Publications
Filter Total Items: 7238
Incorporation of real-time earthquake magnitudes estimated via peak ground displacement scaling in the ShakeAlert Earthquake Early Warning system
The United States earthquake early warning (EEW) system, ShakeAlert®, currently employs two algorithms based on seismic data alone to characterize the earthquake source, reporting the weighted average of their magnitude estimates. Nonsaturating magnitude estimates derived in real time from Global Navigation Satellite System (GNSS) data using peak ground displacement (PGD) scaling relationships off
Authors
Jessica R. Murray, Brendan W. Crowell, Mark Hunter Murray, Carl W Ulberg, Jeffrey McGuire, Mario Aranha, Mike Hagerty
An examination of soil crusts on the floor of Jezero crater, Mars
Martian soils are critically important for understanding the history of Mars, past potentially habitable environments, returned samples, and future human exploration. This paper examines soil crusts on the floor of Jezero crater encountered during initial phases of the Mars 2020 mission. Soil surface crusts have been observed on Mars at other locations, starting with the two Viking Lander missions
Authors
E. M. Hausrath, C. T. Adcock, A. Bechtold, P. S. A. Beck, K. Benison, A. Brown, E. L. Cardarelli, N. A. Carman, B. Chide, J. Christian, B. C. Clark, E. Cloutis, A. Cousin, O. Forni, Travis S. J. Gabriel, O. Gasnault, M. P. Golombek, F. Gomez, M. H. Hecht, T. L. J. Henley, J. Huidobro, J. C. Johnson, M. W. M. Jones, P. B. Kelemen, A. Knight, J. A. Lasue, S. Le Mouelic, J. M. Madariaga, J. N. Maki, L. Mandon, G. Martinez, J. Martinez-Frias, T. H. McConnochie, P. -Y. Meslin, M. -P. Zorzano, H. Newsom, G. Paar, N. Randazzo, C. Royer, S. Siljestroem, M. E. Schmidt, S. Schroeder, M. A. Sephton, R. Sullivan, N. Turenne, A. Udry, S. VanBommel, A. Vaughan, R. C. Wiens, N. Williams
Spatial and temporal analysis of geologic slip rates, Cucamonga Fault, California, USA: Implications for along-strike applications and multi-fault rupture
To constrain fault processes and hazard, fault slip rates may be extrapolated over different fault lengths or time intervals. Here, we investigate slip rates for the Cucamonga Fault (CF). The CF is located at the junction of the Transverse Range fault system with the San Andreas and San Jacinto Faults, and it is hypothesized to connect with these faults, promoting the propagation of large, multi-f
Authors
Devin McPhillips, Katherine Scharer
Effect of thermal and mechanical processes on hydraulic transmissivity evolution
Fracture healing is a critical component of enhanced geothermal systems, the earthquake cycle, and induced seismicity. Accordingly, there is significant interest in understanding the process of healing and its effects on fluid transport. The creation, reactivation, and sustainability of fracture networks depend on complex coupling among thermal, hydraulic, mechanical, and chemical processes. We us
Authors
Tamara Nicole Jeppson, David A. Lockner, Joshua M. Taron, Diane E. Moore, Brian D. Kilgore, Nicholas M. Beeler, Stephen H. Hickman
Applications of nonergodic site response models to ShakeAlert case studies in the Los Angeles area
In this study, we explore whether the Parker and Baltay (2022) site response models for the Los Angeles (LA) basin region can improve ground‐motion forecasts in the U.S. Geological Survey ShakeAlert earthquake early warning system (hereafter ShakeAlert). We implement the peak ground acceleration and peak ground velocity site response models of Parker and Baltay (2022) in ShakeAlert via the earthqu
Authors
Rongrong Lin, Grace Alexandra Parker, Jeffrey McGuire, Annemarie S. Baltay
A review of common natural disasters as analogs for asteroid impact effects and cascading hazards
Modern civilization has no collective experience with possible wide-ranging effects from a medium-sized asteroid impactor. Currently, modeling efforts that predict initial effects from a meteor impact or airburst provide needed information for initial preparation and evacuation plans, but longer-term cascading hazards are not typically considered. However, more common natural disasters, such as vo
