Nicholas van der Elst

Map showing regional faults and Coso field near Ridgecrest

September 30, 2019

Could the M7.1 Ridgecrest, CA Earthquake Sequence Trigger a Large Earthquake Nearby?

Release Date: SEPTEMBER 30, 2019 Two of the first questions that come to mind for anyone who just felt an earthquake are, “Will there be another one?” and “Will it be larger?”.

By

Natural Hazards Mission Area, Earthquake Hazards Program, Earthquake Science Center, Geologic Hazards Science Center

September 30, 2019

Could the M7.1 Ridgecrest, CA Earthquake Sequence Trigger a Large Earthquake Nearby?

Release Date: SEPTEMBER 30, 2019 Two of the first questions that come to mind for anyone who just felt an earthquake are, “Will there be another one?” and “Will it be larger?”.

Learn More

Map showing aftershocks of 7.8 earthquake in Oaxaca, Mexico

May 7, 2018

The Past Holds the Key to the Future of Aftershock Forecasting

Release Date: MAY 7, 2018 The outcomes of past aftershock sequences can be used to describe the range of possibilities for a current sequence.

By

Natural Hazards Mission Area, Earthquake Hazards Program

May 7, 2018

The Past Holds the Key to the Future of Aftershock Forecasting

Release Date: MAY 7, 2018 The outcomes of past aftershock sequences can be used to describe the range of possibilities for a current sequence.

Learn More

October 6, 2014

Operational Earthquake Forecasting – Implementing a Real-Time System for California

It is well know that every earthquake can spawn others (e.g., as aftershocks), and that such triggered events can be large and damaging, as recently demonstrated by L’Aquila, Italy and Christchurch, New Zealand earthquakes. In spite of being an explicit USGS strategic-action priority (http://pubs.usgs.gov/of/2012/1088; page 32), the USGS currently lacks an automated system with which to...

By

John Wesley Powell Center for Analysis and Synthesis

October 6, 2014

Operational Earthquake Forecasting – Implementing a Real-Time System for California

It is well know that every earthquake can spawn others (e.g., as aftershocks), and that such triggered events can be large and damaging, as recently demonstrated by L’Aquila, Italy and Christchurch, New Zealand earthquakes. In spite of being an explicit USGS strategic-action priority (http://pubs.usgs.gov/of/2012/1088; page 32), the USGS currently lacks an automated system with which to forecast

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Filter Total Items: 33

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January 2, 2026

Rapid characterization of the 2025 Mw 8.8 Kamchatka, Russia earthquake Rapid characterization of the 2025 Mw 8.8 Kamchatka, Russia earthquake

The 29 July 2025 Mw 8.8 Kamchatka, Russia, earthquake was the sixth largest instrumentally recorded earthquake. This event was seismically well observed at regional and teleseismic distances, but publicly available near‐source data were sparse at the time of the event, presenting unique challenges for rapid source and impact characterization. The U.S. Geological Survey (USGS) National...

Authors

Harriet Zoe Yin, Kate E. Allstadt, William D Barnhart, Samantha Ann Clapp, Paul S. Earle, Dara Elyse Goldberg, Alex R. Grant, Matt Herman, Kishor S. Jaiswal, Sara K. McBride, Adam T. Ringler, Max Schneider, Eric M. Thompson, Nicholas van der Elst, David Wald, Dun Wang, Charles Worden, William L. Yeck

By

Natural Hazards Mission Area, Earthquake Hazards Program, Earthquake Science Center, Geologic Hazards Science Center

September 12, 2025

Mechanics and statistics of postseismic shaking Mechanics and statistics of postseismic shaking

Analysis of two weeks of continuous post-seismic shaking after the 2019 M7.1 Ridgecrest, CA earthquake sequence using 4 nearby borehole seismometers reveals that continuous ground motions decay as Omori’s law in time and follow the Gutenberg-Richter distribution in logarithmic amplitude. The measured temporal decay in amplitudes agrees with predictions of the rate-and-state framework and...

