Conference Papers
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Browse almost 5,000 conference papers authored by our scientists and refine search by topic, location, year, and advanced search.
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3-D simulations of M9 earthquakes on the Cascadia Megathrust: Key parameters and uncertainty
Geologic and historical records indicate that the Cascadia subduction zone is capable of generating large, megathrust earthquakes up to magnitude 9. The last great Cascadia earthquake occurred in 1700, and thus there is no direct measure on the intensity of ground shaking or specific rupture parameters from seismic recordings. We use 3-D numerical simulations to generate broadband (0-10 Hz) synthe
Authors
Erin Wirth, Arthur Frankel, John Vidale, Nasser A. Marafi, William J. Stephenson
Geothermal implications of a refined composition-age geologic map for the volcanic terrains of southeast Oregon, northeast California, and southwest Idaho, USA
Sufficient temperatures to generate steam likely exist under most of the dominantly volcanic terrains of southeast Oregon, northeast California, and southeast Idaho, USA, but finding sufficient permeability to allow efficient advective heat exchange is an outstanding challenge. A new thematic interpretation of existing state-level geologic maps provides an updated and refined distribution of the c
Authors
Erick Burns, Marshall W. Gannett, David R. Sherrod, Mackenzie K. Keith, Jennifer A. Curtis, James R. Bartolino, John A. Engott, Benjamin P. Scandella, Michelle A. Stern, Alan L. Flint
A reference landform ontology for automated delineation of depression landforms from DEMs
Abstract The landform reference ontology (LFRO) is being developed to formalize ontological distinctions underlying naïve geographic cognition and reasoning about landforms. The LFRO taxonomy is currently based only on form-based distinctions. In this significantly revised version, several new categories have been added to explicate ontological distinctions related to material-spatial dependence
Authors
Gaurav Sinha, Samantha Arundel, Torsten Hahmann, E. Lynn Usery, Kathleen C. Stewart, David Mark
Climate change-driven cliff and beach evolution at decadal to centennial time scales
Here we develop a computationally efficient method that evolves cross-shore profiles of sand beaches with or without cliffs along natural and urban coastal environments and across expansive geographic areas at decadal to centennial time-scales driven by 21st century climate change projections. The model requires projected sea level rise rates, extrema of nearshore wave conditions, bluff recession
Authors
Li H. Erikson, Andrea C. O'Neill, Patrick L. Barnard, Sean Vitousek, Patrick W. Limber
Landsat-8 TIRS thermal radiometric calibration status
The Thermal Infrared Sensor (TIRS) instrument is the thermal-band imager on the Landsat-8 platform. The initial onorbit calibration estimates of the two TIRS spectral bands indicated large average radiometric calibration errors, -0.29 and -0.51 W/m2 sr μm or -2.1K and -4.4K at 300K in Bands 10 and 11, respectively, as well as high variability in the errors, 0.87K and 1.67K (1-σ), respectively. The
Authors
Julia A. Barsi, Brian L. Markham, Matthew Montanaro, Aaron Gerace, Simon Hook, John R. Schott, Nina G. Raqueno, Ron Morfitt
Using remotely sensed data to estimate river characteristics including water-surface velocity and discharge
This paper describes a project combining field studies and analyses directed at providing an assessment of the accuracy of remotely sensed methods for determining river characteristics such as velocity and discharge. In particular, we describe a remote sensing method for surface velocities using mid-wave thermal camera videography combined with image analysis. One of the critical problems in this
Authors
Jonathan M. Nelson, Paul J. Kinzel, Carl J. Legleiter, Richard R. McDonald, Brandon Overstreet, Jeffrey S. Conaway
Source of salinity in the Broken Hill (Australia) Pb-Zn-Ag deposit: Insights from halogen ratios in fluid inclusions
Ratios of Na/Br, Br/Cl, and I/Cl were determined on leachates of fluid inclusions from the Broken Hill Pb-ZnAg deposit in Australia. Paragenetic relations suggest that whereas all analyzed inclusions formed during or after regional metamorphism, ion ratios are not greatly changed from those of the pre-metamorphic ore-forming fluids. Based on relatively high Br/Cl and I/Cl ratios, and low Na/Br rat
Authors
John F. Slack, D.A. Banks, R.T. Wilkin
Statistical relative gain calculation for Landsat 8
The Landsat 8 Operational Land Imager (OLI) is an optical multispectral push-broom sensor with a focal plane consisting of over 7000 detectors per spectral band. Each of the individual imaging detectors contributes one column of pixels to an image. Any difference in the response between neighboring detectors may result in a visible stripe or band in the imagery. An accurate estimate of each detect
Authors
Cody Anderson, Dennis Helder, Drake Jeno (CTR)
Estimating risks for water-quality exceedances of total-copper from highway and urban runoff under predevelopment and current conditions with the Stochastic Empirical Loading and Dilution Model (SELDM)
The stochastic empirical loading and dilution model (SELDM) was used to demonstrate methods for estimating risks for water-quality exceedances of event-mean concentrations (EMCs) of total-copper. Monte Carlo methods were used to simulate stormflow, total-hardness, suspended-sediment, and total-copper EMCs as stochastic variables. These simulations were done for the Charles River Basin upstream of
Authors
Gregory E. Granato, Susan C. Jones
Characterizing meteorological and hydrologic conditions associated with shallow landslide initiation in the coastal bluffs of the Atlantic Highlands, New Jersey
Meteorological and hydrologic conditions associated with shallow landslide initiation in the coastal bluffs of the Atlantic Highlands, New Jersey remain undocumented despite a history of damaging slope movement extending back to at least 1903. This study applies an empirical approach to quantify the rainfall conditions leading to shallow landsliding based on analysis of overlapping historical prec
Authors
Francis Ashland, Alex R. Fiore, Pamela A. Reilly
Numerical simulations of sand production in interbedded hydrate-bearing sediments during depressurization
Geomechanical behavior of hydrate-bearing sediments during gas production is complex, involving changes in hydrate-dependent mechanical properties. When interbedded clay layers are present, the complexity is more pronounced because hydrate dissociation tends to occur preferentially in the sediments adjacent to the clay layers due to clay layers acting as a heat source. This would potentially lead
Authors
Shun Uchida, Jeen-Shang Lin, Evgeniy Myshakin, Yongkoo Seol, Timothy S. Collett, Ray Boswell
Numerical studies of depressurization-induced gas production from an interbedded marine turbidite gas hydrate reservoir model
The numerical simulation of thin hydrate-bearing sand layers interbedded with mud layers is investigated. In this model, the lowest hydrate layer occurs at the base of gas hydrate stability and overlies a thinly-interbedded saline aquifer. The predicted gas rates reach 6.25 MMscf/day (1.77 x 105 m3 /day) after 90 days of continuous depressurization with manageable water production. Development of
Authors
Evgeniy Myshakin, Jeen-Shang Lin, Shun Uchida, Yongkoo Seol, Timothy S. Collett, Ray Boswell