Publications
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S/P amplitude ratios derived from single-component seismograms and their potential use in constraining focal mechanisms for micro-earthquake sequences S/P amplitude ratios derived from single-component seismograms and their potential use in constraining focal mechanisms for micro-earthquake sequences
Focal mechanisms, which reflect the sense of slip in earthquakes, provide important constraints for understanding crustal tectonics and earthquake source physics, including the interactions among earthquakes during mainshock–aftershock sequences or seismic swarms. Focal mechanisms of small (magnitude ≲3.5) earthquakes are usually determined by first‐motion P‐wave polarities, sometimes...
Authors
David R. Shelly, Robert John Skoumal, Jeanne L. Hardebeck
Atmospheric waves and global seismoacoustic observations of the January 2022 Hunga eruption, Tonga Atmospheric waves and global seismoacoustic observations of the January 2022 Hunga eruption, Tonga
The 15 January 2022 climactic eruption of Hunga volcano, Tonga, produced an explosion in the atmosphere of a size that has not been documented in the modern geophysical record. The event generated a broad range of atmospheric waves observed globally by various ground-based and spaceborne instrumentation networks. Most prominent was the surface-guided Lamb wave (≲0.01 hertz), which we...
Authors
Robin S. Matoza, David Fee, Jelle D. Assink, Alexandra M. Iezzi, David N. Green, Keehoon Kim, Liam Toney, Thomas Lecocq, Siddharth Krishnamoorthy, Jean-Marie Lalande, Kiwamu Nishida, Kent L. Gee, Matthew M. Haney, Hugo D. Ortiz, Quentin Brissaud, Leo Martire, Lucie Rolland, Panagiotis Vergados, Alexandra Nippress, Junghyun Park, Shahar Shani-Kadmiel, Alex Witsil, Stephen Arrowsmith, Corentin Caudron, Shingo Watada, Anna Perttu, Benoit Taisne, Pierrick Mialle, Alexis Le Pichon, Julien Vergoz, Patrick Hupe, Philip S. Blom, Roger M. Waxler, Silvio De Angelis, Jonathan Snively, Adam T. Ringler, Robert Anthony, A.D. Jolly, Geoff Kilgour, Gil Averbuch, Maurizio Ripepe, Mie Ichihara, Alejandra Arciniega-Ceballos, Elvira Astafyeva, Lars Ceranna, Sandrine Cevuard, Il-Young Che, Rodrigo de Negri Leiva, Carl W. Ebeling, Laslo G. Evers, Luis E. Franco-Marin, Tom Gabrielson, Katrin Hafner, R. Giles Harrison, Attila Komjathy, Giorgio Lacanna, John J. Lyons, Kenneth A. Macpherson, Emanuele Marchetti, Kathleen McKee, Rob Mellors, Gerardo Mendo-Perez, T. Dylan Mikesell, Edhah Munaibari, Mayra Oyola-Merced, Iseul Park, Christoph Pilger, Cristina Ramos, Mario Ruiz, Roberto Sabatini, Hans Schwaiger, Dorianne Tailpied, Carrick Talmadge, Jerome Vidot, Jeremy Webster, David C. Wilson
A progressive flow-routing model for rapid assessment of debris-flow inundation A progressive flow-routing model for rapid assessment of debris-flow inundation
Debris flows pose a significant hazard to communities in mountainous areas, and there is a continued need for methods to delineate hazard zones associated with debris-flow inundation. In certain situations, such as scenarios following wildfire, where there could be an abrupt increase in the likelihood and size of debris flows that necessitates a rapid hazard assessment, the computational...
Authors
Alexander Gorr, Luke A. McGuire, Ann Youberg, Francis K. Rengers
Classifying Worldwide Standardized Seismograph Network records using a simple convolution neural network Classifying Worldwide Standardized Seismograph Network records using a simple convolution neural network
The U.S. Geological Survey (USGS) maintains an archive of 189,180 digitized scans of analog seismic records from the World‐Wide Standardized Seismograph Network (WWSSN). Although these scans have been made public, the archive is too large to manually review, and few researchers have utilized large numbers of these records. To facilitate further research using this historical dataset, we...
Authors
Nagle Nagle-McNaughton, Adam T. Ringler, Robert Anthony, Alexis Casondra Bianca Alejandro, David C. Wilson, Justin Thomas Wilgus
Microtremor array method using spatial autocorrelation analysis of Rayleigh‑wave data Microtremor array method using spatial autocorrelation analysis of Rayleigh‑wave data
Microtremor array measurements (MAM) and passive surface wave methods in general, have been increasingly used to non-invasively estimate shear-wave velocity structures (Vs) for various purposes. The methods estimate dispersion curves and invert them for retrieving S-wave velocity profiles. This paper summarizes principles, limitations, data collection and processing methods. It intends...
