul F.","contributorId":82273,"corporation":false,"usgs":true,"family":"Woods","given":"Paul","email":"","middleInitial":"F.","affiliations":[],"preferred":false,"id":424759,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Carter, James L. 0000-0002-0104-9776 jlcarter@usgs.gov","orcid":"https://orcid.org/0000-0002-0104-9776","contributorId":3278,"corporation":false,"usgs":true,"family":"Carter","given":"James","email":"jlcarter@usgs.gov","middleInitial":"L.","affiliations":[{"id":438,"text":"National Research Program - Western Branch","active":true,"usgs":true}],"preferred":true,"id":424757,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}} ,{"id":70029894,"text":"70029894 - 2007 - Deriving a light use efficiency model from eddy covariance flux data for predicting daily gross primary production across biomes","interactions":[],"lastModifiedDate":"2017-04-12T16:04:03","indexId":"70029894","displayToPublicDate":"2007-01-01T00:00:00","publicationYear":"2007","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":681,"text":"Agricultural and Forest Meteorology","active":true,"publicationSubtype":{"id":10}},"title":"Deriving a light use efficiency model from eddy covariance flux data for predicting daily gross primary production across biomes","docAbstract":"The quantitative simulation of gross primary production (GPP) at various spatial and temporal scales has been a major challenge in quantifying the global carbon cycle. We developed a light use efficiency (LUE) daily GPP model from eddy covariance (EC) measurements. The model, called EC-LUE, is driven by only four variables: normalized difference vegetation index (NDVI), photosynthetically active radiation (PAR), air temperature, and the Bowen ratio of sensible to latent heat flux (used to calculate moisture stress). The EC-LUE model relies on two assumptions: First, that the fraction of absorbed PAR (fPAR) is a linear function of NDVI; Second, that the realized light use efficiency, calculated from a biome-independent invariant potential LUE, is controlled by air temperature or soil moisture, whichever is most limiting. The EC-LUE model was calibrated and validated using 24,349 daily GPP estimates derived from 28 eddy covariance flux towers from the AmeriFlux and EuroFlux networks, covering a variety of forests, grasslands and savannas. The model explained 85% and 77% of the observed variations of daily GPP for all the calibration and validation sites, respectively. A comparison with GPP calculated from the Moderate Resolution Imaging Spectroradiometer (MODIS) indicated that the EC-LUE model predicted GPP that better matched tower data across these sites. The realized LUE was predominantly controlled by moisture conditions throughout the growing season, and controlled by temperature only at the beginning and end of the growing season. The EC-LUE model is an alternative approach that makes it possible to map daily GPP over large areas because (1) the potential LUE is invariant across various land cover types and (2) all driving forces of the model can be derived from remote sensing data or existing climate observation networks.
","language":"English","publisher":"Elsevier","doi":"10.1016/j.agrformet.2006.12.001","issn":"01681923","usgsCitation":"Yuan, W., Liu, S., Zhou, G., Tieszen, L., Baldocchi, D., Bernhofer, C., Gholz, H., Goldstein, A.H., Goulden, M.L., Hollinger, D., Hu, Y., Law, B.E., Stoy, P., Vesala, T., and Wofsy, S., 2007, Deriving a light use efficiency model from eddy covariance flux data for predicting daily gross primary production across biomes: Agricultural and Forest Meteorology, v. 143, no. 3-4, p. 189-207, https://doi.org/10.1016/j.agrformet.2006.12.001.","productDescription":"19 p.","startPage":"189","endPage":"207","numberOfPages":"19","costCenters":[{"id":222,"text":"Earth Resources Observation and Science (EROS) Center","active":true,"usgs":true}],"links":[{"id":476983,"rank":10000,"type":{"id":41,"text":"Open Access External Repository Page"},"url":"https://escholarship.org/uc/item/0nv498zp","text":"External Repository"},{"id":240683,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":213094,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/j.agrformet.2006.12.001"}],"volume":"143","issue":"3-4","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"5059fedee4b0c8380cd4ef81","contributors":{"authors":[{"text":"Yuan, W.","contributorId":35955,"corporation":false,"usgs":true,"family":"Yuan","given":"W.","email":"","affiliations":[],"preferred":false,"id":424791,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Liu, S.","contributorId":93170,"corporation":false,"usgs":true,"family":"Liu","given":"S.","affiliations":[],"preferred":false,"id":424798,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Zhou, G.","contributorId":12604,"corporation":false,"usgs":true,"family":"Zhou","given":"G.","email":"","affiliations":[],"preferred":false,"id":424786,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Tieszen, L.L.","contributorId":24046,"corporation":false,"usgs":true,"family":"Tieszen","given":"L.L.","email":"","affiliations":[],"preferred":false,"id":424789,"contributorType":{"id":1,"text":"Authors"},"rank":5},{"text":"Baldocchi, D.","contributorId":40368,"corporation":false,"usgs":true,"family":"Baldocchi","given":"D.","affiliations":[],"preferred":false,"id":424793,"contributorType":{"id":1,"text":"Authors"},"rank":6},{"text":"Bernhofer, C.","contributorId":37964,"corporation":false,"usgs":true,"family":"Bernhofer","given":"C.","email":"","affiliations":[],"preferred":false,"id":424792,"contributorType":{"id":1,"text":"Authors"},"rank":7},{"text":"Gholz, H.","contributorId":107938,"corporation":false,"usgs":true,"family":"Gholz","given":"H.","email":"","affiliations":[],"preferred":false,"id":424799,"contributorType":{"id":1,"text":"Authors"},"rank":8},{"text":"Goldstein, Allen H.","contributorId":7452,"corporation":false,"usgs":true,"family":"Goldstein","given":"Allen","email":"","middleInitial":"H.","affiliations":[],"preferred":false,"id":424785,"contributorType":{"id":1,"text":"Authors"},"rank":9},{"text":"Goulden, M. L.","contributorId":35095,"corporation":false,"usgs":false,"family":"Goulden","given":"M.","email":"","middleInitial":"L.","affiliations":[],"preferred":false,"id":424790,"contributorType":{"id":1,"text":"Authors"},"rank":10},{"text":"Hollinger, D.Y.","contributorId":86567,"corporation":false,"usgs":true,"family":"Hollinger","given":"D.Y.","email":"","affiliations":[],"preferred":false,"id":424797,"contributorType":{"id":1,"text":"Authors"},"rank":11},{"text":"Hu, Y.","contributorId":68474,"corporation":false,"usgs":true,"family":"Hu","given":"Y.","email":"","affiliations":[],"preferred":false,"id":424796,"contributorType":{"id":1,"text":"Authors"},"rank":12},{"text":"Law, B. E.","contributorId":17586,"corporation":false,"usgs":true,"family":"Law","given":"B.","email":"","middleInitial":"E.","affiliations":[],"preferred":false,"id":424787,"contributorType":{"id":1,"text":"Authors"},"rank":13},{"text":"Stoy, Paul C.","contributorId":60860,"corporation":false,"usgs":true,"family":"Stoy","given":"Paul C.","affiliations":[],"preferred":false,"id":424795,"contributorType":{"id":1,"text":"Authors"},"rank":14},{"text":"Vesala, T.","contributorId":21355,"corporation":false,"usgs":true,"family":"Vesala","given":"T.","affiliations":[],"preferred":false,"id":424788,"contributorType":{"id":1,"text":"Authors"},"rank":15},{"text":"Wofsy, S.C.","contributorId":44699,"corporation":false,"usgs":true,"family":"Wofsy","given":"S.C.","email":"","affiliations":[],"preferred":false,"id":424794,"contributorType":{"id":1,"text":"Authors"},"rank":16}]}} ,{"id":70029895,"text":"70029895 - 2007 - Holocene sea-level oscillations and environmental changes on the Eastern Black Sea shelf","interactions":[],"lastModifiedDate":"2012-03-12T17:21:09","indexId":"70029895","displayToPublicDate":"2007-01-01T00:00:00","publicationYear":"2007","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2996,"text":"Palaeogeography, Palaeoclimatology, Palaeoecology","printIssn":"0031-0182","active":true,"publicationSubtype":{"id":10}},"title":"Holocene sea-level oscillations and environmental changes on the Eastern Black Sea shelf","docAbstract":"A multi-proxy study of four sediment cores from the Eastern (Caucasian) Black Sea shelf revealed five transgressive-regressive cycles overprinted on the general trend of glacioeustatic sea-level rise during the last 11,000??14C yr. These cycles are well represented in micro-and macrofossil assemblages, sedimentation rates, and grain size variations. The oldest recovered sediments were deposited in the Neoeuxinian semi-freshwater basin (??? 