Publications
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Miocene phosphatization of rocks from the summit of Rio Grande Rise, Southwest Atlantic Ocean Miocene phosphatization of rocks from the summit of Rio Grande Rise, Southwest Atlantic Ocean
Marine phosphorites are an important part of the oceanic phosphorus cycle and are related to the effects of long-term global climate changes. We use petrography, mineralogy, rare earth elements contents, and 87Sr/86Sr-determined carbonate fluorapatite (CFA) and calcite ages to investigate the paragenesis and history of phosphatization of carbonate sediments, limestones, ferromanganese...
Authors
Mariana Benites, James R. Hein, Kira Mizell, Luigi Jovane
Quaternary reelfoot fault deformation in the Obion River Valley, Tennessee, USA Quaternary reelfoot fault deformation in the Obion River Valley, Tennessee, USA
Blind reverse faults are challenging to detect, and earthquake records can be elusive because deep fault slip does not break the surface along readily recognized scarps. The blind Reelfoot fault in the New Madrid seismic zone in the central United States has been the subject of extensive prior investigation; however, the extent of slip at the southern portion of the fault remains...
Authors
Jaime Delano, Richard W. Briggs, Jessica Ann Thompson Jobe, Ryan D. Gold, Simon E. Engelhart
A review of the phyllosilicates in Gale Crater as detected by the CheMin Instrument on the Mars Science Laboratory, Curiosity Rover A review of the phyllosilicates in Gale Crater as detected by the CheMin Instrument on the Mars Science Laboratory, Curiosity Rover
Curiosity, the Mars Science Laboratory (MSL) rover, landed on Mars in August 2012 to investigate the ~3.5-billion-year-old (Ga) fluvio-lacustrine sedimentary deposits of Aeolis Mons (informally known as Mount Sharp) and the surrounding plains (Aeolis Palus) in Gale crater. After nearly nine years, Curiosity has traversed over 25 km, and the Chemistry and Mineralogy (CheMin) X-ray...
Authors
Valerie M. Tu, Elizabeth B. Rampe, Thomas F. Bristow, Michael T. Thorpe, Joanna V. Clark, Nicholas Castle, Abigail A. Fraeman, Lauren A. Edgar, Amy McAdam, Candice C. Bedford, Cherie N. Achilles, David Blake, Steve J. Chipera, Patricia I. Craig, David J. Des Marais, Gordie W. Downs, Robert T. Downs, Valerie K. Fox, John P. Grotzinger, Robert M. Hazen, Douglas W. Ming, Richard V. Morris, Shaunna M. Morrison, Betina Pavri, Tanya S. Peretyazhko, Philippe C. Sarazin, Brad Sutter, Allan H. Treiman, David T. Vaniman, Albert S. Yen, Jon C. Bridges
SSA task force on diversity, equity, and inclusion: Toward a changing, inclusive future in earthquake science SSA task force on diversity, equity, and inclusion: Toward a changing, inclusive future in earthquake science
In the United States, a wide variety of studies show that the geoscience community does not reflect the broader societal makeup (e.g., Velasco and Jaurrieta de Velasco, 2010; Dutt, 2020; Howley, 2020). In fact, only about 10% of all Science, Technology, Engineering, and Mathematics (STEM) Ph.D. degrees are awarded to people of color, although they represent more than a third of the...
Authors
Aaron A. Velasco, Kasey Aderhold, Richard Alfaro-Diaz, Wesley Brown, Mike Brudzinski, Margaret Fraiser, Monique M. Holt, Jim Mori, Gabriela Noriega, Katherine M. Scharer, Denise Templeton, Fabia Terra, Sherilyn Williams-Stroud
Geologic controls of slow-moving landslides near the U.S. West Coast Geologic controls of slow-moving landslides near the U.S. West Coast
Slow-moving landslides, often with nearly imperceptible creeping motion, are an important landscape shaper and a dangerous natural hazard across the globe, yet their spatial distribution and geologic controls are still poorly known owing to a paucity of detailed, large-area observations. Here, we use interferometry of L-band satellite radar images to reveal 617 spatially large (4 × 104...
Authors
Yuankun Xu, William H. Schulz, Zhong Lu, Jinwook Kim, Kelli Wadsworth Baxstrom
Multiple climate change-driven tipping points for coastal systems Multiple climate change-driven tipping points for coastal systems
As the climate evolves over the next century, the interaction of accelerating sea level rise (SLR) and storms, combined with confining development and infrastructure, will place greater stresses on physical, ecological, and human systems along the ocean-land margin. Many of these valued coastal systems could reach “tipping points,” at which hazard exposure substantially increases and...
