Publications
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Accelerating slip rates on the puente hills blind thrust fault system beneath metropolitan Los Angeles, California, USA
Slip rates represent the average displacement across a fault over time and are essential to estimating earthquake recurrence for proba-bilistic seismic hazard assessments. We demonstrate that the slip rate on the western segment of the Puente Hills blind thrust fault system, which is beneath downtown Los Angeles, California (USA), has accel-erated from ~0.22 mm/yr in the late Pleistocene to ~1.33
Authors
Kristian J. Bergen, John H. Shaw, Lorraine A. Leon, James F. Dolan, Thomas L. Pratt, Daniel J. Ponti, Eric Morrow, Wendy Barrera, Edward J. Rhodes, Madhav K. Murari, Lewis A. Owen
The vanishing cryovolcanoes of Ceres
Ahuna Mons is a 4 km tall mountain on Ceres interpreted as a geologically young cryovolcanic dome. Other possible cryovolcanic features are more ambiguous, implying that cryovolcanism is only a recent phenomenon or that other cryovolcanic structures have been modified beyond easy identification. We test the hypothesis that Cerean cryovolcanic domes viscously relax, precluding ancient domes from re
Authors
Michael M. Sori, Shane Byrne, Michael T. Bland, Ali Bramson, Anton Ermakov, Christoper Hamilton, Katharina Otto, Ottaviano Ruesch, Christopher Russell
Connecting the dots: Preprocessing Apollo 15 panoramic camera images for photogrammetric control
No abstract available.
Authors
Kenneth L. Edmundson, Brent A. Archinal, Tammy L. Becker, J.A. Mapel, Mark S. Robinson, M.R. Shepherd
Regional patterns of Mesozoic-Cenozoic magmatism in western Alaska revealed by new U-Pb and 40Ar/39Ar ages
In support of regional geologic framework studies, we obtained 50 new argon-40/argon-39 (40Ar/39Ar) ages and 33 new uranium-lead (U-Pb) ages from igneous rocks of southwestern Alaska. Most of the samples are from the Sleetmute and Taylor Mountains quadrangles; smaller collections or individual samples are from the Bethel, Candle, Dillingham, Goodnews Bay, Holy Cross, Iditarod, Kantishna River, Lak
Authors
Dwight Bradley, Marti L. Miller, Richard M. Friedman, Paul W. Layer, Heather A. Bleick, James V. Jones, Steven E. Box, Susan M. Karl, Nora B. Shew, Timothy S. White, Alison B. Till, Julie A. Dumoulin, Thomas K. Bundtzen, Paul B. O'Sullivan, Thomas D. Ullrich
Ground-rupturing earthquakes on the northern Big Bend of the San Andreas Fault, California, 800 A.D. to Present
Paleoseismic data on the timing of ground-rupturing earthquakes constrain the recurrence behavior of active faults and can provide insight on the rupture history of a fault if earthquakes dated at neighboring sites overlap in age and are considered correlative. This study presents the evidence and ages for 11 earthquakes that occurred along the Big Bend section of the southern San Andreas Fault at
Authors
Katherine M. Scharer, Ray J. Weldon, Glenn Biasi, Ashley Streig, Thomas E. Fumal
Unusual geologic evidence of coeval seismic shaking and tsunamis shows variability in earthquake size and recurrence in the area of the giant 1960 Chile earthquake
An uncommon coastal sedimentary record combines evidence for seismic shaking and coincident tsunami inundation since AD 1000 in the region of the largest earthquake recorded instrumentally: the giant 1960 southern Chile earthquake (Mw 9.5). The record reveals significant variability in the size and recurrence of megathrust earthquakes and ensuing tsunamis along this part of the Nazca-South America
Authors
M. Cisternas, E Garrett, Robert L. Wesson, T. Dura, L. L Ely
Broadband seismic noise attenuation versus depth at the Albuquerque Seismological Laboratory
Seismic noise induced by atmospheric processes such as wind and pressure changes can be a major contributor to the background noise observed in many seismograph stations, especially those installed at or near the surface. Cultural noise such as vehicle traffic or nearby buildings with air handling equipment also contributes to seismic background noise. Such noise sources fundamentally limit our ab
Authors
Charles R. Hutt, Adam T. Ringler, Lind Gee
CO2 diffusion into pore spaces limits weathering rate of an experimental basalt landscape
Basalt weathering is a key control over the global carbon cycle, though in situ measurements of carbon cycling are lacking. In an experimental, vegetation-free hillslope containing 330 m3 of ground basalt scoria, we measured real-time inorganic carbon dynamics within the porous media and seepage flow. The hillslope carbon flux (0.6–5.1 mg C m–2 h–1) matched weathering rates of natural basalt lands
Authors
Joost van Haren, Katerina Dontsova, Greg A. Barron-Gafford, Peter A. Troch, Jon Chorover, Stephen B. DeLong, David D. Breshears, Travis E. Huxman, Jon D. Pelletier, Scott Saleska, Xubin Zeng, Joaquin Ruiz
Subsurface volatile content of martian double-layer ejecta (DLE) craters
Excess ice is widespread throughout the martian mid-latitudes, particularly in Arcadia Planitia, where double-layer ejecta (DLE) craters also tend to be abundant. In this region, we observe the presence of thermokarstically-expanded secondary craters that likely form from impacts that destabilize a subsurface layer of excess ice, which subsequently sublimates. The presence of these expanded crater
Authors
Donna Viola, Alfred S. McEwen, Colin M. Dundas, Shane Byrne
Large earthquakes and creeping faults
Faults are ubiquitous throughout the Earth's crust. The majority are silent for decades to centuries, until they suddenly rupture and produce earthquakes. With a focus on shallow continental active-tectonic regions, this paper reviews a subset of faults that have a different behavior. These unusual faults slowly creep for long periods of time and produce many small earthquakes. The presence of fau
Authors
Ruth A. Harris
Toppling analysis of the Echo Cliffs precariously balanced rock
Toppling analysis of a precariously balanced rock (PBR) can provide insight into the nature of ground motion that has not occurred at that location in the past and, by extension, can constrain peak ground motions for use in engineering design. Earlier approaches have targeted 2D models of the rock or modeled the rock–pedestal contact using spring‐damper assemblies that require recalibration for ea
Authors
Swetha Veeraraghavan, Kenneth W. Hudnut, Swaminathan Krishnan
Solving for source parameters using nested array data: A case study from the Canterbury, New Zealand earthquake sequence
The seismic spectrum can be constructed by assuming a Brune spectral model and estimating the parameters of seismic moment (M0), corner frequency (fc), and high-frequency site attenuation (κ). Using seismic data collected during the 2010–2011 Canterbury, New Zealand, earthquake sequence, we apply the non-linear least-squares Gauss–Newton method, a deterministic downhill optimization technique, to
Authors
Corrie Neighbors, Elizabeth S. Cochran, Kenneth Ryan, Anna E. Kaiser