Publications
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Probing reservoir-triggered earthquakes in Koyna, India, through scientific deep drilling
We report here the salient features of the recently concluded International Continental Scientific Drilling Program (ICDP) workshop in Koyna, India. This workshop was a sequel to the earlier held ICDP workshop in Hyderabad and Koyna in 2011. A total of 49 experts (37 from India and 12 from 8 other countries) spent 3 days reviewing the work carried out during the last 3 years based on the recommend
Authors
H. Gupta, Shailesh Nayak, William L. Ellsworth, Y. J. B. Rao, S. Rajan, B.K. Bansal, N. Purnachandra Rao, S. Roy, K. Arora, R. Mohan, V. M. Tiwari, H. V. S. Satyanarayana, P. K. Patro, D. Shashidhar, K. Mallika
CyberShake-derived ground-motion prediction models for the Los Angeles region with application to earthquake early warning
Real-time applications such as earthquake early warning (EEW) typically use empirical ground-motion prediction equations (GMPEs) along with event magnitude and source-to-site distances to estimate expected shaking levels. In this simplified approach, effects due to finite-fault geometry, directivity and site and basin response are often generalized, which may lead to a significant under- or overes
Authors
Maren Bose, Robert Graves, David Gill, Scott Callaghan, Phillip J. Maechling
Frictional properties of exhumed fault gouges in DFDP-1 cores, Alpine Fault, New Zealand
Principal slip zone gouges recovered during the Deep Fault Drilling Project (DFDP-1), Alpine Fault, New Zealand, were deformed in triaxial friction experiments at temperatures, T, of up to 350°C, effective normal stresses, σn′, of up to 156 MPa, and velocities between 0.01 and 3 µm/s. Chlorite/white mica-bearing DFDP-1A blue gouge, 90.62 m sample depth, is frictionally strong (friction coefficient
Authors
Carolyn Boulton, Diane E. Moore, David A. Lockner, Virginia G. Toy, John Townend, Rupert Southerland
Structure and seismic hazard of the Ventura Avenue anticline and Ventura fault, California: Prospect for large, multisegment ruptures in the Western Transverse Ranges
The Ventura Avenue anticline is one of the fastest uplifting structures in southern California, rising at ∼5 mm/yr. We use well data and seismic reflection profiles to show that the anticline is underlain by the Ventura fault, which extends to seismogenic depth. Fault offset increases with depth, implying that the Ventura Avenue anticline is a fault‐propagation fold. A decrease in the uplift rate
Authors
Judith Hubbard, John H. Shaw, James F. Dolan, Thomas L. Pratt, Lee J. McAuliffe, Thomas K. Rockwell
Hillslope-scale experiment demonstrates role of convergence during two-step saturation
Subsurface flow and storage dynamics at hillslope scale are difficult to ascertain, often in part due to a lack of sufficient high-resolution measurements and an incomplete understanding of boundary conditions, soil properties, and other environmental aspects. A continuous and extreme rainfall experiment on an artificial hillslope at Biosphere 2's Landscape Evolution Observatory (LEO) resulted in
Authors
A. I. Gevaert, A. J. Teuling, R. Uijlenhoet, Stephen B. DeLong, T. E. Huxman, L. A. Pangle, David D. Breshears, J. Chorover, John D. Pelletier, S. R. Saleska, X. Zeng, Peter A. Troch
A method and example of seismically imaging near‐surface fault zones in geologically complex areas using Vp, Vs, and their ratios
The determination of near‐surface (vadose zone and slightly below) fault locations and geometries is important because assessment of ground rupture, strong shaking, geologic slip rates, and rupture histories occurs at shallow depths. However, seismic imaging of fault zones at shallow depths can be difficult due to near‐surface complexities, such as weathering, groundwater saturation, massive (nonl
Authors
Rufus D. Catchings, Michael J. Rymer, Mark R. Goldman, Robert R. Sickler, Coyn J. Criley
The 17 May 2012 M4.8 earthquake near Timpson, East Texas: An event possibly triggered by fluid injection