Authors
Patrick L. Barnard, Jenifer Dugan, Henry M. Page, Nathan J. Wood, Juliette A. Finzi Hart, Daniel Cayan, Li H. Erikson, David A. Hubbard, Monique Myers, John M. Melack, Samuel F. Iacobellis
Late Holocene slip rate of the Mojave section of the San Andreas Fault near Palmdale, California Late Holocene slip rate of the Mojave section of the San Andreas Fault near Palmdale, California
The geologic slip rate on the Mojave section of the San Andreas fault is poorly constrained, despite its importance for understanding earthquake hazard, apparent discrepancies between geologic and geodetic slip rates along this fault section, and long‐term fault interactions in southern California. Here, we use surficial geologic mapping, excavations, and radiocarbon and luminescence...
Authors
Elaine Young, Eric Cowgill, Katherine M. Scharer, Emery Anderson-Merritt, Amanda Keen-Zebert, Ray J. Weldon
Why do my squiggles look funny? A gallery of compromised seismic signals Why do my squiggles look funny? A gallery of compromised seismic signals
Seismic instruments are highly sensitive and capable of recording a large range of different Earth signals. The high sensitivity of these instruments also makes them prone to various failures. Although many failures are very obvious, such as a dead channel, there are other more subtle failures that easily go unnoticed by both network operators and data users. This work documents several...
Authors
Adam T. Ringler, David B. Mason, G. Laske, Tyler Storm, M. Templeton
Extent of impact of deep-sea nodule mining midwater plumes is influenced by sediment loading, turbulence and thresholds Extent of impact of deep-sea nodule mining midwater plumes is influenced by sediment loading, turbulence and thresholds
Deep-sea polymetallic nodule mining research activity has substantially increased in recent years, but the expected level of environmental impact is still being established. One environmental concern is the discharge of a sediment plume into the midwater column. We performed a dedicated field study using sediment from the Clarion Clipperton Fracture Zone. The plume was monitored and...
Authors
Carlos Munoz-Royo, Thomas Peacock, Matthew Alford, Jerome Smith, Arnaud Le Boyer, Chinmay Kulkarni, Pierre Lermusiaux, Patrick Haley, C Mirabito, Dayang Wang, Eric Adams, Raphael Ouillon, Alexander Breugem, Boudewijn Decrop, Thijs Lanckreit, Rohit Supekar, Andrew Rzeznik, Amy Gartman, Se-Jong Ju
Spectral damping scaling factors for horizontal components of ground motions from subduction earthquakes using NGA-Subduction data Spectral damping scaling factors for horizontal components of ground motions from subduction earthquakes using NGA-Subduction data
This article develops global models of damping scaling factors (DSFs) for subduction zone earthquakes that are functions of the damping ratio, spectral period, earthquake magnitude, and distance. The Next Generation Attenuation for subduction earthquakes (NGA-Sub) project has developed the largest uniformly processed database of recorded ground motions to date from seven subduction...
Authors
Sanaz Rezaeian, L. Al Atik, N. M. Kuehn, N. A. Abrahamson, Y. Bozorgnia, S. Mazzoni, Kyle Withers, K. Campbell
Multiple melt source origin of the Line Islands (Pacific Ocean) Multiple melt source origin of the Line Islands (Pacific Ocean)
The Line Islands volcanic chain in the central Pacific Ocean exhibits many characteristics of a hotspot-generated seamount chain; however, the lack of a predictable age progression has stymied previous models for the origin of this feature. We combined plate-tectonic reconstructions with seamount age dates and available geochemistry to develop a new model that involves multiple melt...
Authors
Robert Pockalny, Ginger Barth, Barry Eakins, Katherine A. Kelley, Christina Wertman
Hazard analysis of landslides triggered by Typhoon Chata’an on July 2, 2002, in Chuuk State, Federated States of Micronesia Hazard analysis of landslides triggered by Typhoon Chata’an on July 2, 2002, in Chuuk State, Federated States of Micronesia
More than 250 landslides were triggered across the eastern volcanic islands of Chuuk State in the Federated States of Micronesia by torrential rainfall from tropical storm Chata’an on July 2, 2002. Landslides triggered during nearly 20 inches of rainfall in less than 24 hours caused 43 fatalities and the destruction or damage of 231 structures, including homes, schools, community centers...
Authors
Edwin L. Harp, Mark E. Reid, John A. Michael