Publications

On May 10, 2003, the first historical eruption of Anatahan volcano in the western Pacific Mariana Islands was fortuitously recorded by a broadband seismograph installed on the island only 4 days prior to the eruption. This station, located 7 km WNW of the active crater, together with another broadband seismograph on Sarigan Island 45 km to the north, continued to operate throughout the 2...

Within the Commonwealth of the Northern Mariana Islands (CNMI), Anatahan is one of nine active subaerial volcanoes that pose hazards to major air-traffic routes from airborne volcanic ash. The 2003-2004 eruptive activity of Anatahan volcano affected the region's aviation operations for 3 days in May 2003. On the first day of the eruption (10 May 2003), two international flights from...

The ion microprobe has the capability to generate high resolution, high precision isotopic measurements, but analysis of the isotopic composition of strontium, as measured by the 87Sr/86Sr ratio, has been hindered by isobaric interferences. Here we report the first high precision measurements of 87Sr/86Sr by ion microprobe in calcium carbonate samples with moderate Sr concentrations. We...

The June 1912 eruption of Novarupta filled nearby glacial valleys on the Alaska Peninsula with ash-flow tuff (ignimbrite), and post-eruption observations of thousands of steaming fumaroles led to the name ‘Valley of Ten Thousand Smokes’ (VTTS). By the late 1980s most fumarolic activity had ceased, but the discovery of thermal springs in mid-valley in 1987 suggested continued cooling of...

The first historical eruption of Anatahan volcano began on May 10, 2003. Samples of tephra from early in the eruption were analyzed for major and trace elements, and Sr, Nd, Pb, Hf, and O isotopic compositions. The compositions of these tephras are compared with those of prehistoric samples of basalt and andesite, also newly reported here. The May 2003 eruptives are medium-K andesites...

Data acquired by three continuously recording thermal infrared thermometers situated on the north rim of Pu'u'O' o Crater at Kilauea Volcano during 2002 revealed episodes of periodic thermal pulses originating from a degassing vent on the crater floor. These thermal pulses are interpreted as gas release (jetting events) associated with gas pistoning, a mechanism observed previously at...

We examine 20-yr data sets of seismic activity from 10 volcanic areas in the western United States for annual periodic signals (seasonality), focusing on large calderas (Long Valley caldera and Yellowstone) and stratovolcanoes (Cascade Range). We apply several statistical methods to test for seasonality in the seismic catalogs. In 4 of the 10 regions, statistically significant seasonal...

A catastrophic lahar began on 30 October 1998, as hurricane precipitation triggered a small flank collapse of Casita volcano, a complex and probably dormant stratovolcano. The initial rockslide‐debris avalanche evolved on the flank to yield a watery debris flood with a sediment concentration less than 60 per cent by volume at the base of the volcano. Within 2·5 km, however, the watery flow...

Rhyodacite tephra and three lavas erupted ∼27 ka, interpreted to be early leaks from the climactic magma chamber of Mount Mazama, contain ubiquitous resorbed crystals (antecrysts) that were recycled from young granodiorite and related plutonic rocks of the same magmatic system. The shallow composite pluton is represented by blocks ejected in the 7.7-ka climactic eruption that formed...

In March 1996, an intense earthquake swarm beneath Akutan Island, Alaska, was accompanied by extensive ground cracking but no eruption of Akutan volcano. Radar interferograms produced from L-band JERS-1 and C-band ERS-1/2 images show uplift associated with the swarm by as much as 60 cm on the western part of the island. The JERS-1 interferogram has greater coherence, especially in areas...

Thermal infrared (TIR) data from the MASTER airborne imaging spectrometer were acquired over Mount St. Helens in Sept and Oct, 2004, before and after the onset of recent eruptive activity. Pre‐eruption data showed no measurable increase in surface temperatures before the first phreatic eruption on Oct 1. MASTER data acquired during the initial eruptive episode on Oct 14 showed maximum...

Interferometric synthetic aperture radar (InSAR) is a remote sensing technique capable of measuring ground surface deformation with sub-centimeter precision and spatial resolution in tens-of­meters over a large region. This paper describes basics of InSAR and highlights our studies of Alaskan volcanoes with InSAR images acquired from European ERS-l and ERS-2, Canadian Radarsat-l, and...