William L Yeck, PhD
I am a seismologist at the USGS Geologic Hazards Science Center, in Golden, Colorado. Much of my research is focused on operational tools that allow the National Earthquake Information Center to rapidly and accurately detect and model the source characteristics of earthquakes. I use these tools to better understand the seismotectonics of significant events.
Education:
2015 - Ph.D. in Geophysics, University of Colorado at Boulder
2008 - B.S. in Physics, Astronomy-Physics, (Minor in Archeology), University of Wisconsin - Madison
Publications:
Please visit my google scholar page for the most up-to-date list of my publications: Click Here
Science and Products
Improving Earthquake Monitoring with Deep Learning
Release Date: MARCH 12, 2021 On January 20, 2021 at 8:32am light shaking interrupted breakfast customers at a local coffee shop south of downtown Los Angeles, California. Everyone paused briefly while they waited to see if it was going to stop… or start shaking harder.
Supporting Data and Models for An unexplained tsunami: Was there megathrust slip during the 2020 Mw7.6 Sand Point, Alaska, earthquake?
This data release contains several input data and inversion output files used to model the October 19, 2020, Mw7.6 Sand Point, Alaska, earthquake and tsunami. The broadband seismic data in this data release are from globally distributed seismometers from networks G (https://doi.org/10.18715/GEOSCOPE.G), GE (https://doi.org/10.14470/TR560404), GR (https://doi.org/10.25928/mbx6-hr74), GS...
Supporting Data and Models for Characterizing the February 2023 Kahramanmaraş, Türkiye, Earthquake Sequence
This data release pertains to the February 2023 Kahramanmaraş, Türkiye earthquake sequence and complements the following publication: Goldberg, D.E. et al. (2023) Rapid Characterization of the February 2023 Kahramanmaraş, Türkiye, Earthquake Sequence, The Seismic Record. (xx), 1, doi: 10.1785/0320230009. Child Items "2023-02-06 Mw7.8 Pazarcık Earthquake Finite Fault Data and Model" and...
Waveform Data and Metadata used to National Earthquake Information Center Deep-Learning Models
These data were used to train the Machine Learning models supporting the USGS software release "NEIC Machine Learning Applications Software" (https://doi.org/10.5066/P9ICQPUR), and its companion publication in Seismological Research Letters "Leveraging Deep Learning in Global 24/7 Real-Time Earthquake Monitoring at the National Earthquake Information Center" (https://doi.org/XXXXX)...
Spatiotemporal Analysis of the Foreshock-Mainshock-Aftershock Sequence of the 6 July 2017 M5.8 Lincoln, Montana, Earthquake - Data Release
We used matched filter detection and multiple-event relocation techniques to characterize the spatiotemporal evolution of the sequence. Our analysis is from the 14 closest seismic stations to the earthquake sequence, which included seven permanent stations from the Montana Regional Seismic Network, one permanent station from the ANSS backbone network and three temporary seismic stations...
Earthquake Catalogs supporting manuscript "Afterslip Enhanced Aftershock Activity During the 2017 Earthquake Sequence Near Sulphur Peak, Idaho"
This ScienceBase entry contains three seismic catalogs supporting and described by the manuscript - Koper, K. D., Pankow, K. L., Pechmann, J. C., Hale, J. M., Burlacu, R., Yeck, W. L., et al (2018). Afterslip Enhanced Aftershock Activity During the 2017 Earthquake Sequence Near Sulphur Peak, Idaho. Geophysical Research Letters, 45. https://doi.org/10.1029/2018GL078196. These are included...
A database of instrumentally recorded ground motion intensity measurements from induced earthquakes in Oklahoma and Kansas
The database contains uniformly processed ground motion intensity measurements (peak horizontal ground motions and 5-percent-damped pseudospectral accelerations for oscillator periods 0.110 s). The earthquake event set includes more than 3,800 M≥3 earthquakes in Oklahoma and Kansas from January 2009 to December 2016. Ground motion time series were collected out to 500 km. We also...
