Publications
Educational Publications
Educational Publications
Selected publications about earthquakes In plain language.
Filter Total Items: 2785
Preliminary assessment of a previously unknown fault zone beneath the Daytona Beach sand blow cluster near Marianna, Arkansas Preliminary assessment of a previously unknown fault zone beneath the Daytona Beach sand blow cluster near Marianna, Arkansas
We collected new high‐resolution P‐wave seismic‐reflection data to explore for possible faults beneath a roughly linear cluster of early to mid‐Holocene earthquake‐induced sand blows to the south of Marianna, Arkansas. The Daytona Beach sand blow deposits are located in east‐central Arkansas about 75 km southwest of Memphis, Tennessee, and about 80 km south of the southwestern end of the...
Authors
Jackson K. Odum, Robert Williams, William J. Stephenson, Martitia P. Tuttle, Hadar Al-Shukri
Characterizing potentially induced earthquake rate changes in the Brawley Seismic Zone, southern California Characterizing potentially induced earthquake rate changes in the Brawley Seismic Zone, southern California
The Brawley seismic zone (BSZ), in the Salton trough of southern California, has a history of earthquake swarms and geothermal energy exploitation. Some earthquake rate changes may have been induced by fluid extraction and injection activity at local geothermal fields, particularly at the North Brawley Geothermal Field (NBGF) and at the Salton Sea Geothermal Field (SSGF). We explore this...
Authors
Andrea L. Llenos, Andrew J. Michael
Persistent slip rate discrepancies in the eastern California (USA) shear zone Persistent slip rate discrepancies in the eastern California (USA) shear zone
Understanding fault slip rates in the eastern California shear zone (ECSZ) using GPS geodesy is complicated by potentially overlapping strain signals due to many sub-parallel strike-slip faults and by inconsistencies with geologic slip rates. The role of fault system geometry in describing ECSZ deformation may be investigated with total variation regularization, which algorithmically...
Authors
Eileen Evans, Wayne R. Thatcher, Frederick Pollitz, Jessica R. Murray
Dense lower crust elevates long-term earthquake rates in the New Madrid seismic zone Dense lower crust elevates long-term earthquake rates in the New Madrid seismic zone
Knowledge of the local state of stress is critical in appraising intraplate seismic hazard. Inverting earthquake moment tensors, we demonstrate that principal stress directions in the New Madrid seismic zone (NMSZ) differ significantly from those in the surrounding region. Faults in the NMSZ that are incompatible with slip in the regional stress field are favorably oriented relative to...
Authors
William Brower Levandowski, Oliver S. Boyd, Leonardo Ramirez-Guzman
Rapid estimation of earthquake magnitude from the arrival time of the peak high-frequency amplitude Rapid estimation of earthquake magnitude from the arrival time of the peak high-frequency amplitude
We propose a simple approach to measure earthquake magnitude M using the time difference (Top) between the body‐wave onset and the arrival time of the peak high‐frequency amplitude in an accelerogram. Measured in this manner, we find that Mw is proportional to 2logTop for earthquakes 5≤Mw≤7, which is the theoretical proportionality if Top is proportional to source dimension and stress...
Authors
Shunta Noda, Shunroku Yamamoto, William L. Ellsworth
The Earthquake‐Source Inversion Validation (SIV) Project The Earthquake‐Source Inversion Validation (SIV) Project
Finite‐fault earthquake source inversions infer the (time‐dependent) displacement on the rupture surface from geophysical data. The resulting earthquake source models document the complexity of the rupture process. However, multiple source models for the same earthquake, obtained by different research teams, often exhibit remarkable dissimilarities. To address the uncertainties in...
