Publications
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Depth determination of the 2010 El Mayor‐Cucapah earthquake sequence (M ≥ 4.0)
The 2010 MW 7.2 El Mayor‐Cucapah earthquake ruptured a zone of ~120 km in length in northern Baja California. The geographic distribution of this earthquake sequence was well constrained by waveform relocation. The depth distribution, however, was poorly determined as it is near the edge of, or outside, the Southern California Seismic Network. Here we use two complementary methods to constrain the
Authors
C. Yu, E. Hauksson, Z. Zhan, Elizabeth S. Cochran, D. Helmberger
Lithosphere and shallow asthenosphere rheology from observations of post-earthquake relaxation
In tectonically active regions, post-earthquake motions are generally shaped by a combination of continued fault slippage (afterslip) on a timescale of days to months and viscoelastic relaxation of the lower crust and upper mantle on a timescale of days to years. Transient crustal motions have been observed following numerous magnitude >~7 earthquakes in various tectonic settings: continental rift
Authors
Fred Pollitz
Measurement of sounds emitted by certain high-resolution geophysical survey systems
Scientific questions regarding the impact of anthropomorphic noise in the marine environment have resulted in an increasing number of regulatory requirements and precautionary mitigation strategies to reduce the risks associated with high-resolution marine geophysical surveys performed in waters subjected to government jurisdiction. An example of regulatory frameworks includes the Marine Mammal Pr
Authors
Steven E Crocker, Frank D Fratantonio, Patrick E. Hart, David S. Foster, Thomas F. O'Brien, Stanley Labak
Extreme coastal water level in Washington state: Guidance to support sea level rise planning
This document provides guidelines for assessing exposure to future coastal flooding during extreme coastal water level events – whether these are due to tides, surge, wave run-up, or, more likely, a combination of the three. These guidelines provide information about the current and future magnitude of extreme coastal water levels across Washington State and the underlying processes that influence
Authors
I.M. Miller, Nathan R. vanArendonk, Eric E. Grossman
Seismic design and hazard maps: Before and after
The 1994 Northridge earthquake generated world-record ground motions. At the time, the horizontal peak ground acceleration of 1.8 g measured by a seismometer in Tarzana was the largest ever. The same is true of the peak ground velocity of 148 cm/s measured in Granada Hills. Both measurements were within approximately 15 km of the source of the earthquake; they were also near most of the damage des
Authors
Nicolas Luco
Refining the Baseline Sediment Budget for the Klamath River, California
Four dams in the Klamath River Hydroelectric Project (KHP) in Oregon and California (Figure 1) are currently scheduled to be removed over a period of a few weeks or months, beginning in January 2021. The Klamath dam removal will be the largest in the world by almost all measures, and is an unprecedented opportunity to advance science of river responses to such events. The KHP contains approximatel
Authors
Chauncey W. Anderson, Scott A. Wright, Liam N. Schenk, Katherine Skalak, Jennifer A. Curtis, Amy E. East, Adam Benthem
Morphology and genesis of giant seafloor depressions on the southeasterncontinental shelf of the Korean Peninsula
We identify and describe five giant seafloor depressions from the southeastern continental shelf of the Korean Peninsula using multibeam bathymetry, sub-bottom profiler, and multi-channel seismic reflection data, supplemented by piston cores. Multibeam bathymetry data from the shelf show four crescent-shaped depressions (SD1 to SD4) and one near-circular depression (SD5) within a group of NW-SE tr
Authors
Deniz Cukur, Gee-Soo Kong, Jong-Hwa Chun, Moo-Hee Kang, In-Kwon Um, Taekhyun Kwon, Samuel E. Jordan, Kyong-O Kim
Petrologic and mineral physics database for use with the U.S. Geological Survey National Crustal Model
We present a petrologic and mineral physics database as part of the U.S. Geological Survey National Crustal Model (NCM). Each of 209 geologic units, 134 of which are currently part of the geologic framework within the NCM, was assigned a mineralogical composition according to generalized classifications with some refinement for specific geologic formations. This report is concerned with the petrol
Authors
Theron Sowers, Oliver S. Boyd
A combinatorial approach to determine earthquake magnitude distributions on a variable slip-rate fault
Combinatorial methods are used to determine the spatial distribution of earthquake magnitudes on a fault whose slip rate varies along strike. Input to the problem is a finite sample of earthquake magnitudes that span 5 kyr drawn from a truncated Pareto distribution. The primary constraints to the problem are maximum and minimum values around the target slip-rate function indicating where feasible
Authors
Eric L. Geist, Thomas E. Parsons
The major coral reefs of Maui Nui, Hawai‘i—distribution, physical characteristics, oceanographic controls, and environmental threats
Coral reefs are widely recognized as critical to Hawaiʻi’s economy, food resources, and protection from damaging storm waves. Yet overfishing, land-based pollution, and climate change are threatening the health and sustainability of those reefs, and accordingly, both the Federal and State governments have called for protection and effective management. In 2000, the U.S. Coral Reef Task Force state
Authors
Michael E. Field, Curt D. Storlazzi, Ann E. Gibbs, Nicole L. D'Antonio, Susan A. Cochran
Satellite observations of surface deformation at the Coso Geothermal Field, California
Surface deformation time series and rates are identified at the Coso Geothermal Field (CGF) and surrounding areas by applying interferometric synthetic aperture radar (InSAR) to satellite scenes from Envisat (June 2004 ̶ October 2010) and Sentinel (November 2014 – April 2018). The measurements are done in the line of sight (LOS) to each satellite, within an area of size ~450 km2, at the location
Authors
Mariana Eneva, Andrew Barbour, David Adams, Vicky Hsiao, Kelly Blake, Giacomo Falorni, Roberto Locatelli