From space, it is sometimes difficult to tell where land ends and
sea ice begins in the southern Sea
of Okhotsk. This is particularly evident in this detailed astronaut
photograph of the northeastern tip of Urup Island, one of the many
islands in the Kuril
chain, which extends from northern
Japan to the Kamchatka Peninsula of Russia.
The approximately 120-kilometer-long island extends to the southwest
from the point illustrated in the image; like the other Kuril Islands,
Urup was formed from volcanic processes along the active subduction
boundary between the Pacific and Okhotsk tectonic plates. The
northeastern tip of the island and three small islands to the northeast
are recognizable by their uniform cover of white snow and shadowing
along the northwestern coastlines.
Sea ice that formed to the north in the Sea of Okhotsk has been piled
up against the islands by prevailing northwesterly winds, forming an
irregular mass connecting the islands (image center). The orientation
of patchy low clouds over Urup Island (image lower left) also suggests
that northwesterly winds are present.
Smaller ice floes are breaking off from the main ice mass at gaps
between the islands and forming fingerlike projections of ice fragments
that extend to the southeast (image lower right). Surface winds may be
channeled through these gaps and accelerated, hastening the breakup and
movement of ice.
Astronaut photograph ISS023-E-15093
was acquired on March 30, 2010, with a Nikon D2Xs digital camera fitted
with an 800 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
23 crew. The image in this article 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.