10,500-9000??14C yr BP) and contain a Caspian-type mollusk fauna dominated by Dreissena rostriformis. Low ??18O and ??13C values are measured on this species. The first appearance of marine mollusks and ostracodes from the Mediterranean is established in this part of the Black Sea at ??? 8200??14C yr BP, i.e., about 1000-2000??yr later than the appearance of marine microfossils in the deeper part of the sea. The Early Holocene (Bugazian to Vityazevian) condensed section of shell and shelly mud sediments with at least two hiatuses represent a high-energy shelf-edge facies. It contains a transitional assemblage representing a mixture of Caspian and Mediterranean fauna. This pattern suggests a dual-flow regime via the Bosphorus after 8200??14C yr BP. Caspian species disappear and oligohaline species decrease in abundance during the Vityazevian-Prekalamitian cycle. Later, during the Middle to Late Holocene, low sea-level stands are characterized by shell layers, whereas silty mud with various mollusk and ostracode assemblages rapidly accumulated during transgressions. Restricted mud accumulation, as well as benthic faunal composition and abundance, suggest high-energy and well-ventilated bottom water during low sea-level stands. A trend of 18O enrichment in mollusk shells points to an increase in bottom-water salinity during the Vityazevian to Kalamitian transgressions (??? 7000 to 5700??14C yr BP) due to a more open connection with the Mediterranean, while a pronounced increase in polyhaline species abundance is established during the Kalamitian to Djemetean transgressions (??? 6400 to 2700??14C yr BP). However, the composition of the faunal assemblage indicates that bottom-water salinity never exceeded modern values of 18-20??psu. ?? 2006 Elsevier B.V. All rights reserved.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Palaeogeography, Palaeoclimatology, Palaeoecology","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1016/j.palaeo.2006.09.014","issn":"00310182","usgsCitation":"Ivanova, E., Murdmaa, I., Chepalyga, A., Cronin, T.M., Pasechnik, I., Levchenko, O., Howe, S.S., Manushkina, A., and Platonova, E., 2007, Holocene sea-level oscillations and environmental changes on the Eastern Black Sea shelf: Palaeogeography, Palaeoclimatology, Palaeoecology, v. 246, no. 2-4, p. 228-259, https://doi.org/10.1016/j.palaeo.2006.09.014.","startPage":"228","endPage":"259","numberOfPages":"32","costCenters":[],"links":[{"id":212658,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/j.palaeo.2006.09.014"},{"id":240180,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"246","issue":"2-4","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a31f1e4b0c8380cd5e399","contributors":{"authors":[{"text":"Ivanova, E.V.","contributorId":6259,"corporation":false,"usgs":true,"family":"Ivanova","given":"E.V.","email":"","affiliations":[],"preferred":false,"id":424800,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Murdmaa, I.O.","contributorId":6260,"corporation":false,"usgs":true,"family":"Murdmaa","given":"I.O.","email":"","affiliations":[],"preferred":false,"id":424801,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Chepalyga, A.L.","contributorId":39200,"corporation":false,"usgs":true,"family":"Chepalyga","given":"A.L.","email":"","affiliations":[],"preferred":false,"id":424803,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Cronin, T. M. 0000-0002-2643-0979","orcid":"https://orcid.org/0000-0002-2643-0979","contributorId":42613,"corporation":false,"usgs":true,"family":"Cronin","given":"T.","email":"","middleInitial":"M.","affiliations":[{"id":40020,"text":"Florence Bascom Geoscience Center","active":true,"usgs":true}],"preferred":false,"id":424804,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Pasechnik, I.V.","contributorId":17427,"corporation":false,"usgs":true,"family":"Pasechnik","given":"I.V.","email":"","affiliations":[],"preferred":false,"id":424802,"contributorType":{"id":1,"text":"Authors"},"rank":5},{"text":"Levchenko, O.V.","contributorId":84563,"corporation":false,"usgs":true,"family":"Levchenko","given":"O.V.","email":"","affiliations":[],"preferred":false,"id":424805,"contributorType":{"id":1,"text":"Authors"},"rank":6},{"text":"Howe, S. S.","contributorId":103293,"corporation":false,"usgs":true,"family":"Howe","given":"S.","email":"","middleInitial":"S.","affiliations":[],"preferred":false,"id":424807,"contributorType":{"id":1,"text":"Authors"},"rank":7},{"text":"Manushkina, A.V.","contributorId":85776,"corporation":false,"usgs":true,"family":"Manushkina","given":"A.V.","email":"","affiliations":[],"preferred":false,"id":424806,"contributorType":{"id":1,"text":"Authors"},"rank":8},{"text":"Platonova, E.A.","contributorId":105918,"corporation":false,"usgs":true,"family":"Platonova","given":"E.A.","email":"","affiliations":[],"preferred":false,"id":424808,"contributorType":{"id":1,"text":"Authors"},"rank":9}]}} ,{"id":70029896,"text":"70029896 - 2007 - Developing methods to assess and predict the population level effects of environmental contaminants.","interactions":[],"lastModifiedDate":"2013-03-24T14:15:43","indexId":"70029896","displayToPublicDate":"2007-01-01T00:00:00","publicationYear":"2007","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2006,"text":"Integrated Environmental Assessment and Management","active":true,"publicationSubtype":{"id":10}},"title":"Developing methods to assess and predict the population level effects of environmental contaminants.","docAbstract":"The field of ecological toxicity seems largely to have drifted away from what its title implies--assessing and predicting the ecological consequences of environmental contaminants--moving instead toward an emphasis on individual effects and physiologic case studies. This paper elucidates how a relatively new ecological methodology, interaction assessment (INTASS), could be useful in addressing the field's initial goals. Specifically, INTASS is a model platform and methodology, applicable across a broad array of taxa and habitat types, that can be used to construct population dynamics models from field data. Information on environmental contaminants and multiple stressors can be incorporated into these models in a form that bypasses the problems inherent in assessing uptake, chemical interactions in the environment, and synergistic effects in the organism. INTASS can, therefore, be used to evaluate the effects of contaminants and other stressors at the population level and to predict how changes in stressor levels or composition of contaminant mixtures, as well as various mitigation measures, might affect population dynamics.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Integrated Environmental Assessment and Management","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1897/IEAM_2005-080.1","issn":"15513777","usgsCitation":"Emlen, J., and Springman, K., 2007, Developing methods to assess and predict the population level effects of environmental contaminants.: Integrated Environmental Assessment and Management, v. 3, no. 2, p. 157-165, https://doi.org/10.1897/IEAM_2005-080.1.","startPage":"157","endPage":"165","numberOfPages":"9","costCenters":[],"links":[{"id":477121,"rank":10000,"type":{"id":40,"text":"Open Access Publisher Index Page"},"url":"https://doi.org/10.1897/ieam_2005-080.1","text":"Publisher Index Page"},{"id":212659,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1897/IEAM_2005-080.1"},{"id":240181,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"3","issue":"2","noUsgsAuthors":false,"publicationDate":"2007-04-01","publicationStatus":"PW","scienceBaseUri":"505a0011e4b0c8380cd4f586","contributors":{"authors":[{"text":"Emlen, J.M.","contributorId":63979,"corporation":false,"usgs":true,"family":"Emlen","given":"J.M.","email":"","affiliations":[],"preferred":false,"id":424809,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Springman, K.R.","contributorId":79302,"corporation":false,"usgs":true,"family":"Springman","given":"K.R.","email":"","affiliations":[],"preferred":false,"id":424810,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70029898,"text":"70029898 - 2007 - Global warming and climate forcing by recent albedo changes on Mars","interactions":[],"lastModifiedDate":"2012-03-12T17:21:09","indexId":"70029898","displayToPublicDate":"2007-01-01T00:00:00","publicationYear":"2007","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2840,"text":"Nature","active":true,"publicationSubtype":{"id":10}},"title":"Global warming and climate forcing by recent albedo changes on Mars","docAbstract":"For hundreds of years, scientists have tracked the changing appearance of Mars, first by hand drawings and later by photographs. Because of this historical record, many classical albedo patterns have long been known to shift in appearance over time. Decadal variations of the martian surface albedo are generally attributed to removal and deposition of small amounts of relatively bright dust on the surface. Large swaths of the surface (up to 56 million km2) have been observed to darken or brighten by 10 per cent or more. It is unknown, however, how these albedo changes affect wind circulation, dust transport and the feedback between these processes and the martian climate. Here we present predictions from a Mars general circulation model, indicating that the observed interannual albedo alterations strongly influence the martian environment. Results indicate enhanced wind stress in recently darkened areas and decreased wind stress in brightened areas, producing a positive feedback system in which the albedo changes strengthen the winds that generate the changes. The simulations also predict a net annual global warming of surface air temperatures by ???0.65 K, enhancing dust lifting by increasing the likelihood of dust devil generation. The increase in global dust lifting by both wind stress and dust devils may affect the mechanisms that trigger large dust storm initiation, a poorly understood phenomenon, unique to Mars. In addition, predicted increases in summertime air temperatures at high southern latitudes would contribute to the rapid and steady scarp retreat that has been observed in the south polar residual ice for the past four Mars years. Our results suggest that documented albedo changes affect recent climate change and large-scale weather patterns on Mars, and thus albedo variations are a necessary component of future atmospheric and climate studies. ??2007 Nature Publishing Group.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Nature","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1038/nature05718","issn":"00280836","usgsCitation":"Fenton, L., Geissler, P., and Haberle, R., 2007, Global warming and climate forcing by recent albedo changes on Mars: Nature, v. 446, no. 7136, p. 646-649, https://doi.org/10.1038/nature05718.","startPage":"646","endPage":"649","numberOfPages":"4","costCenters":[],"links":[{"id":240213,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":212688,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1038/nature05718"}],"volume":"446","issue":"7136","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a2964e4b0c8380cd5a8eb","contributors":{"authors":[{"text":"Fenton, L.K.","contributorId":102189,"corporation":false,"usgs":true,"family":"Fenton","given":"L.K.","affiliations":[],"preferred":false,"id":424819,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Geissler, P.E.","contributorId":67636,"corporation":false,"usgs":true,"family":"Geissler","given":"P.E.","email":"","affiliations":[],"preferred":false,"id":424817,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Haberle, R.M.","contributorId":94461,"corporation":false,"usgs":true,"family":"Haberle","given":"R.M.","email":"","affiliations":[],"preferred":false,"id":424818,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70029899,"text":"70029899 - 2007 - A post-Calumet shoreline along southern Lake Michigan","interactions":[],"lastModifiedDate":"2012-03-12T17:21:09","indexId":"70029899","displayToPublicDate":"2007-01-01T00:00:00","publicationYear":"2007","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2411,"text":"Journal of Paleolimnology","active":true,"publicationSubtype":{"id":10}},"title":"A post-Calumet shoreline along southern Lake Michigan","docAbstract":"The southern shore of Lake Michigan is the type area for many of ancestral Lake Michigan's late Pleistocene lake phases, but coastal deposits and features of the Algonquin phase of northern Lake Michigan, Lake Huron, and Lake Superior are not recognized in the area. Isostatic rebound models suggest that Algonquin phase deposits should be 100 m or more below modern lake level. A relict shoreline, however, exists along the lakeward margin of the Calumet Beach that was erosional west of Deep River and depositional east of the river. For this post-Calumet shoreline, the elevation of basal foreshore deposits east of Deep River and the base of the scarp west of Deep River indicate a slightly westward dipping water plane that is centered at ???184 m above mean sea level. Basal foreshore elevations also indicate that lake level fell ???2 m during the development of the shoreline. The pooled mean of radiocarbon dates from the surface of the peat below post-Calumet shoreline foreshore deposits indicate that the lake transgressed over the peat at 10,560 ?? 70 years B.P. Pollen assemblages from the peat are consistent with this age. The elevation and age of the post-Calumet shoreline are similar to the Main Algonquin phase of Lake Huron. Recent isostatic rebound models do not adequately address a high-elevation Algonquin-age shoreline along the southern shore of Lake Michigan, but the Goldthwait (1908) hinge-line model does. ?? 2006 Springer Science+Business Media B.V.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Journal of Paleolimnology","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1007/s10933-006-9046-1","issn":"09212728","usgsCitation":"Capps, D., Thompson, T., and Booth, R., 2007, A post-Calumet shoreline along southern Lake Michigan: Journal of Paleolimnology, v. 37, no. 3, p. 395-409, https://doi.org/10.1007/s10933-006-9046-1.","startPage":"395","endPage":"409","numberOfPages":"15","costCenters":[],"links":[{"id":212720,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1007/s10933-006-9046-1"},{"id":240248,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"37","issue":"3","noUsgsAuthors":false,"publicationDate":"2006-12-13","publicationStatus":"PW","scienceBaseUri":"5059e4e5e4b0c8380cd469e0","contributors":{"authors":[{"text":"Capps, D.K.","contributorId":62833,"corporation":false,"usgs":true,"family":"Capps","given":"D.K.","email":"","affiliations":[],"preferred":false,"id":424821,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Thompson, T.A.","contributorId":73226,"corporation":false,"usgs":true,"family":"Thompson","given":"T.A.","email":"","affiliations":[],"preferred":false,"id":424822,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Booth, R.K.","contributorId":47122,"corporation":false,"usgs":true,"family":"Booth","given":"R.K.","email":"","affiliations":[],"preferred":false,"id":424820,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70029904,"text":"70029904 - 2007 - Assessment of exploration bias in data-driven predictive models and the estimation of undiscovered resources","interactions":[],"lastModifiedDate":"2012-03-12T17:21:08","indexId":"70029904","displayToPublicDate":"2007-01-01T00:00:00","publicationYear":"2007","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2832,"text":"Natural Resources Research","onlineIssn":"1573-8981","printIssn":"1520-7439","active":true,"publicationSubtype":{"id":10}},"title":"Assessment of exploration bias in data-driven predictive models and the estimation of undiscovered resources","docAbstract":"The spatial distribution of discovered resources may not fully mimic the distribution of all such resources, discovered and undiscovered, because the process of discovery is biased by accessibility factors (e.g., outcrops, roads, and lakes) and by exploration criteria. In data-driven predictive models, the use of training sites (resource occurrences) biased by exploration criteria and accessibility does not necessarily translate to a biased predictive map. However, problems occur when evidence layers correlate with these same exploration factors. These biases then can produce a data-driven model that predicts known occurrences well, but poorly predicts undiscovered resources. Statistical assessment of correlation between evidence layers and map-based exploration factors is difficult because it is difficult to quantify the \"degree of exploration.