Publications
Educational Publications
Educational Publications
Selected publications about earthquakes In plain language.
Filter Total Items: 2785
Testing rate‐and‐state predictions of aftershock decay with distance Testing rate‐and‐state predictions of aftershock decay with distance
We analyze aftershocks of the 2019 M 7.1 Ridgecrest mainshock and isolated M 5–6 mainshocks in southern California to test predictions made by the rate‐and‐state friction model of Dieterich (1994). Rate‐and‐state friction predicts that the seismicity rate after a stress step follows Omori decay, where the Omori c‐value, which is the saturation in aftershock rate observed at small times...
Authors
Morgan T. Page, Nicholas van der Elst, Sebastian Hainzl
Are the horizontal-to-vertical spectral ratios of earthquakes and microtremors the same? Are the horizontal-to-vertical spectral ratios of earthquakes and microtremors the same?
We consider the similarities and differences between earthquake and microtremor horizontal‐to‐vertical spectral ratios (eHVSR and mHVSR, respectively) using a dataset of 161 sites in southern California. Quantitative comparisons are made in terms of the eHVSR and mHVSR lognormal median curves, as well as the frequencies and amplitudes associated with the fundamental‐ and higher‐mode...
Authors
Joseph Vantassel, Makbule Ilgac, Adda Athanasopoulos Zekkos, Alan Yong, Behzad Hassani, Antony Martin
Precariously balanced rocks in northern New York and Vermont, U.S.A.: Ground-motion constraints and implications for fault sources Precariously balanced rocks in northern New York and Vermont, U.S.A.: Ground-motion constraints and implications for fault sources
Precariously balanced rocks (PBRs) and other fragile geologic features have the potential to constrain the maximum intensity of earthquake ground shaking over millennia. Such constraints may be particularly useful in the eastern United States (U.S.), where few earthquake‐source faults are reliably identified, and moderate earthquakes can be felt at great distances due to low seismic...
Authors
Devin McPhillips, Thomas L. Pratt
Application of non-stationary shear-wave velocity randomization approach to predict 1D seismic site response and its variability at two downhole array recordings Application of non-stationary shear-wave velocity randomization approach to predict 1D seismic site response and its variability at two downhole array recordings
Accounting for uncertainties in seismic site response is crucial to improving the performance of one-dimensional (1D) ground response analyses (GRAs) at downhole array recording sites. In addition to site effects, uncertainties in 1D-GRAs can also be contributed from the seismic source and/or path. Though often representing not more than one percent of the distance (path) from the source...
Authors
Eliane Youssef, Cecile Cornou, Dalia Youssef Abdel Massih, Tamara Al-Bittar, Alan Yong, Fabrice Hollender
Distinguishing natural sources from anthropogenic noise in seismic data Distinguishing natural sources from anthropogenic noise in seismic data
No abstract available.
Authors
Sean Maher, Margaret Elizabeth Glasgow, Elizabeth S. Cochran, Zhigang Peng
Plan to coordinate post-earthquake investigations supported by the National Earthquake Hazards Reduction Program (NEHRP) Plan to coordinate post-earthquake investigations supported by the National Earthquake Hazards Reduction Program (NEHRP)
Introduction This report presents a plan supported by the National Earthquake Hazards Reduction Program (NEHRP) to coordinate domestic and international post-earthquake investigations (herein called “the Plan”). Post-earthquake scientific and engineering investigations are undertaken to capture critical information to understand the causes and impacts of the event, lessons from which can
Authors
Chris Poland, Jonathan D. Bray, Laurie Johnson, Sissy Nikolaou, Ellen Rathje, Brian Sherrod
ShakeAlert® and schools: Incorporating earthquake early warning in school districts in Alaska, California, Oregon, and Washington ShakeAlert® and schools: Incorporating earthquake early warning in school districts in Alaska, California, Oregon, and Washington
The U.S. Geological Survey-managed ShakeAlert® earthquake early warning system is the first public alerting system in the United States to provide rapid mass notification when an earthquake is detected. Although public alert delivery via mobile phones began in California in 2019 followed by Oregon and Washington in 2021, little is known about what might drive widespread implementation in...