Authors

Timothy Hugh Clements, Elizabeth S. Cochran, Sarah E. Minson, Nicholas van der Elst, Clara Yoon, Annemarie S. Baltay Sundstrom, Morgan T. Page

By

Natural Hazards Mission Area, Earthquake Hazards Program, Earthquake Science Center

September 2, 2025

A scientific vision and roadmap for earthquake rupture forecast developments, a USGS perspective A scientific vision and roadmap for earthquake rupture forecast developments, a USGS perspective

We articulate a scientific vision and roadmap for the development of improved Earthquake Rupture Forecast models, which are one of the two main modeling components used in modern seismic hazard and risk analysis. One primary future objective is to provide fully time-dependent models that include both elastic rebound and spatiotemporal clustering nationwide, which is particularly...

Authors

Edward H. Field, Alexandra Elise Hatem, Bruce E. Shaw, Morgan T. Page, P. Martin Mai, Kevin Ross Milner, Andrea L. Llenos, Andrew J. Michael, Frederick Pollitz, Jessica Ann Thompson Jobe, Thomas E. Parsons, Olaf Zielke, David R. Shelly, Alice-Agnes Gabriel, Devin McPhillips, Richard W. Briggs, Elizabeth S. Cochran, Nico Luco, Mark D. Petersen, Peter M. Powers, Justin Rubinstein, Allison Shumway, Nicholas van der Elst, Yuehua Zeng, Christopher DuRoss, Jason M. Altekruse

By

Geologic Hazards Science Center

May 29, 2025

Meet the people where they are: Assessing user needs for aftershock forecast products in El Salvador, Mexico and the United States Meet the people where they are: Assessing user needs for aftershock forecast products in El Salvador, Mexico and the United States

Aftershock forecasts can help communities reduce their seismic risk by conveying how many aftershocks can be expected following a large earthquake, and how the expected number of aftershocks and their corresponding ground shaking evolves over time and space. Prior work finds that graphical forecast products may communicate such information better than only text or numbers. To identify...

Authors

Max Schneider, Anne Wein, Sara K. McBride, Nicholas van der Elst, Julia Becker, Raul Castro, Manuel Diaz, Hector Gonzalez-Huizar, Jeanne L. Hardebeck, Andrew J. Michael, Luis E. Mixco, Morgan T. Page

By

Natural Hazards Mission Area, Earthquake Hazards Program, Earthquake Science Center

May 21, 2025

Bayesian ETAS modeling for the Pacific Northwest: Uncovering effects of tectonic regimes, regional differences, and swarms on aftershock parameters Bayesian ETAS modeling for the Pacific Northwest: Uncovering effects of tectonic regimes, regional differences, and swarms on aftershock parameters

The Pacific Northwest (PNW) of North America has high seismic hazard due to numerous earthquake sources under populated areas. It hosts several tectonic regimes and subregional seismic zones that are hypothesized to have different patterns of earthquake and aftershock occurrence. It is also predisposed to earthquake swarms, which can complicate the statistical modeling of these patterns...

Authors

Max Schneider, Michael Barall, Peter Guttorp, Jeanne L. Hardebeck, Andrew J. Michael, Morgan T. Page, Nicholas van der Elst

By

Natural Hazards Mission Area, Earthquake Hazards Program, Earthquake Science Center

October 1, 2024

Onset of aftershocks: Constraints on the Rate-and-State model Onset of aftershocks: Constraints on the Rate-and-State model

Aftershock rates typically decay with time t after the mainshock according to the Omori–Utsu law, R(t)=K(c+t)−p⁠, with parameters K, c, and p. The rate‐and‐state (RS) model, which is currently the most popular physics‐based seismicity model, also predicts an Omori–Utsu decay with p = 1 and a c‐value that depends on the size of the coseismic stress change. Because the mainshock‐induced...