\" However, if such a degree-of-exploration map can be produced, the benefits can be enormous. Not only does it become possible to assess this correlation, but it becomes possible to predict undiscovered, instead of discovered, resources. Using geothermal systems in Nevada, USA, as an example, a degree-of-exploration model is created, which then is resolved into purely explored and unexplored equivalents, each occurring within coextensive study areas. A weights-of-evidence (WofE) model is built first without regard to the degree of exploration, and then a revised WofE model is calculated for the \"explored fraction\" only. Differences in the weights between the two models provide a correlation measure between the evidence and the degree of exploration. The data used to build the geothermal evidence layers are perceived to be independent of degree of exploration. Nevertheless, the evidence layers correlate with exploration because exploration has preferred the same favorable areas identified by the evidence patterns. In this circumstance, however, the weights for the \"explored\" WofE model minimize this bias. Using these revised weights, posterior probability is extrapolated into unexplored areas to estimate undiscovered deposits. ?? International Association for Mathematical Geology 2007.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Natural Resources Research","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1007/s11053-007-9037-6","issn":"15207439","usgsCitation":"Coolbaugh, M., Raines, G.L., and Zehner, R.E., 2007, Assessment of exploration bias in data-driven predictive models and the estimation of undiscovered resources: Natural Resources Research, v. 16, no. 2, p. 199-207, https://doi.org/10.1007/s11053-007-9037-6.","startPage":"199","endPage":"207","numberOfPages":"9","costCenters":[],"links":[{"id":212780,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1007/s11053-007-9037-6"},{"id":240318,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"16","issue":"2","noUsgsAuthors":false,"publicationDate":"2007-05-16","publicationStatus":"PW","scienceBaseUri":"5059ee2ee4b0c8380cd49beb","contributors":{"authors":[{"text":"Coolbaugh, M.F.","contributorId":55034,"corporation":false,"usgs":true,"family":"Coolbaugh","given":"M.F.","affiliations":[],"preferred":false,"id":424841,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Raines, G. L.","contributorId":90720,"corporation":false,"usgs":true,"family":"Raines","given":"G.","middleInitial":"L.","affiliations":[],"preferred":false,"id":424843,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Zehner, R. E.","contributorId":67933,"corporation":false,"usgs":true,"family":"Zehner","given":"R.","email":"","middleInitial":"E.","affiliations":[],"preferred":false,"id":424842,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70029906,"text":"70029906 - 2007 - Relative influence of streamflows in assessing temporal variability in stream habitat","interactions":[],"lastModifiedDate":"2012-03-12T17:21:08","indexId":"70029906","displayToPublicDate":"2007-01-01T00:00:00","publicationYear":"2007","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2529,"text":"Journal of the American Water Resources Association","active":true,"publicationSubtype":{"id":10}},"title":"Relative influence of streamflows in assessing temporal variability in stream habitat","docAbstract":"The effects of streamflows on temporal variation in stream habitat were analyzed from the data collected 6-11 years apart at 38 sites across the United States. Multiple linear regression was used to assess the variation in habitat caused by streamflow at the time of sampling and high flows between sampling. In addition to flow variables, the model also contained geomorphic and land use factors. The regression model was statistically significant (p < 0.05; R 2 = 0.31-0.46) for 5 of 14 habitat variables: mean wetted stream depth, mean bankfull depth, mean wetted stream width, coefficient of variation of wetted stream width, and the percent frequency of bank erosion. High flows between samples accounted for about 16% of the total variation in the frequency of bank erosion. Streamflow at the time of sampling was the main source of variation in mean stream depth and contributed to the variation in mean stream width and the frequency of bank erosion. Urban land use (population change) accounted for over 20% of the total variation in mean bankfull depth, 15% of the total variation in the coefficient of variation of stream width, and about 10% of the variation in mean stream width. ?? 2007 American Water Resources Association.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Journal of the American Water Resources Association","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1111/j.1752-1688.2007.00051.x","issn":"1093474X","usgsCitation":"Goldstein, R.M., Meador, M.R., and Ruhl, K., 2007, Relative influence of streamflows in assessing temporal variability in stream habitat: Journal of the American Water Resources Association, v. 43, no. 3, p. 642-650, https://doi.org/10.1111/j.1752-1688.2007.00051.x.","startPage":"642","endPage":"650","numberOfPages":"9","costCenters":[],"links":[{"id":240354,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":212810,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1111/j.1752-1688.2007.00051.x"}],"volume":"43","issue":"3","noUsgsAuthors":false,"publicationDate":"2007-05-07","publicationStatus":"PW","scienceBaseUri":"505aa68ce4b0c8380cd84ef6","contributors":{"authors":[{"text":"Goldstein, R. M.","contributorId":98305,"corporation":false,"usgs":true,"family":"Goldstein","given":"R.","email":"","middleInitial":"M.","affiliations":[],"preferred":false,"id":424849,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Meador, M. R.","contributorId":74400,"corporation":false,"usgs":true,"family":"Meador","given":"M.","email":"","middleInitial":"R.","affiliations":[],"preferred":false,"id":424847,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Ruhl, K.E.","contributorId":92869,"corporation":false,"usgs":true,"family":"Ruhl","given":"K.E.","email":"","affiliations":[],"preferred":false,"id":424848,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70029910,"text":"70029910 - 2007 - Regression models for estimating coseismic landslide displacement","interactions":[],"lastModifiedDate":"2012-03-12T17:21:08","indexId":"70029910","displayToPublicDate":"2007-01-01T00:00:00","publicationYear":"2007","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1517,"text":"Engineering Geology","active":true,"publicationSubtype":{"id":10}},"title":"Regression models for estimating coseismic landslide displacement","docAbstract":"Newmark's sliding-block model is widely used to estimate coseismic slope performance. Early efforts to develop simple regression models to estimate Newmark displacement were based on analysis of the small number of strong-motion records then available. The current availability of a much larger set of strong-motion records dictates that these regression equations be updated. Regression equations were generated using data derived from a collection of 2270 strong-motion records from 30 worldwide earthquakes. The regression equations predict Newmark displacement in terms of (1) critical acceleration ratio, (2) critical acceleration ratio and earthquake magnitude, (3) Arias intensity and critical acceleration, and (4) Arias intensity and critical acceleration ratio. These equations are well constrained and fit the data well (71% < R2 < 88%), but they have standard deviations of about 0.5 log units, such that the range defined by the mean ?? one standard deviation spans about an order of magnitude. These regression models, therefore, are not recommended for use in site-specific design, but rather for regional-scale seismic landslide hazard mapping or for rapid preliminary screening of sites. ?? 2007 Elsevier B.V. All rights reserved.