Authors
Koichi Hayashi, Michael W. Asten, William J. Stephenson, Cecile Cornou, Manuel Hobiger, Marco Pilz, Hiroaki Yamanaka
2022 Crustal Deformation Modeling Workshop Report 2022 Crustal Deformation Modeling Workshop Report
The 2022 Crustal Deformation Modeling Workshop was held June 20–24 at the Colorado School of Mines in Golden, Colorado. The workshop included two days of tutorials on the use of the open-source software PyLith for crustal deformation modeling followed by three days of science talks and discussions. The workshop focused on three primary themes: (1) Earthquake cycle modeling; (2)...
Authors
Brad T. Aagaard, Sylvain Barbot, Brittany Erickson, Matthew Knepley, Mark Simons, Charles Williams
Improving the Development Pipelines for USGS Earthquake Hazards Program Real-Time and Scenario Products Improving the Development Pipelines for USGS Earthquake Hazards Program Real-Time and Scenario Products
The real-time and scenario products of the U.S. Geological Survey (USGS) Earthquake Hazards Program, such as the ComCat catalog, Did You Feel It?, ShakeMap, ShakeCast, and PAGER, are highly visible and used by a wide variety of stakeholders. We propose two significant enhancements to the development pipelines for the Earthquake Hazards Program real-time and scenario products that have...
Authors
Brad T. Aagaard, David J. Wald, Eric M. Thompson, Mike Hearne, Lisa Sue Schleicher
Improved resolution across the Global Seismographic Network: A new era in low-frequency seismology Improved resolution across the Global Seismographic Network: A new era in low-frequency seismology
The Global Seismographic Network (GSN)—a global network of ≈150 very broadband stations—is used by researchers to study the free oscillations of the Earth (≈0.3–10 mHz) following large earthquakes. Normal‐mode observations can provide information about the radial density and anisotropic velocity structure of the Earth (including near the core–mantle boundary), but only when signal‐to...
Authors
Adam T. Ringler, Robert Anthony, P. Thompson Davis, Carl Ebeling, K. Hafner, R. Mellors, S. Schneider, David C. Wilson
A geomorphic-process-based cellular automata model of colluvial wedge morphology and stratigraphy A geomorphic-process-based cellular automata model of colluvial wedge morphology and stratigraphy
The development of colluvial wedges at the base of fault scarps following normal-faulting earthquakes serves as a sedimentary record of paleoearthquakes and is thus crucial in assessing seismic hazard. Although there is a large body of observations of colluvial wedge development, connecting this knowledge to the physics of sediment transport can open new frontiers in our understanding...
Authors
Harrison J. Gray, Christopher B. DuRoss, Sylvia Nicovich, Ryan D. Gold
MTH5: An archive and exchangeable data format for magnetotelluric time series data MTH5: An archive and exchangeable data format for magnetotelluric time series data
Magnetotellurics (MT) is a passive electromagnetic geophysical method that measures variations in subsurface electrical resistivity. MT data are collected in the time domain and processed in the frequency domain to produce estimates of a transfer function representing the Earth’s electrical structure. Unfortunately, the MT community lacks metadata and data standards for time series data...
Authors
Jared R. Peacock, Karl Kappler, Lindsey Heagy, Timothy Ronan, Anna Kelbert, Andrew Frassetto
Updates to and applications of the USGS National Crustal Model for seismic hazard studies Updates to and applications of the USGS National Crustal Model for seismic hazard studies
The U.S. Geological Survey (USGS) National Crustal Model (NCM) is being developed to assist in the modeling of seismic hazards across the conterminous United States. The NCM is composed of a grid of geophysical profiles, extending from the Earth’s surface into the upper mantle. It is constructed from a 3D geologic framework and geophysical rules defined by: (1) a petrologic and mineral...
Authors
Oliver S. Boyd
Synthesizing ground magnetic disturbance using dipole-aligned loop elementary currents and Biot-Savart relationship Synthesizing ground magnetic disturbance using dipole-aligned loop elementary currents and Biot-Savart relationship
This report presents a method for constructing a simplified numerical description of the electric current distributions in the ionosphere and gap region based on dipole-aligned loop elementary currents (DALECs). A theoretical basis for DALECs is presented, along with a prototypical algorithm for constructing an elementary numerical DALEC. The algorithm is verified and validated by...
Authors
E. Joshua Rigler, Michael Wiltberger