The
Northern Patagonian Ice Field, located in southern
Chile, is the smaller of two remnant parts in which the
Patagonian Ice Sheet in the
Andes Mountains of lower
South America can be divided. It is completely contained within the boundaries of
Laguna San Rafael National Park. The Northern Patagonian Ice Field is a vestige of the
Patagonian Ice Sheet, an extensive
ice sheet that covered all of Chilean
Patagonia and the westernmost parts of Argentine Patagonia during the
Quaternary glaciations. Today, with its
glaciers largely in retreat and only an area of , it is still the second largest continuous mass of ice outside of the
polar regions. Survival is based on its elevation , 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.