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Engineering Geology","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1016/j.enggeo.2007.01.013","issn":"00137952","usgsCitation":"Jibson, R., 2007, Regression models for estimating coseismic landslide displacement: Engineering Geology, v. 91, no. 2-4, p. 209-218, https://doi.org/10.1016/j.enggeo.2007.01.013.","startPage":"209","endPage":"218","numberOfPages":"10","costCenters":[],"links":[{"id":212840,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/j.enggeo.2007.01.013"},{"id":240392,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"91","issue":"2-4","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"50e4a5cee4b0e8fec6cdc006","contributors":{"authors":[{"text":"Jibson, R.W.","contributorId":8467,"corporation":false,"usgs":true,"family":"Jibson","given":"R.W.","email":"","affiliations":[],"preferred":false,"id":424866,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}} ,{"id":70029913,"text":"70029913 - 2007 - Automated classifications of topography from DEMs by an unsupervised nested-means algorithm and a three-part geometric signature","interactions":[],"lastModifiedDate":"2023-08-25T11:46:22.779709","indexId":"70029913","displayToPublicDate":"2007-01-01T00:00:00","publicationYear":"2007","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1801,"text":"Geomorphology","active":true,"publicationSubtype":{"id":10}},"title":"Automated classifications of topography from DEMs by an unsupervised nested-means algorithm and a three-part geometric signature","docAbstract":"An iterative procedure that implements the classification of continuous topography as a problem in digital image-processing automatically divides an area into categories of surface form; three taxonomic criteria–slope gradient, local convexity, and surface texture–are calculated from a square-grid digital elevation model (DEM). The sequence of programmed operations combines twofold-partitioned maps of the three variables converted to greyscale images, using the mean of each variable as the dividing threshold. To subdivide increasingly subtle topography, grid cells sloping at less than mean gradient of the input DEM are classified by designating mean values of successively lower-sloping subsets of the study area (nested means) as taxonomic thresholds, thereby increasing the number of output categories from the minimum 8 to 12 or 16. Program output is exemplified by 16 topographic types for the world at 1-km spatial resolution (SRTM30 data), the Japanese Islands at 270 m, and part of Hokkaido at 55 m. Because the procedure is unsupervised and reflects frequency distributions of the input variables rather than pre-set criteria, the resulting classes are undefined and must be calibrated empirically by subsequent analysis. Maps of the example classifications reflect physiographic regions, geological structure, and landform as well as slope materials and processes; fine-textured terrain categories tend to correlate with erosional topography or older surfaces, coarse-textured classes with areas of little dissection. In Japan the resulting classes approximate landform types mapped from airphoto analysis, while in the Americas they create map patterns resembling Hammond's terrain types or surface-form classes; SRTM30 output for the United States compares favorably with Fenneman's physical divisions. Experiments are suggested for further developing the method; the Arc/Info AML and the map of terrain classes for the world are available as online downloads.
The largest abrupt climatic reversal of the Holocene interglacial, the cooling event 8.6–8.2 thousand years ago (ka), was probably caused by catastrophic release of glacial Lake Agassiz-Ojibway, which slowed Atlantic meridional overturning circulation (AMOC) and cooled global climate. Geophysical surveys and sediment cores from Chesapeake Bay reveal the pattern of sea level rise during this event. Sea level rose ∼14 m between 9.5 to 7.5 ka, a pattern consistent with coral records and the ICE-5G glacio-isostatic adjustment model. There were two distinct periods at ∼8.9–8.8 and ∼8.2–7.6 ka when Chesapeake marshes were drown as sea level rose rapidly at least ∼12 mm yr−1. The latter event occurred after the 8.6–8.2 ka cooling event, coincided with extreme warming and vigorous AMOC centered on 7.9 ka, and may have been due to Antarctic Ice Sheet decay.
","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Geophysical Research Letters","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","publisher":"Wiley","doi":"10.1029/2007GL031318","issn":"00948276","usgsCitation":"Cronin, T.M., Vogt, P., Willard, D., Thunell, R., Halka, J., Berke, M., and Pohlman, J., 2007, Rapid sea level rise and ice sheet response to 8,200-year climate event: Geophysical Research Letters, v. 34, no. 20, L20603; 6 p., https://doi.org/10.1029/2007GL031318.","productDescription":"L20603; 6 p.","numberOfPages":"6","costCenters":[],"links":[{"id":477226,"rank":10000,"type":{"id":41,"text":"Open Access External Repository Page"},"url":"https://hdl.handle.net/1912/3348","text":"External Repository"},{"id":213041,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1029/2007GL031318"},{"id":240621,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"34","issue":"20","noUsgsAuthors":false,"publicationDate":"2007-10-24","publicationStatus":"PW","scienceBaseUri":"505a94fee4b0c8380cd81743","contributors":{"authors":[{"text":"Cronin, T. M. 0000-0002-2643-0979","orcid":"https://orcid.org/0000-0002-2643-0979","contributorId":42613,"corporation":false,"usgs":true,"family":"Cronin","given":"T.","email":"","middleInitial":"M.","affiliations":[{"id":40020,"text":"Florence Bascom Geoscience Center","active":true,"usgs":true}],"preferred":false,"id":424924,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Vogt, P.R.","contributorId":38312,"corporation":false,"usgs":true,"family":"Vogt","given":"P.R.","email":"","affiliations":[],"preferred":false,"id":424922,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Willard, Debra A. 0000-0003-4878-0942","orcid":"https://orcid.org/0000-0003-4878-0942","contributorId":85982,"corporation":false,"usgs":true,"family":"Willard","given":"Debra A.","affiliations":[],"preferred":false,"id":424925,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Thunell, R.","contributorId":96836,"corporation":false,"usgs":true,"family":"Thunell","given":"R.","email":"","affiliations":[],"preferred":false,"id":424926,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Halka, J.","contributorId":40021,"corporation":false,"usgs":true,"family":"Halka","given":"J.","email":"","affiliations":[],"preferred":false,"id":424923,"contributorType":{"id":1,"text":"Authors"},"rank":5},{"text":"Berke, M.","contributorId":103878,"corporation":false,"usgs":true,"family":"Berke","given":"M.","email":"","affiliations":[],"preferred":false,"id":424927,"contributorType":{"id":1,"text":"Authors"},"rank":6},{"text":"Pohlman, J.","contributorId":19949,"corporation":false,"usgs":true,"family":"Pohlman","given":"J.","email":"","affiliations":[],"preferred":false,"id":424921,"contributorType":{"id":1,"text":"Authors"},"rank":7}]}} ,{"id":70029925,"text":"70029925 - 2007 - Beyond SaGMRotI: Conversion to SaArb, SaSN, and SaMaxRot","interactions":[],"lastModifiedDate":"2023-07-21T12:05:00.791509","indexId":"70029925","displayToPublicDate":"2007-01-01T00:00:00","publicationYear":"2007","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1135,"text":"Bulletin of the Seismological Society of America","onlineIssn":"1943-3573","printIssn":"0037-1106","active":true,"publicationSubtype":{"id":10}},"title":"Beyond SaGMRotI: Conversion to SaArb, SaSN, and SaMaxRot","docAbstract":"In the seismic design of structures, estimates of design forces are usually provided to the engineer in the form of elastic response spectra. Predictive equations for elastic response spectra are derived from empirical recordings of ground motion. The geometric mean of the two orthogonal horizontal components of motion is often used as the response value in these predictive equations, although it is not necessarily the most relevant estimate of forces within the structure. For some applications it is desirable to estimate the response value on a randomly chosen single component of ground motion, and in other applications the maximum response in a single direction is required. We give adjustment factors that allow converting the predictions of geometric-mean ground-motion predictions into either of these other two measures of seismic ground-motion intensity. In addition, we investigate the relation of the strike-normal component of ground motion to the maximum response values. We