Authors
Rachel M. Adams, Holly Davies, Lori Peek, Meghan Mordy, Jennifer Tobin, Jolie Breeden, Sara K. McBride, Robert Michael deGroot
The impact of source time function complexity on stress drop estimates The impact of source time function complexity on stress drop estimates
Earthquake stress drop—a key parameter for describing the energetics of earthquake rupture—can be estimated in several different, but theoretically equivalent, ways. However, independent estimates for the same earthquakes sometimes differ significantly. We find that earthquake source complexity plays a significant role in why theoretically (for simple rupture models) equivalent methods...
Authors
James S. Neely, Sunyoung Park, Annemarie S. Baltay Sundstrom
Uncertainty and spatial correlation in station measurements for mb magnitude estimation Uncertainty and spatial correlation in station measurements for mb magnitude estimation
The body‐wave magnitude () is a long‐standing network‐averaged, amplitude‐based magnitude used to estimate the magnitude of seismic sources from teleseismic observations. The U.S. Geological Survey National Earthquake Information Center (NEIC) relies on in its global real‐time earthquake monitoring mission. Although waveform modeling‐based moment magnitudes are the modern standard to
Authors
William L. Yeck, Adam T. Ringler, David R. Shelly, Paul S. Earle, Harley M. Benz, David C. Wilson
Status and performance of the ShakeAlert® earthquake early warning system: 2019-2023 Status and performance of the ShakeAlert® earthquake early warning system: 2019-2023
The U.S. Geological Survey (USGS)‐operated ShakeAlert® system is the United States West Coast earthquake early warning system (Given et al., 2018). In this study we detail ShakeAlert’s performance during some of the largest events seen by the system thus far. Statewide public alerting using ShakeAlert messages was authorized in California in October 2019. Over the next few years, public...
Authors
A.I. Lux, Deborah Smith, M. Böse, Jeffrey J. McGuire, Jessie K. Saunders, Minh Huynh, I. Stubailo, Jennifer R Andrews, G. Lotto, B. Crowell, S. Crane, R. M. Allen, Douglas D. Given, R. Hartog, T. Heaton, A. Husker, J. Marty, Leland O'Driscoll, Harold J. Tobin, Sara K. McBride, D. Toomey
Developing, testing, and communicating earthquake forecasts: Current practices and future directions Developing, testing, and communicating earthquake forecasts: Current practices and future directions
While deterministically predicting the time and location of earthquakes remains impossible, earthquake forecasting models can provide estimates of the probabilities of earthquakes occurring within some region over time. To enable informed decision-making of civil protection, governmental agencies, or the public, Operational Earthquake Forecasting (OEF) systems aim to provide...
Authors
Leila Mizrahi, Irina Dallo, Nicholas van der Elst, Annemarie Christophersen, Ilaria Spassiani, Maximillian J. Werner, Pablo Iturrieta, Jose Bayona, Iunio Iervolino, Max Schneider, Morgan T. Page, Jiancang Zhuang, Marcus Herrmann, Andrew J. Michael, Guiseppe Falcone, Warner Marzocchi, David A. Rhoades, Matthew Gerstenberger, Laura Gulia, Danijel Schorlemmer, Julia Becker, Marta Han, Lorena Kuratle, Michele Marti, Stefan Wiemer
Shallow faulting and folding beneath south‐central Seattle, Washington State, from land‐based high‐resolution seismic‐reflection imaging Shallow faulting and folding beneath south‐central Seattle, Washington State, from land‐based high‐resolution seismic‐reflection imaging
The geologic framework of the Seattle fault zone (SFZ) has been extensively studied, but the structure and fault strand locations in the central portion of the fault zone through the city of Seattle have remained controversial. Much of what is known about the SFZ has come from light detection and ranging (lidar)‐topographic surveys and paleoseismic investigations of fault scarps...
Authors
William J. Stephenson, Jack K. Odum, Thomas L. Pratt