Publications

The High Resolution Stereo Camera (HRSC) has been orbiting the planet Mars since January 2004 onboard the ESA Mars Express mission and delivers imagery which is being used for topographic mapping of the planet. The HRSC team is currently conducting a systematic inter-comparison of different alternatives for the production of high resolution Digital Terrain Models (DTMs) from the...

In March of 2004, the U.S. Geological Survey conducted a geophysical survey in the Withlacoochee River of west-central Florida. This report serves as an archive of unprocessed digital boomer seismic reflection data, trackline maps, navigation files, GIS information, Field Activity Collection System (FACS) logs, observer's logbook, and FGDC metadata. Filtered and gained digital images of...

Numerical models are presented that simulate several active tectonic processes. These models include a continent that is thermally and mechanically coupled with viscous mantle flow. The assumption of rigid continents allows use of solid body equations to describe the continents' motion and to calculate their velocities. The starting point is a quasi-steady state model of mantle...

Interferometric synthetic aperture radar (InSAR) imagery documents the consistent subsidence, during the interval 1992–1999, of a pyroclastic flow deposit (PFD) emplaced during the 1986 eruption of Augustine Volcano, Alaska. We construct finite element models (FEMs) that simulate thermoelastic contraction of the PFD to account for the observed subsidence. Three-dimensional problem...

This paper quantifies atmospheric mercury (Hg) emissions from substrates and fumaroles associated with three hydrothermal systems: Lassen Volcanic Center, California (LVC); Yellowstone Caldera, Wyoming (YC); and Dixie Valley, Nevada (DV). Substrate Hg fluxes were measured using field chamber methods at thermal and nonthermal sites. The highest Hg fluxes (up to 541 ng m−2 h−1) were...

Major-element and volatile (H2O, CO2, S) compositions of glasses from the submarine flanks of Kilauea Volcano record its growth from pre-shield into tholeiite shield-stage. Pillow lavas of mildly alkalic basalt at 2600–1900 mbsl on the upper slope of the south flank are an intermediate link between deeper alkalic volcaniclastics and the modern tholeiite shield. Lava clast glasses from...

The extensive impact cratering record on Mars combined with evidence from SNC meteorites suggests that a significant fraction of the surface is composed of materials subjected to variable shock pressures. Pressure-induced structural changes in minerals during high-pressure shock events alter their thermal infrared spectral emission features, particularly for feldspars, in a predictable...

The Panoramic Camera (Pancam) on the Mars Exploration Rover Opportunity acquired visible/near‐infrared multispectral observations of soils and rocks under varying viewing and illumination geometries that were modeled using radiative transfer theory to improve interpretations of the microphysical and surface scattering nature of materials in Meridiani Planum. Nearly 25,000 individual...

We report the results of two soil CO2 efflux surveys by the closed chamber circulation method at the Puhimau thermal area in the upper East Rift Zone (ERZ) of Kilauea volcano, Hawaii. The surveys were undertaken in 1996 and 1998 to constrain how much CO2 might be reaching the ERZ after degassing beneath the summit caldera and whether the Puhimau thermal area might be a significant...

We present new seismic refraction/wide-angle-reflection data across the Altyn Tagh Range and its adjacent basins. We find that the crustal velocity structure, and by inference, the composition of the crust changes abruptly beneath the Cherchen fault, i.e., ∼100 km north of the northern margin of the Tibetan plateau. North of the Cherchen fault, beneath the Tarim basin, a platform-type...

Young volcanic deposits in Kahoolawe Island, cutting up through the caldera-filling lava, colluvium and talus in the west wall of Kanapou Bay, had long been stratigraphically considered the rejuvenated-stage products. New K-Ar ages, combined with magnetic polarity data, show that young volcanism was at about 0.98-1.04 Ma and indicate no substantial quiescence between the filling of the...

A field of giant sand waves, among the largest in the world, recently was mapped in high resolution for the first time during a multibeam survey in 2004 and 2005 through the strait of the Golden Gate at the mouth of San Francisco Bay in California (Figure la). This massive bed form field covers an area of approximately four square kilometers in water depths ranging from 30 to 106 meters...