show that the strike-normal component of ground motion seldom corresponds to the maximum horizontal-component response value (in particular, at distances greater than about 3 km from faults), and that focusing on this case in exclusion of others can result in the underestimation of the maximum component. This research provides estimates of the maximum response value of a single component for all cases, not just near-fault strike-normal components. We provide modification factors that can be used to convert predictions of ground motions in terms of the geometric mean to the maximum spectral acceleration (SaMaxRot) and the random component of spectral acceleration (SaArb). Included are modification factors for both the mean and the aleatory standard deviation of the logarithm of the motions.","language":"English","publisher":"Seismological Society of America","doi":"10.1785/0120070007","issn":"00371106","usgsCitation":"Watson-Lamprey, J., and Boore, D., 2007, Beyond SaGMRotI: Conversion to SaArb, SaSN, and SaMaxRot: Bulletin of the Seismological Society of America, v. 97, no. 5, p. 1511-1524, https://doi.org/10.1785/0120070007.","productDescription":"14 p.","startPage":"1511","endPage":"1524","numberOfPages":"14","costCenters":[],"links":[{"id":240622,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"97","issue":"5","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"5059f0d1e4b0c8380cd4a920","contributors":{"authors":[{"text":"Watson-Lamprey, J. A.","contributorId":27266,"corporation":false,"usgs":true,"family":"Watson-Lamprey","given":"J. A.","affiliations":[],"preferred":false,"id":424928,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Boore, D.M. 0000-0002-8605-9673","orcid":"https://orcid.org/0000-0002-8605-9673","contributorId":64226,"corporation":false,"usgs":true,"family":"Boore","given":"D.M.","affiliations":[],"preferred":false,"id":424929,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70029930,"text":"70029930 - 2007 - Quantifying tolerance indicator values for common stream fish species of the United States","interactions":[],"lastModifiedDate":"2012-03-12T17:21:09","indexId":"70029930","displayToPublicDate":"2007-01-01T00:00:00","publicationYear":"2007","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":"Quantifying tolerance indicator values for common stream fish species of the United States","docAbstract":"The classification of fish species tolerance to environmental disturbance is often used as a means to assess ecosystem conditions. Its use, however, may be problematic because the approach to tolerance classification is based on subjective judgment. We analyzed fish and physicochemical data from 773 stream sites collected as part of the U.S. Geological Survey's National Water-Quality Assessment Program to calculate tolerance indicator values for 10 physicochemical variables using weighted averaging. Tolerance indicator values (TIVs) for ammonia, chloride, dissolved oxygen, nitrite plus nitrate, pH, phosphorus, specific conductance, sulfate, suspended sediment, and water temperature were calculated for 105 common fish species of the United States. Tolerance indicator values for specific conductance and sulfate were correlated (rho = 0.87), and thus, fish species may be co-tolerant to these water-quality variables. We integrated TIVs for each species into an overall tolerance classification for comparisons with judgment-based tolerance classifications. Principal components analysis indicated that the distinction between tolerant and intolerant classifications was determined largely by tolerance to suspended sediment, specific conductance, chloride, and total phosphorus. Factors such as water temperature, dissolved oxygen, and pH may not be as important in distinguishing between tolerant and intolerant classifications, but may help to segregate species classified as moderate. Empirically derived tolerance classifications were 58.8% in agreement with judgment-derived tolerance classifications. Canonical discriminant analysis revealed that few TIVs, primarily chloride, could discriminate among judgment-derived tolerance classifications of tolerant, moderate, and intolerant. To our knowledge, this is the first empirically based understanding of fish species tolerance for stream fishes in the United States.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Ecological Indicators","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1016/j.ecolind.2006.02.004","issn":"1470160X","usgsCitation":"Meador, M.R., and Carlisle, D., 2007, Quantifying tolerance indicator values for common stream fish species of the United States: Ecological Indicators, v. 7, no. 2, p. 329-338, https://doi.org/10.1016/j.ecolind.2006.02.004.","startPage":"329","endPage":"338","numberOfPages":"10","costCenters":[],"links":[{"id":212660,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/j.ecolind.2006.02.004"},{"id":240182,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"7","issue":"2","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a91efe4b0c8380cd80559","contributors":{"authors":[{"text":"Meador, M. R.","contributorId":74400,"corporation":false,"usgs":true,"family":"Meador","given":"M.","email":"","middleInitial":"R.","affiliations":[],"preferred":false,"id":424950,"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":424951,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70029931,"text":"70029931 - 2007 - Response of the St. Joseph River to lake level changes during the last 12,000 years in the Lake Michigan basin","interactions":[],"lastModifiedDate":"2012-03-12T17:21:09","indexId":"70029931","displayToPublicDate":"2007-01-01T00:00:00","publicationYear":"2007","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2411,"text":"Journal of Paleolimnology","active":true,"publicationSubtype":{"id":10}},"title":"Response of the St. Joseph River to lake level changes during the last 12,000 years in the Lake Michigan basin","docAbstract":"The water level of the Lake Michigan basin is currently 177 m above sea level. Around 9,800 14C years B.P., the lake level in the Lake Michigan basin had dropped to its lowest level in prehistory, about 70 m above sea level. This low level (Lake Chippewa) had profound effects on the rivers flowing directly into the basin. Recent studies of the St. Joseph River indicate that the extreme low lake level rejuvenated the river, causing massive incision of up to 43 m in a valley no more than 1.6 km wide. The incision is seen 25 km upstream of the present shoreline. As lake level rose from the Chippewa low, the St. Joseph River lost competence and its estuary migrated back upstream. Floodplain and channel sediments partially refilled the recently excavated valley leaving a distinctly non-classical morphology of steep sides with a broad, flat bottom. The valley walls of the lower St. Joseph River are 12-18 m tall and borings reveal up to 30 m of infill sediment below the modern floodplain. About 3 ?? 108 m3 of sediment was removed from the St. Joseph River valley during the Chippewa phase lowstand, a massive volume, some of which likely resides in a lowstand delta approximately 30 km off-shore in Lake Michigan. The active floodplain below Niles, Michigan, is inset into an upper terrace and delta graded to the Calumet level (189 m) of Lake Chicago. In the lower portion of the terrace stratigraphy a 1.5-2.0 m thick section of clast-supported gravel marks the entry of the main St. Joseph River drainage above South Bend, Indiana, into the Lake Michigan basin. This gravel layer represents the consolidation of drainage that probably occurred during final melting out of ice-marginal kettle chains allowing stream piracy to proceed between Niles and South Bend. It is unlikely that the St. Joseph River is palimpsest upon a bedrock valley. The landform it cuts across is a glaciofluvial-deltaic feature rather than a classic unsorted moraine that would drape over pre-glacial topography. ?? 2006 Springer Science+Business Media B.V.