Skip to main content
U.S. flag

An official website of the United States government

Morgan T Page

Morgan Page is a geophysicist in the Earthquake Science Center.

Science and Products

stark landscape with a rip going across the surface from front to back

Southern California Earthquake Hazards

Southern California has the highest level of earthquake risk in the United States, with half of the expected financial losses from earthquakes in the Nation expected to occur in southern California. Sitting astride the Pacific - North American plate boundary at the Big Bend of the San Andreas Fault, Southern California has over 300 faults capable of producing magnitude 6 and larger earthquakes...
By
Natural Hazards Mission Area, Earthquake Hazards Program
Southern California Earthquake Hazards

Southern California Earthquake Hazards

Southern California has the highest level of earthquake risk in the United States, with half of the expected financial losses from earthquakes in the Nation expected to occur in southern California. Sitting astride the Pacific - North American plate boundary at the Big Bend of the San Andreas Fault, Southern California has over 300 faults capable of producing magnitude 6 and larger earthquakes...
Learn More
Map showing regional faults and Coso field near Ridgecrest

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

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

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
The Past Holds the Key to the Future of Aftershock Forecasting

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
USGS science for a changing world logo

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

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
Learn More
USGS science for a changing world logo

Joint USGS - GEM Group on Global Probabilistic Modeling of Earthquake Recurrence Rates and Maximum Magnitudes

Despite the best monitoring networks, the highest rate of earthquakes and the longest continuous recorded history in the world, this year’s M=9.0 Tohoku, Japan, earthquake was completely unforeseen. The Japanese had expected no larger than a M=8 quake in the Japan trench, 1/30 th the size of the Tohoku temblor. This year also saw the devastating M=6.3 Christchurch, New Zealand earthquake...
By
John Wesley Powell Center for Analysis and Synthesis
Joint USGS - GEM Group on Global Probabilistic Modeling of Earthquake Recurrence Rates and Maximum Magnitudes

Joint USGS - GEM Group on Global Probabilistic Modeling of Earthquake Recurrence Rates and Maximum Magnitudes

Despite the best monitoring networks, the highest rate of earthquakes and the longest continuous recorded history in the world, this year’s M=9.0 Tohoku, Japan, earthquake was completely unforeseen. The Japanese had expected no larger than a M=8 quake in the Japan trench, 1/30 th the size of the Tohoku temblor. This year also saw the devastating M=6.3 Christchurch, New Zealand earthquake and the M
Learn More

Data Release for the 2023 U.S. 50-State National Seismic Hazard Model - Overview Data Release for the 2023 U.S. 50-State National Seismic Hazard Model - Overview

This data release contains data sets associated with the 2023 50-State National Seismic Hazard Model Update. The 2023 50-State National Seimsic Hazard Model (NSHM) Update includes an update to the NSHMs for the conterminous U.S (CONUS, last updated in 2018), Alaska (AK, last updated in 2007), and Hawaii (last updated in 2001). Data sets include inputs like seismicity catalogs used as...
By
Earthquake Hazards Program
Filter Total Items: 43

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 Cochran, Sarah Minson, Nicholas van der Elst, Clara Yoon, Annemarie Baltay Sundstrom, Morgan Page
By
Natural Hazards Mission Area, Earthquake Hazards Program, Earthquake Science Center

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 Field, Alexandra Hatem, Bruce Shaw, Morgan Page, P. Mai, Kevin Ross Milner, Andrea Llenos, Andrew Michael, Frederick Pollitz, Jessica Jobe, Thomas Parsons, Olaf Zielke, David Shelly, Alice-Agnes Gabriel, Devin McPhillips, Richard Briggs, Elizabeth Cochran, Nico Luco, Mark Petersen, Peter Powers, Justin Rubinstein, Allison Shumway, Nicholas van der Elst, Yuehua Zeng, Christopher DuRoss, Jason Altekruse
By
Geologic Hazards Science Center

