Publications
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Trimming the UCERF3-TD logic tree: Model order reduction for an earthquake rupture forecast considering loss exceedance Trimming the UCERF3-TD logic tree: Model order reduction for an earthquake rupture forecast considering loss exceedance
The Uniform California Earthquake Rupture Forecast version 3-Time Dependent depicts California’s seismic faults and their activity. Its logic tree has 5760 leaves. Considering 30 more model combinations related to ground motion produces 172,800 distinct models representing so-called epistemic uncertainties. To calculate risk to a portfolio of buildings, one also considers millions of...
Authors
Keith Porter, Kevin Milner, Ned Field
Intense alteration on early Mars revealed by high-aluminum rocks at Jezero Crater Intense alteration on early Mars revealed by high-aluminum rocks at Jezero Crater
The NASA Perseverance rover discovered light-toned float rocks scattered across the surface of Jezero crater that are particularly rich in alumina ( ~ 35 wt% Al2O3) and depleted in other major elements (except silica). These unique float rocks have heterogeneous mineralogy ranging from kaolinite/halloysite-bearing in hydrated samples, to spinel-bearing in dehydrated samples also...
Authors
C. Royer, C.C. Bedford, J.R. Johnson, B.H.N. Horgan, A. Broz, O. Forni, S. Connell, R.C. Wiens, L. Mandon, B.S. Kathir, E.M. Hausrath, A. Udry, J.M. Madariaga, E. Dehouck, Ryan Anderson, P.S.A. Beck, O. Beyssac, É. Clavé, S.M. Clegg, E. Cloutis, T. Fouchet, Travis Gabriel, B.J. Garczynski, A. Klidaras, H.T. Manelski, L.E. Mayhew, J. Nunez, A.M. Ollila, S.E. Schröder, J.I. Simon, U. Wolf, K.M. Stack, A. Cousin, S. Maurice
Imaging of seismic discontinuities using an adjoint method Imaging of seismic discontinuities using an adjoint method
For imaging of seismic discontinuities at depth, reverse time migration (RTM) is a powerful method to apply to recordings of seismic events. It is especially powerful when an extensive receiver array, numerous seismic sources, or both, permit adequate reconstruction of incident and scattered wavefields at depth. Reconstructing either the incident or scattered wavefield at depth becomes...
Authors
Frederick Pollitz, Leah Langer
Cave climate 100 meters below the surface in the pseudokarst of the Kilauea Southwest Rift Zone, Hawaii Cave climate 100 meters below the surface in the pseudokarst of the Kilauea Southwest Rift Zone, Hawaii
Kīlauea volcano hosts numerous pit craters that are inferred to have formed in competent bedrock (lava flows with minor tephra and other sediments), including Wood Valley Pit Crater. The Wood Valley Pit Crater is a 50-meter-deep, nearly circular pit that includes access to a cave entrance, which provides an opportunity to monitor cave climate throughout a cave that is ordinarily...
Authors
Timothy Titus, Glen Cushing, Chris Okubo, Kaj Williams
Afterslip and creep in the rate-dependent framework: Joint inversion of borehole strain and GNSS displacements for the Mw 7.1 Ridgecrest earthquake Afterslip and creep in the rate-dependent framework: Joint inversion of borehole strain and GNSS displacements for the Mw 7.1 Ridgecrest earthquake
The elusive transition toward afterslip following an earthquake is challenging to capture with typical data resolution limits. A dense geodetic network recorded the Mw 7.1 Ridgecrest earthquake, including 16 Global Navigation Satellite System (GNSS) stations and 3 borehole strainmeters (BSM). The sub-nanostrain precision and sub-second sampling rate of BSMs bridges a gap between...
Authors
Catherine Hannagan, Richard Bennett, Andrew Barbour, Amanda Hughes
Ice cave climate monitoring at Sunset Crater National Monument, Arizona Ice cave climate monitoring at Sunset Crater National Monument, Arizona
The purpose of this project was to monitor the cave climate of the Sunset Crater National Monument “Bonito Flow” Ice Cave. The main purpose of the climate monitoring was to determine if “Ice Cave” was still an ice cave, i.e., a cave that contains perennial ice. The data acquired from 2 March 2021 to 13 Dec. 2022 consisted of temperature, humidity, and pressure throughout the cave...
Authors
Timothy Titus, Kaj Williams, Glen Cushing, Amber Gullikson
Planetary caves from Mercury to Pluto? Planetary caves from Mercury to Pluto?
On Earth, caves are unique environments at the intersection of geology, climate, and biology. Given that the same terrestrial speleogenetic processes exist throughout the solar system, it would be surprising if caves beyond Earth did not exist. Thousands of potential cave entrances (or subsurface access points) have been identified from Earth’s Moon to Pluto’s moon, Charon. To date, our...
Authors
Timothy Titus, Janna Wynne, Michael Malaska, Penelope Boston
What do we know without the catalog? Eliciting prior beliefs from experts for aftershock models What do we know without the catalog? Eliciting prior beliefs from experts for aftershock models
Fitting parametric seismological models to earthquake catalogs often comes with numerical challenges, especially when catalogs are small. An alternative way to quantify parameter values for a seismic region is by eliciting expert opinions on the seismological characteristics that each parameter corresponds to. For instance, expert beliefs on aftershock patterns can be formulated into...
Authors
Max Schneider, Peter Guttorp
The solar cycle, geology, and geoelectric hazards for power grids The solar cycle, geology, and geoelectric hazards for power grids
When sunspots are large and numerous, intense magnetic storms are likely to occur on the Earth. Magnetic storms can generate electric fields in the Earth, and these fields can, in turn, interfere with electric power transmission grids that are grounded at the Earth’s surface. Across the contiguous United States, geoelectric hazards are highest in the Upper Midwest and in the East. These...
Authors
Jeffrey Love, Steven Sobieszczyk, E. Rigler, Anna Kelbert, Kristen Lewis
Evaluation of an open earthquake early warning system in Mexico, and laboratory tests of their sensors Evaluation of an open earthquake early warning system in Mexico, and laboratory tests of their sensors
Microelectromechanical system (MEMS) accelerometers are useful for seismological and engineering applications because of their ability to record unsaturated large seismic signals. Recent advances in MEMS technologies enable the design of instruments with improved capabilities that also allow the recording of small signals. As a result, MEMS can be useful across a broad dynamic range and...
Authors
Vaclav Kuna, Adam Ringler, Diego Melgar
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
Preliminary observations of the April 5th, 2024, Mw4.8 New Jersey earthquake Preliminary observations of the April 5th, 2024, Mw4.8 New Jersey earthquake
On 5 April 2024, 10:23 a.m. local time, a moment magnitude 4.8 earthquake struck Tewksbury Township, New Jersey, about 65 km west of New York City. Millions of people from Virginia to Maine and beyond felt the ground shaking, resulting in the largest number (>180,000) of U.S. Geological Survey (USGS) “Did You Feel It?” reports of any earthquake. A team deployed by the Geotechnical...
Authors
Oliver Boyd, William Barnhart, James Bourke, Martin Chapman, Paul Earle, Guo-chin Huang, Jessica Jobe, Won-Young Kim, Frederick Link, Mairi Litherland, Andrew Lloyd, Maureen Long, Sara K. McBride, Andrew Michael, Walter Mooney, Gregory Moutain, Sissy Nikolaou, Alexandros Savvaidas, Felix Waldhauser, Cecily Wolfe, Clara Yoon