Publications

The petrology and geochemistry of 2006 eruptive products of Augustine Volcano, Alaska, have been investigated through analyses of whole-rock samples, phenocrysts, silicate melt inclusions, and matrix glasses to constrain processes of magma evolution, eruption, and degassing. Particular attention was directed toward the concentrations and geochemical relationships involving the magmatic...

In-place measurements of environmental magnetic susceptibility of pyroclastic flows, surges and lahars emplaced during the 2006 eruption of Augustine Volcano show that primary volume magnetic susceptibilities of pyroclastic materials decreased where the flows encountered water and steam. The Rocky Point pyroclastic flow, the largest flow of the eruption sequence, encountered a small pond...

Lightning and other electrical activity were measured during the 2006 eruption of Augustine Volcano. We found two phases of the activity, the explosive phase corresponding to the explosive eruptions and the plume phase. We classified the lightning into three types, vent discharges, near-vent lightning, and plume lightning. Vent discharges are small, 10 to 100 m sparks, that occur at rate...

Satellite observations played an important role in monitoring the 2006 eruption of Augustine Volcano. It represented the first opportunity for observers to use, in an operational setting, new Web-based tools and techniques developed by the Alaska Volcano Observatory remote sensing group. The 'Okmok Algorithm' was used to analyze thermal infrared satellite data and highlight changes in...

Long-exposure visible-light images of Augustine Volcano were obtained using a charge-coupled device (CCD) camera during several nights of the 2006 eruption. The camera was located 105 km away, at Homer, Alaska, yet showed persistent bright emissions from the north flank of the volcano corresponding to steam releases, pyroclastic flows, and rockfalls originating near the summit. The...

Augustine Volcano has been a prolific producer of large debris avalanches during the Holocene. Originating as landslides from the steep upper edifice, these avalanches typically slide into the surrounding ocean. At least one debris avalanche that occurred in 1883 during an eruption initiated a far-traveled tsunami. The possible occurrence of another edifice collapse and ensuing tsunami...

Each of the three phases of the 2006 eruption at Augustine Volcano had a distinctive eruptive style and flowage deposits. From January 11 to 28, the explosive phase comprised short vulcanian eruptions that punctuated dome growth and produced volcanowide pyroclastic flows and more energetic hot currents whose mobility was influenced by efficient mixing with and vaporization of snow...

A late Wisconsin volcano erupted onto the JurassicCretaceous sedimentary bedrock of Augustine Island in lower Cook Inlet in Alaska. Olivine basalt interacting with water erupted explosively. Rhyolitic eruptive debris then swept down the south volcano flank while late Wisconsin glaciers from mountains on western mainland surrounded the island. Early to middle Holocene deposits probably...

Deposits from the 2006 eruption of Augustine Volcano, Alaska, record a complex history of magma mixing before and during the eruption. The eruption produced five major lithologies: low-silica andesite scoria (LSAS; 56.5 to 58.7 weight percent SiO2), mostly during the initial explosive phase; high-silica andesite pumice (HSA; 62.2 to 63.3 weight percent SiO2), prevalent during the...

Augustine Volcano erupted explosively after 20 years of quiescence on January 11, 2006, followed by approximately 2 months of dome building and lava extrusion. This is the best monitored eruption in Alaska to date; the diverse complementary datasets gathered enable an interdisciplinary interpretation of volcanic activity. An analysis of reduced displacement (continuous measure of seismic...

Thermal infrared (TIR) images provided a timely pre- and syn-eruption record of summit changes, lava flow emplacement, and pyroclastic-flow-deposit distribution during the Alaska Volcano Observatory's (AVO) response to the 2006 eruption of Augustine Volcano. A series of images from both handheld and helicopter mounted forward looking infrared radiometers (FLIR) captured detailed views...

For the first time in the United States, a modern geodetic network of continuously recording Global Positioning System (GPS) receivers has measured a complete eruption cycle at a stratovolcano, Augustine Volcano in Alaska, from the earliest precursory unrest through the return to background quiescence. The on-island network consisted of five continuously recording, telemetered GPS...