Publications

Isotope tracer methods were used to determine flow paths, recharge areas, and relative age for ground water in the Kilauea volcano area on the Island of Hawaii. Stable isotopes in rainfall show three distinct isotopic gradients with elevation, which are correlated with trade-wind, rain shadow, and high-elevation climatological patterns. Temporal variations in isotopic composition of...

Geologists commonly infer the flow conditions and the physical properties of debris flows from the sedimentologic, stratigraphic, and morphologic characteristics of their deposits. However, such inferences commonly lack corroboration by direct observation because the capricious nature of debris flows makes systematic observation and measurement of natural events both difficult and...

The purpose of this report is to make available fluid-inclusion information from drill holes in five geothermal areas: The Geysers and Long Valley caldera in northern California; Steamboat Springs, Nevada; the Ahuachapan field of El Salvador, Central America; and the Mutnovsky geothermal field, Kamchatka Peninsula, Russia. These data were produced at the request of various individuals to...

Native Hawaiian forest birds are facing a major extinction crisis with more than 75% of species recorded in historical times either extinct or endangered. Reasons for this catastrophe include habitat destruction, competition with non-native species, and introduction of predators and avian diseases. We tested susceptibility of Iiwi (Vestiaria coccinea), a declining native species, and...

New heat-capacity measurements are reported for four rock types; Westerly granite from Bradford, RI, andesite from Lake County, OR, peridotite from Sonoma County, CA, and basalt from the Columbia River Group. Measurements were made on powders of the rocks in the temperature range of 340 to about 1000 K. Our measured heat-capacity values for rocks and other measurements of heat capacity...

No significant change in the rate of strain accumulation in a 40×120 km trilateration network spanning the San Gabriel mountains was observed from 1977.5 to 1991.8 despite an apparent increase in seismicity (ML > 4.5) beginning in late 1987 in the northern Los Angeles basin immediately to the south. The observed deformation (0.13±0.01 µstrain/yr right‐lateral shear across a vertical...

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...

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...

From 24 August 1989 until 18 June 1991, Mount St. Helens produced at least 28 shallow, explosion-like seismic events with signatures similar to those produced by gas explosions on the dome during the mid 1980s. At least six were accompanied by violent emission of non-juvenile tephra, ejection of blocks of rock nearly 1 km from the vent, and avalanching of debris off the north side of the...

A commercially-available lightning-detection system was temporarily deployed near Cook Inlet, Alaska in an attempt to remotely monitor volcanogenic lightning associated with eruptions of Redoubt Volcano. The system became operational on February 14, 1990; lightning was detected in 11 and located in 9 of the 13 subsequent eruptions. The lightning was generated by ash clouds rising from...

No abstract available.