| Northern Patagonian Ice Field, Chile: The Northern Patagonian
Ice Field (NPIF), centered near 47°S, 73.5°W, is the smaller of two
remnant ice masses crowning the Andes Mountains of lower South
America. The NPIF is a vestige of an extensive ice sheet that covered
much of Patagonia just over a million years ago. Today, with its
glaciers largely in retreat and only an area of 4,200 sq km, it is
still the largest continuous mass of ice outside of the polar
regions. Survival is based on its elevation (1, 100 to 1,500 m),
favorable terrain, and a cool, moist, marine climate. The ice field
has 28 exit glaciers, the largest two—San Quintin and San
Rafael—nearly reach sea level to the west at the Pacific Ocean.
Smaller exit glaciers, like San Valentin and Nef, feed numerous
rivers and glacially carved lakes to the east. This photo taken by
the crew of STS-108 in December, 2001, offers a remarkably clear view
of the northern two-thirds of this bright, icy feature, its glaciers,
and its northern and eastern flanks. Arms of Lake General Carrera are
visible on the right of the image. Such photos offer unsurpassed
visual context information about the state of this remote locale and
details of its features and processes. |
