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The Mars Orbiter for Resources, Ices, and Environments (MORIE) science goals and instrument trades in radar, imaging, and spectroscopy The Mars Orbiter for Resources, Ices, and Environments (MORIE) science goals and instrument trades in radar, imaging, and spectroscopy

The Mars Orbiter for Resources, Ices, and Environments (MORIE) was selected as one of NASA's 2019 Planetary Mission Concept Studies. The mission builds upon recent discoveries and current knowledge gaps linked to two primary scientific questions: (1) when did elements of the cryosphere form and how are ice deposits linked to current, recent, and ancient climate, and (2) how does the...
Authors
Wendy M. Calvin, Nathaniel E. Putzig, Colin M. Dundas, Ali M Bramson, Briony H. N. Horgan, Kim D Seelos, Hanna G Sizemore, Bethany L. Ehlmann, Gareth A Morgan, John W Holt, Scott L. Murchie, G Wesley Patterson

A maximum rupture model for the central and southern Cascadia subduction zone—reassessing ages for coastal evidence of megathrust earthquakes and tsunamis A maximum rupture model for the central and southern Cascadia subduction zone—reassessing ages for coastal evidence of megathrust earthquakes and tsunamis

A new history of great earthquakes (and their tsunamis) for the central and southern Cascadia subduction zone shows more frequent (17 in the past 6700 yr) megathrust ruptures than previous coastal chronologies. The history is based on along-strike correlations of Bayesian age models derived from evaluation of 554 radiocarbon ages that date earthquake evidence at 14 coastal sites. We...
Authors
Alan Nelson, Christopher DuRoss, Robert C. Witter, Harvey M. Kelsey, Simon E. Engelhart, Shannon A. Mahan, Harrison J. Gray, Andrea D. Hawkes, Benjamin P. Horton, Jason S. Padgett

Shear-wave velocity site characterization in Oklahoma from joint inversion of multi-method surface seismic measurements: Implications for central U.S. Ground Motion Prediction Shear-wave velocity site characterization in Oklahoma from joint inversion of multi-method surface seismic measurements: Implications for central U.S. Ground Motion Prediction

We analyze multimethod shear (SH)‐wave velocity ( ⁠ VS) site characterization data acquired at three permanent and 25 temporary seismograph stations in Oklahoma that recorded M 4+ earthquakes within a 50 km hypocentral distance of at least one of the 2016 M 5.1 Fairview, M 5.8 Pawnee, or M 5.0 Cushing earthquakes to better constrain earthquake ground‐motion modeling in the region. We...
Authors
William J. Stephenson, Jackson K. Odum, Stephen H. Hartzell, Alena L. Leeds, Robert Williams

Spatiotemporal clustering of great earthquakes on a transform fault controlled by geometry Spatiotemporal clustering of great earthquakes on a transform fault controlled by geometry

Minor changes in geometry along the length of mature strike-slip faults may act as conditional barriers to earthquake rupture, terminating some and allowing others to pass. This hypothesis remains largely untested because palaeoearthquake data that constrain spatial and temporal patterns of fault rupture are generally imprecise. Here we develop palaeoearthquake event data that encompass...
Authors
Jamie D. Howarth, Nicolas C. Barth, Sean J. Fitzsimons, Keith B. Richards-Dinger, Kate Clark, Glenn Biasi, Ursula A. Cochran, Robert M. Langridge, Kelvin R. Berryman, Rupert Sutherland

Changes in seabed mining Changes in seabed mining

Chapter 23 of the First World Ocean Assessment (WOA I) focused on marine mining, and particularly on established extractive industries, which are predominantly confined to near-shore areas, where shallow-water, near-shore aggregate and placer deposits, and somewhat deeper water phosphate deposits are found (United Nations, 2017a). At the time of publication, there were no commercially...
Authors
James R. Hein, Pedro Madureira, Maria Joao Bebianno, Ana Colaço, Luis M. Pinheiro, Richard Roth, Pradeep K. Singh, Anastasia Strati, Joshua T. Tuhumwire

The value of US coral reefs for flood risk reduction The value of US coral reefs for flood risk reduction

Habitats, such as coral reefs, can mitigate increasing flood damages through coastal protection services. We provide a fine-scale, national valuation of the flood risk reduction benefits of coral habitats to people, property, economies and infrastructure. Across 3,100 km of US coastline, the top-most 1 m of coral reefs prevents the 100-yr flood from growing by 23% (113 km2), avoiding...
Authors
Borja G. Reguero, Curt D. Storlazzi, Ann E. Gibbs, James B. Shope, Aaron Cole, Kristen A. Cumming, Mike Beck

