Publications
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Geomorphic evolution of a gravel‐bed river under sediment‐starved vs. sediment‐rich conditions: River response to the world's largest dam removal
Understanding river response to sediment pulses is a fundamental problem in geomorphic process studies, with myriad implications for river management. However, because large sediment pulses are rare and usually unanticipated, they are seldom studied at field scale. We examine fluvial response to a massive (~20 Mt) sediment pulse released by the largest dam removal globally, on the Elwha...
Authors
Amy East, Joshua B. Logan, Mark C. Mastin, Andrew C. Ritchie, Jennifer A. Bountry, Christopher S. Magirl, Joel B. Sankey
3-D Simulations of M9 earthquakes on the Cascadia Megathrust: Methodology and results
No abstract available.
Authors
Arthur Frankel, Erin Wirth Moriarty, J. Vidale, William J. Stephenson, Nasser A. Marafi
Role of fault gouge during Interaction between hydraulic fracture and a preexisting fracture
Enhanced reservoir connectivity generally requires maximizing the intersection between hydraulic fracture (HF) and preexisting underground natural fractures (NF), while having the hydraulic fracture continue to propagate across the natural fractures. Observations of downhole core samples suggest that these natural fractures are in fact veins filled with minerals such as calcite (Mighani...
Authors
Saied Mighani, David Lockner, Brian D. Kilgore, Brian Evans
Quantifying post-wildfire hillslope erosion with lidar
Following a wildfire, flooding and debris- flow hazards are common and pose a threat to human life and infrastructure in steep burned terrain. Wildfire enhances both water runoff and soil erosion, which ultimately shape the debris flow potential. The erosional processes that route excess sediment from hillslopes to debris-flow channels in recently burned areas, however, are poorly...
Authors
Francis K. Rengers, Luke A. McGuire
Effects of simulated magnitude 9 earthquake motions on structures in the Pacific Northwest
The Cascadia Subduction Zone (CSZ) produces long-duration, large-magnitude earthquakes that could severely affect structures in the Pacific Northwest (PNW). The impact of synthetic M9.0 CSZ earthquakes on buildings in the Pacific Northwest is studied using eight reinforced concrete wall archetypes that range from 4 to 40 stories. These archetypes were subjected to an ensemble of...
Authors
Nasser A. Marafi, M. Eberhard, J. Berman, Erin Wirth, Arthur Frankel, J. Vidale
A proposed seismic velocity profile database model
We describe the data model that we intend to use in a publicly available site profile database under development for the United States. The initial implementation of the database contains data from California. Currently, our prototype data model consists of JavaScript Object Notation (JSON) format files for storing metadata and data. For a site to be included in the database, the minimum...
Authors
Shamsher Sadiq, Okan Ilkan, Sean Kamran Ahdi, Yousef Bozorgina, Youssef M.A. Hashash, Dong Youp Kwak, Duhee Park, Alan K. Yong, Jonathan P. Stewart
Serpentinite‐rich gouge in a creeping segment of the Bartlett Springs Fault, northern California: Comparison with SAFOD and implications for seismic hazard
An exposure of a creeping segment of the Bartlett Springs Fault (BSF), part of the San Andreas Fault system in northern California, is a ~1.5‐m‐wide zone of serpentinite‐bearing fault gouge cutting through Late Pleistocene fluvial deposits. The fault gouge consists of porphyroclasts of antigorite serpentinite, talc, chlorite, and tremolite‐actinolite, along with some Franciscan...
Authors
Diane E. Moore, Robert McLaughlin, James Lienkaemper
Overview of spirit microscopic imager results
This paper provides an overview of Mars Exploration Rover Spirit Microscopic Imager (MI) operations and the calibration, processing, and analysis of MI data. The focus of this overview is on the last five Earth years (2005–2010) of Spirit's mission in Gusev crater, supplementing the previous overview of the first 450 sols of the Spirit MI investigation. Updates to radiometric calibration...
Authors
Kenneth E. Herkenhoff, Steve W. Squyres, Raymond E. Arvidson, Shoshanna B Cole, Rob Sullivan, Aileen Yingst, Nathalie A. Cabrol, Ella (Contractor) Lee, Janet Richie, Robert M. Sucharski, Fred J. Calef, James F. Bell, Mary G. Chapman, Paul E. Geissler, Lauren A. Edgar, Brenda Franklin, Joel A. Hurowitz, Elsa H. Jensen, Jeffrey R. Johnson, Randolph L. Kirk, Peter Lanagan, Kevin F. Mullins, Craig Leff, Justin N. Maki, Bonnie L. Redding, Melissa S. Rice, Michael H. Sims, Richard Springer, Annette Sunda, Nicole Spanovich, Laurence A. Soderblom, Alicia F. Vaughan
Honolulu Magnetic Observatory
Tucked in a grove of thorny mesquite trees, on an ancient coral reef on the south side of the Hawaiian island of Oahu, west of Pearl Harbor, a small unmanned observatory quietly records the Earth’s time-varying magnetic field. The Honolulu Magnetic Observatory is 1 of 14 that the U.S. Geological Survey Geomagnetism Program operates at various locations across the United States and its...
Authors
Jeffrey J. Love, Carol A. Finn
The extreme space weather event in September 1909
We evaluate worldwide low-latitude auroral activity associated with the great magnetic storm of September 1909 for which a minimum Dst value of −595 nT has recently been determined. From auroral observations, we calculate that the equatorward boundary of the auroral oval in the 1909 event was in the range from 31°–35° invariant latitude (assuming auroral height of 400 km) to 37°–38° (800...
Authors
Hisashi Hayakawa, Yusuke Ebihara, Edward W. Cliver, Kentaro Hattori, Shin Toriumi, Jeffrey J. Love, Norio Umemura, Kosuke Namekata, Takahito Sakaue, Takuya Takahashi, Kazunari Shibata
Revisiting earthquakes in the Los Angeles, California, basin during the early instrumental period: Evidence for an association with oil production
A total of seven independent ML ≥ 4.0 earthquakes occurred in the Los Angeles, California, basin, during the early instrumental period between 1932 and 1952, the largest of which was the 1933 Long Beach earthquake. Revising available macroseismic and instrumental data for a total of 6 4.0 ≤ ML ≤ 5.1 events between 1938 and 1944, we conclude that early instrumental locations can be...
Authors
Susan E. Hough, Roger G. Bilham
Subsurface controls on the development of the Cape Fear Slide Complex, central US Atlantic Margin
The Cape Fear Slide is one of the largest (>25 000 km3) submarine slope failure complexes on the US Atlantic margin. Here we use a combination of new high-resolution multichannel seismic data (MCS) from the National Science Foundation Geodynamic Processes at Rifting and Subducting Margins (NSF GeoPRISMS) Community Seismic Experiment and legacy industry MCS to derive detailed stratigraphy...
Authors
Jenna C. Hill, Daniel Brothers, Matthew J. Hornbach, Derek E. Sawyer, Donna J. Shillington, Anne Bécel