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Using geologic structures to constrain constitutive laws not accessible in the laboratory

In this essay, we explore a central problem of structural geology today, and in the foreseeable future, which is the determination of constitutive laws governing rock deformation to produce geologic structures. Although laboratory experiments provide much needed data and insights about constitutive laws, these experiments cannot cover the range of conditions and compositions relevant to the format
Authors
Johanna Nevitt, Jessica M. Warren, Kathryn M. Kumamoto, David D. Pollard

Environmental controls, emergent scaling, and predictions of greenhouse gas (GHG) fluxes in coastal salt marshes

Coastal salt marshes play an important role in mitigating global warming by removing atmospheric carbon at a high rate. We investigated the environmental controls and emergent scaling of major greenhouse gas (GHG) fluxes such as carbon dioxide (CO2) and methane (CH4) in coastal salt marshes by conducting data analytics and empirical modeling. The underlying hypothesis is that the salt marsh GHG fl
Authors
Omar I. Abdul-Aziz, Khandker S. Ishitaq, Jianwu Tang, Serena Moseman-Valtierra, Kevin D. Kroeger, Meagan Gonneea Eagle, Jordan Mora, Kate Morkeski

The Santa Cruz Basin submarine landslide complex, southern California: Repeated failure of uplifted basin sediment

The Santa Cruz Basin (SCB) is one of several fault-bounded basins within the California Continental Borderland that has drawn interest over the years for its role in the tectonic evolution of the region, but also because it contains a record of a variety of modes of sedimentary mass transport (i.e., open slope vs. canyon-confined systems). Here, we present a suite of new high-resolution marine geo

Authors
Daniel S. Brothers, Katherine L. Maier, Jared W. Kluesner, James E. Conrad, Jason Chaytor

A multiscale natural community and species-level vulnerability assessment of the Gulf Coast, USA

Vulnerability assessments combine quantitative and qualitative evaluations of the exposure, sensitivity, and adaptive capacity of species or natural communities to current and future threats. When combined with the economic, ecological or evolutionary value of the species, vulnerability assessments quantify the relative risk to regional species and natural communities and can enable informed prior
Authors
Joshua S. Reece, Amanda Watson, Patricia (Soupy) Dalyander, C. Edwards, Laura Geselbracht, Megan K. LaPeyre, Blair Tirpak, John M. Tirpak, Mark Woodrey

Why aftershock duration matters for probabilistic seismic hazard assessment

Most hazard assessments assume that high background seismicity rates indicate a higher probability of large shocks and, therefore, of strong shaking. However, in slowly deforming regions, such as eastern North America, Australia, and inner Honshu, this assumption breaks down if the seismicity clusters are instead aftershocks of historic and prehistoric mainshocks. Here, therefore we probe the circ
Authors
Shinji Toda, Ross S. Stein

Combining conflicting Bayesian models to develop paleoseismic records—An example from the Wasatch Fault Zone, Utah

Bayesian statistical analyses of paleoseismic data result in the probabilistic determination of earthquake times using geochronological data evaluated in the context of a stratigraphic model. However, a fundamental problem in paleoseismology is how to use the Bayesian approach to model sparse and/or conflicting geochronological datasets, such as those derived from sites exhibiting episodic sedimen
Authors
Christopher DuRoss, Scott E. K. Bennett, Richard W. Briggs, Stephen Personius, Ryan D. Gold, Nadine G. Reitman, Adam I. Hiscock, Shannon A. Mahan

Impact of pore fluid chemistry on fine-grained sediment fabric and compressibility

Fines, defined here as grains or particles, less than 75 μm in diameter, exist nearly ubiquitously in natural sediment, even those classified as coarse. Macroscopic sediment properties, such as compressibility, which relates applied effective stress to the resulting sediment deformation, depend on the fabric of fines. Unlike coarse grains, fines have sizes and masses small enough to be more strong
Authors
Junbong Jang, Shuang C. Cao, Laura A. Stern, Jongwon Jung, William F. Waite

Using stereo satellite imagery to account for ablation, entrainment, and compaction in volume calculations for rock avalanches on Glaciers: Application to the 2016 Lamplugh Rock Avalanche in Glacier Bay National Park, Alaska

The use of preevent and postevent digital elevation models (DEMs) to estimate the volume of rock avalanches on glaciers is complicated by ablation of ice before and after the rock avalanche, scour of material during rock avalanche emplacement, and postevent ablation and compaction of the rock avalanche deposit. We present a model to account for these processes in volume estimates of rock avalanche
Authors
Erin Bessette-Kirton, Jeffrey A. Coe, Wendy Zhou

ShakeMap-based prediction of earthquake-induced mass movements in Switzerland calibrated on historical observations

In Switzerland, nearly all historical Mw ~ 6 earthquakes have induced damaging landslides, rockslides and snow avalanches that, in some cases, also resulted in damage to infrastructure and loss of lives. We describe the customisation to Swiss conditions of a globally calibrated statistical approach originally developed to rapidly assess earthquake-induced landslide likelihoods worldwide. The proba
Authors
Carlo Cauzzi, Donat Fah, David J. Wald, John Clinton, Stephane Losey, Stefan Wiemer

Regional spectral analysis of moderate earthquakes in northeastern North America—Final Report to the Nuclear Regulatory Commission, Project V6240, Task 3

We analyze the Fourier spectra of S+Lg+surface wave groups from the horizontal and vertical components of broadband and accelerogram recordings of 120 small and moderate (2< Mw <6) earthquakes recorded by Canadian and American stations sited on rock at distances from 3 to 600 kilometers. There are seven Mw 4.0–4.5, six Mw 4.5–5.0, and three Mw ≥5 earthquakes in this event set. We test the regional
Authors
Jack Boatwright

Landslides triggered by the 14 November 2016 Mw 7.8 Kaikōura Earthquake, New Zealand

The 14 November 2016 MwMw 7.8 Kaikōura earthquake generated more than 10,000 landslides over a total area of about 10,000  km210,000  km2, with the majority concentrated in a smaller area of about 3600  km23600  km2. The largest landslide triggered by the earthquake had an approximate volume of 20(±2)  M m320(±2)  M m3, with a runout distance of about 2.7 km, forming a dam on the Hapuku River. In
Authors
C. Massey, D. Townsend, Ellen M. Rathje, Kate E. Allstadt, B. Lukovic, Yoshihiro Kaneko, Brendon A. Bradley, J. Wartman, Randall W. Jibson, D. N. Petley, Nick Horspool, I. Hamling, J. Carey, S. Cox, John Davidson, S. Dellow, Jonathan W. Godt, Christopher Holden, Katherine D. Jones, Anna E. Kaiser, M. Little, B. Lyndsell, S. McColl, R. Morgenstern, Francis K. Rengers, D. Rhoades, B. Rosser, D. Strong, C. Singeisen, M. Villeneuve

Analysis of mean seismic ground motion and its uncertainty based on the UCERF3 geologic slip rate model with uncertainty for California

The Uniform California Earthquake Rupture Forecast v.3 (UCERF3) model (Field et al., 2014) considers epistemic uncertainty in fault‐slip rate via the inclusion of multiple rate models based on geologic and/or geodetic data. However, these slip rates are commonly clustered about their mean value and do not reflect the broader distribution of possible rates and associated probabilities. Here, we con
Authors
Yuehua Zeng