Publications
Filter Total Items: 2585
Continuity of the West Napa–Franklin fault zone inferred from guided waves generated by earthquakes following the 24 August 2014 Mw 6.0 South Napa Earthquake
We measure peak ground velocities from fault‐zone guided waves (FZGWs), generated by on‐fault earthquakes associated with the 24 August 2014 Mw 6.0 South Napa earthquake. The data were recorded on three arrays deployed across north and south of the 2014 surface rupture. The observed FZGWs indicate that the West Napa fault zone (WNFZ) and the Franklin fault (FF) are continuous in the subsurface for
Authors
Rufus D. Catchings, Mark R. Goldman, Y.-G. Li, Joanne H. Chan
Responses of a 58-story RC dual core shear wall and outrigger frame building inferred from two earthquakes
Responses of a dual core shear-wall and outrigger-framed 58-story building recorded during the Mw6.0 Napa earthquake of 24 August 2014 and the Mw3.8 Berkeley earthquake of 20 October 2011 are used to identify its dynamic characteristics and behavior. Fundamental frequencies are 0.28 Hz (NS), 0.25 Hz (EW), and 0.43 Hz (torsional). Rigid body motions due to rocking are not significant. Average drift
Authors
Mehmet Çelebi
Seismic imaging of the metamorphism of young sediment into new crystalline crust in the actively rifting Imperial Valley, California
Plate-boundary rifting between transform faults is opening the Imperial Valley of southern California and the rift is rapidly filling with sediment from the Colorado River. Three 65–90 km long seismic refraction profiles across and along the valley, acquired as part of the 2011 Salton Seismic Imaging Project, were analyzed to constrain upper crustal structure and the transition from sediment to un
Authors
Liang Han, John Hole, Joann Stock, Gary S. Fuis, Colin F. Williams, Jonathan Delph, Kathy Davenport, Amanda Livers
Calibrated acoustic emission system records M -3.5 to M -8 events generated on a saw-cut granite sample
Acoustic emission (AE) analyses have been used for decades for rock mechanics testing, but because AE systems are not typically calibrated, the absolute sizes of dynamic microcrack growth and other physical processes responsible for the generation of AEs are poorly constrained. We describe a calibration technique for the AE recording system as a whole (transducers + amplifiers + digitizers + sampl
Authors
Gregory C. McLaskey, David A. Lockner
A brackish diatom, Pseudofrustulia lancea gen. et sp. nov. (Bacillariophyceae), from the Pacific coast of Oregon (USA)
Light and electron microscope observations show that a brackish diatom taxon should be classified as a new species of a new genus; Pseudofrustulia lancea gen. et sp. nov. We propose separating Pseudofrustulia from other similar genera such as Frickea, Frustulia, Amphipleura, Muelleria, and Envekadea on the basis of its thickened axial ribs, raphe endings, axial costae, morphology of helictoglossa,
Authors
Yuki Sawai, Tamotsu Nagumo, Alan R. Nelson
Active faulting on the Wallula fault zone within the Olympic-Wallowa lineament, Washington State, USA
The Wallula fault zone is an integral feature of the Olympic-Wallowa lineament, an ∼500-km-long topographic lineament oblique to the Cascadia plate boundary, extending from Vancouver Island, British Columbia, to Walla Walla, Washington. The structure and past earthquake activity of the Wallula fault zone are important because of nearby infrastructure, and also because the fault zone defines part o
Authors
Brian Sherrod, Richard J. Blakely, John P. Lasher, Andrew P. Lamb, Shannon A. Mahan, Franklin F. Foit, Elizabeth Barnett
Three ingredients for Improved global aftershock forecasts: Tectonic region, time-dependent catalog incompleteness, and inter-sequence variability
Following a large earthquake, seismic hazard can be orders of magnitude higher than the long‐term average as a result of aftershock triggering. Because of this heightened hazard, emergency managers and the public demand rapid, authoritative, and reliable aftershock forecasts. In the past, U.S. Geological Survey (USGS) aftershock forecasts following large global earthquakes have been released on an
Authors
Morgan T. Page, Nicholas van der Elst, Jeanne L. Hardebeck, Karen Felzer, Andrew J. Michael
Continental rupture and the creation of new crust in the Salton Trough rift, southern California and northern Mexico: Results from the Salton Seismic Imaging Project
A refraction and wide-angle reflection seismic profile along the axis of the Salton Trough, California and Mexico, was analyzed to constrain crustal and upper mantle seismic velocity structure during active continental rifting. From the northern Salton Sea to the southern Imperial Valley, the crust is 17-18 km thick and approximately one-dimensional. The transition at depth from Colorado River sed
Authors
Liang Han, John A. Hole, Joann M. Stock, Gary S. Fuis, Annie Kell, Neal W. Driscoll, Graham M. Kent, Michael J. Rymer, Antonio Gonzalez-Fernandez, Octavio Aburto-Oropeza
Tearing the terroir: Details and implications of surface rupture and deformation from the 24 August 2014 M6.0 South Napa earthquake, California
The Mw 6.0 South Napa earthquake of 24 August 2014 caused slip on several active fault strands within the West Napa Fault Zone (WNFZ). Field mapping identified 12.5 km of surface rupture. These field observations, near-field geodesy and space geodesy, together provide evidence for more than ~30 km of surface deformation with a relatively complex distribution across a number of subparallel lineamen
Authors
Stephen B. DeLong, Andrea Donnellan, Daniel J. Ponti, Ron S. Rubin, James J. Lienkaemper, Carol S. Prentice, Timothy E. Dawson, Gordon G. Seitz, David P. Schwartz, Kenneth W. Hudnut, Carla M. Rosa, Alexandra J. Pickering, Jay W. Parker
Maximum magnitude (Mmax) in the central and eastern United States for the 2014 U.S. Geological Survey Hazard Model
Probabilistic seismic‐hazard assessment (PSHA) requires an estimate of Mmax, the moment magnitude M of the largest earthquake that could occur within a specified area. Sparse seismicity hinders Mmax estimation in the central and eastern United States (CEUS) and tectonically similar regions worldwide (stable continental regions [SCRs]). A new global catalog of moderate‐to‐large SCR earthquakes is a
Authors
Russell L. Wheeler
Developments in new fluid rotational seismometers: Instrument performance and future directions
In this article we describe prototype designs and tests for low-cost rota- tional medium- and strong-motion seismometers using three types of proof mass (two liquid and one solid) and a number of transducer configurations. This article describes the third set of designs and tests in our development program. The details of our results for most of these are in the E electronic supplement to this art
Authors
John R. Evans, Jan T. Kozák, Petr Jedlicka
Far-field pressurization likely caused one of the largest injection induced earthquakes by reactivating a large pre-existing basement fault structure
The Mw 5.1 Fairview, Oklahoma, earthquake on 13 February 2016 and its associated seismicity produced the largest moment release in the central and eastern United States since the 2011 Mw 5.7 Prague, Oklahoma, earthquake sequence and is one of the largest earthquakes potentially linked to wastewater injection. This energetic sequence has produced five earthquakes with Mw 4.4 or larger. Almost all o
Authors
William L. Yeck, Matthew Weingarten, Harley M. Benz, Daniel E. McNamara, E. Bergman, R.B Herrmann, Justin L. Rubinstein, Paul S. Earle