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 Hardebeck, Andrew Michael, Luis Mixco, Morgan Page
By
Natural Hazards Mission Area, Earthquake Hazards Program, Earthquake Science Center

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 Hardebeck, Andrew Michael, Morgan Page, Nicholas van der Elst
By
Natural Hazards Mission Area, Earthquake Hazards Program, Earthquake Science Center

What 25+ years of "Did You Feel It" intensities tell us about shaking in California What 25+ years of "Did You Feel It" intensities tell us about shaking in California

“When will the Big One happen?” is a question that people often have for earthquake scientists. But while waiting for the “Big One” to occur, people will usually experience frightening or damaging shaking from multiple relatively smaller‐magnitude earthquakes. Given this context, it raises the question: “Where does most of the damage come from?” Could smaller, yet more frequent...
Authors
Jenna Marie Chaffeur, Jessie Saunders, Sarah Minson, Annemarie Baltay Sundstrom, Elizabeth Cochran, Susan E. Hough, Vince Quitoriano, Morgan Page, James Blair
By
Natural Hazards Mission Area, Earthquake Hazards Program, Earthquake Science Center, Geologic Hazards Science Center

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 Page, Nicholas van der Elst
By
Natural Hazards Mission Area, Earthquake Hazards Program, Earthquake Science Center

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 Page, Nicholas van der Elst, Sebastian Hainzl
By
Natural Hazards Mission Area, Earthquake Hazards Program, Earthquake Science Center

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 Werner, Pablo Iturrieta, Jose Bayona, Iunio Iervolino, Max Schneider, Morgan Page, Jiancang Zhuang, Marcus Herrmann, Andrew Michael, Guiseppe Falcone, Warner Marzocchi, David 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

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 Hardebeck, Andrea Llenos, Andrew Michael, Morgan Page, Max Schneider, Nicholas van der Elst
By
Natural Hazards Mission Area, Earthquake Hazards Program, Earthquake Science Center, Geologic Hazards Science Center

The 2023 US 50-State National Seismic Hazard Model: Overview and implications The 2023 US 50-State National Seismic Hazard Model: Overview and implications

The US National Seismic Hazard Model (NSHM) was updated in 2023 for all 50 states using new science on seismicity, fault ruptures, ground motions, and probabilistic techniques to produce a standard of practice for public policy and other engineering applications (defined for return periods greater than ∼475 or less than ∼10,000 years). Changes in 2023 time-independent seismic hazard...
Authors
Mark Petersen, Allison Shumway, Peter Powers, Edward Field, Morgan Moschetti, Kishor Jaiswal, Kevin Milner, Sanaz Rezaeian, Arthur Frankel, Andrea Llenos, Andrew Michael, Jason Altekruse, Sean Ahdi, Kyle Withers, Charles Mueller, Yuehua Zeng, Robert Chase, Leah Salditch, Nico Luco, Kenneth S. Rukstales, Julie Herrick, Demi Girot, Brad Aagaard, Adrian Bender, Michael Blanpied, Richard Briggs, Oliver Boyd, Brandon Clayton, Christopher DuRoss, Eileen L. Evans, Peter J. Haeussler, Alexandra Hatem, Kirstie Haynie, Elizabeth Hearn, Kaj Johnson, Zachary Kortum, N. Kwong, Andrew Makdisi, Henry Mason, Daniel McNamara, Devin McPhillips, P. Okubo, Morgan Page, Frederick Pollitz, Justin Rubinstein, Bruce Shaw, Zheng-Kang Shen, Brian Shiro, James Smith, William Stephenson, Eric Thompson, Jessica Jobe, Erin Wirth, Robert C. Witter
By
Natural Hazards Mission Area, Earthquake Hazards Program, Geologic Hazards Science Center, Supplemental Appropriations for Disaster Recovery Activities

The USGS 2023 Conterminous U.S. time‐independent earthquake rupture forecast The USGS 2023 Conterminous U.S. time‐independent earthquake rupture forecast

