A spaceborne image of Onekotan Island
The image shows a Russian volcanic island, known as Onekotan. It was acquired by an astronaut, aboard the International Space Station, the largest spacecraft ever launched into space.
Credit: NASA/JSC

 

NASA recently published a wonderful spaceborne image of a snow-covered Russian volcanic island, located near the northern end of the Kuril Islands chain, in the northwestern Pacific Ocean. The image was acquired by an astronaut, aboard the International Space Station (ISS), orbiting Earth at an altitude of about 350 km.


The island, known as Onekotan Island, is uninhabited, and features volcanic cones and calderas. Calderas are depressions formed when a volcano outpours its magma, in an explosive eruption, and then the overlaying material collapses into the evacuated space. Magma is a mixture of molten rocks, volatiles and solids, found beneath Earth’s surface.


The astronaut photograph shows the northern region of the island (image right), dominated by the Nemo Peak volcano, which began developing within an older caldera, approximately 9,500 years ago. The last recorded eruption at Nemo Peak occurred in the early 18th century.


The southern part of the island was formed by the 7.5 km wide Tao-Rusyr Caldera. The caldera is filled by a lake and Krenitzyn Peak, a volcano that has only erupted once in recorded history, in 1952.


Stretching between northeastern Japan and the Kamchatka Peninsula of Russia, the Kurils are an island arc located along the Pacific “Ring of Fire.” The Ring of Fire is a huge horseshoe-shaped region, encircling most of the Pacific Basin, featuring high volcanic and tectonic activity. It is over 40,000 km in length. Island arcs form along an active boundary between two tectonic plates, where one plate is moving beneath the other (subduction process). Magma, generated by subduction supplies volcanoes, which eventually form volcanic islands over the subduction boundary.


References
NASA Earth Observatory
http://earthobservatory.nasa.gov/IOTD/view.php?id=48785
Wikipedia


Aymen Mohamed Ibrahem
Senior Astronomy Specialist