Aftershock Catalog for the November 2011 Prague, Oklahoma Earthquake Sequence
The dataset contains the catalog of 5446 events and arrival times resulting from subspace detection processing and relocation in the for the 2011 Prague, Oklahoma, aftershock sequence. Lines beginning with "E" contain event information in the following order: event ID, origin year, origin month, origin day, origin hour, origin minute, origin second, latitude, longitude, depth, and...
Filter Total Items: 36
An unexplained tsunami: Was there megathrust slip during the 2020 Mw7.6 Sand Point, Alaska, earthquake?
On October 19, 2020, the Mw7.6 Sand Point earthquake struck south of the Shumagin Islands in Alaska. Moment tensors indicate the earthquake was primarily strike-slip, yet the event produced an enigmatic tsunami that was larger and more widespread than expected for an earthquake of that magnitude and mechanism. Using a suite of hydrodynamic, seismic, and geodetic modeling techniques, we...
Authors
Sean R. Santellanes, Dara Elyse Goldberg, Pablo Koch, Diego Melgar, William L. Yeck, Brendan W. Crowell, Jiun-Ting Lin
Surface-wave relocation and characterization of the October 2023 tsunamigenic seismic unrest near Sofugan volcano, Izu Islands, Japan
A moderate-magnitude earthquake swarm occurred in the remote Izu Islands region of Japan between October 1 and 8, 2023. The swarm included 151 shallow earthquakes cataloged by the U.S. Geological Survey, which notably included a roughly 2.5-hr episode of 15 successive magnitude (M) 5.5 earthquakes. Origin times were coincident with regionally recorded tsunami waves, but tsunamigenesis...
Authors
Chanel Ashlie Deane, Jeremy Pesicek, Stephanie Prejean, Paul S. Earle, David R. Shelly, William L. Yeck
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
Noise constraints on global body‐wave measurement thresholds
Intermediate sized earthquakes (≈M4–6.5) are often measured using the teleseismic body‐wave magnitude (𝑚b). 𝑚b measurements are especially critical at the lower end of this range when teleseismic waveform modeling techniques (i.e., moment tensor analysis) are difficult. The U.S. Geological Survey National Earthquake Information Center (NEIC) determines the location and magnitude of all...
Authors
Adam T. Ringler, David C. Wilson, Paul S. Earle, William L. Yeck, David B. Mason, Justin Thomas Wilgus
Subduction intraslab-interface fault interactions in the 2022 Mw 6.4 Ferndale, California earthquake sequence
The Mendocino triple junction, the intersection of the Pacific, North American, and Gorda plates, activates a collection of disparate faults that reconcile Cascadia subduction with San Andreas transform motion. The December 20, 2022, Mw 6.4 Ferndale, California earthquake occurred within this complex zone as strike-slip faulting within the subducting Gorda slab. Here, we analyze the...
Authors
David R. Shelly, Dara Elyse Goldberg, Kathryn Zerbe Materna, Robert John Skoumal, Jeanne L. Hardebeck, Clara Yoon, William L. Yeck, Paul S. Earle
Rapid estimation of single-station earthquake magnitudes with machine learning on a global scale
The foundation of earthquake monitoring is the ability to rapidly detect, locate, and estimate the size of seismic sources. Earthquake magnitudes are particularly difficult to rapidly characterize because magnitude types are only applicable to specific magnitude ranges, and location errors propagate to substantial magnitude errors. We developed a method for rapid estimation of single...
Authors
Sydney Dybing, William L. Yeck, Hank M. Cole, Diego Melgar
The 2022 Chaos Canyon landslide in Colorado: Insights revealed by seismic analysis, field investigations, and remote sensing
An unusual, high-alpine, rapid debris slide originating in ice-rich debris occurred on June 28, 2022, at 16:33:16 MDT at the head of Chaos Canyon, a formerly glacier-covered valley in Rocky Mountain National Park, CO, USA. In this study, we integrate eyewitness videos and seismic records of the event with meteorological data, field observations, pre- and post-event satellite imagery, and...
