Iceland's Vatnajokull

As fall marches toward winter in the Northern Hemisphere, Iceland's rugged terrain casts long shadows back on itself, exaggerating the topography of the island's snow-covered mountains, particularly along the eastern coast. On the northeastern portion of the island'd largest ice cap—Vatnajokull—what appears to be another of the season's long shadows is actually a layer of ash from the recent eruption of the sub-glacial volcano that lies beneath the thick ice. The Grimsvötn Volcano and Vatnajökull engage in a cycle of creation and destruction, build-up and release. Beneath a sheet of ice 200 meters thick in places, Grimsvötn simmers, its crater filled with a lake of meltwater dammed by ice blockages. The immense mass of water and ice presses down on the volcano, holding explosive eruptions in check. This is a MODIS image.