We present the 2023 U.S. Geological Survey time‐independent earthquake rupture forecast for the conterminous United States, which gives authoritative estimates of the magnitude, location, and time‐averaged frequency of potentially damaging earthquakes throughout the region. In addition to updating virtually all model components, a major focus has been to provide a better representation...
Authors
Edward Field, Kevin Milner, Alexandra Hatem, Peter Powers, Frederick Pollitz, Andrea Llenos, Yuehua Zeng, Kaj Johnson, Bruce Shaw, Devin McPhillips, Jessica Jobe, Allison Shumway, Andrew Michael, Zheng-Kang Shen, Eileen L. Evans, Elizabeth Hearn, Charles Mueller, Arthur Frankel, Mark Petersen, Christopher DuRoss, Richard Briggs, Morgan Page, Justin Rubinstein, Julie Herrick
By
Natural Hazards Mission Area, Earthquake Hazards Program, Geologic Hazards Science Center, Earthquake Science Center

A multifault earthquake threat for the Seattle metropolitan region revealed by mass tree mortality A multifault earthquake threat for the Seattle metropolitan region revealed by mass tree mortality

Compound earthquakes involving simultaneous ruptures along multiple faults often define a region’s upper threshold of maximum magnitude. Yet, the potential for linked faulting remains poorly understood given the infrequency of these events in the historic era. Geological records provide longer perspectives, although temporal uncertainties are too broad to clearly pinpoint single...
Authors
Bryan Black, Jessie K. Pearl, Charlotte Pearson, Patrick T. Pringle, David C. Frank, Morgan Page, Brendan M. Buckley, Edward Cook, Grant Harley, Karen J. King, Jonathan Hughes, David Reynolds, Brian Sherrod
By
Natural Hazards Mission Area, Earthquake Hazards Program, Earthquake Science Center
Threat of Earthquakes Occurring in Central United States Still Alive

Threat of Earthquakes Occurring in Central United States Still Alive

Earthquake activity in the New Madrid Seismic Zone in the central United States does not seem to be slowing down.  In a new study published in the...

Read Article

Science and Products

stark landscape with a rip going across the surface from front to back

Southern California Earthquake Hazards

Southern California has the highest level of earthquake risk in the United States, with half of the expected financial losses from earthquakes in the Nation expected to occur in southern California. Sitting astride the Pacific - North American plate boundary at the Big Bend of the San Andreas Fault, Southern California has over 300 faults capable of producing magnitude 6 and larger earthquakes...
By
Natural Hazards Mission Area, Earthquake Hazards Program
Southern California Earthquake Hazards

Southern California Earthquake Hazards

Southern California has the highest level of earthquake risk in the United States, with half of the expected financial losses from earthquakes in the Nation expected to occur in southern California. Sitting astride the Pacific - North American plate boundary at the Big Bend of the San Andreas Fault, Southern California has over 300 faults capable of producing magnitude 6 and larger earthquakes...
Learn More
Map showing regional faults and Coso field near Ridgecrest

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

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

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
The Past Holds the Key to the Future of Aftershock Forecasting

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
USGS science for a changing world logo

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

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
Learn More
USGS science for a changing world logo

Joint USGS - GEM Group on Global Probabilistic Modeling of Earthquake Recurrence Rates and Maximum Magnitudes

Despite the best monitoring networks, the highest rate of earthquakes and the longest continuous recorded history in the world, this year’s M=9.0 Tohoku, Japan, earthquake was completely unforeseen. The Japanese had expected no larger than a M=8 quake in the Japan trench, 1/30 th the size of the Tohoku temblor. This year also saw the devastating M=6.3 Christchurch, New Zealand earthquake...
By
John Wesley Powell Center for Analysis and Synthesis
Joint USGS - GEM Group on Global Probabilistic Modeling of Earthquake Recurrence Rates and Maximum Magnitudes

Joint USGS - GEM Group on Global Probabilistic Modeling of Earthquake Recurrence Rates and Maximum Magnitudes