The productivity of Cascadia aftershock sequences The productivity of Cascadia aftershock sequences

This study addresses questions about the productivity of Cascadia mainshock–aftershock sequences using earthquake catalogs produced by the Geological Survey of Canada and the Pacific Northwest Seismic Network. Questions concern the likelihood that future moderate to large intermediate depth intraslab earthquakes in Cascadia would have as few detectable aftershocks as those documented...
Authors
Joan S. Gomberg, Paul Bodin

Regional calibration of hybrid ground‐motion simulations in moderate seismicity areas: Application to the Upper Rhine Graben Regional calibration of hybrid ground‐motion simulations in moderate seismicity areas: Application to the Upper Rhine Graben

This study presents the coupling of the spectral decomposition results for anelastic attenuation, stress drop, and site effects with the Graves‐Pitarka (GP) hybrid ground‐motion simulation methodology, as implemented on the Southern California Earthquake Center (SCEC) broadband platform (BBP). It is targeted to applications in the Upper Rhine graben (URG), which is among the seismically...
Authors
Hoby N. T. Razafindrakoto, Fabrice Cotton, Dino Bindi, Marco Pilz, Robert Graves, Sanjay Bora

Alternating wet and dry depositional environments recorded in the stratigraphy of Mt Sharp at Gale Crater, Mars Alternating wet and dry depositional environments recorded in the stratigraphy of Mt Sharp at Gale Crater, Mars

The Curiosity rover is exploring Hesperian-aged stratigraphy in Gale crater, Mars, where a transition from clay-bearing units to a layered sulfate-bearing unit has been interpreted to represent a major environmental transition of unknown character. We present the first description of key facies in the sulfate-bearing unit, recently observed in the distance by the rover, and propose a...
Authors
William Rapin, Gilles Dromart, Dave Rubin, Laticia Le Deit, Nicolas Mangold, Lauren A. Edgar, Olivier Gasnault, Kenneth E. Herkenhoff, S. Lemouelic, Ryan B. Anderson, S. Maurice, V. Fox, B. L. Ehlmann, J. L. Dickson, R. C. Wiens

Reconstructing the dynamics of the highly similar May 2016 and June 2019 Iliamna Volcano, Alaska ice–rock avalanches from seismoacoustic data Reconstructing the dynamics of the highly similar May 2016 and June 2019 Iliamna Volcano, Alaska ice–rock avalanches from seismoacoustic data

Surficial mass wasting events are a hazard worldwide. Seismic and acoustic signals from these often remote processes, combined with other geophysical observations, can provide key information for monitoring and rapid response efforts and enhance our understanding of event dynamics. Here, we present seismoacoustic data and analyses for two very large ice–rock avalanches occurring on...
Authors
Liam Toney, David Fee, Kate E. Allstadt, Matthew M. Haney, Robin S. Matoza

Diagenesis revealed by fine-scale features at Vera Rubin ridge, Gale crater, Mars Diagenesis revealed by fine-scale features at Vera Rubin ridge, Gale crater, Mars

Fine-scale (submillimeter to centimeter) depositional and diagenetic features encountered during the Curiosity rover's traverse in Gale crater provide a means to understand the geologic history of Vera Rubin ridge (VRR). VRR is a topographically high feature on the lower north slope of Aeolis Mons, a 5-km high stratified mound within Gale crater. We use high-spatial resolution images...
Authors
Kristen A. Bennett, Frances Rivera-Hernandez, Connor Tinker, Briony H. N. Horgan, Deirdra M. Fey, C. S. Edwards, Lauren A. Edgar, Rachel Kronyak, Kenneth S. Edgett, Abigail A. Fraeman, Linda C. Kah, Marie Henderson, Nathan Stein, Erwin Dehouck, Amy Williams

Improving paleoseismic earthquake magnitude estimates with rupture length information: Application to the Puget Lowland, Washington State, U.S.A. Improving paleoseismic earthquake magnitude estimates with rupture length information: Application to the Puget Lowland, Washington State, U.S.A.

Both earthquake displacement and rupture length correlate with magnitude, and therefore observations of each from past earthquakes can be used to estimate the magnitude of those earthquakes in the absence of instrumental records. We extend the Bayesian inversion method of Biasi and Weldon (2006), which estimates paleoearthquake magnitude from displacement observations, to incorporate...
Authors
Richard Styron, Brian L. Sherrod
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