Publications
Filter Total Items: 1857
The Landscape Evolution Observatory: a large-scale controllable infrastructure to study coupled Earth-surface processes
Zero-order drainage basins, and their constituent hillslopes, are the fundamental geomorphic unit comprising much of Earth's uplands. The convergent topography of these landscapes generates spatially variable substrate and moisture content, facilitating biological diversity and influencing how the landscape filters precipitation and sequesters atmospheric carbon dioxide. In light of these signific
Authors
Luke A. Pangle, Stephen B. DeLong, Nate Abramson, John Adams, Greg A. Barron-Gafford, David D. Breshears, Paul D. Brooks, Jon Chorover, William E. Dietrich, Katerina Dontsova, Matej Durcik, Javier Espeleta, T.P.A. Ferré, Regis Ferriere, Whitney Henderson, Edward A. Hunt, Travis E. Huxman, David Millar, Brendan Murphy, Guo-Yue Niu, Mitch Pavao-Zuckerman, Jon D. Pelletier, Craig Rasmussen, Joaquin Ruiz, Scott Saleska, Marcel Schaap, Michael Sibayan, Peter A. Troch, Markus Tuller, Joost van Haren, Xubin Zeng
Coping with earthquakes induced by fluid injection
Large areas of the United States long considered geologically stable with little or no detected seismicity have recently become seismically active. The increase in earthquake activity began in the mid-continent starting in 2001 (1) and has continued to rise. In 2014, the rate of occurrence of earthquakes with magnitudes (M) of 3 and greater in Oklahoma exceeded that in California (see the figure).
Authors
Arthur F. McGarr, Barbara Bekins, Nina Burkardt, James W. Dewey, Paul S. Earle, William L. Ellsworth, Shemin Ge, Stephen H. Hickman, Austin F. Holland, Ernest Majer, Justin L. Rubinstein, Anne Sheehan
The 21 May 2014 Mw 5.9 Bay of Bengal earthquake: macroseismic data suggest a high‐stress‐drop event
A modest but noteworthy Mw 5.9 earthquake occurred in the Bay of Bengal beneath the central Bengal fan at 21:51 Indian Standard Time (16:21 UTC) on 21 May 2014. Centered over 300 km from the eastern coastline of India (Fig. 1), it caused modest damage by virtue of its location and magnitude. However, shaking was very widely felt in parts of eastern India where earthquakes are uncommon. Media outle
Authors
Stacey Martin, Susan E. Hough
Strike-parallel and strike-normal coordinate system around geometrically complicated rupture traces: use by NGA-West2 and further improvements
We present a two-dimensional system of generalized coordinates for use with geometrically complex fault ruptures that are neither straight nor continuous. The coordinates are a generalization of the conventional strike-normal and strike-parallel coordinates of a single straight fault. The presented conventions and formulations are applicable to a single curved trace, as well as multiple traces rep
Authors
Paul A. Spudich, Brian Chiou
Simulation of acceleration field of the Lushan earthquake (Ms7.0, April 20, 2013, China)
The acceleration field of the Lushan earthquake (Ms7.0, April 20, 2013, China) is simulated using a new modified version of the stochastic finite-fault method (EXSIM) based on a dynamic corner frequency approach. To incorporate the effect of heterogeneous slip distribution on the variation of source spectrum, we adopt an empirical source spectral model and derive the corresponding dynamic paramete
Authors
Wang Guoxin, Ding Yang, Roger D. Borcherdt
Update of the Graizer-Kalkan ground-motion prediction equations for shallow crustal continental earthquakes
A ground-motion prediction equation (GMPE) for computing medians and standard deviations of peak ground acceleration and 5-percent damped pseudo spectral acceleration response ordinates of maximum horizontal component of randomly oriented ground motions was developed by Graizer and Kalkan (2007, 2009) to be used for seismic hazard analyses and engineering applications. This GMPE was derived from t
Authors
Vladimir Graizer, Erol Kalkan
Comment on “Models of stochastic, spatially varying stress in the crust compatible with focal‐mechanism data, and how stress inversions can be biased toward the stress rate” by Deborah Elaine Smith and Thomas H. Heaton
Smith and Heaton (2011) propose a model in which stress in the crust is fractal‐like and highly variable on a range of length scales, including short length‐scales of ~1 km. Smith and Heaton (2011) motivate the need for stress heterogeneity on short length‐scales by citing observations such as short length‐scale changes in stress directions inferred from borehole breakouts, short length‐scale chan
Authors
Jeanne L. Hardebeck
Ground motion observations of the 2014 South Napa earthquake
Ground motions of the South Napa earthquake (24 August 2014; M 6.0) were recorded at 19 stations within 20 km and 292 stations within 100 km of the rupture surface trace, generating peak ground motions in excess of 50%g and 50 cm/s in and near Napa Valley. This large dataset allows us to compare the ground motion from the earthquake to existing ground‐motion prediction equations (GMPEs) in consid
Authors
Annemarie S. Baltay, John Boatwright
Direct measurement of asperity contact growth in quartz at hydrothermal conditions
Earthquake recurrence requires interseismic fault restrengthening which results from solid state deformation in room-temperature friction and indentation experiments. In contrast exhumed fault zones show solution-transport processes such as pressure solution and contact overgrowths influence fault zone properties . In the absence of fluid flow, overgrowths are driven by gradients in surface curvat
Authors
Nicholas M. Beeler, Stephen H. Hickman
Late Quaternary slip history of the Mill Creek strand of the San Andreas fault in San Gorgonio Pass, southern California: The role of a subsidiary left-lateral fault in strand switching
The fault history of the Mill Creek strand of the San Andreas fault (SAF) in the San Gorgonio Pass region, along with the reconstructed geomorphology surrounding this fault strand, reveals the important role of the left-lateral Pinto Mountain fault in the regional fault strand switching. The Mill Creek strand has 7.1–8.7 km total slip. Following this displacement, the Pinto Mountain fault offset t
Authors
Katherine J. Kendrick, Jonathan C. Matti, Shannon A. Mahan
A robust calibration technique for acoustic emission systems based on momentum transfer from a ball drop
We describe a technique to estimate the seismic moment of acoustic emissions and other extremely small seismic events. Unlike previous calibration techniques, it does not require modeling of the wave propagation, sensor response, or signal conditioning. Rather, this technique calibrates the recording system as a whole and uses a ball impact as a reference source or empirical Green’s function. To c
Authors
Gregory C. McLaskey, David A. Lockner, Brian D. Kilgore, Nicholas M. Beeler
Causal factors for seismicity near Azle, Texas
In November 2013, a series of earthquakes began along a mapped ancient fault system near Azle, Texas. Here we assess whether it is plausible that human activity caused these earthquakes. Analysis of both lake and groundwater variations near Azle shows that no significant stress changes were associated with the shallow water table before or during the earthquake sequence. In contrast, pore-pressure
Authors
Matthew J. Hornbach, Heather R. DeShon, William L. Ellsworth, Brian W. Stump, Chris Hayward, Cliff Frohlich, Harrison R. Oldham, Jon E. Olson, M. Beatrice Magnani, Casey Brokaw, James H. Luetgert