Publications
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Electrical resistivity investigation of fluvial geomorphology to evaluate potential seepage conduits to agricultural lands along the San Joaquin River, Merced County, California, 2012–13
Increased flows in the San Joaquin River, part of the San Joaquin River Restoration Program, are designed to help restore fish populations. However, increased seepage losses could result from these higher restoration flows, which could exacerbate existing drainage problems in neighboring agricultural lands and potentially damage crops. Channel deposits of abandoned river meanders that are hydrauli
Authors
Krishangi D. Groover, Matthew K. Burgess, James F. Howle, Steven P. Phillips
Simulation of earthquake ground motions in the eastern United States using deterministic physics‐based and site‐based stochastic approaches
Earthquake ground‐motion recordings are scarce in the central and eastern United States (CEUS) for large‐magnitude events and at close distances. We use two different simulation approaches, a deterministic physics‐based method and a site‐based stochastic method, to simulate ground motions over a wide range of magnitudes. Drawing on previous results for the modeling of recordings from the 2011 Mw 5
Authors
Sanaz Rezaeian, Stephen H. Hartzell, Xiaodan Sun, Carlos Mendoza
Tidal triggering of earthquakes suggests poroelastic behavior on the San Andreas Fault
Tidal triggering of earthquakes is hypothesized to provide quantitative information regarding the fault's stress state, poroelastic properties, and may be significant for our understanding of seismic hazard. To date, studies of regional or global earthquake catalogs have had only modest successes in identifying tidal triggering. We posit that the smallest events that may provide additional evidenc
Authors
Andrew Delorey, Nicholas van der Elst, Paul Johnson
Relations between some horizontal‐component ground‐motion intensity measures used in practice
Various measures using the two horizontal components of recorded ground motions have been used in a number of studies that derive ground‐motion prediction equations and construct maps of shaking intensity. We update relations between a number of these measures, including those in Boore et al. (2006) and Boore (2010), using the large and carefully constructed global database of ground motions from
Authors
David Boore, Tadahiro Kishida
Compartmentalization of the Coso East Flank geothermal field imaged by 3-D full-tensor MT inversion
Previous magnetotelluric (MT) studies of the high-temperature Coso geothermal system in California identified a subvertical feature of low resistivity (2–5 Ohm m) and appreciable lateral extent (>1 km) in the producing zone of the East Flank field. However, these models could not reproduce gross 3-D effects in the recorded data. We perform 3-D full-tensor inversion and retrieve a resistivity model
Authors
Nathaniel J. Lindsey, J. Ole Kaven, Nicholas C. Davatzes, Gregory A. Newman
The role of initial coherence and path materials in the dynamics of three rock avalanche case histories
BackgroundRock avalanches are flow-like landslides that can travel at extremely rapid velocities and impact surprisingly large areas. The mechanisms that lead to the unexpected mobility of these flows are unknown and debated. Mechanisms proposed in the literature can be broadly classified into those that rely on intrinsic characteristics of the rock avalanche material, and those that rely on extri
Authors
Jordan Aaron, Scott McDougall, Jeffrey R. Moore, Jeffrey A. Coe, Oldrich Hungr
Paleoseismic potential of sublacustrine landslide records in a high-seismicity setting (south-central Alaska)
Sublacustrine landslide stratigraphy is considered useful for quantitative paleoseismology in low-seismicity settings. However, as the recharging of underwater slopes with sediments is one of the factors that governs the recurrence of slope failures, it is not clear if landslide deposits can provide continuous paleoseismic records in settings of frequent strong shaking. To test this, we selected t
Authors
Nore Praet, Jasper Moernaut, Maarten Van Daele, Evelien Boes, Peter J. Haeussler, Michael Strupler, Sabine Schmidt, Michael G. Loso, Marc De Batist
Ground motion in the presence of complex Topography II: Earthquake sources and 3D simulations
Eight seismic stations were placed in a linear array with a topographic relief of 222 m over Mission Peak in the east San Francisco Bay region for a period of one year to study topographic effects. Seventy‐two well‐recorded local earthquakes are used to calculate spectral amplitude ratios relative to a reference site. A well‐defined fundamental resonance peak is observed with individual station am
Authors
Stephen H. Hartzell, Leonardo Ramirez-Guzman, Mark Meremonte, Alena L. Leeds
Modeling strong‐motion recordings of the 2010 Mw 8.8 Maule, Chile, earthquake with high stress‐drop subevents and background slip
Strong‐motion recordings of the Mw 8.8 Maule earthquake were modeled using a compound rupture model consisting of (1) a background slip distribution with large correlation lengths, relatively low slip velocity, and long peak rise time of slip of about 10 s and (2) high stress‐drop subevents (asperities) on the deeper portion of the rupture with moment magnitudes 7.9–8.2, high slip velocity, and ri
Authors
Arthur Frankel
Dynamic strains for earthquake source characterization
Strainmeters measure elastodynamic deformation associated with earthquakes over a broad frequency band, with detection characteristics that complement traditional instrumentation, but they are commonly used to study slow transient deformation along active faults and at subduction zones, for example. Here, we analyze dynamic strains at Plate Boundary Observatory (PBO) borehole strainmeters (BSM) as
Authors
Andrew J. Barbour, Brendan W. Crowell
Development and utilization of USGS ShakeCast for rapid post-earthquake assessment of critical facilities and infrastructure
The ShakeCast system is an openly available, near real-time post-earthquake information management system. ShakeCast is widely used by public and private emergency planners and responders, lifeline utility operators and transportation engineers to automatically receive and process ShakeMap products for situational awareness, inspection priority, or damage assessment of their own infrastructure or
Authors
David J. Wald, Kuo-wan Lin, C. A. Kircher, Kishor S. Jaiswal, Nicolas Luco, L. Turner, Daniel Slosky
Paleomagnetism and 40Ar/39Ar geochronology of the Plio-Pleistocene Boring Volcanic Field: Implications for the geomagnetic polarity time scale and paleosecular variation
Paleomagnetic directions and 40Ar/39Ar ages have been determined for samples of lava flows from the same outcrops, where possible, for 84 eruptive units ranging in age from 3200 ka to 60 ka within the Boring Volcanic Field (BVF) of the Pacific Northwest, USA. This study expands upon our previous results for the BVF, and compares the combined results with the current geomagnetic polarity time scale
Authors
Jonathan T. Hagstrum, Robert J. Fleck, Russell C. Evarts, Andrew T. Calvert
By
Energy and Minerals Mission Area, Natural Hazards Mission Area, Energy Resources Program, Geomagnetism Program, Mineral Resources Program, National Cooperative Geologic Mapping Program, National Laboratories Program, Science and Decisions Center, Volcano Hazards Program, Geologic Hazards Science Center, Geology, Minerals, Energy, and Geophysics Science Center, Geosciences and Environmental Change Science Center, Volcano Science Center