Saturday, 22 June 2013

Volcanoes from outer space NASA's striking photographs of erupting volcanoes as seen from space. III

volcanos from space


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


 volcanos from space


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


 volcanos from space


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