Authors
Kate E. Allstadt, Jeffrey A. Coe, Elaine Collins, Francis K. Rengers, Anne Mangeney, Scott M. Esser, Jana Pursley, William L. Yeck, John Bellini, Lance R. Brady
Rapid Source Characterization of the 2023 Mw 6.8 Al Haouz, Morocco, Earthquake
The U.S. Geological Survey (USGS) National Earthquake Information Center (NEIC) estimates source characteristics of significant damaging earthquakes, aiming to place events within their seismotectonic framework. Contextualizing the 8 September 2023, Mw 6.8 Al Haouz, Morocco, earthquake is challenging, because it occurred in an enigmatic region of active surface faulting, and low...
Authors
William L. Yeck, Alexandra Elise Hatem, Dara Elyse Goldberg, William D. Barnhart, Jessica Ann Thompson Jobe, David R. Shelly, Antonio H. Villaseñor, Harley M. Benz, Paul S. Earle
MLAAPDE: A machine learning dataset for determining global earthquake source parameters
The Machine Learning Asset Aggregation of the Preliminary Determination of Epicenters (MLAAPDE) dataset is a labeled waveform archive designed to enable rapid development of machine learning (ML) models used in seismic monitoring operations. MLAAPDE consists of more than 5.1 million recordings of 120 s long three‐component broadband waveform data (raw counts) for P, Pn, Pg, S, Sn, and Sg...
Authors
Hank M. Cole, William L. Yeck, Harley M. Benz
Inconsistent citation of the Global Seismographic Network in scientific publications
The highly used Global Seismographic Network (GSN) is a pillar of the seismological research community and contributes to numerous groundbreaking publications. Despite its wide recognition, this survey found that the GSN is not consistently acknowledged in scientific literature and is underrepresented by roughly a factor of 3 in citation searches. Publication tracking is a key metric...
Authors
Molly Staats, Kasey Aderhold, Katrin N. Hafner, Colleen Dalton, Megan Flanagan, Harriet Lau, Frederick Simons, Martin Vallée, Shawn Wei, William L. Yeck, Andy Frassetto, Robert Busby
Rapid characterization of the February 2023 Kahramanmaraş, Turkey, earthquake sequence
The 6 February 2023 Mw 7.8 Pazarcık and subsequent Mw 7.5 Elbistan earthquakes generated strong ground shaking that resulted in catastrophic human and economic loss across south‐central Türkiye and northwest Syria. The rapid characterization of the earthquakes, including their location, size, fault geometries, and slip kinematics, is critical to estimate the impact of significant seismic...
Authors
Dara Elyse Goldberg, Tuncay Taymaz, Nadine G. Reitman, Alexandra Elise Hatem, Seda Yolsal-Çevikbilen, William D. Barnhart, Tahir Serkan Irmak, David J. Wald, Taylan Öcalan, William L. Yeck, Berkan Özkan, Jessica Ann Thompson Jobe, David R. Shelly, Eric M. Thompson, Christopher DuRoss, Paul S. Earle, Richard W. Briggs, Harley M. Benz, Ceyhun Erman, Ali Hasan Doğan, Cemali Altuntaş
Dense geophysical observations reveal a triggered, concurrent multi-fault rupture at the Mendocino Triple Junction
A central question of earthquake science is how far ruptures can jump from one fault to another, because cascading ruptures can increase the shaking of a seismic event. Earthquake science relies on earthquake catalogs and therefore how complex ruptures get documented and cataloged has important implications. Recent investments in geophysical instrumentation allow us to resolve...
Authors
William L. Yeck, David R. Shelly, Dara Elyse Goldberg, Kathryn Zerbe Materna, Paul S. Earle
SYNthetic DEPTH Phase Modeling (SYNDEPTH)
This python code models event depths by comparing high-frequency (~0.5-0.04 Hz) teleseismic body-wave waveforms to synthetics. High-frequency body waves contain depth information, primarily in the form of depth phases. While lower frequencies are used to generate moment tensor solutions, high-frequency body waves allow for more accurate estimates of source depth. A moment tensor solution...
neic-machine-learning
NEIC Machine Learning Applications contains various seismic machine learning algorithms developed and used by by the United States Geological Survey, National Earthquake Information Center. These algorithms apply machine learning techniques to seismic processing problems such as seismic phase classification, source-receiver distance classification, and seismic wave arrival time repicking...
neic-glass3
neic-glass3 is an open source and platform independent seismic event detection and association algorithm developed by the United States Geological Survey (USGS) National Earthquake Information Center (NEIC) and Caryl Erin Johnson, PhD, Introspective Systems LLC. This algorithm converts a time series of seismic phase arrival times, back azimuth estimates from array beams, and cross...
