Publications
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Viscoelastic fault-based model of crustal deformation for the 2023 update to the U.S. National Seismic Hazard Model Viscoelastic fault-based model of crustal deformation for the 2023 update to the U.S. National Seismic Hazard Model
The 2023 update to the National Seismic Hazard (NSHM) model is informed by several deformation models that furnish geodetically estimated fault slip rates. Here I describe a fault‐based model that permits estimation of long‐term slip rates on discrete faults and the distribution of off‐fault moment release. It is based on quantification of the earthquake cycle on a viscoelastic model of...
Authors
Frederick Pollitz
Sedimentary organics in Glen Torridon, Gale Crater, Mars: Results from the SAM instrument suite and supporting laboratory analyses Sedimentary organics in Glen Torridon, Gale Crater, Mars: Results from the SAM instrument suite and supporting laboratory analyses
The Sample Analysis at Mars (SAM) suite instrument on board NASA's Curiosity rover has characterized the inorganic and organic chemical composition of seven samples from the Glen Torridon (GT) clay-bearing unit. A variety of organic molecules were detected with SAM using pyrolysis (up to ∼850°C) and wet chemistry experiments coupled with evolved gas analysis (EGA) and gas chromatography...
Authors
Maeva Millan, Amy Williams, Amy McAdam, Jennifer Eigenbrode, A. Steele, C Freissinet, D. P. Glavin, C. Szopa, A. Buch, Roger E. Summons, J. M. T. Lewis, G. M. Wong, C. H. House, B. Sutter, O. McIntosh, A. B. Bryk, H. B. Franz, C. Pozarycki, J. C. Stern, R. Navarro-Gonzalez, R. H. Williams, D. P. Archer, V. Fox, Kristen A. Bennett, S. Teinturier, C. Malespin, S. S. Johnson, P. R. Mahaffy
Geology and stratigraphic correlation of the Murray and Carolyn Shoemaker formations across the Glen Torridon region, Gale crater, Mars Geology and stratigraphic correlation of the Murray and Carolyn Shoemaker formations across the Glen Torridon region, Gale crater, Mars
The Glen Torridon (GT) region within Gale crater, Mars, occurs in contact with the southern side of Vera Rubin ridge (VRR), a well-defined geomorphic feature that is comparatively resistant to erosion. Prior to detailed ground-based investigation of GT, its geologic relationship with VRR was unknown. Distinct lithologic subunits within the Jura member (Murray formation), which forms the...
Authors
Christopher M. Fedo, Alexander Bryk, Lauren A. Edgar, Kristen A. Bennett, Valerie K. Fox, William E. Dietrich, Steve G. Banham, Sanjeev Gupta, Kathryn M. Stack, Rebecca Williams, John P. Grotzinger, Nathan Stein, Dave Rubin, Gwenael Caravaca, Ray E. Arvidson, Madison N Hughes, Abigail A. Fraeman, Ashwin R. Vasavada, Juergen Schieber, Brad Sutter
Earthquakes in the shadows: Why aftershocks occur at surprising locations Earthquakes in the shadows: Why aftershocks occur at surprising locations
For decades there has been a debate about the relative effects of dynamic versus static stress triggering of aftershocks. According to the static Coulomb stress change hypothesis, aftershocks should not occur in stress shadows—regions where static Coulomb stress has been reduced. We show that static stress shadows substantially influence aftershock occurrence following three M ≥ 7...
Authors
Jeanne L. Hardebeck, Ruth A. Harris
Using machine learning techniques with incomplete polarity datasets to improve earthquake focal mechanism determination Using machine learning techniques with incomplete polarity datasets to improve earthquake focal mechanism determination
Earthquake focal mechanisms are traditionally produced using P‐wave first‐motion polarities and commonly require well‐recorded seismicity. A recent approach that is less dependent on high signal‐to‐noise exploits similar waveforms to produce relative polarity measurements between earthquake pairs. Utilizing these relative polarity measurements, it is possible to produce composite focal...
Authors
Robert Skoumal, David R. Shelly, Jeanne L. Hardebeck
A late Cenozoic kinematic model for fault motion within greater Cascadia A late Cenozoic kinematic model for fault motion within greater Cascadia
Widely accepted tectonic reconstructions indicate at least 100 km of coast-parallel northwestward translation of the Sierra Nevada block of California and 15–20° clockwise rotation of most of Oregon since the current phase of Basin and Range extension began ∼17 Ma. These reconstructions require at least 100 km of convergence between the central Coast Range of Oregon and rigid North...
Authors
Douglas S. Wilson, Patricia A. McCrory
Comparing root cohesion estimates from three models at a shallow landslide in the Oregon Coast Range Comparing root cohesion estimates from three models at a shallow landslide in the Oregon Coast Range
Although accurate root cohesion model estimates are essential to quantify the effect of vegetation roots on shallow slope stability, few means exist to independently validate such model outputs. One validation approach for cohesion estimates is back-calculation of apparent root cohesion at a landslide site with well-documented failure conditions. The catchment named CB1, near Coos Bay...