Authors

Sebastian Hainzl, Morgan T. Page, Nicholas van der Elst

By

Natural Hazards Mission Area, Earthquake Hazards Program, Earthquake Science Center

September 23, 2024

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

By

Natural Hazards Mission Area, Earthquake Hazards Program, Earthquake Science Center

August 13, 2024

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

By

Natural Hazards Mission Area, Earthquake Hazards Program, Earthquake Science Center

July 25, 2024

Aftershock forecasting Aftershock forecasting

Aftershocks can compound the impacts of a major earthquake, disrupting recovery efforts and potentially further damaging weakened buildings and infrastructure. Forecasts of the probability of aftershocks can therefore aid decision-making during earthquake response and recovery. Several countries issue authoritative aftershock forecasts. Most aftershock forecasts are based on simple...

Authors

Jeanne L. Hardebeck, Andrea L. Llenos, Andrew J. Michael, Morgan T. Page, Max Schneider, Nicholas van der Elst

By

Natural Hazards Mission Area, Earthquake Hazards Program, Earthquake Science Center, Geologic Hazards Science Center

September 9, 2023

a-positive: A robust estimator of the earthquake rate in incomplete or saturated catalogs a-positive: A robust estimator of the earthquake rate in incomplete or saturated catalogs

Detection thresholds in earthquake catalogs frequently change in time due to station coverage improvements and network saturation effects during active periods such as mainshock-aftershock cascades. This presents a challenge to seismicity-rate estimation; there is a tradeoff between using as low a minimum magnitude as possible to maximize data while not undercounting the rate due to...

Authors

Nicholas van der Elst, Morgan T. Page

By

Natural Hazards Mission Area, Earthquake Hazards Program, Earthquake Science Center

June 14, 2023

Modern products for a vintage event: An update on the 1933 Long Beach, California, earthquake Modern products for a vintage event: An update on the 1933 Long Beach, California, earthquake

When a notable earthquake occurs in the United States, a range of familiar real‐ and near‐real‐time products are produced by the U.S. Geological Survey (USGS) Advanced National Seismic System (ANSS), and made available via the ANSS Comprehensive Earthquake Catalog. For historical and early instrumental earthquakes, similar results and products are developed depending on data availability...

Authors

Susan E. Hough, J. Luke Blair, Sonia Ellison, Robert Graves, Scott Haefner, Eric M. Thompson, Nicholas van der Elst, Morgan T. Page, David J. Wald

By

Natural Hazards Mission Area, Earthquake Hazards Program, Earthquake Science Center, Geologic Hazards Science Center

March 17, 2023

Fault roughness at seismogenic depths and links to earthquake behavior Fault roughness at seismogenic depths and links to earthquake behavior

Fault geometry affects the initiation, propagation, and cessation of earthquake rupture, as well as, potentially, the statistical behavior of earthquake sequences. We analyze 18,250 (−0.27

Authors

Elizabeth S. Cochran, Morgan T. Page, Nicholas van der Elst, Zachary E. Ross, Daniel T. Trugman

By

Natural Hazards Mission Area, Earthquake Hazards Program, Earthquake Science Center

Nicholas van der Elst

Seismometer installation in Ridgecrest, California

Seismometer installation in Ridgecrest, California

Seismometer installation in Ridgecrest, California

Seismometer installation in Ridgecrest, California

Seismometer installation in Ridgecrest, California

Seismometer installation in Ridgecrest, California

Nicholas van der Elst

Science and Products

Could the M7.1 Ridgecrest, CA Earthquake Sequence Trigger a Large Earthquake Nearby?

The Past Holds the Key to the Future of Aftershock Forecasting

Operational Earthquake Forecasting – Implementing a Real-Time System for California

Science and Products

Could the M7.1 Ridgecrest, CA Earthquake Sequence Trigger a Large Earthquake Nearby?

The Past Holds the Key to the Future of Aftershock Forecasting

Operational Earthquake Forecasting – Implementing a Real-Time System for California