Science and Products
Improving Earthquake Monitoring with Deep Learning
Release Date: MARCH 12, 2021 On January 20, 2021 at 8:32am light shaking interrupted breakfast customers at a local coffee shop south of downtown Los Angeles, California. Everyone paused briefly while they waited to see if it was going to stop… or start shaking harder.
Supporting Data and Models for An unexplained tsunami: Was there megathrust slip during the 2020 Mw7.6 Sand Point, Alaska, earthquake?
This data release contains several input data and inversion output files used to model the October 19, 2020, Mw7.6 Sand Point, Alaska, earthquake and tsunami. The broadband seismic data in this data release are from globally distributed seismometers from networks G (https://doi.org/10.18715/GEOSCOPE.G), GE (https://doi.org/10.14470/TR560404), GR (https://doi.org/10.25928/mbx6-hr74), GS...
Supporting Data and Models for Characterizing the February 2023 Kahramanmaraş, Türkiye, Earthquake Sequence
This data release pertains to the February 2023 Kahramanmaraş, Türkiye earthquake sequence and complements the following publication: Goldberg, D.E. et al. (2023) Rapid Characterization of the February 2023 Kahramanmaraş, Türkiye, Earthquake Sequence, The Seismic Record. (xx), 1, doi: 10.1785/0320230009. Child Items "2023-02-06 Mw7.8 Pazarcık Earthquake Finite Fault Data and Model" and...
Waveform Data and Metadata used to National Earthquake Information Center Deep-Learning Models
These data were used to train the Machine Learning models supporting the USGS software release "NEIC Machine Learning Applications Software" (https://doi.org/10.5066/P9ICQPUR), and its companion publication in Seismological Research Letters "Leveraging Deep Learning in Global 24/7 Real-Time Earthquake Monitoring at the National Earthquake Information Center" (https://doi.org/XXXXX)...
Spatiotemporal Analysis of the Foreshock-Mainshock-Aftershock Sequence of the 6 July 2017 M5.8 Lincoln, Montana, Earthquake - Data Release
We used matched filter detection and multiple-event relocation techniques to characterize the spatiotemporal evolution of the sequence. Our analysis is from the 14 closest seismic stations to the earthquake sequence, which included seven permanent stations from the Montana Regional Seismic Network, one permanent station from the ANSS backbone network and three temporary seismic stations...
Earthquake Catalogs supporting manuscript "Afterslip Enhanced Aftershock Activity During the 2017 Earthquake Sequence Near Sulphur Peak, Idaho"
This ScienceBase entry contains three seismic catalogs supporting and described by the manuscript - Koper, K. D., Pankow, K. L., Pechmann, J. C., Hale, J. M., Burlacu, R., Yeck, W. L., et al (2018). Afterslip Enhanced Aftershock Activity During the 2017 Earthquake Sequence Near Sulphur Peak, Idaho. Geophysical Research Letters, 45. https://doi.org/10.1029/2018GL078196. These are included...
A database of instrumentally recorded ground motion intensity measurements from induced earthquakes in Oklahoma and Kansas
The database contains uniformly processed ground motion intensity measurements (peak horizontal ground motions and 5-percent-damped pseudospectral accelerations for oscillator periods 0.110 s). The earthquake event set includes more than 3,800 M≥3 earthquakes in Oklahoma and Kansas from January 2009 to December 2016. Ground motion time series were collected out to 500 km. We also...
Aftershock Catalog for the November 2011 Prague, Oklahoma Earthquake Sequence
The dataset contains the catalog of 5446 events and arrival times resulting from subspace detection processing and relocation in the for the 2011 Prague, Oklahoma, aftershock sequence. Lines beginning with "E" contain event information in the following order: event ID, origin year, origin month, origin day, origin hour, origin minute, origin second, latitude, longitude, depth, and...
