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Bedrock geochemistry and alteration history of the clay-bearing Glen Torridon region of Gale crater, Mars

Glen Torridon is a topographic trough located on the slope of Aeolis Mons, Gale crater, Mars. It corresponds to what was previously referred to as the “clay-bearing unit”, due to the relatively strong spectral signatures of clay minerals (mainly ferric smectites) detected from orbit. Starting in January 2019, the Curiosity rover explored Glen Torridon for more than 700 sols (Martian days). The obj
Authors
Erwin Dehouck, Agnes Cousin, Nicolas Mangold, Jens Frydenvang, Olivier Gasnault, Olivier Forni, William Rapin, Patrick J. Gasda, Gwenael Caravaca, Gael David, Candice C. Bedford, Jeremie Lasue, Pierre-Yves Meslin, Kristin Rammelkamp, Marine Desjardins, Stephane Le Mouelic, Michael T. Thorpe, Valerie K. Fox, Kristen A. Bennett, Alexander Bryk, Nina L. Lanza, Sylvestre Maurice, Roger C. Wiens

An efficient, analytic solution using order statistics for probabilistic seismic‐hazard assessment without the Poisson assumption

Standard approaches to probabilistic seismic‐hazard assessment (PSHA) assume that earthquakes are random, independent events that follow a Poisson distribution of occurrences in a given time period (Cornell, 1968). To overcome the limitations of the Poisson assumption, such as ignoring earthquake clustering, we introduce an analytic method for PSHA that uses order statistics to allow for arbitrary
Authors
Andrew J. Michael, Andrea L. Llenos

Global and regional sea level rise scenarios for the United States

This report and accompanying datasets from the U.S. Sea Level Rise and Coastal Flood Hazard Scenarios and Tools Interagency Task Force provide 1) sea level rise scenarios to 2150 by decade that include estimates of vertical land motion and 2) a set of extreme water level probabilities for various heights along the U.S. coastline. These data are available at 1-degree grids along the U.S. coastline
Authors
William Sweet, Ben Hamlington, Robert E. Kopp, Christopher Weaver, Patrick L. Barnard, David Bekaert, William Brooks, Michael Craghan, Gregory Dusek, Thomas Frederikse, Gregory Garner, Ayesha S. Genz, John P. Krasting, Eric Larour, Doug Marcy, John J. Marra, Jayantha Obeysekera, Mark Osler, Matthew Pendleton, Daniel Roman, Lauren Schmied, Will Veatch, Kathleen D. White, Casey Zuzak

Quantifying the sensitivity of microearthquake slip inversions to station distribution using a dense nodal array

To investigate the sensitivity of slip inversions to station distribution and choice of empirical Green’s function (EGF), we examine three microearthquakes that occurred within the high‐density LArge‐n Seismic Survey in Oklahoma (LASSO) nodal seismic array. The LASSO array’s dense distribution of 1825 geophones provides an exceptional level of spatial and azimuthal coverage, allowing for more accu
Authors
Colin Nathanael Pennington, Hilary Chang, Justin Rubinstein, Rachel E Abercrombie, Nori Nakata, Takahiko Uchide, Elizabeth S. Cochran

A unified perspective of seismicity and fault coupling along the San Andreas Fault

The San Andreas Fault (SAF) showcases the breadth of possible earthquake sizes and occurrence behavior; in particular, the central SAF is a microcosm of such diversity. This section also exhibits the spectrum of fault coupling from locked to creeping. Here, we show that the observations of aseismic slip, temporal clustering of seismicity, and spatial variations in earthquake size distributions are
Authors
Y.-K. Liu, Z. Ross, Elizabeth S. Cochran, N. Lapusta

Validating predicted site response in sedimentary basins from 3D ground motion simulations

We introduce procedures to validate site response in sedimentary basins as predicted using ground motion simulations. These procedures aim to isolate contributions of site response to computed intensity measures relative to those from seismic source and path effects. In one of the validation procedures, simulated motions are analyzed in the same manner as earthquake recordings to derive non-ergodi
Authors
Chukwuebuka C Nweke, Jonathan P. Stewart, Robert Graves, Christine A. Goulet, Scott J Brandenberg

