Publications

The 2019 Ridgecrest, California, earthquake sequence involved predominantly right‐lateral strike slip on a northwest–southeast‐trending subvertical fault in the 6 July M 7.1 mainshock, preceded by left‐lateral strike slip on a northeast–southwest‐trending subvertical fault in the 4 July M 6.4 foreshock. To characterize the postseismic deformation, we assemble displacements measured by...

The HayWired Earthquake Scenario—Engineering Implications is the second volume of U.S. Geological Survey (USGS) Scientific Investigations Report 2017–5013, which describes the HayWired scenario, developed by USGS and its partners. The scenario is a hypothetical yet scientifically realistic earthquake sequence that is being used to better understand hazards for the San Francisco Bay...

We present an ergodic site response model with regional adjustments for use with subduction zone ground-motion models. The model predicts site amplification of peak ground acceleration, peak ground velocity, and 5% damped pseudo-spectral accelerations of the orientation-independent horizonal component for oscillator periods from 0.01 to 10 s. The model depends on the time-averaged shear...

In a recent study, Hough and Martin (2021) considered the extent to which socioeconomic factors influence the numbers and distribution of contributed reports available to characterize the effects of both historical and recent large earthquakes. In this study I explore the question further, focusing on analysis of widely felt earthquakes near major population centers in northern and...

The mechanical, physical, and frictional properties of incoming materials play an important role in subduction zone structure and slip behavior because these properties influence the strength of the accretionary wedge and megathrust plate boundary faults. Incoming sediment sections often show an increase in compressional wave speed (Vp) and a decrease in porosity with depth due to...

This paper studies the impacts of sea-level rise on liquefaction triggering and severity around the San Francisco Bay Area, California, for the M 7.0 “HayWired” earthquake scenario along the Hayward fault. This work emerged from stakeholder engagement for the US Geological Survey releases of the HayWired earthquake scenario and the Coastal Storm Modeling System projects, in which local...

We identify aspects of finite‐source parameterization that strongly affect the accuracy of estimated ground motion for earthquake early warning (EEW). EEW systems aim to alert users to impending shaking before it reaches them. The U.S. West Coast EEW system, ShakeAlert, currently uses two algorithms based on seismic data to characterize the earthquake’s location, magnitude, and origin...

During rock friction experiments at large displacement, room temperature and humidity, and following a hold test, the fracture energy increases approximately as the square of the logarithm of hold duration. While it's been long known that failure strength increases with log hold time, here the slip weakening distance, dh, also increases. The weakening distance increase is large, hundreds...

We thank David Wald (Wald, 2021; henceforth, W21) for his interest in our recent article (Hough and Martin, 2021; henceforth, HM21). Although different perspectives are vital in science, we are concerned that W21 misrepresents HM21 as an oblique criticism of the U.S. Geological Survey “Did You Feel It?” (DYFI) system, calling for HM21 to be retracted. Readers who are interested in the...

The HayWired earthquake scenario, led by the U.S. Geological Survey (USGS), anticipates the impacts of a hypothetical moment magnitude 7.0 earthquake on the Hayward Fault. The fault runs along the east side of California’s San Francisco Bay and is among the most active and dangerous in the United States, passing through a densely urbanized and interconnected region. A scientifically...

Seismic instrumentation, recorded earthquake responses, and collaborative studies of the response records from four tall California buildings are summarized in this summary paper. These buildings include the tallest San Francisco building, the 61-story Salesforce Tower, and the tallest California building, the 73-story Wilshire Grand Tower, as well as a 51-story residential building in...

The USGS ShakeAlert® earthquake early warning (EEW) system is operational and providing public alerting in three West Coast states: California, Washington, and Oregon. Since 2006 the USGS has pursued a strategy of incrementally developing and rolling out EEW for increasingly larger areas and uses. As funding from federal and state budgets grew the system became more capable, detection...