Publications
Filter Total Items: 2009
Migration of seismicity from the mantle to the upper crust beneath Harrat Lunayyir volcanic field, Saudi Arabia
Harrat Lunayyir is a volcanic field in Saudi Arabia that experienced a Mw~5.4 earthquake driven by an upper-crustal dike intrusion in May 2009. This volcanic field has exhibited numerous forms of volcanic seismicity both prior to and since the 2009 dike intrusion. Significantly, earthquakes within the lithospheric mantle and, rarely, the lower crust are present in the two-decade long...
Authors
Alexander R. Blanchette, Simon L. Klemperer, Walter D. Mooney, Turki A. Sehli
Implications of physics-based M9 ground motions on liquefaction-induced damage in the Cascadia Subduction Zone: Looking forward and backward
Given the likelihood of future M9 Cascadia Subduction Zone (CSZ) earthquakes, various estimates of the resulting, regional ground motions have been made, including a suite of 30 physics-based simulations that reflect key modeling uncertainties. However, because the last CSZ interface rupture occurred in 1700 CE, the shaking expected in such an event is especially uncertain, as are the...
Authors
Ryan A. Rasanen, Alex R.R. Grant, Andrew James Makdisi, Brett W. Maurer, Erin Wirth
Macroseismology
In this chapter I discuss the use of so-called macroseismic data, i.e., reports of damage and other effects of shaking on humans and the built environment, to improve the characterization of earthquakes and the ground motions they produce. Macroseismic data are critical not only to investigate earthquakes that occurred before the start of the instrumental era in seismology, but are also...
Authors
Susan E. Hough
Paleoseismology and paleogeodesy using coral microatolls
Establishing the rupture extent and slip distribution of individual paleo-earthquakes is vital for assessing fault behavior including the persistence of rupture segmentation, recurrence patterns, and similarity of successive events, key issues in both fault mechanics and hazard assessment. Techniques with high temporal and geodetic precision as well as a wide distribution of study sites...
Authors
Belle E. Philibosian
Remote single-station seismic monitoring of the July–October 2022 earthquake swarm at Tau volcano, American Samoa
From July to October 2022, a non-eruptive volcanic earthquake swarm occurred within ~15 km of Taʻū Island, located in eastern American Samoa. Felt reports from local residents were the only available information about the swarm when it started, as American Samoa lacked a seismic monitoring network. We developed a consistent single-station catalog for the entire swarm, using seismic data...
Authors
Clara Yoon, Robert Skoumal, Andrew J. Michael, Arthur D. Jolly, Andria P. Ellis, Drew T. Downs, Peter Dotray, Natalia I. Deligne, Jefferson Chang, Ninfa Lucia Bennington, Aaron Wech, Matthew M. Haney, Alicia J. Hotovec-Ellis, Elinor Lutu-McMoore, Marcus Langkilde
A high-resolution 3-D P-wave velocity structure of the south-central Cascadia subduction zone from wide-angle shore-crossing seismic refraction data
This study addresses a significant gap in understanding the features of the south-central Cascadia subduction zone, a region characterized by complex geologic, tectonic, and seismic transitions both offshore and onshore. Unlike other segments along this margin, this area lacks a 3-D velocity model to delineate its structural and geological features on a fine scale. To address this void...
Authors
Asif Ashraf, Emilie Hooft, Douglas Toomey, Anne Trehu, Sarah Nolan, Erin Wirth, Kevin M. Ward
Examining the role of elevated and sustained strain in dynamically triggering earthquakes on the Anza section of the San Jacinto fault
Microearthquakes can be dynamically triggered in southern California by remote earthquakes. However, directly connecting dynamic triggering mechanisms with observational data remains challenging. One proposed failure mechanism suggests that both the amplitude and duration of cyclic fatigue caused by the passing seismic wave contribute to triggering occurrence. Here, we measure dynamic...
Authors
Nicolas DeSalvio, Andrew Barbour, Wenyuan Fan
Long-term trends in microseismicity during operational shut-ins at the Coso Geothermal Field, California
Pausing injection and production can lead to induced seismicity in a variety of settings, with some of the largest events occurring during these so-called shut-ins. In geothermal fields, shut-ins are periodically conducted for maintenance on wells and surface infrastructure, thereby offering recurring means of estimating stress changes in the subsurface that lead to increased seismicity...
Authors
Joanna Holmgren, J. Ole Kaven, Volker Oye
ShakeAlert® version 3: Expected performance in large earthquakes
The ShakeAlert earthquake early warning (EEW) system partners along with U.S. Geological Survey (USGS) licensed operators deliver EEW alerts to the public and trigger automated systems when a significant earthquake is expected to impact California, Oregon, or Washington. ShakeAlert’s primary goal is to provide usable warning times before the arrival of damaging shaking. EEW is most...
Authors
Jeffrey J. McGuire, Carl W. Ulberg, Angela I. Lux, Maren Bose, J.R. Andrews, Deborah Smith, B. Crowell, Jessica R. Murray, I. Henson, R. Hartog, C. Felizardo, Minh Huynh, M. Aranha, Grace Alexandra Parker, Annemarie S. Baltay Sundstrom, Mark Hunter Murray, Glenn Biasi, Stephen Guiwits, J.K. Saunders, Andrew D. Good, V. Marcelo Santillan, C.W. Scrivener, Walter M. Szeliga, Timothy I. Melbourne, Victor Kress, Robert M. de Groot, Sara McBride, Douglas D. Given, Richard Allen, Thomas H. Heaton, Allen L. Husker, Valerie I. Thomas, Harold Tobin, Sumant Jha, Julian Bunn
Mapping bedrock outcrops in the Sierra Nevada Mountains (California, USA) using machine learning
Accurate, high-resolution maps of bedrock outcrops can be valuable for applications such as models of land–atmosphere interactions, mineral assessments, ecosystem mapping, and hazard mapping. The increasing availability of high-resolution imagery can be coupled with machine learning techniques to improve regional bedrock outcrop maps. In the United States, the existing 30 m U.S...
Authors
Apoorva Ramesh Shastry, Corina Cerovski-Darriau, Brian Coltin, Jonathan D. Stock
3D viscoelastic models of slip-deficit rate along the Cascadia subduction zone
Interseismic deformation in the Pacific Northwest is constrained by the horizontal crustal velocity field derived from the Global Positioning System (GPS) in addition to vertical rates derived from GPS, leveling, and tide gauge measurements. Such measurements were folded in to deformation models of fault slip rates as part of the 2023 National Seismic Hazard Model (NSHM) update. Here I...
Authors
Frederick Pollitz
Haunted Summerville: Ghostly lights or earthquake lights?
Among the colorful local lore in the Charleston, South Carolina, area, are a number of ghost stories, shared not only over campfires but also in published books. Among the most well-known of the stories is the tale of the Summerville Light. Local lore holds that a strange light sometimes seen in a remote area is a lantern carried by the ghost of a local woman who once waited hours for...
Authors
Susan E. Hough