The Lunar Geophysical Network landing site science rationale

The Lunar Geophysical Network (LGN) mission is proposed to land on the Moon in 2030 and deploy packages at four locations to enable geophysical measurements for 6–10 yr. Returning to the lunar surface with a long-lived geophysical network is a key next step to advance lunar and planetary science. LGN will greatly expand our primarily Apollo-based knowledge of the deep lunar interior by identifying
Authors
Heidi Haviland, Renee C. Weber, Clive Neal, Philippe Lognonné, Raphael Garcia, Nicholas Schmerr, Seiichi Nagihara, Robert Grimm, Douglas Currie, Simone Dell'Agnello, Thomas R. Watters, Mark Panning, Catherine L. Johnson, Ryuhei Yamada, Martin Knapmeyer, Lillian R. Ostrach, Taichi Kawamura, Noah Petro, Paul Bremner

Partitioning ground motion uncertainty when conditioned on station data

Rapid estimation of earthquake ground shaking and proper accounting of associated uncertainties in such estimates when conditioned on strong‐motion station data or macroseismic intensity observations are crucial for downstream applications such as ground failure and loss estimation. The U.S. Geological Survey ShakeMap system is called upon to fulfill this objective in light of increased near‐real‐
Authors
Davis T. Engler, Charles Worden, Eric M. Thompson, Kishor S. Jaiswal

How similar was the 1983 Mw 6.9 Borah Peak earthquake rupture to its surface-faulting predecessors along the northern Lost River fault zone (Idaho, USA)?

We excavated trenches at two paleoseismic sites bounding a trans-basin bedrock ridge (the Willow Creek Hills) along the northern Lost River fault zone to explore the uniqueness of the 1983 Mw 6.9 Borah Peak earthquake compared to its prehistoric predecessors. At the Sheep Creek site on the southernmost Warm Springs section, two earthquakes occurred at 9.8−14.0 ka (95% confidence) and 6.5−7.1 ka; e
Authors
Christopher DuRoss, Richard W. Briggs, Ryan D. Gold, Alexandra Elise Hatem, Austin John Elliott, Jaime Delano, Ivan Medina-Cascales, Harrison J. Gray, Shannon A. Mahan, Sylvia Nicovich, Zachery Lifton, Emily J. Kleber, Greg N. McDonald, Adam Hiscock, Mike Bunds, Nadine G. Reitman

Three Mw ≥ 4.7 earthquakes within the Changning (China) shale gas field ruptured shallow faults intersecting with hydraulic fracturing wells

From 2017 to 2019, three destructive earthquakes (27 January 2017 Mw 4.7, 16 December 2018 Mw 5.2, and 3 January 2019 Mw 4.8) occurred in the Changning shale gas field in the southwest Sichuan Basin, China. Previous seismological studies attributed these events to hydraulic fracturing (HF), but were unable to identify the causative seismogenic faults and their slip behaviors. Here, we use Sentinel
Authors
Shuai Wang, Guoyan Jiang, Xinglin Lei, Andrew Barbour, Xibin Tan, Caijun Xu, Xiwei Xu

Fast rupture of the 2009 Mw 6.9 Canal de Ballenas earthquake in the Gulf of California dynamically triggers seismicity in California

In the Gulf of California, Mexico, the relative motion across the North America-Pacific boundary is accommodated by a series of marine transform faults and spreading centers. About 40 M>6 earthquakes have occurred in the region since 1960. On 3 August 2009, an Mw 6.9 earthquake occurred near Canal de Ballenas in the region. The earthquake was a strike-slip event with a shallow hypocenter that is l
Authors
Wenyuan Fan, Ryo Okuwaki, Andrew Barbour, Yihe Huang, Guoqing Lin, Elizabeth S. Cochran

Observation-constrained multicycle dynamic models of the southern San Andreas and the northern San Jacinto Faults: Addressing complexity in paleoearthquake extent and recurrence with realistic 2D fault geometry

Understanding mechanical conditions that lead to complexity in earthquakes is important to seismic hazard analysis. In this study, we simulate physics-based multicycle dynamic models of the San Andreas fault (Carrizo through San Bernardino sections) and the San Jacinto fault (Claremont and Clark strands). We focus on a complex fault geometry based on the Southern California Earthquake Center Commu
Authors
Dunyu Liu, Benchuan Duan, Katherine Scharer, Doug Yule