John A. Power (Former Employee)

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...

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...

The 2005-6 eruption of Augustine Volcano in the Cook Inlet region, Alaska, greatly increased public desire for volcano hazard information, as this eruption was the most significant in Cook Inlet since 1992. In response to this heightened concern, the Alaska Volcano Observatory (AVO) increased ongoing efforts to deliver specific eruption-focused information to communities nearest to the...

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...

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...

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...

In September of 2004, UNAVCO and the National Science Foundation (NSF) funded EarthScope Plate Boundary Observatory (PBO) installed five permanent Continuous Global Positioning System (CGPS) stations on Augustine Volcano, supplementing one existing CGPS station operated by the Alaska Volcano Observatory. All six CGPS stations proved crucial to scientists for detecting and monitoring the...

Before and during the 2006 eruption of Augustine Volcano, the Alaska Volcano Observatory (AVO) installed a network of telemetered and nontelemetered cameras in Homer, Alaska, and on Augustine Island. On December 1, 2005, a network camera was installed at the Homer Field Station, a University of Alaska Fairbanks Geophysical Institute (UAF/GI) facility on a bluff near Homer, where...

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...

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...

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...