Professional name: Erin A. Wirth
My research focuses on earthquake hazards, specifically in subduction zone settings. I am currently using 3-D numerical simulations to predict earthquake ground motions associated with large earthquakes in the Cascadia subduction zone, as well as on crustal faults systems. I integrate my work with geologic and geophysical observations from previous earthquakes, and work closely with engineers and social scientists to improve earthquake resilience in the Pacific Northwest. I am also interested in the generation of strong ground motions by distinct patches on the megathrust (i.e., as observed in the 2011 M9.0 Tohoku, Japan earthquake) and the amplification of ground motions by deep sedimentary basins (e.g., the Seattle basin).
My other research interests focus on using seismic observations and numerical modeling to characterize the structure and dynamics of Earth’s interior. Previously, I have used seismological techniques (such as receiver functions and shear wave splitting) to interrogate deformational processes and the extent of hydration in subduction systems worldwide.
Education
2014 Ph.D. Geology & Geophysics, Yale University
2011 M.Phil. Geology & Geophysics, Yale University
2009 B.S. Physics, New York University
Appointments
2017-Present Research Geophysicist, U.S. Geological Survey, Seattle, WA
2017-Present Affiliate Assistant Professor, University of Washington
2014-2018 Duty Seismologist, Pacific Northwest Seismic Network, University of Washington
2014-2017 Postdoctoral Research Associate, Department of Earth & Space Sciences, University of Washington
2009-2014 Graduate Student Researcher, Department of Geology & Geophysics, Yale University
Science and Products
Filter Total Items: 16
Topographic response to simulated Mw 6.5-7.0 earthquakes on the Seattle Fault
We explore the response of ground motions to topography during large crustal fault earthquakes by simulating several magnitude 6.5–7.0 rupture scenarios on the Seattle fault, Washington State. Kinematic simulations are run using a 3D spectral element code and a detailed seismic velocity model for the Puget Sound region. This model includes realistic surface topography and a near‐surface low‐veloci
Authors
Ian Patrick Stone, Erin Wirth, Arthur Frankel
The occurrence and hazards of great subduction zone earthquakes
Subduction zone earthquakes result in some of the most devastating natural hazards on Earth. Knowledge of where great (moment magnitude M ≥ 8) subduction zone earthquakes can occur and how they rupture is critical to constraining future seismic and tsunami hazards. Since the occurrence of well-instrumented great earthquakes, such as the 2004 M9.1 Sumatra–Andaman and 2011 M9.1 Tohoku earthquakes, t
Authors
Erin Wirth, Valerie J. Sahakian, Laura M Wallace, Daniel Melnick
Effect of fixing earthquake depth in ShakeAlert algorithms on performance for intraslab earthquakes
We investigate whether assuming a fixed shallow depth in the ShakeAlert network‐based earthquake early warning system is sufficient to produce accurate ground‐motion based alerts for intraslab earthquakes. ShakeAlert currently uses a fixed focal depth of 8 km to estimate earthquake location and magnitude. This is an appropriate way to reduce computational costs without compromising alert accuracy
Authors
Mika Thompson, J. Renate Hartog, Erin Wirth
Structure and Qp-Qs relations in the Seattle and Tualatin basins from converted seismic phases
We use converted body‐wave phases from local earthquakes to constrain depth to basement and average attenuation relations for the Seattle basin in Washington and the Tualatin basin in Oregon. P‐, P‐to‐S‐(Ps), S‐to‐P‐(Sp), and S‐wave arrivals are present in three‐component recordings of magnitude 2.5–4.0 earthquakes at seismic stations located in these basins. Based on their relative travel times,
Authors
Ian Stone, Erin Wirth, Arthur Frankel
Expected warning times from the ShakeAlert earthquake early warning system for earthquakes in the Pacific Northwest