Filter Total Items: 36
An unexplained tsunami: Was there megathrust slip during the 2020 Mw7.6 Sand Point, Alaska, earthquake?
On October 19, 2020, the Mw7.6 Sand Point earthquake struck south of the Shumagin Islands in Alaska. Moment tensors indicate the earthquake was primarily strike-slip, yet the event produced an enigmatic tsunami that was larger and more widespread than expected for an earthquake of that magnitude and mechanism. Using a suite of hydrodynamic, seismic, and geodetic modeling techniques, we...
Authors
Sean R. Santellanes, Dara Elyse Goldberg, Pablo Koch, Diego Melgar, William L. Yeck, Brendan W. Crowell, Jiun-Ting Lin
Surface-wave relocation and characterization of the October 2023 tsunamigenic seismic unrest near Sofugan volcano, Izu Islands, Japan
A moderate-magnitude earthquake swarm occurred in the remote Izu Islands region of Japan between October 1 and 8, 2023. The swarm included 151 shallow earthquakes cataloged by the U.S. Geological Survey, which notably included a roughly 2.5-hr episode of 15 successive magnitude (M) 5.5 earthquakes. Origin times were coincident with regionally recorded tsunami waves, but tsunamigenesis...
Authors
Chanel Ashlie Deane, Jeremy Pesicek, Stephanie Prejean, Paul S. Earle, David R. Shelly, William L. Yeck
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
Noise constraints on global body‐wave measurement thresholds
Intermediate sized earthquakes (≈M4–6.5) are often measured using the teleseismic body‐wave magnitude (𝑚b). 𝑚b measurements are especially critical at the lower end of this range when teleseismic waveform modeling techniques (i.e., moment tensor analysis) are difficult. The U.S. Geological Survey National Earthquake Information Center (NEIC) determines the location and magnitude of all...
Authors
Adam T. Ringler, David C. Wilson, Paul S. Earle, William L. Yeck, David B. Mason, Justin Thomas Wilgus
Subduction intraslab-interface fault interactions in the 2022 Mw 6.4 Ferndale, California earthquake sequence
The Mendocino triple junction, the intersection of the Pacific, North American, and Gorda plates, activates a collection of disparate faults that reconcile Cascadia subduction with San Andreas transform motion. The December 20, 2022, Mw 6.4 Ferndale, California earthquake occurred within this complex zone as strike-slip faulting within the subducting Gorda slab. Here, we analyze the...
Authors
David R. Shelly, Dara Elyse Goldberg, Kathryn Zerbe Materna, Robert John Skoumal, Jeanne L. Hardebeck, Clara Yoon, William L. Yeck, Paul S. Earle
Rapid estimation of single-station earthquake magnitudes with machine learning on a global scale
The foundation of earthquake monitoring is the ability to rapidly detect, locate, and estimate the size of seismic sources. Earthquake magnitudes are particularly difficult to rapidly characterize because magnitude types are only applicable to specific magnitude ranges, and location errors propagate to substantial magnitude errors. We developed a method for rapid estimation of single...
Authors
Sydney Dybing, William L. Yeck, Hank M. Cole, Diego Melgar
The 2022 Chaos Canyon landslide in Colorado: Insights revealed by seismic analysis, field investigations, and remote sensing
An unusual, high-alpine, rapid debris slide originating in ice-rich debris occurred on June 28, 2022, at 16:33:16 MDT at the head of Chaos Canyon, a formerly glacier-covered valley in Rocky Mountain National Park, CO, USA. In this study, we integrate eyewitness videos and seismic records of the event with meteorological data, field observations, pre- and post-event satellite imagery, and...
Authors
Kate E. Allstadt, Jeffrey A. Coe, Elaine Collins, Francis K. Rengers, Anne Mangeney, Scott M. Esser, Jana Pursley, William L. Yeck, John Bellini, Lance R. Brady
Rapid Source Characterization of the 2023 Mw 6.8 Al Haouz, Morocco, Earthquake
The U.S. Geological Survey (USGS) National Earthquake Information Center (NEIC) estimates source characteristics of significant damaging earthquakes, aiming to place events within their seismotectonic framework. Contextualizing the 8 September 2023, Mw 6.8 Al Haouz, Morocco, earthquake is challenging, because it occurred in an enigmatic region of active surface faulting, and low...