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Journal of Paleolimnology","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1007/s10933-006-9045-2","issn":"09212728","usgsCitation":"Kincare, K., 2007, Response of the St. Joseph River to lake level changes during the last 12,000 years in the Lake Michigan basin: Journal of Paleolimnology, v. 37, no. 3, p. 383-394, https://doi.org/10.1007/s10933-006-9045-2.","startPage":"383","endPage":"394","numberOfPages":"12","costCenters":[],"links":[{"id":212661,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1007/s10933-006-9045-2"},{"id":240183,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"37","issue":"3","noUsgsAuthors":false,"publicationDate":"2007-01-11","publicationStatus":"PW","scienceBaseUri":"505aaa73e4b0c8380cd8633b","contributors":{"authors":[{"text":"Kincare, K.A.","contributorId":61876,"corporation":false,"usgs":true,"family":"Kincare","given":"K.A.","affiliations":[],"preferred":false,"id":424952,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}} ,{"id":70029932,"text":"70029932 - 2007 - Large-scale causes of variation in the serpentine vegetation of California","interactions":[],"lastModifiedDate":"2012-03-12T17:21:09","indexId":"70029932","displayToPublicDate":"2007-01-01T00:00:00","publicationYear":"2007","noYear":false,"publicationType":{"id":24,"text":"Conference Paper"},"publicationSubtype":{"id":19,"text":"Conference Paper"},"title":"Large-scale causes of variation in the serpentine vegetation of California","docAbstract":"Serpentine vegetation in California ranges from forest to shrubland and grassland, harbors many rare and endemic species, and is only moderately altered by invasive exotic species at the present time. To better understand the factors regulating the distribution of common/representative species, endemic/rare species, and the threat of exotics in this important flora, we analyzed broad-scale community patterns and environmental conditions in a geographically stratified set of samples from across the state. We considered three major classes of environmental influences: climate (especially precipitation), soils (especially the Mg2+/Ca2+ ratio), and the indirect influences of climate on soils. We used ordination to identify the major axes of variation in common species abundances, structural equation models to analyze the relationship of community axes and endemic and exotic species richness to the environment, and group analysis techniques to identify consistent groupings of species and characterize their properties. We found that community variation could be explained by a two-axis ordination. One axis ranged from conifer forest to grassland and was strongly related to precipitation. The second axis ranged from chaparral to grassland and had little relationship to current environmental conditions, suggesting a possible role for successional history. Precipitation and elevation were respectively the largest influences on endemic and exotic richness, followed by Mg 2+/Ca2+. The results also support the idea that long-term precipitation patterns have altered the Mg2+/Ca2+ ratio via selective leaching, resulting in indirect influences on endemics (positive) and exotics (negative) but not affecting the abundances of common species. We discuss implications of these findings for the conservation of the California serpentine flora. ?? 2007 Springer Science+Business Media B.V.","largerWorkTitle":"Plant and Soil","language":"English","doi":"10.1007/s11104-007-9196-6","issn":"0032079X","usgsCitation":"Grace, J., Safford, H., and Harrison, S., 2007, Large-scale causes of variation in the serpentine vegetation of California, in Plant and Soil, v. 293, no. 1-2, p. 121-132, https://doi.org/10.1007/s11104-007-9196-6.","startPage":"121","endPage":"132","numberOfPages":"12","costCenters":[],"links":[{"id":240214,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":212689,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1007/s11104-007-9196-6"}],"volume":"293","issue":"1-2","noUsgsAuthors":false,"publicationDate":"2007-02-09","publicationStatus":"PW","scienceBaseUri":"505a4492e4b0c8380cd66bfd","contributors":{"authors":[{"text":"Grace, J.B. 0000-0001-6374-4726","orcid":"https://orcid.org/0000-0001-6374-4726","contributorId":38938,"corporation":false,"usgs":true,"family":"Grace","given":"J.B.","affiliations":[],"preferred":false,"id":424954,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Safford, H.D.","contributorId":22293,"corporation":false,"usgs":true,"family":"Safford","given":"H.D.","email":"","affiliations":[],"preferred":false,"id":424953,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Harrison, S.","contributorId":76129,"corporation":false,"usgs":true,"family":"Harrison","given":"S.","affiliations":[],"preferred":false,"id":424955,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70029936,"text":"70029936 - 2007 - Self-gravity wake structures in Saturn's a ring revealed by Cassini vims","interactions":[],"lastModifiedDate":"2012-03-12T17:21:09","indexId":"70029936","displayToPublicDate":"2007-01-01T00:00:00","publicationYear":"2007","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":914,"text":"Astronomical Journal","active":true,"publicationSubtype":{"id":10}},"title":"Self-gravity wake structures in Saturn's a ring revealed by Cassini vims","docAbstract":"During the summer of 2005, the Visual and Infrared Mapping Spectrometer onboard the Cassini spacecraft observed a series of occultations of the star o Ceti (Mira) by Saturn's rings. These observations revealed pronounced variations in the optical depth of the A ring with longitude, which can be attributed to oriented structures in the rings known as self-gravity wakes. While the wakes themselves are only tens of meters across and below the resolution of the measurements, we are able to obtain information about the orientation and shapes of these structures by comparing the observed transmission at different longitudes with predictions from a simple model. Our findings include the following: (1) The orientation of the wakes varies systematically with radius, trailing by between 64?? and 72?? relative to the local radial direction. (2) The maximum transmission peaks at roughly 8% for B = 3.45?? in the middle A ring (???129,000 km). (3) Both the wake orientation and maximum transmission vary anomalously in the vicinity of two strong density waves (Janus 5:4 and Mimas 5:3). (4) The ratio of the wake vertical thickness H to the wake pattern wavelength ?? (assuming infinite, straight, regularly-spaced wake structures) varies from 0.12 to 0.09 across the A ring. Gravitational instability theory predicts ?? ??? 60 m, which suggests that the wake structures in the A ring are only ???6 m thick. ?? 2007. The American Astronomical Society. All rights reserved.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Astronomical Journal","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1086/516828","issn":"00046256","usgsCitation":"Hedman, M., Nicholson, P.D., Salo, H., Wallis, B., Buratti, B.J., Baines, K.H., Brown, R.H., and Clark, R.N., 2007, Self-gravity wake structures in Saturn's a ring revealed by Cassini vims: Astronomical Journal, v. 133, no. 6, p. 2624-2629, https://doi.org/10.1086/516828.","startPage":"2624","endPage":"2629","numberOfPages":"6","costCenters":[],"links":[{"id":477119,"rank":10000,"type":{"id":41,"text":"Open Access External Repository Page"},"url":"https://doi.org/10.1086/516828","text":"External Repository"},{"id":212749,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1086/516828"},{"id":240285,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"133","issue":"6","noUsgsAuthors":false,"publicationDate":"2007-04-23","publicationStatus":"PW","scienceBaseUri":"505b8d00e4b08c986b318214","contributors":{"authors":[{"text":"Hedman, M.M.","contributorId":91694,"corporation":false,"usgs":true,"family":"Hedman","given":"M.M.","email":"","affiliations":[],"preferred":false,"id":424977,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Nicholson, P. D.","contributorId":54330,"corporation":false,"usgs":false,"family":"Nicholson","given":"P.","email":"","middleInitial":"D.","affiliations":[],"preferred":false,"id":424973,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Salo, H.","contributorId":79303,"corporation":false,"usgs":true,"family":"Salo","given":"H.","email":"","affiliations":[],"preferred":false,"id":424975,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Wallis, B.D.","contributorId":88562,"corporation":false,"usgs":true,"family":"Wallis","given":"B.D.","email":"","affiliations":[],"preferred":false,"id":424976,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Buratti, B. J.","contributorId":69280,"corporation":false,"usgs":false,"family":"Buratti","given":"B.","email":"","middleInitial":"J.","affiliations":[],"preferred":false,"id":424974,"contributorType":{"id":1,"text":"Authors"},"rank":5},{"text":"Baines, K. H.","contributorId":37868,"corporation":false,"usgs":false,"family":"Baines","given":"K.","email":"","middleInitial":"H.","affiliations":[],"preferred":false,"id":424972,"contributorType":{"id":1,"text":"Authors"},"rank":6},{"text":"Brown, R. H.","contributorId":19931,"corporation":false,"usgs":false,"family":"Brown","given":"R.","email":"","middleInitial":"H.","affiliations":[],"preferred":false,"id":424971,"contributorType":{"id":1,"text":"Authors"},"rank":7},{"text":"Clark, R. N.","contributorId":6568,"corporation":false,"usgs":true,"family":"Clark","given":"R.","email":"","middleInitial":"N.","affiliations":[],"preferred":false,"id":424970,"contributorType":{"id":1,"text":"Authors"},"rank":8}]}} ,{"id":70029937,"text":"70029937 - 2007 - Paleovalley fills: Trunk vs. tributary","interactions":[],"lastModifiedDate":"2012-03-12T17:21:09","indexId":"70029937","displayToPublicDate":"2007-01-01T00:00:00","publicationYear":"2007","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":701,"text":"American Association of Petroleum Geologists Bulletin","active":true,"publicationSubtype":{"id":10}},"title":"Paleovalley fills: Trunk vs. tributary","docAbstract":"A late Mississippian-early Pennsylvanian eustatic sea level drop resulted in a complex lowstand drainage network being eroded across the Illinois Basin in the eastern United States. This drainage system was filled during the early part of the Pennsylvanian. Distinct differences can be recognized between the trunk and tributary paleovalley fills. Fills preserved within the trunk systems tend to be fluvially dominated and consist of bed-load deposits of coarse- to medium-grained sandstone and conglomerate. Conversely, the incised valleys of tributary systems tend to be filled with dark mudstone, thinly interbedded sandstones, and mudstones and siltstones. These finer grained facies exhibit marine influences manifested by tidal rhythmites, certain traces fossils, and macro- and microfauna. Examples of tributary and trunk systems, separated by no more than 7 km (4.3 mi) along strike, exhibit these styles of highly contrasting fills. Useful analogs for understanding this Pennsylvanian system include the Quaternary glacial sluiceways present in the lower Ohio, White, and Wabash river valleys of Indiana (United States) and the modern Amazon River (Brazil). Both the Amazon River and the Quaternary rivers of Indiana have (or had) trunk rivers that are (were) dominated by large quantities of bed load relative to their tributaries. The trunk valley systems of these analogs aggraded much more rapidly than their tributary valleys, which evolved into lakes because depositional rates along the trunk are (were) so high that the mouths of the tributaries have been dammed by bed-load deposits. These Holocene systems illustrate that sediment yields can significantly influence the nature of fill successions within incised valleys independent of rates of sea level changes or proximity to highstand coastlines. Copyright ?? 2007. The American Association of Petroleum Geologists. All rights reserved.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"American Association of Petroleum Geologists Bulletin","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1306/11060606022","issn":"01491423","usgsCitation":"Kvale, E., and Archer, A., 2007, Paleovalley fills: Trunk vs. tributary: American Association of Petroleum Geologists Bulletin, v. 91, no. 6, p. 809-821, https://doi.org/10.1306/11060606022.","startPage":"809","endPage":"821","numberOfPages":"13","costCenters":[],"links":[{"id":212750,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1306/11060606022"},{"id":240286,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"91","issue":"6","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a745fe4b0c8380cd775ea","contributors":{"authors":[{"text":"Kvale, E.P.","contributorId":76076,"corporation":false,"usgs":true,"family":"Kvale","given":"E.P.","affiliations":[],"preferred":false,"id":424979,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Archer, A.W.","contributorId":8620,"corporation":false,"usgs":true,"family":"Archer","given":"A.W.","affiliations":[],"preferred":false,"id":424978,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70029939,"text":"70029939 - 2007 - Early vegetation development on an exposed reservoir: Implications for dam removal","interactions":[],"lastModifiedDate":"2012-03-12T17:21:09","indexId":"70029939","displayToPublicDate":"2007-01-01T00:00:00","publicationYear":"2007","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":"Early vegetation development on an exposed reservoir: Implications for dam removal","docAbstract":"The 4-year drawdown of Horsetooth Reservoir, Colorado, for dam maintenance, provides a case study analog of vegetation response on sediment that might be exposed from removal of a tall dam. Early vegetation recovery on the exposed reservoir bottom was a combination of (1) vegetation colonization on bare, moist substrates typical of riparian zones and reservoir sediment of shallow dams and (2) a shift in moisture status from mesic to the xeric conditions associated with the pre-impoundment upland position of most of the drawdown zone. Plant communities changed rapidly during the first four years of exposure, but were still substantially different from the background upland plant community. Predictions from the recruitment box model about the locations of Populus deltoides subsp. monilifera (plains cottonwood) seedlings relative to the water surface were qualitatively confirmed with respect to optimum locations. However, the extreme vertical range of water surface elevations produced cottonwood seed regeneration well outside the predicted limits of drawdown rate and height above late summer stage. The establishment and survival of cottonwood at high elevations and the differences between the upland plant community and the community that had developed after four years of exposure suggest that vegetation recovery following tall dam removal will follow a trajectory very different from a simple reversal of the response to dam construction, involving not only long time scales of establishment and growth of upland vegetation, but also possibly decades of persistence of legacy vegetation established during the reservoir to upland transition. ?? 2007 Springer Science+Business Media, LLC.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Environmental Management","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1007/s00267-006-0018-z","issn":"0364152X","usgsCitation":"Auble, G., Shafroth, P., Scott, M.L., and Roelle, J.E., 2007, Early vegetation development on an exposed reservoir: Implications for dam removal: Environmental Management, v. 39, no. 6, p. 806-818, https://doi.org/10.1007/s00267-006-0018-z.","startPage":"806","endPage":"818","numberOfPages":"13","costCenters":[],"links":[{"id":477135,"rank":10000,"type":{"id":40,"text":"Open Access Publisher Index Page"},"url":"https://doi.org/10.1007/s00267-006-0018-z","text":"Publisher Index Page"},{"id":212783,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1007/s00267-006-0018-z"},{"id":240321,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"39","issue":"6","noUsgsAuthors":false,"publicationDate":"2007-04-19","publicationStatus":"PW","scienceBaseUri":"505a0492e4b0c8380cd50a76","contributors":{"authors":[{"text":"Auble, G.T.","contributorId":19505,"corporation":false,"usgs":true,"family":"Auble","given":"G.T.","email":"","affiliations":[],"preferred":false,"id":424985,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Shafroth, P.B.","contributorId":65041,"corporation":false,"usgs":true,"family":"Shafroth","given":"P.B.","email":"","affiliations":[],"preferred":false,"id":424986,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Scott, M. L.","contributorId":75090,"corporation":false,"usgs":true,"family":"Scott","given":"M.","middleInitial":"L.","affiliations":[],"preferred":false,"id":424987,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Roelle, J. E.","contributorId":91066,"corporation":false,"usgs":true,"family":"Roelle","given":"J.","email":"","middleInitial":"E.","affiliations":[],"preferred":false,"id":424988,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}} ]}