Despite the best monitoring networks, the highest rate of earthquakes and the longest continuous recorded history in the world, this year’s M=9.0 Tohoku, Japan, earthquake was completely unforeseen. The Japanese had expected no larger than a M=8 quake in the Japan trench, 1/30 th the size of the Tohoku temblor. This year also saw the devastating M=6.3 Christchurch, New Zealand earthquake and the M
Learn More

Data Release for the 2023 U.S. 50-State National Seismic Hazard Model - Overview Data Release for the 2023 U.S. 50-State National Seismic Hazard Model - Overview

This data release contains data sets associated with the 2023 50-State National Seismic Hazard Model Update. The 2023 50-State National Seimsic Hazard Model (NSHM) Update includes an update to the NSHMs for the conterminous U.S (CONUS, last updated in 2018), Alaska (AK, last updated in 2007), and Hawaii (last updated in 2001). Data sets include inputs like seismicity catalogs used as...
By
Earthquake Hazards Program
Filter Total Items: 43

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 Cochran, Sarah Minson, Nicholas van der Elst, Clara Yoon, Annemarie Baltay Sundstrom, Morgan Page
By
Natural Hazards Mission Area, Earthquake Hazards Program, Earthquake Science Center

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 Field, Alexandra Hatem, Bruce Shaw, Morgan Page, P. Mai, Kevin Ross Milner, Andrea Llenos, Andrew Michael, Frederick Pollitz, Jessica Jobe, Thomas Parsons, Olaf Zielke, David Shelly, Alice-Agnes Gabriel, Devin McPhillips, Richard Briggs, Elizabeth Cochran, Nico Luco, Mark Petersen, Peter Powers, Justin Rubinstein, Allison Shumway, Nicholas van der Elst, Yuehua Zeng, Christopher DuRoss, Jason Altekruse
By
Geologic Hazards Science Center

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 Hardebeck, Andrew Michael, Luis Mixco, Morgan Page
By
Natural Hazards Mission Area, Earthquake Hazards Program, Earthquake Science Center

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 Hardebeck, Andrew Michael, Morgan Page, Nicholas van der Elst
By
Natural Hazards Mission Area, Earthquake Hazards Program, Earthquake Science Center

What 25+ years of "Did You Feel It" intensities tell us about shaking in California What 25+ years of "Did You Feel It" intensities tell us about shaking in California

“When will the Big One happen?” is a question that people often have for earthquake scientists. But while waiting for the “Big One” to occur, people will usually experience frightening or damaging shaking from multiple relatively smaller‐magnitude earthquakes. Given this context, it raises the question: “Where does most of the damage come from?” Could smaller, yet more frequent...
Authors
Jenna Marie Chaffeur, Jessie Saunders, Sarah Minson, Annemarie Baltay Sundstrom, Elizabeth Cochran, Susan E. Hough, Vince Quitoriano, Morgan Page, James Blair
By
Natural Hazards Mission Area, Earthquake Hazards Program, Earthquake Science Center, Geologic Hazards Science Center

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 Page, Nicholas van der Elst
By
Natural Hazards Mission Area, Earthquake Hazards Program, Earthquake Science Center

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 Page, Nicholas van der Elst, Sebastian Hainzl
By
Natural Hazards Mission Area, Earthquake Hazards Program, Earthquake Science Center

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 Werner, Pablo Iturrieta, Jose Bayona, Iunio Iervolino, Max Schneider, Morgan Page, Jiancang Zhuang, Marcus Herrmann, Andrew Michael, Guiseppe Falcone, Warner Marzocchi, David 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

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 Hardebeck, Andrea Llenos, Andrew Michael, Morgan Page, Max Schneider, Nicholas van der Elst
By
Natural Hazards Mission Area, Earthquake Hazards Program, Earthquake Science Center, Geologic Hazards Science Center

The 2023 US 50-State National Seismic Hazard Model: Overview and implications The 2023 US 50-State National Seismic Hazard Model: Overview and implications