Authors
William L. Yeck, Alexandra Elise Hatem, Dara Elyse Goldberg, William D. Barnhart, Jessica Ann Thompson Jobe, David R. Shelly, Antonio H. Villaseñor, Harley M. Benz, Paul S. Earle
MLAAPDE: A machine learning dataset for determining global earthquake source parameters
The Machine Learning Asset Aggregation of the Preliminary Determination of Epicenters (MLAAPDE) dataset is a labeled waveform archive designed to enable rapid development of machine learning (ML) models used in seismic monitoring operations. MLAAPDE consists of more than 5.1 million recordings of 120 s long three‐component broadband waveform data (raw counts) for P, Pn, Pg, S, Sn, and Sg...
Authors
Hank M. Cole, William L. Yeck, Harley M. Benz
Inconsistent citation of the Global Seismographic Network in scientific publications
The highly used Global Seismographic Network (GSN) is a pillar of the seismological research community and contributes to numerous groundbreaking publications. Despite its wide recognition, this survey found that the GSN is not consistently acknowledged in scientific literature and is underrepresented by roughly a factor of 3 in citation searches. Publication tracking is a key metric...
Authors
Molly Staats, Kasey Aderhold, Katrin N. Hafner, Colleen Dalton, Megan Flanagan, Harriet Lau, Frederick Simons, Martin Vallée, Shawn Wei, William L. Yeck, Andy Frassetto, Robert Busby
Rapid characterization of the February 2023 Kahramanmaraş, Turkey, earthquake sequence
The 6 February 2023 Mw 7.8 Pazarcık and subsequent Mw 7.5 Elbistan earthquakes generated strong ground shaking that resulted in catastrophic human and economic loss across south‐central Türkiye and northwest Syria. The rapid characterization of the earthquakes, including their location, size, fault geometries, and slip kinematics, is critical to estimate the impact of significant seismic...
Authors
Dara Elyse Goldberg, Tuncay Taymaz, Nadine G. Reitman, Alexandra Elise Hatem, Seda Yolsal-Çevikbilen, William D. Barnhart, Tahir Serkan Irmak, David J. Wald, Taylan Öcalan, William L. Yeck, Berkan Özkan, Jessica Ann Thompson Jobe, David R. Shelly, Eric M. Thompson, Christopher DuRoss, Paul S. Earle, Richard W. Briggs, Harley M. Benz, Ceyhun Erman, Ali Hasan Doğan, Cemali Altuntaş
Dense geophysical observations reveal a triggered, concurrent multi-fault rupture at the Mendocino Triple Junction
A central question of earthquake science is how far ruptures can jump from one fault to another, because cascading ruptures can increase the shaking of a seismic event. Earthquake science relies on earthquake catalogs and therefore how complex ruptures get documented and cataloged has important implications. Recent investments in geophysical instrumentation allow us to resolve...
Authors
William L. Yeck, David R. Shelly, Dara Elyse Goldberg, Kathryn Zerbe Materna, Paul S. Earle
SYNthetic DEPTH Phase Modeling (SYNDEPTH)
This python code models event depths by comparing high-frequency (~0.5-0.04 Hz) teleseismic body-wave waveforms to synthetics. High-frequency body waves contain depth information, primarily in the form of depth phases. While lower frequencies are used to generate moment tensor solutions, high-frequency body waves allow for more accurate estimates of source depth. A moment tensor solution...
neic-machine-learning
NEIC Machine Learning Applications contains various seismic machine learning algorithms developed and used by by the United States Geological Survey, National Earthquake Information Center. These algorithms apply machine learning techniques to seismic processing problems such as seismic phase classification, source-receiver distance classification, and seismic wave arrival time repicking...
neic-glass3
neic-glass3 is an open source and platform independent seismic event detection and association algorithm developed by the United States Geological Survey (USGS) National Earthquake Information Center (NEIC) and Caryl Erin Johnson, PhD, Introspective Systems LLC. This algorithm converts a time series of seismic phase arrival times, back azimuth estimates from array beams, and cross...