On May 2, 2008 Chile's Chaiten Volcano erupted after 9,000 years of
inactivity. Now, 4 weeks later, the eruption continues, with ash-, water-,
and sulfur-laden plumes blowing hundreds of kilometers to the east and
north over Chile and Argentina. On May 24, ASTER captured a day-night pair
of thermal infrared images of the eruption, displayed here in enhanced,
false colors. At the time of the daytime acquisition (left image) most of
the plume appears dark blue because it is too thick for upwelling ground
radiation to penetrate. At the edges it appears orange, indicating the
presence of ash and sulfur dioxide. In the nighttime image (right), the
plume is orange and red near the source, and becomes more yellow-orange
further away from the vent. The possible cause is that ash is settling out
of the plume further downwind, revealing the dominant presence of sulfur
dioxide.
The images were acquired May 24, 2008, cover an area of 37 x 26.5 km, and
are located near 42.7 degrees south latitude, 72.7 degrees west longitude.
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.