Authors
P. Martin Mai, Danijel Schorlemmer, Morgan T. Page, Jean-Paul Ampuero, Kimiyuki Asano, Mathieu Causse, Susana Custodio, Wenyuan Fan, Gaetano Festa, Martin Galis, Frantisek Gallovic, Walter Imperatori, Martin Kaser, Dmytro Malytskyy, Ryo Okuwaki, Frederick Pollitz, Luca Passone, Hoby N. T. Razafindrakoto, Haruko Sekiguchi, Seok Goo Song, Surendra N. Somala, Kiran K. S. Thingbaijam, Cedric Twardzik, Martin van Driel, Jagdish C. Vyas, Rongjiang Wang, Yuji Yagi, Olaf Zielke
The Eastern California Shear Zone as the northward extension of the southern San Andreas Fault The Eastern California Shear Zone as the northward extension of the southern San Andreas Fault
Cluster analysis offers an agnostic way to organize and explore features of the current GPS velocity field without reference to geologic information or physical models using information only contained in the velocity field itself. We have used cluster analysis of the Southern California Global Positioning System (GPS) velocity field to determine the partitioning of Pacific-North America...
Authors
Wayne R. Thatcher, James C. Savage, Robert W. Simpson
Noise reduction in long‐period seismograms by way of array summing Noise reduction in long‐period seismograms by way of array summing
Long‐period (>100 s period) seismic data can often be dominated by instrumental noise as well as local site noise. When multiple collocated sensors are installed at a single site, it is possible to improve the overall station noise levels by applying stacking methods to their traces. We look at the noise reduction in long‐period seismic data by applying the time–frequency phase‐weighted...
Authors
Adam T. Ringler, David C. Wilson, Tyler Storm, Benjamin T. Marshall, Charles R. Hutt, Austin Holland
Kinematic ground motion simulations on rough faults including effects of 3D stochastic velocity perturbations Kinematic ground motion simulations on rough faults including effects of 3D stochastic velocity perturbations
We describe a methodology for generating kinematic earthquake ruptures for use in 3D ground‐motion simulations over the 0–5 Hz frequency band. Our approach begins by specifying a spatially random slip distribution that has a roughly wavenumber‐squared fall‐off. Given a hypocenter, the rupture speed is specified to average about 75%–80% of the local shear wavespeed and the prescribed slip...
Authors
Robert Graves, Arben Pitarka
Hydra—The National Earthquake Information Center’s 24/7 seismic monitoring, analysis, catalog production, quality analysis, and special studies tool suite Hydra—The National Earthquake Information Center’s 24/7 seismic monitoring, analysis, catalog production, quality analysis, and special studies tool suite
This report provides an overview of the capabilities and design of Hydra, the global seismic monitoring and analysis system used for earthquake response and catalog production at the U.S. Geological Survey National Earthquake Information Center (NEIC). Hydra supports the NEIC’s worldwide earthquake monitoring mission in areas such as seismic event detection, seismic data insertion and...
Authors
John M. Patton, Michelle R. Guy, Harley M. Benz, Raymond P. Buland, Brian K. Erickson, David S. Kragness
Comparisons between vs30 and spectral response for 30 sites in Newcastle, Australia from collocated seismic cone penetrometer, active- and passive-source vs data Comparisons between vs30 and spectral response for 30 sites in Newcastle, Australia from collocated seismic cone penetrometer, active- and passive-source vs data
Although the time‐averaged shear‐wave velocity down to 30 m depth (VS30) can be a proxy for estimating earthquake ground‐motion amplification, significant controversy exists about its limitations when used as a single parameter for the prediction of amplification. To examine this question in absence of relevant strong‐motion records, we use a range of different methods to measure the...
Authors
Theodora Volti, David Burbidge, Clive Collins, Michael W. Asten, Jackson K. Odum, William J. Stephenson, Chris Pascal, Josef Holzschuh
Responses of a tall building in Los Angeles, California as inferred from local and distant earthquakes Responses of a tall building in Los Angeles, California as inferred from local and distant earthquakes
Increasing inventory of tall buildings in the United States and elsewhere may be subjected to motions generated by near and far seismic sources that cause long-period effects. Multiple sets of records that exhibited such effects were retrieved from tall buildings in Tokyo and Osaka ~ 350 km and 770 km from the epicenter of the 2011 Tohoku earthquake. In California, very few tall...
Authors
Mehmet Çelebi, Hasan Ulusoy, Nori Nakata