Publications
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Objective definition of rainfall intensity-duration thresholds for post-fire flash floods and debris flows in the area burned by the Waldo Canyon fire, Colorado, USA
We present an objectively defined rainfall intensity-duration (I-D) threshold for the initiation of flash floods and debris flows for basins recently burned in the 2012 Waldo Canyon fire near Colorado Springs, Colorado, USA. Our results are based on 453 rainfall records which include 8 instances of hazardous flooding and debris flow from 10 July 2012 to 14 August 2013. We objectively defined the t
Authors
Dennis M. Staley, Joseph E. Gartner, Jason W. Kean
NGA-West 2 GMPE average site coefficients for use in earthquake-resistant design
Site coefficients corresponding to those in tables 11.4–1 and 11.4–2 of Minimum Design Loads for Buildings and Other Structures published by the American Society of Civil Engineers (Standard ASCE/SEI 7-10) are derived from four of the Next Generation Attenuation West2 (NGA-W2) Ground-Motion Prediction Equations (GMPEs). The resulting coefficients are compared with those derived by other researcher
Authors
Roger D. Borcherdt
Chance findings about early holocene tidal marshes of Grays Harbor, Washington, in relation to rapidly rising seas and great subduction earthquakes
Tidal marshes commonly build upward apace with gradual rise in the level of the sea. It is expected, however, that few tidal marshes will keep up with accelerated sea-level rise later in this century. Tidal marshes have been drowned, moreover, after subsiding during earthquakes.
This report tells of ancient marshes that endured rapid sea-level rise in a region that subsides during earthquakes. The
Authors
James B. Phipps, Eileen Hemphill-Haley, Brian F. Atwater
Curiosity’s robotic arm-mounted Mars Hand Lens Imager (MAHLI): Characterization and calibration status
MAHLI (Mars Hand Lens Imager) is a 2-megapixel, Bayer pattern color CCD camera with a macro lens mounted on a rotatable turret at the end of the 2-meters-long robotic arm aboard the Mars Science Laboratory rover, Curiosity. The camera includes white and longwave ultraviolet LEDs to illuminate targets at night. Onboard data processing services include focus stack merging and data compression. Here
Authors
Kenneth S. Edgett, Michael A. Caplinger, Justin N. Maki, Michael A. Ravine, F. Tony Ghaemi, Sean McNair, Kenneth E. Herkenhoff, Brian M. Duston, Reg G. Wilson, R. Aileen Yingst, Megan R. Kennedy, Michelle E. Minitti, Aaron J. Sengstacken, Kimberley D. Supulver, Leslie J. Lipkaman, Gillian M. Krezoski, Marie J. McBride, Tessa L. Jones, Brian E. Nixon, Jason K. Van Beek, Daniel J. Krysak, Randolph L. Kirk
Cascadia subducting plate fluids channelled to fore-arc mantle corner: ETS and silica deposition
In this study we first summarize the constraints that on the Cascadia subduction thrust, there is a 70 km gap downdip between the megathrust seismogenic zone and the Episodic Tremor and Slip (ETS) that lies further landward; there is not a continuous transition from unstable to conditionally stable sliding. Seismic rupture occurs mainly offshore for this hot subduction zone. ETS lies onshore. We t
Authors
Roy D. Hyndman, Patricia A. McCrory, Aaron Wech, Han Kao, Jay Ague
Vertical deformation through a complete seismic cycle at Isla Santa María, Chile
Individual great earthquakes are posited to release the elastic strain energy that has accumulated over centuries by the gradual movement of tectonic plates1, 2. However, knowledge of plate deformation during a complete seismic cycle—two successive great earthquakes and the intervening interseismic period—remains incomplete3. A complete seismic cycle began in south-central Chile in 1835 with an ea
Authors
Robert L. Wesson, Daniel Melnick, Marco Cisternas, Marcos Moreno, Lisa Ely
A century of oilfield operations and earthquakes in the greater Los Angeles Basin, southern California
Most of the seismicity in the Los Angeles Basin (LA Basin) occurs at depth below the sediments and is caused by transpressional tectonics related to the big bend in the San Andreas fault. However, some of the seismicity could be associated with fluid extraction or injection in oil fields that have been in production for almost a century and cover ∼ 17% of the basin. In a recent study, first the in
Authors
Egill Hauksson, Thomas Goebel, Jean-Paul Ampuero, Elizabeth S. Cochran
Improved rapid magnitude estimation for a community-based, low-cost MEMS accelerometer network
Immediately following the Mw 7.2 Darfield, New Zealand, earthquake, over 180 Quake‐Catcher Network (QCN) low‐cost micro‐electro‐mechanical systems accelerometers were deployed in the Canterbury region. Using data recorded by this dense network from 2010 to 2013, we significantly improved the QCN rapid magnitude estimation relationship. The previous scaling relationship (Lawrence et al., 2014) did
Authors
Angela Chung, Elizabeth S. Cochran, Anna E. Kaiser, Carl M. Christensen, Battalgazi Yildirim, Jesse F. Lawrence
On the reliability of Quake-Catcher Network earthquake detections
Over the past two decades, there have been several initiatives to create volunteer‐based seismic networks. The Personal Seismic Network, proposed around 1990, used a short‐period seismograph to record earthquake waveforms using existing phone lines (Cranswick and Banfill, 1990; Cranswicket al., 1993). NetQuakes (Luetgert et al., 2010) deploys triaxial Micro‐Electromechanical Systems (MEMS) sensors
Authors
Battalgazi Yildirim, Elizabeth S. Cochran, Angela Chung, Carl M. Christensen, Jesse F. Lawrence
Measurements of the initiation of post-wildfire runoff during rainstorms using in situ overland flow detectors
Overland flow detectors (OFDs) were deployed in 2012 on a hillslope burned by the 2010 Fourmile Canyon fire near Boulder, Colorado, USA. These detectors were simple, electrical resistor-type instruments that output a voltage (0–2·5 V) and were designed to measure and record the time of runoff initiation, a signal proportional to water depth, and the runoff hydrograph during natural convective rain
Authors
John A. Moody, Richard G. Martin
Increasing seismicity in the U. S. midcontinent: Implications for earthquake hazard
Earthquake activity in parts of the central United States has increased dramatically in recent years. The space-time distribution of the increased seismicity, as well as numerous published case studies, indicates that the increase is of anthropogenic origin, principally driven by injection of wastewater coproduced with oil and gas from tight formations. Enhanced oil recovery and long-term producti
Authors
William L. Ellsworth, Andrea L. Llenos, Arthur F. McGarr, Andrew J. Michael, Justin L. Rubinstein, Charles S. Mueller, Mark D. Petersen, Eric Calais
Postearthquake relaxation evidence for laterally variable viscoelastic structure and water content in the Southern California mantle
I reexamine the lower crust and mantle relaxation following two large events in the Mojave Desert: the 1992 M7.3 Landers and 1999 M7.1 Hector Mine, California, earthquakes. Time series from continuous GPS sites out to 300 km from the ruptures are used to constrain models of postseismic relaxation. Crustal motions in the Mojave Desert region are elevated above background for several years following
Authors
Fred Pollitz