Authors
Timothy N. Titus, D. G. Robertson, Joel B. Sankey, Larry G. Mastin, Francis K. Rengers
Regolith of the crater floor units, Jezero crater, Mars: Textures, composition and implications for provenance
A multi-instrument study of the regolith of Jezero crater floor units by the Perseverance rover has identified three types of regolith: fine-grained, coarse-grained, and mixed-type. Mastcam-Z, WATSON, and SuperCam RMI were used to characterize regolith texture, particle size, and roundedness where possible. Mastcam-Z multispectral and SuperCam LIBS data were used to constrain the composition of th
Authors
Alicia Vaughan, Michelle E. Minitti, Emily L. Cardarelli, Jeffrey R. Johnson, Linda C. Kah, Paolo Pilleri, Mellisa S. Rice, Mark Sephton, Briony H. N. Horgan, Roger C. Wiens, R. Aileen Yingst, Maria-Paz Zorzano Mier, Ryan Anderson, James F. III Bell, Adrian J. Brown, Edward A. Cloutis, Agnes Cousin, Kenneth E. Herkenhoff, Elisabeth M. Housrath, Alexander G. Hayes, Kjartan M. Kinch, Marco Merusi, Chase C. Million, Robert Sullivan, Sandra M. Siljestrom, Michael St. Clair
Revising supraglacial rock avalanche magnitudes and frequencies in Glacier Bay National Park, Alaska
The frequency of large supraglacial landslides (rock avalanches) occurring in glacial environments is thought to be increasing due to feedbacks with climate warming and permafrost degradation. However, it is difficult to (i) test this; (ii) establish cause–effect relationships; and (iii) determine associated lag-times, due to both temporal and spatial biases in detection rates. Here we applied the
Authors
William Smith, Stuart A. Dunning, Neil Ross, Jon Telling, Erin K. Bessette-Kirton, Dan H. Shugar, Jeffrey A. Coe, M. Geertsema
Using corrected and imputed polarity measurements to improve focal mechanisms in a regional earthquake catalog near the Mt. Lewis Fault Zone, California
We utilized relative polarity measurements and machine learning techniques to better resolve focal mechanisms and stress orientations considering a catalog of ∼29,000 relocated earthquakes that occurred during 1984–2021 in the southeastern San Francisco Bay Area. Earthquake focal mechanisms are commonly produced using P wave first motion polarities, which traditionally requires events to be well-r
Authors
Robert Skoumal, Jeanne L. Hardebeck, David R. Shelly
Investigations of ambient noise velocity variations in a region of induced seismicity near Greeley, Colorado
Wastewater injection has induced earthquakes in Northeastern Colorado since 2014. We apply ambient noise correlation techniques to determine temporal changes in seismic velocities in the region. We find no clear correlation between seismic velocity fluctuations and either injection volumes or seismicity patterns. We do observe apparent annual variations in velocity that may be associated with hydr
Authors
Thomas Clifford, Anne Sheehan, Morgan P. Moschetti
Damage amplification during repetitive seismic waves in mechanically loaded rocks
Cycles of stress build-up and release are inherent to tectonically active planets. Such stress oscillations impart strain and damage, prompting mechanically loaded rocks and materials to fail. Here, we investigate, under uniaxial conditions, damage accumulation and weakening caused by time-dependent creep (at 60, 65, and 70% of the rocks’ expected failure stress) and repeating stress oscillations
Authors
Anthony Lamur, Jackie E. Kendrick, Lauren N. Schaefer, Yan Lavallée, Ben M. Kennedy
Simulating debris flow and levee formation in the 2D shallow flow model D-Claw: Channelized and unconfined flow
Debris flow runout poses a hazard to life and infrastructure. The expansion of human population into mountainous areas and onto alluvial fans increases the need to predict and mitigate debris flow runout hazards. Debris flows on unconfined alluvial fans can exhibit spontaneous self-channelization through levee formation that reduces lateral spreading and extends runout distances compared to unchan
Authors
Ryan P. Jones, Francis K. Rengers, Katherine R. Barnhart, David L. George, Dennis M. Staley, Jason W. Kean