Publications

Regional seismic waveforms, continuous and campaign-mode GPS data, and surface slip measurements were used to obtain a kinematic model of the rupture process of the November 3, 2002 Mw 7.9 Denali, Alaska, earthquake. The event initiated as a Mw 7.0 reverse slip event on the north-dipping Susitna Glacier fault with subsequent right-lateral slip distributed over approximately 300 km of the...

The 3 November 2002 Denali fault, Alaska, earthquake resulted in 341 km of surface rupture on the Susitna Glacier, Denali, and Totschunda faults. The rupture proceeded from west to east and began with a 48-km-long break on the previously unknown Susitna Glacier thrust fault. Slip on this thrust averaged about 4 m (Crone et al., 2004). Next came the principal surface break, along 226 km...

We compare the frictional strengths of 17 sheet structure mineral powders, measured under dry and water-saturated conditions, to identify the factors that cause many of them to be relatively weak. The dry coefficient of friction μ ranges upward from 0.2 for graphite, leveling off at 0.8 for margarite, clintonite, gibbsite, kaolinite, and lizardite. The values of μ (dry) correlate...

The northeast Mojave domain, a type locality for bookshelf faulting, is a region of east striking, left-lateral faults in the northeast corner of the Mojave block, a block otherwise dominated by ∼N40°W striking, right-lateral faults. Paleomagnetic evidence suggests that blocks within the domain have rotated clockwise about a vertical axis as much as 60° since 12.8 Ma [Schermer et al...

We present an updated model of the Juan de Fuca slab beneath southern British Columbia, Washington, Oregon, and northern California, and use this model to separate earthquakes occurring above and below the slab surface. The model is based on depth contours previously published by Fluck and others (1997). Our model attempts to rectify a number of shortcomings in the original model and...

We perform inverse kinematic and forward dynamic models of the M 7.9 2002 Denali fault, Alaska, earthquake to shed light on the rupture process and dynamics of this event, which took place on a geometrically complex fault system in central Alaska. We use a combination of local seismic and Global Positioning System (GPS) data for our kinematic inversion and find that the slip distribution...

Data from the 2002 Denali fault earthquake recorded at 26 sites in and near Anchorage, Alaska, show a number of systematic features important in studies of site response and in constructing long-period spectra for use in earthquake engineering. The data demonstrate that National Earthquake Hazards Reduction Program (NEHRP) site classes are a useful way of grouping stations according to...

The ground motion hazard for Sumatra and the Malaysian peninsula is calculated in a probabilistic framework, using procedures developed for the US National Seismic Hazard Maps. We constructed regional earthquake source models and used standard published and modified attenuation equations to calculate peak ground acceleration at 2% and 10% probability of exceedance in 50 years for rock...

Crustal-scale seismic-velocity models across the Denali fault zone along the Richardson Highway show a 50-km-thick crust, a near vertical fault trace, and a 5-km-wide damage zone associated with the fault near Trans-Alaska Pipeline Pump Station 10, which provided the closest strong ground motion recordings of the 2002 Denali fault earthquake. We compare models, derived from seismic...

During the MW 7.1 Hector Mine earthquake, peak ground velocities recorded at sites in the central San Bernardino basin region were up to 2 times larger and had significantly longer durations of strong shaking than sites just outside the basin. To better understand the effects of 3D structure on the long-period ground-motion response in this region, we have performed finite-difference...

Chronosequential analysis of soil properties has proven to be a valuable approach for estimating ages of geomorphic surfaces where no independent age control exists. In this study we examined pedogenic silica as an indicator of relative ages of soils and geomorphic surfaces, and assessed potential sources of the silica. Pedogenic opaline silica was quantified by tiron (4,5-dihydroxy-1,3...

Mathematical models of soil nonlinearity in common use and recently developed nonlinear codes compared to investigate the range of their predictions. We consider equivalent linear formulations with and without frequency-dependent moduli and damping ratios and nonlinear formulations for total and effective stress. Average velocity profiles to 150 m depth with midrange National Earthquake...