The ShakeAlert® earthquake early warning system has been live since October 2019 for the testing of public alerting to mobile devices in California and will soon begin testing this modality in Oregon and Washington. The Pacific Northwest presents new challenges and opportunities for ShakeAlert owing to the different types of earthquakes that occur in the Cascadia subduction zone. Many locations in
Authors
Jeffrey J. McGuire, Deborah E. Smith, Arthur D. Frankel, Erin A. Wirth, Sara K. McBride, Robert M. de Groot
Toward an integrative geological and geophysical view of Cascadia subduction zone earthquakes
The Cascadia subduction zone (CSZ) is an exceptional geologic environment for recording evidence of land level changes, tsunamis, and ground motion that reveals at least 19 great megathrust earthquakes over the past 10 kyr. Such earthquakes are among the most impactful natural hazards on Earth, transcend national boundaries, and can have global impact. Reducing the societal impacts of future event
Authors
Maureen A. L. Walton, Lydia M. Staisch, Tina Dura, Jessie Kathleen Pearl, Brian L. Sherrod, Joan S. Gomberg, Simon E. Engelhart, Anne Trehu, Janet Watt, Jonathan P. Perkins, Robert C. Witter, Noel Bartlow, Chris Goldfinger, Harvey Kelsey, Ann Morey, Valerie J. Sahakian, Harold Tobin, Kelin Wang, Ray Wells, Erin Wirth
By
Natural Hazards Mission Area, Coastal and Marine Hazards and Resources Program, National Cooperative Geologic Mapping Program, Geosciences and Environmental Change Science Center, Pacific Coastal and Marine Science Center, Core Preparation and Analysis Laboratory and Sample Repositories, Deep Sea Exploration, Mapping and Characterization, Subduction Zone Science
Ensemble ShakeMaps for magnitude 9 earthquakes on the Cascadia Subduction Zone
We develop ensemble ShakeMaps for various magnitude 9 (MM 9) earthquakes on the Cascadia megathrust. Ground‐shaking estimates are based on 30 MM 9 Cascadia earthquake scenarios, which were selected using a logic‐tree approach that varied the hypocenter location, down‐dip rupture limit, slip distribution, and location of strong‐motion‐generating subevents. In a previous work, Frankel et al. (2018)
Authors
Erin Wirth, Alex R. R. Grant, Nasser A. Marafi, Arthur Frankel
Basin amplification effects in the Puget Lowland, Washington from strong motion recordings and 3D simulations
Sedimentary basins in the Puget Sound region, Washington State, increase ground‐motion intensity and duration of shaking during local earthquakes. We analyze Pacific Northwest Seismic Network and U.S. Geological Survey strong‐motion recordings of five local earthquakes (M 3.9–6.8), including the 2001 Nisqually earthquake, to characterize sedimentary basin effects within the Seattle and Tacoma basi
Authors
Mika Thompson, Erin Wirth, Arthur Frankel, J. Renate Hartog, John E. Vidale
Impacts of simulated M9 Cascadia Subduction Zone motions on idealized systems
Ground motions have been simulated for a magnitude 9 (M9) Cascadia Subduction Zone earthquake, which will affect the Puget Lowland region, including cities underlain by the Seattle, Everett, and Tacoma sedimentary basins. The current national seismic maps do not account for the effects of these basins on the risk-targeted Maximum Considered Earthquake (MCER). The simulated motions for Seattle had
Authors
Nasser A. Marafi, Marc Eberhard, Jeffrey W. Berman, Erin Wirth, Arthur Frankel
Impact of down-dip rupture limit and high stress drop subevents on coseismic land-level change during Cascadia megathrust earthquakes
Seismic hazard associated with Cascadia megathrust earthquakes is strongly dependent on the landward rupture extent and heterogeneous fault properties. We use 3-D numerical simulations and a seismic velocity model for Cascadia to estimate coseismic deformation due to ~M9 earthquake scenarios. Our earthquake source model is based on observations of the 2010 M8.8 Maule and 2011 M9.0 Tohoku earthquak
Authors
Erin A. Wirth, Arthur Frankel
SKS splitting beneath Mount St. Helens: Constraints on subslab mantle entrainment
Observations of seismic anisotropy can provide direct constraints on the character of mantle flow in subduction zones, critical for our broader understanding of subduction dynamics. Here we present over 750 new SKS splitting measurements in the vicinity of Mount St. Helens in the Cascadia subduction zone using a combination of stations from the iMUSH broadband array and Cascades Volcano Observator
