Snow cover highlights the calderas and volcanic cones that form the
northern and southern ends of Onekotan Island, part of the Russian
Federation in the western Pacific Ocean. Calderas are depressions formed
when a volcano empties its magma chamber in an explosive eruption and
then the overlaying material collapses into the evacuated space.
In this astronaut photograph from the International Space Station,
the northern end of the island (image right) is dominated by the Nemo Peak volcano, which
began forming within an older caldera approximately 9,500 years ago.
The last recorded eruption at Nemo Peak occurred in the early 18th
The southern end of the island was formed by the 7.5 kilometer (4.6 mile) wide Tao-Rusyr Caldera. The caldera is filled by Kal’tsevoe Lake and Krenitzyn Peak, a volcano that has only erupted once in recorded history (in 1952).
Extending between northeastern Japan and the Kamchatka Peninsula of
Russian, the Kurils are an island arc located along the Pacific “Ring of Fire.” Island arcs form along an active boundary between two tectonic plates,
where one plate is being driven beneath the other (subduction). Magma
generated by the subduction process feeds volcanoes—which eventually
form volcanic islands over the subduction boundary.
Astronaut photograph ISS026-E-16287
was acquired on January 9, 2011, with a Nikon D2Xs digital camera using
an 180 mm lens, and is provided by the ISS Crew Earth Observations
experiment and Image Science & Analysis Laboratory, Johnson Space
Center. The image was taken by the Expedition 26 crew. The image has been cropped and enhanced to improve contrast. Lens artifacts have been removed. The International Space Station Program supports the laboratory as part of the ISS National Lab
to help astronauts take pictures of Earth that will be of the greatest
value to scientists and the public, and to make those images freely
available on the Internet. Additional images taken by astronauts and
cosmonauts can be viewed at the NASA/JSC Gateway to Astronaut Photography of Earth. Caption by William L. Stefanov, NASA-JSC.