Publications

Apparent phreatic explosion craters, caldera-floor volcanic cones, and geothermal features outline a ring fracture zone along which Mount Mazama collapsed to form the Crater Lake caldera during its climactic eruption about 6,850 yr B.P. Within a few years, subaerial deposits infilled the phreatic craters and then formed a thick wedge (10-20 m) of mass flow deposits shed from caldera walls. Intense

The Foothills Metamorphic Belt is an accreted terrane consisting of Paleozoic and Mesozoic metamorphic rocks that separates the Great Valley from the Sierra Nevada batholith in northern and central California. Until recently, the only available geophysical data for this area were reconnaissance refraction surveys, and gravity and magnetic data. New insights into the structure of the deep crust are

We apply a linear, finite-fault waveform inversion scheme to the near-source strong-motion records, the teleseismic body waves, and the long-period Rayleigh waves recorded for the 3 March 1985 Chile earthquake to recover the mainshock rupture history. The data contain periods between about 2 and 350 sec and are inverted by allowing a variable dislocation rise time at each point on the fault. The r

A prototype early warning system to provide San Francisco and Oakland, California a few tens-of-seconds warning of incoming strong ground shaking from already-occurred M ≧ 3.7 aftershocks of the magnitude 7.1 17 October 1989 Loma Prieta earthquake was operational on 28 October 1989. The prototype system consisted of four components: ground motion sensors in the epicentral area, a central receiver,

Compilation of a simplified geologic/geomorphic map onto digital terrain models of the Valles Marineris permitted an evaluation of elevations in the vicinity of the troughs and the calculation of depth of troughs below surrounding plateaus, thickness of deposits inside the troughs, volumes of void spaces above geologic/geomorphic units, and volumes of deposits. The central troughs north Ophir, nor

Recently Brown et al. (1991) showed that Triton's internal heat source could amount to 5–20% of the absorbed insolation on Triton, thus significantly affecting volatile transport and atmospheric pressure. Subsequently, Kirk and Brown (1991a) used simple analytical models of the effect of internal heat on the distribution of volatiles on Triton's surface, confirming the speculation of Brown et al.

Velocity measurements were made for two time intervals on the Smith Glacier ice tongue (1973–88 and 1988–90) and three on the Dotson Ice Shelf (1972–88, 1973–88 and 1988–90). The Smith Glacier ice tongue velocities for the two intervals are similar near the grounding line but show a progressive increase toward the terminus in the late 1980s. The Dotson Ice Shelf velocities remained virtually const

No abstract available.

Hot springs along the Owyhee River in southeastern Oregon between Three Forks and Lake Owyhee could be part of a north flowing regional system or a series of small separate geothermal systems Heat for the waters could be from a very young (Holocene) volcanic activity (basalt flows) of the Owyhee Uplands or the regional heat flow. The springs discharge warm to hot, dilute, slightly alkaline, sodium

Tropical storms of various kinds are as much a depositional event as an erosional event. Much attention is given to the destructive aspects of major storms because of the loss of life and property, but little is known about their beneficial effects to coastal accretion. While we can usually measure and map the instantaneous effects of a tropical storm, we can only speculate about the long-term eff

No abstract available.

No abstract available.