The US National Seismic Hazard Model (NSHM) was updated in 2023 for all 50 states using new science on seismicity, fault ruptures, ground motions, and probabilistic techniques to produce a standard of practice for public policy and other engineering applications (defined for return periods greater than ∼475 or less than ∼10,000 years). Changes in 2023 time-independent seismic hazard...
Authors
Mark Petersen, Allison Shumway, Peter Powers, Edward Field, Morgan Moschetti, Kishor Jaiswal, Kevin Milner, Sanaz Rezaeian, Arthur Frankel, Andrea Llenos, Andrew Michael, Jason Altekruse, Sean Ahdi, Kyle Withers, Charles Mueller, Yuehua Zeng, Robert Chase, Leah Salditch, Nico Luco, Kenneth S. Rukstales, Julie Herrick, Demi Girot, Brad Aagaard, Adrian Bender, Michael Blanpied, Richard Briggs, Oliver Boyd, Brandon Clayton, Christopher DuRoss, Eileen L. Evans, Peter J. Haeussler, Alexandra Hatem, Kirstie Haynie, Elizabeth Hearn, Kaj Johnson, Zachary Kortum, N. Kwong, Andrew Makdisi, Henry Mason, Daniel McNamara, Devin McPhillips, P. Okubo, Morgan Page, Frederick Pollitz, Justin Rubinstein, Bruce Shaw, Zheng-Kang Shen, Brian Shiro, James Smith, William Stephenson, Eric Thompson, Jessica Jobe, Erin Wirth, Robert C. Witter
By
Natural Hazards Mission Area, Earthquake Hazards Program, Geologic Hazards Science Center, Supplemental Appropriations for Disaster Recovery Activities

The USGS 2023 Conterminous U.S. time‐independent earthquake rupture forecast The USGS 2023 Conterminous U.S. time‐independent earthquake rupture forecast

We present the 2023 U.S. Geological Survey time‐independent earthquake rupture forecast for the conterminous United States, which gives authoritative estimates of the magnitude, location, and time‐averaged frequency of potentially damaging earthquakes throughout the region. In addition to updating virtually all model components, a major focus has been to provide a better representation...
Authors
Edward Field, Kevin Milner, Alexandra Hatem, Peter Powers, Frederick Pollitz, Andrea Llenos, Yuehua Zeng, Kaj Johnson, Bruce Shaw, Devin McPhillips, Jessica Jobe, Allison Shumway, Andrew Michael, Zheng-Kang Shen, Eileen L. Evans, Elizabeth Hearn, Charles Mueller, Arthur Frankel, Mark Petersen, Christopher DuRoss, Richard Briggs, Morgan Page, Justin Rubinstein, Julie Herrick
By
Natural Hazards Mission Area, Earthquake Hazards Program, Geologic Hazards Science Center, Earthquake Science Center

A multifault earthquake threat for the Seattle metropolitan region revealed by mass tree mortality A multifault earthquake threat for the Seattle metropolitan region revealed by mass tree mortality

Compound earthquakes involving simultaneous ruptures along multiple faults often define a region’s upper threshold of maximum magnitude. Yet, the potential for linked faulting remains poorly understood given the infrequency of these events in the historic era. Geological records provide longer perspectives, although temporal uncertainties are too broad to clearly pinpoint single...
Authors
Bryan Black, Jessie K. Pearl, Charlotte Pearson, Patrick T. Pringle, David C. Frank, Morgan Page, Brendan M. Buckley, Edward Cook, Grant Harley, Karen J. King, Jonathan Hughes, David Reynolds, Brian Sherrod
By
Natural Hazards Mission Area, Earthquake Hazards Program, Earthquake Science Center
Threat of Earthquakes Occurring in Central United States Still Alive

Threat of Earthquakes Occurring in Central United States Still Alive

Earthquake activity in the New Madrid Seismic Zone in the central United States does not seem to be slowing down.  In a new study published in the...

Read Article
Was this page helpful?