Volcanoes from outer space NASA's striking photographs of erupting volcanoes as seen from space. III
Llullaillaco Volcano: The summit of South Americaâs
Llullaillaco Volcano has an elevation of 22,110 feet above sea level,
making it the highest historically active volcano in the world. The
current stratovolcano--a cone-shaped volcano built from successive
layers of thick lava flows and eruption products like ash and rock
fragments--is built on top of an older stratovolcano. The last explosive
eruption of the volcano, based on historical records, occurred in 1877.
This photograph of Llullaillaco, taken from aboard the International
Space Station, illustrates an interesting volcanic feature known as a
coulee. Coulees are formed from highly viscous, thick lavas that flow
onto a steep surface. As they flow slowly downwards, the top of the flow
cools and forms a series of parallel ridges oriented at 90 degrees to
the direction of flow (somewhat similar in appearance to the pleats of
an accordion). The sides of the flow can also cool faster than the
center, leading to the formation of wall-like structures known as flow
levees. Llullaillaco is also a well-known archaeological site; the
mummified remains of three Inca children, ritually sacrificed 500 years
ago, were discovered on the summit in 1999. Image Credit: NASA
Eyjafjallajokull Volcano in Infrared On Sat., April 17, 2010,
the Advanced Land Imager (ALI) instrument aboard NASA's Earth
Observing-1 (EO-1) spacecraft obtained this false-color infrared image
of Iceland's Eyjafjallajokull volcano. A strong thermal source (denoted
in red) is visible at the base of the Eyjafjallajokull plume. Above and
to the right, strong thermal emission is also seen from the lava flows
located at Fimmvorduhals between March 20 and April 13, 2010, where lava
first reached the surface, generating impressive lava fountains and
lava flows. As the Fimmvorduhals episode was in a location with no ice
cap, there was little of the violent interaction between lava and water
that took place at Eyjafjallajokull and that generated the massive
volcanic plume. To the east of Fimmvorduhals is the Myrdalsjokull ice
cap, beneath which slumbers the mighty Katla volcano. Katla has erupted
20 times in recorded history, with the last eruption occurring in 1918.
Image Credit: NASA/JPL/EO-1 Mission/GSFC/Ashley Davies
Pavlof Volcano: From Station Astronauts aboard the
International Space Station (ISS) photographed this striking view of
Pavlof Volcano on May 18, 2013. The oblique perspective from the ISS
reveals the three dimensional structure of the ash plume, which is often
obscured by the top-down view of most remote sensing satellites.
Situated in the Aleutian Arc about 625 miles (1,000 kilometers)
southwest of Anchorage, Pavlof began erupting on May 13, 2013. The
volcano jetted lava into the air and spewed an ash cloud 20,000 feet
(6,000 meters) high. When photograph ISS036-E-2105 (top) was taken, the
space station was about 475 miles south-southeast of the volcano (49.1°
North latitude, 157.4° West longitude). The volcanic plume extended
southeastward over the North Pacific Ocean. ⺠Additional
information/larger images. Image Credit: NASA
No comments:
Post a Comment