Publications
Filter Total Items: 1858
Pressure core analysis of geomechanical and fluid flow properties of seals associated with gas hydrate-bearing reservoirs in the Krishna-Godavari Basin, offshore India
Physical properties of the sediment directly overlying a gas hydrate reservoir provide important controls on the effectiveness of depressurizing that reservoir to extract methane from gas hydrate as an energy resource. The permeability of overlying sediment determines if a gas hydrate reservoir’s upper contact will provide an effective seal that enables efficient reservoir depressurization. Comp
Authors
Junbong Jang, Sheng Dai, J. Yoneda, William F. Waite, Laura A. Stern, Lee-Gray Boze, Timothy S. Collett, Pushpendra Kumar
Shear failure of a granite pin traversing a sawcut fault
Fault heterogeneities such as bumps, bends, and stepovers are commonly observed on natural faults, but are challenging to recreate under controlled laboratory conditions. We study deformation and microseismicity of a 76 mm-diameter Westerly granite cylinder with a sawcut fault with known frictional properties. An idealized asperity is added by emplacing a precision-ground 21 mm-diameter solid gran
Authors
Gregory C. McLaskey, David A. Lockner
Broadband synthetic seismograms for magnitude 9 earthquakes on the Cascadia Megathrust based on 3D simulations and stochastic synthetics, Part 2: Rupture parameters and variability
We used a combination of 3D finite‐difference simulations (<1 Hz) and 1D stochastic synthetics (>1 Hz) to generate broadband (0–10 Hz) synthetic seismograms for numerous Mw 9 earthquake rupture scenarios on the Cascadia megathrust. Slip consists of multiple high‐stress‐drop subevents (Mw 8) with short rise times on the deeper portions of the fault, superimposed on a background slip distribution
Authors
Erin A. Wirth, Arthur Frankel, Nasser A. Marafi, John E. Vidale, William J. Stephenson
Granite IP network default route disappearance—Diagnosis and solution
The U.S. Geological Survey (USGS) National Strong Motion Project (NSMP) operates numerous strong-motion seismographs to monitor ground shaking and structural response caused by large, nearby earthquakes. This report describes a problem NSMP scientists encountered communicating over the Internet with several Kinemetrics, Inc., Granite strong-motion recorders.The Granite strong-motion recorders (“Gr
Authors
Lawrence M. Baker
Characterizing the Los Angeles Aqueduct crossing of the San Andreas Fault for improved earthquake resilience
The five-mile-long Elizabeth Tunnel, which crosses the San Andreas fault (SAF) zone near Lake Hughes, California, is part of the Los Angeles Aqueduct (LAA) that delivers water from Owens Valley to the City of Los Angeles. Geologic characterization of the Elizabeth Tunnel alignment is focused on developing a better understanding of fault displacement hazards at the SAF crossing to support design of
Authors
Scott Lindvall, Scott Kerwin, Chris Heron, Craig A. Davis, Jeff Tyson, Jim Chestnut, Kevin Mass, Mike Farr, Katherine Scharer, Devin McPhillips
Tilt Trivia: A free multiplayer app to learn geoscience concepts and definitions
Today’s technology is opening up new ways to learn. Here, we introduce Tilt Trivia, a suite of quiz‐style, multiplayer games for use on mobile devices and tablets (Android or Apple) to help students learn simple definitions and facts. This mobile device game was built using the Unity engine and has a multiplayer functionality that runs seamlessly, all day, every day. A single game consists of 6–10
Authors
Debi Kilb, Alan Yang, Nathan Garrett, Kristine L. Pankow, Justin L. Rubinstein, Lisa Linville
KG²B, a collaborative benchmarking exercise for estimating the permeability of the Grimsel granodiorite - Part 2: modeling, microstructures and complementary data
Measuring and modelling the permeability of tight rocks remains a challenging task. In addition to the traditional sources of errors that affect more permeable formations (e.g. sample selection, non-representative specimens, disturbance introduced during sample acquisition and preparation), tight rocks can be particularly prone to solid–fluid interactions and thus more sensitive to the methods, pr
Authors
Christian David, J. Wassermann, F. Amann, J.M. Klaver, C. Davy, J. Sarout, L. Esteban, E.H. Rutter, Q. Hu, L. Louis, P. Delage, David A. Lockner, A.P.S. Selvadurai, T Vanorio, A. Amann Hildenbrand, P.G. Meredith, J. Browning, T.M. Mitchell, C. Madonna, J. Billiotte, T. Reuschle, D. Lasseux, J. Fortin, R. Lenormand, D. Loggia, F. Nono, G. Boitnott, E. Jahns, Fleury. M., G. Berthe, P. Braun, D. Grégoire, L. Perrier, P. Polito, Y. Jannot, A. Sommier, B. Krooss, R. Fink, A. Clark
Turing-style tests for UCERF3 synthetic catalogs
Epidemic-Type Aftershock Sequence (ETAS) catalogs generated from the 3rd Uniform California Earthquake Rupture Forecast (UCERF3) model are unique in that they are the first to combine a complex, fault-based long-term forecast with short-term earthquake clustering statistics. We present Turing-style tests to examine whether these synthetic catalogs can successfully imitate observed earthquake behav
Authors
Morgan T. Page, Nicholas van der Elst
The science, engineering applications, and policy implications of simulation-based PSHA
We summarize scientific methods for developing probabilistic seismic hazard assessments from 3-D earthquake ground motion simulations, describe current use of simulated ground motions for engineering applications, and discuss on-going efforts to incorporate these effects in the U.S. national seismic hazard model. The 3-D simulations provide important, additional information about earthquake ground
Authors
Morgan P. Moschetti, Sandra P. Chang, C.B Crouse, Arthur Frankel, Robert Graves, H Puangnak, Nicolas Luco, Christine A. Goulet, Sanaz Rezaeian, Allison Shumway, Peter M. Powers, Mark D. Petersen, Scott Callaghan, T.H. Jordan, Kevin R. Milner
Frictional properties and 3-D stress analysis of the southern Alpine Fault, New Zealand
New Zealand's Alpine Fault (AF) ruptures quasi-periodically in large-magnitude earthquakes. Paleoseismological evidence suggests that about half of all recognized AF earthquakes terminated at the boundary between the Central and South Westland sections of the fault. There, fault geometry and the polarity of uplift change. The South Westland AF exhibits oblique-normal fault motion on a structure or
Authors
Carolyn Boulton, Nicolas C. Barth, Diane E. Moore, David A. Lockner, John Townend, Daniel R. Faulkner
To catch a quake
A revolution in seismic detection technology is underway, capturing unprecedented observations of earthquakes and their impacts. These sensor innovations provide real-time ground shaking observations that could improve emergency response following damaging earthquakes and may advance our understanding of the physics of earthquake ruptures.
Authors
Elizabeth S. Cochran
Using geologic structures to constrain constitutive laws not accessible in the laboratory
In this essay, we explore a central problem of structural geology today, and in the foreseeable future, which is the determination of constitutive laws governing rock deformation to produce geologic structures. Although laboratory experiments provide much needed data and insights about constitutive laws, these experiments cannot cover the range of conditions and compositions relevant to the format
Authors
Johanna Nevitt, Jessica M. Warren, Kathryn M. Kumamoto, David D. Pollard