Authors
Collin Cronkite-Ratcliff, Kevin M. Schmidt, Charlotte Wirion
Spaceborne InSAR mapping of landslides and subsidence in rapidly deglaciating terrain, Glacier Bay National Park and Preserve and vicinity, Alaska and British Columbia Spaceborne InSAR mapping of landslides and subsidence in rapidly deglaciating terrain, Glacier Bay National Park and Preserve and vicinity, Alaska and British Columbia
The Glacier Bay area in southeastern Alaska and British Columbia, encompassing Glacier Bay National Park and Preserve, has experienced rapid glacier retreat since the end of the Little Ice Age in the mid-1800s. The impact that rapid deglaciation has had on the slope stability of valley walls and on the sedimentation of fans and deltas adjacent to fjords and inlets is an ongoing research...
Authors
Jinwook Kim, Jeffrey A. Coe, Zhong Lu, Nikita N. Avdievitch, Chad Hults
Impact of sedimentary basins on Green’s functions for static slip inversion Impact of sedimentary basins on Green’s functions for static slip inversion
Earthquakes often occur in regions with complex material structure, such as sedimentary basins or mantle wedges. However, the majority of co-seismic modelling studies assume a simplified, often homogeneous elastic structure in order to expedite the process of model construction and speed up calculations. These co-seismic forward models are used to produce Green’s functions for finite...
Authors
Leah Langer, Stephen Beller, Evan Tyler Hirakawa, Jeroen Tromp
Geoelectric constraints on the Precambrian assembly and architecture of southern Laurentia Geoelectric constraints on the Precambrian assembly and architecture of southern Laurentia
Using images from an updated and expanded three-dimensional electrical conductivity synthesis model for the contiguous United States (CONUS), we highlight the key continent-scale geoelectric structures that are associated with the Precambrian assembly of southern Laurentia. Conductivity anomalies are associated with the Trans-Hudson orogen, the Penokean suture, the ca. 1.8–1.7 Ga...
Authors
Benjamin Scott Murphy, Paul A. Bedrosian, Anna Kelbert
Development of a companion questionnaire for “Did You Feel It?”: Assessing response in earthquakes where an earthquake early warning may have been received Development of a companion questionnaire for “Did You Feel It?”: Assessing response in earthquakes where an earthquake early warning may have been received
Earthquake early warning (EEW) systems are relatively new technologies having first emerged as regional systems in the 1990s. Japan was the first nation to develop and implement a nationwide system in October 2007, and in the United States, ShakeAlert® became available on the entire length of the US West Coast in May 2021. Assessing how EEW is perceived and utilized by alert recipients...
Authors
James D. Goltz, David J. Wald, Sara K. McBride, Robert Michael deGroot, Jolie Breeden, Ann Bostrom
Aqueously altered igneous rocks sampled on the floor of Jezero crater, Mars Aqueously altered igneous rocks sampled on the floor of Jezero crater, Mars
The Perseverance rover landed in Jezero crater, Mars, to investigate ancient lake and river deposits. We report observations of the crater floor, below the crater’s sedimentary delta, finding the floor consists of igneous rocks altered by water. The lowest exposed unit, informally named Séítah, is a coarsely crystalline olivine-rich rock, which accumulated at the base of a magma body. Fe...
Authors
K.A. Farley, K.M. Stack, D.L. Shuster, B.H.N. Horgan, J.A. Hurowitz, J. D. Tarnas, J.I. Simon, V.Z. Sun, E.L. Scheller, K.R. Moore, S.M. McLennan, P.M. Vasconcelos, R. C. Wiens, A.H. Treiman, L.E. Mayhew, O. Beyssac, T.V. Kizovski, N. J. Tosca, K.H. Williford, L.S. Crumpler, L.W. Beegle, J.F. Bell III, B.L. Ehlmann, Y. Liu, J.N. Maki, M. E. Schmidt, A.C. Allwood, H.E.F. Amundsen, R. Ghartia, T. Bosak, A.J. Brown, B. C. Clark, A. Cousin, O. Forni, Travis S.J. Gabriel, Y. Goreva, S. Gupta, S.-E. Hamran, C.D.K. Herd, K. Hickman-Lewis, J.R. Johnson, L.C. Kah, P. B. Kelemen, K.B. Kinch, L. Mandon, N. Mangold, C. Quantun-Nataf, M.S. Rice, P.S. Russell, S. Sharma, S. Siljestroem, A. Steele, R. Sullivan, M. Wadhwa, B. P. Weiss, A.J. Williams, B.V. Wogsland, P.A. Willis, T.A. Acosta-Maeda, B. Peck, K. Benzerara, S. Bernard, A.S. Burton, E. L. Cardarelli, B. Chide, E. Clave, E.A. Cloutis, A.D. Czaja, V. Debaille, E. Dehouck, A.G. Fairen, D.T. Flannery, S.Z. Fleron, T. Fouchet, J. Frydenvang, B.J. Garczynski, E.F. Gibbons, E.M. Hausrath, A.G. Hayes, J. Henneke, J.L. Jorgensen, E.M. Kelly, J. Lasue, S. Le Mouelic, J. M. Madariaga, S. Maurice, M. Merusi, P. #NAME? Meslin, S.M. Milkovich, C.C. Million, R.C. Moeller, J.I. Nunez, A.M. Ollila, G. Paar, D.A. Paige, D.A.K. Pedersen, P. Pilleri, C. Pilorget, P.C. Pinet, J.W. Rice Jr., C. Royer, V. Sautter, M. Schulte, M. A. Sephton, S.K. Sharma, S.F. Sholes, N. Spanovich, M. St. Clair, C.D. Tate, K. Uckert, S.J. VanBommel, A.G. Yanchilina, M. #NAME? Zorzano