This study summarizes our investigation of the 17 May 2012 MW-RMT4.8 earthquake near Timpson, Texas, the largest earthquake recorded historically in eastern Texas. To identify preshocks and aftershocks of the 17 May event we examined the arrivals recorded at Nacogdoches (NATX) 30 km from the 17 May epicenter, at nearby USArray Transportable Array stations, and at eight temporary stations deployed
Authors
Cliff Frohlich, William L. Ellsworth, Wesley Brown, Michael Brunt, James Luetgert, Tim G. MacDonald, Steven Walters
Laboratory constraints on models of earthquake recurrence
In this study, rock friction ‘stick-slip’ experiments are used to develop constraints on models of earthquake recurrence. Constant-rate loading of bare rock surfaces in high quality experiments produces stick-slip recurrence that is periodic at least to second order. When the loading rate is varied, recurrence is approximately inversely proportional to loading rate. These laboratory events initiat
Authors
Nicholas M. Beeler, Terry Tullis, Jenni Junger, Brian D. Kilgore, David L. Goldsby
Stress-based aftershock forecasts made within 24h post mainshock: Expected north San Francisco Bay area seismicity changes after the 2014 M=6.0 West Napa earthquake
We calculate stress changes resulting from the M = 6.0 West Napa earthquake on north San Francisco Bay area faults. The earthquake ruptured within a series of long faults that pose significant hazard to the Bay area, and we are thus concerned with potential increases in the probability of a large earthquake through stress transfer. We conduct this exercise as a prospective test because the skill o
Authors
Thomas E. Parsons, Margaret Segou, Volkan Sevilgen, Kevin Milner, Edward H. Field, Shinji Toda, Ross S. Stein
Elders recall an earlier tsunami on Indian Ocean shores
Ten years on, the Indian Ocean tsunami of 26 December 2004 still looms large in efforts to reduce coastal risk. The disaster has spurred worldwide advances in tsunami detection and warning, tsunami-risk assessment, and tsunami awareness [Satake, 2014].
Nearly a lifetime has passed since the northwestern Indian Ocean last produced a devastating tsunami. Documentation of this tsunami, in November 1
Authors
Din Mohammad Kakar, Ghazala Naeem, Abdullah Usman, Haider Hasan, Hira Lohdi, Seshachalam Srinivasalu, Vanessa Andrade, C.P. Rajendran, Abdolmajid Naderi Beni, Mohammad Ali Hamzeh, Goesta Hoffmann, Noora Al Balushi, Nora Gale, Ardito Kodijat, Hermann M. Fritz, Brian F. Atwater
A continuous record of intereruption velocity change at Mount St. Helens from coda wave interferometry
In September 2004, Mount St. Helens volcano erupted after nearly 18 years of quiescence. However, it is unclear from the limited geophysical observations when or if the magma chamber replenished following the 1980–1986 eruptions in the years before the 2004–2008 extrusive eruption. We use coda wave interferometry with repeating earthquakes to measure small changes in the velocity structure of Moun
Authors
Alicia J. Hotovec-Ellis, Joan S. Gomberg, John Vidale, Ken C. Creager
Key recovery factors for the August 24, 2014, South Napa Earthquake
Through discussions between the Federal Emergency Management Agency (FEMA) and the U.S. Geological Survey (USGS) following the South Napa earthquake, it was determined that several key decision points would be faced by FEMA for which additional information should be sought and provided by USGS and its partners. This report addresses the four tasks that were agreed to. These tasks are (1) assessmen
Authors
Kenneth W. Hudnut, Thomas M. Brocher, Carol S. Prentice, John Boatwright, Benjamin A. Brooks, Brad T. Aagaard, J. Luke Blair, Jon Peter B. Fletcher, Jemile Erdem, Charles W. Wicks, Jessica R. Murray, Fred F. Pollitz, John O. Langbein, Jerry L. Svarc, David P. Schwartz, Daniel J. Ponti, Suzanne Hecker, Stephen B. DeLong, Carla M. Rosa, Brenda Jones, Rynn M. Lamb, Anne M. Rosinski, Timothy P. McCrink, Timothy E. Dawson, Gordon G. Seitz, Craig Glennie, Darren Hauser, Todd Ericksen, Dan Mardock, Don F. Hoirup, Jonathan D. Bray, Ron S. Rubin