These Multi-angle Imaging SpectroRadiometer (MISR) images from Terra
orbit 8476 capture the July 22, 2001 explosion of the Mt. Etna volcano.
Etna is located near the eastern coast of Sicily, to the southwest of
mainland Italy. Major eruptions have been issuing from both summit and
flank vents. Fine ash falling onto the Province of Catania closed the
local airport, and a state of emergency was declared for the town of
Nicolosi, which was threatened by lava flows from the southern flanks
of the volcano.
At the bottom of this image set are true-color views from MISR's 70-degree
forward-viewing camera, the vertical-viewing (nadir) camera, and the 70-degree
backward-viewing camera. Each covers an area of 143 kilometers x 88 kilometers.
The upper image is a stereo anaglyph created from the instrument's 70-degree
and 46-degree forward views, and covers an area of 438 kilometers x 300 kilometers.
To facilitate stereo viewing, the images are oriented with north at the left.
Viewing the stereo image in 3-D requires red/blue glasses with the red filter
placed over your left eye. Information on ordering 3-D glasses is available at
http://photojournal.jpl.nasa.gov/Help/VendorList.html#Glasses.
Two plumes of differing compositions are seen to be emanating from Etna. The bright, brownish plume drifting southeast over the Ionian Sea is composed primarily of tiny frozen fragments of lava, known as ash. A fainter, bluish-white plume is also visible, especially near the summit, and is most apparent in the 70-degree forward view. It contains very fine droplets of dilute sulfuric acid. In addition to the particulate plumes visible in these images, the volcano also expels gases such as water vapor, sulfur dioxide, and carbon dioxide.
Although the Etna volcano is one of the world's most studied volcanoes, it is
difficult to classify, being a mixture of overlapping shield and strato
volcanoes, partially destroyed by repeated caldera collapse, and partially
buried by younger volcanic structures. Eruptions are related to a complex
tectonic situation, including subducting plates, numerous major faults
intersecting at the volcano, and perhaps also to hot-spot volcanism.
For more information on Etna, refer to Michigan Technological University's
Department of Geological Engineering and Sciences
(http://www.geo.mtu.edu/~boris/ETNA.html)
and to the Smithsonian Institution's Global Volcanism Program
(http://www.volcano.si.edu/gvp/usgs/).
Mt. Etna is Europe's highest (3315 meters) and most active volcano. In ancient
Greek mythology, Etna was identified with the forge of Volcan.
Image credit: NASA/GSFC/LaRC/JPL, MISR Team.
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