Publications

After an 11‐year period of repose, Pavlof volcano on the Alaska Peninsula (Figure 1) began an episode of Strombolian eruption lasting 31 days, from 14 August to 13 September 2007.The eruption began abruptly on 14 August after a minor increase in seismicity the previous day. Nearly continuous lava fountaining, explosions, and lahars caused by minor disruption of the ice and snow cover on the volcan

Gareloi Volcano (178.794 degrees W and 51.790 degrees N) is located on Gareloi Island in the Delarof Islands group of the Aleutian Islands, about 2,000 kilometers west-southwest of Anchorage and about 150 kilometers west of Adak, the westernmost community in Alaska. This small (about 8x10 kilometer) volcano has been one of the most active in the Aleutians since its discovery by the Bering expediti

It is rare that a geologic map exists for a volcano prior to such a catastrophic modification as that produced by the eruption of Mount St. Helens in 1980. As such, this map provides an important historical record of the volcano prior to that eruption. The map has not been reviewed or checked for conformity to USGS editorial standards or stratigraphic nomenclature, and it has not been digitized. T

This contribution reports radiocarbon ages obtained from charcoal, wood and other samples collected between 1979 and 2001 in Lassen Volcanic National Park and vicinity and a few samples from other nearby localities. Most of the samples are from the Chaos Crags and Cinder Cone eruptive sequences. Brief summaries are given of the Chaos Crags and Cinder Cone eruptive sequences.

On 29 May 2006 a large rockfall off the Mount St. Helens lava dome produced an atmospheric plume that was reported by airplane pilots to have risen to 6,000 m above sea level and interpreted to be a result of an explosive event. However, subsequent field reconnaissance found no evidence of a ballistic field, indicating that there was no explosive component. The rockfall produced complex seismic an

An Md 4.5 earthquake located ∼12 km east of Mount Rainier occurred on 8 October 2006 at 02:48 UTC (figure 1). Although not large enough to be damaging or of major tectonic significance, a summary description of the earthquake is warranted because of its proximity to Mount Rainier, and because earthquakes of Md ≥ 4.5 are relatively rare in this region. Previous events of Md ≥ 4.5 have occurred appr

Volcanic eruptions and other potentially hazardous natural phenomena occur independently of any human actions. However, such phenomena can cause disasters when a society fails to foresee the hazardous manifestations and adopt adequate measures to reduce its vulnerability. One of the causes of such a failure is the lack of a consistent perception of the changing hazards posed by an ongoing eruption

No abstract available.

The current eruption at Mount St. Helens is characterized by dome building and shallow, repetitive, long-period (LP) earthquakes. Waveform cross-correlation reveals remarkable similarity for a majority of the earthquakes over periods of several weeks. Stacked spectra of these events display multiple peaks between 0.5 and 2 Hz that are common to most stations. Lower-amplitude very-long-period (VLP)

From November 1999 through July 2000, a broadband seismic experiment was carried out at Popocatépetl Volcano to record seismic activity over a wide period range (0.04–100 s). We present an overview of the seismicity recorded during this experiment and discuss results of analyses of long-period (LP) and very-long-period (VLP) seismic signals recorded at stations nearest to the crater over a four-mo

Scoria-cone eruptions are typically low in volume and explosivity compared with eruptions from stratovolcanoes, but they can affect local populations profoundly. Scoria-cone eruption effects vary dramatically due to eruption style, tephra blanket extent, climate, types of land use, the culture and complexity of the affected group, and resulting governmental action. A comparison of a historic erupt

The main goal of this study is to improve the modelling of the source mechanism associated with the generation of long period (LP) signals in volcanic areas. Our intent is to evaluate the effects that detailed structural features of the volcanic models play in the generation of LP signal and the consequent retrieval of LP source characteristics. In particular, effects associated with the presence