Authors
Caroline M Eakin, Erin A. Wirth, Abraham Wallace, Carl W Ulberg, Kenneth C Creager, Geoffrey A Abers
Source-dependent amplification of earthquake ground motions in deep sedimentary basins
Deep sedimentary basins amplify long-period shaking from seismic waves, increasing the seismic hazard for cities within such basins. We perform 3-D simulations of point source earthquakes distributed around the Seattle and Tacoma basins in Washington State, to examine the dependence of basin amplification on source azimuth, depth, and earthquake type. For periods between 1-10 s, the pattern of amp
Authors
Erin Wirth, John E. Vidale, Arthur Frankel, Thomas L. Pratt
Science and Products
- Publications
Filter Total Items: 16
Topographic response to simulated Mw 6.5-7.0 earthquakes on the Seattle Fault
We explore the response of ground motions to topography during large crustal fault earthquakes by simulating several magnitude 6.5–7.0 rupture scenarios on the Seattle fault, Washington State. Kinematic simulations are run using a 3D spectral element code and a detailed seismic velocity model for the Puget Sound region. This model includes realistic surface topography and a near‐surface low‐velociAuthorsIan Patrick Stone, Erin Wirth, Arthur FrankelThe occurrence and hazards of great subduction zone earthquakes
Subduction zone earthquakes result in some of the most devastating natural hazards on Earth. Knowledge of where great (moment magnitude M ≥ 8) subduction zone earthquakes can occur and how they rupture is critical to constraining future seismic and tsunami hazards. Since the occurrence of well-instrumented great earthquakes, such as the 2004 M9.1 Sumatra–Andaman and 2011 M9.1 Tohoku earthquakes, tAuthorsErin Wirth, Valerie J. Sahakian, Laura M Wallace, Daniel MelnickEffect of fixing earthquake depth in ShakeAlert algorithms on performance for intraslab earthquakes
We investigate whether assuming a fixed shallow depth in the ShakeAlert network‐based earthquake early warning system is sufficient to produce accurate ground‐motion based alerts for intraslab earthquakes. ShakeAlert currently uses a fixed focal depth of 8 km to estimate earthquake location and magnitude. This is an appropriate way to reduce computational costs without compromising alert accuracyAuthorsMika Thompson, J. Renate Hartog, Erin WirthStructure and Qp-Qs relations in the Seattle and Tualatin basins from converted seismic phases
We use converted body‐wave phases from local earthquakes to constrain depth to basement and average attenuation relations for the Seattle basin in Washington and the Tualatin basin in Oregon. P‐, P‐to‐S‐(Ps), S‐to‐P‐(Sp), and S‐wave arrivals are present in three‐component recordings of magnitude 2.5–4.0 earthquakes at seismic stations located in these basins. Based on their relative travel times,AuthorsIan Stone, Erin Wirth, Arthur FrankelExpected warning times from the ShakeAlert earthquake early warning system for earthquakes in the Pacific Northwest
The ShakeAlert® earthquake early warning system has been live since October 2019 for the testing of public alerting to mobile devices in California and will soon begin testing this modality in Oregon and Washington. The Pacific Northwest presents new challenges and opportunities for ShakeAlert owing to the different types of earthquakes that occur in the Cascadia subduction zone. Many locations inAuthorsJeffrey J. McGuire, Deborah E. Smith, Arthur D. Frankel, Erin A. Wirth, Sara K. McBride, Robert M. de GrootToward an integrative geological and geophysical view of Cascadia subduction zone earthquakes
