Publications
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Supraslab earthquake clusters above the subduction plate boundary offshore Sanriku, northeastern Japan: Seismogenesis in a graveyard of detached seamounts?
Thousands of offshore repeating earthquakes with low‐angle thrust focal mechanisms occur along the subduction plate boundary of NE Japan. Double‐difference relocation methods using P‐ and S‐wave arrivals reveal clusters of events above these repeating events. To assure good depth control we restrict our study to events that are close to seismic stations. These “supraslab” earthquake clusters are r
Authors
Naoki Uchida, Stephen H. Kirby, Tomomi Okada, Ryota Hino, Akira Hasegawa
Guidelines for Standardized Testing of Broadband Seismometers and Accelerometers
Testing and specification of seismic and earthquake-engineering sensors and recorders has been marked by significant variations in procedures and selected parameters. These variations cause difficulty in comparing such specifications and test results.
In July 1989, and again in May 2005, the U.S. Geological Survey hosted international pub-lic/private workshops with the goal of defining widely acc
Authors
Charles R. Hutt, John R. Evans, Fred Followill, Robert L. Nigbor, Erhard Wielandt
The role of material properties in the cratering record of young platy-ridged lava on Mars
Platy‐ridged surfaces in the Elysium Planitia region of Mars exhibit different crater densities on rafted plates and polygonally patterned areas between them. Rather than being indicative of different ages, these differences provide insight into the variable strength of different types of lava surface. The sizes of small craters, and the resulting size‐frequency distribution (SFD), depend on the m
Authors
Colin M. Dundas, Laszlo P. Keszthelyi, Veronica J. Bray, Alfred S. McEwen
Early warning of rainfall-induced shallow landslides and debris flows in the USA
The state of knowledge and resources available to issue alerts of precipitation-induced landslides vary across the USA. Federal and state agencies currently issue warnings of the potential for shallow, rapidly moving landslides and debris flows in a few areas along the Pacific coast and for areas affected by Atlantic hurricanes. However, these agencies generally lack resources needed to provide co
Authors
Rex L. Baum, Jonathan W. Godt
Averaging and sampling for magnetic-observatory hourly data
A time and frequency-domain analysis is made of the effects of averaging and sampling methods used for constructing magnetic-observatory hourly data values. Using 1-min data as a proxy for continuous, geomagnetic variation, we construct synthetic hourly values of two standard types: instantaneous "spot" measurements and simple 1-h "boxcar" averages. We compare these average-sample types with other
Authors
Jeffrey J. Love, V.C. Tsai, Jennifer L. Gannon
Movie‐maps of low‐latitude magnetic storm disturbance
We present 29 movie‐maps of low‐latitude horizontal‐intensity magnetic disturbance for the years 1999–2006: 28 recording magnetic storms and 1 magnetically quiescent period. The movie‐maps are derived from magnetic vector time series data collected at up to 25 ground‐based observatories. Using a technique similar to that used in the calculation of Dst, a quiet time baseline is subtracted from the
Authors
Jeffrey J. Love, Jennifer L. Gannon
Oscillating load-induced acoustic emission in laboratory experiment
Spatial and temporal patterns of acoustic emission (AE) were studied. A pre-fractured cylinder of granite was loaded in a triaxial machine at 160 MPa confining pressure until stick-slip events occurred. The experiments were conducted at a constant strain rate of 10−7 s−1 that was modulated by small-amplitude sinusoidal oscillations with periods of 175 and 570 seconds. Amplitude of the oscillations
Authors
Alexander Ponomarev, David A. Lockner, S. Stroganova, S. Stanchits, V. Smirnov
Observations of drainage network change in a recently burned watershed using terrestrial laser scanning
Wildfire enhances the geomorphic response of a watershed to precipitation events, effectively altering the form of the hillslope and channel drainage network. Typically, drainage networks expand following rainfall on a recently burned watershed. Expansion of drainage networks following wildfire increases in erosion and sediment transport rates, and the probability of flash-flooding and debris-flow
Authors
Dennis Staley, Thad Wasklewicz, Jason Kean
The Mars Astrobiology Explorer-Cacher (MAX-C): A potential rover mission for 2018
Executive SummaryIntroductionScientific Priorities for a Possible Late-Decade Rover MissionDevelopment of a Spectrum of Possible Mission ConceptsEvaluation, Prioritization of Candidate Mission ConceptsStrategy to Achieve Primary In Situ ObjectivesRelationship to a Potential Sample Return CampaignConsensus Mission VisionConsiderations Related to Landing Site SelectionSome Engineering Considerations
Authors
Lisa Pratt, Carl Allen, Abby Allwood, Ariel D. Anbar, Sushil Atreya, Mike Carr, Dave Des Marais, Daniel Glavin, John Grant, Vicky Hamilton, Kenneth E. Herkenhoff, Victoria J. Hipkin, Tom McCollom, Alfred McEwen, Scott McLennan, Ralph Milliken, Doug Ming, Gian Gabrielle Ori, John Parnell, Francois Poulet, Barbara Sherwood Lollar, Frances Westall
Evaluating the meaning of “layer” in the Martian north polar layered deposits and the impact on the climate connection
Using data from the High Resolution Imaging Science Experiment (HiRISE) aboard the Mars Reconnaissance Orbiter, we reassess the methods by which layers within the north polar layered deposits (NPLD) can be delineated and their thicknesses measured. Apparent brightness and morphology alone are insufficient for this task; high resolution topographic data are necessary. From these analyses, we find t
Authors
Kathryn E. Fishbaugh, Shane Byrne, Kenneth E. Herkenhoff, Randolph L. Kirk, Corey M. Fortezzo, Patrick S. Russell, Alfred S. McEwen
Workshop targets development of geodetic transient detection methods: 2009 SCEC Annual Meeting: Workshop on transient anomalous strain detection; Palm Springs, California, 12-13 September 2009
The Southern California Earthquake Center (SCEC) is a community of researchers at institutions worldwide working to improve understanding of earthquakes and mitigate earthquake risk. One of SCEC's priority objectives is to “develop a geodetic network processing system that will detect anomalous strain transients.” Given the growing number of continuously recording geodetic networks consisting of h
Authors
Jessica R. Murray-Moraleda, Rowena Lohman
Determination of stress parameters for eight well-recorded earthquakes in eastern North America
We determined the stress parameter, Δσ, for the eight earthquakes studied by Atkinson and Boore (2006), using an updated dataset and a revised point-source stochastic model that captures the effect of a finite fault. We consider four geometrical-spreading functions, ranging from 1/R at all distances to two- or three-part functions. The Δσ values are sensitive to the rate of geometrical spreading a
Authors
D. M. Boore, K.W. Campbell, G. M. Atkinson