Publications

Whether large and very large earthquakes are distinguishable from each other early on in the rupture process has been a subject often debated over the past several decades. Studies have shown that the frequency content of radiated seismic energy in the first few seconds of an earthquake scales with the final magnitude of the event, implying determinism. Other studies have shown that the...

The U.S. Geological Survey National Earthquake Information Center leads real-time efforts to provide rapid and accurate assessments of the impacts of global earthquakes, including estimates of ground shaking, ground failure, and the resulting human impacts. These efforts primarily rely on analysis of the seismic wavefield to characterize the source of the earthquake, which in turn...

On the 4th and 5th of March 2005, about 100 rainfall-induced landslides occurred along volcanic slopes of Camaldoli Hill in Naples, Italy. These started as soil slips in the upper substratum of incoherent and welded volcaniclastic deposits, then evolved downslope according to debris avalanche and debris flow mechanisms. This specific case of slope instability on complex volcaniclastic...

Executive Summary Damaging earthquakes occur regularly around the world; since the turn of the 20th century, hundreds of earthquakes have caused significant loss of life and (or) millions of dollars or more in economic losses. While most of these did not directly affect the United States and its Territories, by studying worldwide seismicity we can better understand how to mitigate the...

No abstract available.

In this paper we show that ML-MC is a viable and regionally portable depth discriminant and therefore may contribute in nuclear test ban treaty verification. A recent study found that the difference between local magnitude (ML) and coda duration magnitude (MC) discriminates shallow seismic events (mining blasts, mining-induced earthquakes, and shallow tectonic earthquakes) from deeper...

We invert the shear-wave displacement spectra obtained from 30 three-component, broadband waveforms recorded within 300 km of the 6 November 2011 Mw 5.7 Prague, Oklahoma earthquake to recover the site-response contribution using an inversion method that simultaneously inverts for source, path, and site effects. Site-response functions identify resonant frequencies within a range of 0.1...

High-resolution optical satellite imagery is used to quantify vertical surface deformation associated with the intraplate 20 May 2016 Mw 6.0 Petermann Ranges earthquake, Northern Territory, Australia. The 21 ╓ 1 km long NW-trending rupture resulted from reverse motion on a northeast-dipping fault. Vertical surface offsets of up to 0.7 ╓ 0.1 m distributed across a 0.5-to-1 km wide...

Unconsolidated, near-surface sediments can have a profound influence on the amplitudes and frequencies of ground shaking during earthquakes, and these effects should be accounted for when using amplitude observations for seismic hazard assessments. This study explores methods to use teleseismic arrivals recorded on linear receiver arrays to characterize widespread, shallow sedimentary...

Tsunamis generated by landslides in Glacier Bay are uncommon, but have potential to be extraordinarily destructive when they occur. This article identifies areas that are susceptible to landslides that could generate tsunamis and discusses approaches to characterize hazard and risk from these events.

Supraglacial landslides result from the catastrophic failure of periglacial rock slopes and deposit large volumes of rock and ice onto the glacier surface. The most remarkable features of these landslides are their prominent long flowbands and a high mobility that exceeds that of their counterparts in other environments. Based on field surveys, high-resolution digital elevation models...

Static and quasi-static Coulomb stress changes produced by large earthquakes can modify the probability of occurrence of subsequent events on neighboring faults. This approach is based on physical (Coulomb stress changes) and statistical (probability calculations) models, which are influenced by the quality and quantity of data available in the study region. Here, we focus on the Wasatch...