The Cascadia subduction zone (CSZ) is an exceptional geologic environment for recording evidence of land level changes, tsunamis, and ground motion that reveals at least 19 great megathrust earthquakes over the past 10 kyr. Such earthquakes are among the most impactful natural hazards on Earth, transcend national boundaries, and can have global impact. Reducing the societal impacts of future eventAuthorsMaureen A. L. Walton, Lydia M. Staisch, Tina Dura, Jessie Kathleen Pearl, Brian L. Sherrod, Joan S. Gomberg, Simon E. Engelhart, Anne Trehu, Janet Watt, Jonathan P. Perkins, Robert C. Witter, Noel Bartlow, Chris Goldfinger, Harvey Kelsey, Ann Morey, Valerie J. Sahakian, Harold Tobin, Kelin Wang, Ray Wells, Erin WirthByNatural Hazards Mission Area, Coastal and Marine Hazards and Resources Program, National Cooperative Geologic Mapping Program, Geosciences and Environmental Change Science Center, Pacific Coastal and Marine Science Center, Core Preparation and Analysis Laboratory and Sample Repositories, Deep Sea Exploration, Mapping and Characterization, Subduction Zone ScienceEnsemble ShakeMaps for magnitude 9 earthquakes on the Cascadia Subduction Zone
We develop ensemble ShakeMaps for various magnitude 9 (MM 9) earthquakes on the Cascadia megathrust. Ground‐shaking estimates are based on 30 MM 9 Cascadia earthquake scenarios, which were selected using a logic‐tree approach that varied the hypocenter location, down‐dip rupture limit, slip distribution, and location of strong‐motion‐generating subevents. In a previous work, Frankel et al. (2018)AuthorsErin Wirth, Alex R. R. Grant, Nasser A. Marafi, Arthur FrankelBasin amplification effects in the Puget Lowland, Washington from strong motion recordings and 3D simulations
Sedimentary basins in the Puget Sound region, Washington State, increase ground‐motion intensity and duration of shaking during local earthquakes. We analyze Pacific Northwest Seismic Network and U.S. Geological Survey strong‐motion recordings of five local earthquakes (M 3.9–6.8), including the 2001 Nisqually earthquake, to characterize sedimentary basin effects within the Seattle and Tacoma basiAuthorsMika Thompson, Erin Wirth, Arthur Frankel, J. Renate Hartog, John E. VidaleImpacts of simulated M9 Cascadia Subduction Zone motions on idealized systems
Ground motions have been simulated for a magnitude 9 (M9) Cascadia Subduction Zone earthquake, which will affect the Puget Lowland region, including cities underlain by the Seattle, Everett, and Tacoma sedimentary basins. The current national seismic maps do not account for the effects of these basins on the risk-targeted Maximum Considered Earthquake (MCER). The simulated motions for Seattle hadAuthorsNasser A. Marafi, Marc Eberhard, Jeffrey W. Berman, Erin Wirth, Arthur FrankelImpact of down-dip rupture limit and high stress drop subevents on coseismic land-level change during Cascadia megathrust earthquakes
Seismic hazard associated with Cascadia megathrust earthquakes is strongly dependent on the landward rupture extent and heterogeneous fault properties. We use 3-D numerical simulations and a seismic velocity model for Cascadia to estimate coseismic deformation due to ~M9 earthquake scenarios. Our earthquake source model is based on observations of the 2010 M8.8 Maule and 2011 M9.0 Tohoku earthquakAuthorsErin A. Wirth, Arthur FrankelSKS splitting beneath Mount St. Helens: Constraints on subslab mantle entrainment
Observations of seismic anisotropy can provide direct constraints on the character of mantle flow in subduction zones, critical for our broader understanding of subduction dynamics. Here we present over 750 new SKS splitting measurements in the vicinity of Mount St. Helens in the Cascadia subduction zone using a combination of stations from the iMUSH broadband array and Cascades Volcano ObservatorAuthorsCaroline M Eakin, Erin A. Wirth, Abraham Wallace, Carl W Ulberg, Kenneth C Creager, Geoffrey A AbersSource-dependent amplification of earthquake ground motions in deep sedimentary basins
Deep sedimentary basins amplify long-period shaking from seismic waves, increasing the seismic hazard for cities within such basins. We perform 3-D simulations of point source earthquakes distributed around the Seattle and Tacoma basins in Washington State, to examine the dependence of basin amplification on source azimuth, depth, and earthquake type. For periods between 1-10 s, the pattern of ampAuthorsErin Wirth, John E. Vidale, Arthur Frankel, Thomas L. Pratt - News