Since last spring, the U.S. Geological Survey's Alaska Volcano Observatory
(AVO) has detected increasing volcanic unrest at Augustine Volcano in Cook
Inlet, Alaska near Anchorage. Based on all available monitoring data, AVO
regards that an eruption similar to 1976 and 1986 is the most probable
outcome. During January, activity has been episodic, and characterized by
emission of steam and ash plumes, rising to altitudes in excess of 9,000
m (30,000 ft), and posing hazards to aircraft in the vicinity. An ASTER
image was acquired at 12:42 AST on January 12, 2006, during an eruptive
phase of Augustine. The perspective rendition shows the eruption plume
derived from the ASTER image data. ASTER's stereo viewing capability was
used to calculate the 3-dimensional topography of the eruption cloud as it
was blown to the south by prevailing winds. From a maximum height of 3060
m (9950 ft), the plume cooled and its top descended to 1900 m (6175 ft).
The perspective view shows the ASTER data draped over the plume top
topography, combined with a base image acquired in 2000 by the Landsat
satellite, that is itself draped over ground elevation data from the
Shuttle Radar Topography Mission. The topographic relief has been
increased 1.5 times for this illustration. Comparison of the ASTER plume
topography data with ash dispersal models and weather radar data will
allow the National Weather Service to validate and improve such models.
These models are used to forecast volcanic ash plume trajectories and
provide hazard alerts and warnings to aircraft in the Alaska region.
ASTER is one of five Earth-observing instruments launched December 18,
1999, on NASA's Terra satellite. The instrument was built by Japan's
Ministry of Economy, Trade and Industry. A joint U.S./Japan science team
is responsible for validation and calibration of the instrument and the
data products.
The broad spectral coverage and high spectral resolution of ASTER provides
scientists in numerous disciplines with critical information for surface
mapping, and monitoring of dynamic conditions and temporal change. Example
applications are: monitoring glacial advances and retreats; monitoring
potentially active volcanoes; identifying crop stress; determining cloud
morphology and physical properties; wetlands evaluation; thermal pollution
monitoring; coral reef degradation; surface temperature mapping of soils
and geology; and measuring surface heat balance.
The U.S. science team is located at NASA's Jet Propulsion Laboratory,
Pasadena, Calif. The Terra mission is part of NASA's Science Mission
Directorate.
Size: Roughly 25 km (15 miles) across; scale varies in this perspective
view
Location: 59.3 deg. North latitude, 153.4 deg. West longitude
Orientation: View from southwest towards the northeast
Vertical Exaggeration: 2
Eruption plume and Elevation: 30 m ASTER, (1-arcsecond)
Image Data: Landsat bands 7, 4 and 2
Ground Topography Data: SRTM 90 m data, acquired January 2000
Date Acquired: ASTER: January 12, 2006; Landsat: September 17, 2000