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Summer in the Arctic National Wildlife Refuge
This page contains archived content and is no longer being updated. At the time of publication, it represented the best available science. However, more recent observations and studies may have rendered some content obsolete.
This colorful image of the Arctic National Wildlife Refuge and the
Beaufort Sea was acquired by the Multi-angle Imaging SpectroRadiometers
nadir (vertical-viewing) camera on August 16, 2000. The swirling patterns apparent on the Beaufort Sea are small ice
floes driven by turbulent water patterns, or eddies, caused by the
interactions of water masses of differing salinity and temperature. By
this time of year, all of the seasonal ice which surrounds the north
coast of Alaska in winter has broken up, although the perennial pack ice
remains further north. The morphology of the perennial ice packs edge
varies in response to the prevailing wind. If the wind is blowing
strongly toward the perennial pack (that is, to the north), the ice edge
will be more compact. In this image the ice edge is diffuse, and the
patterns reflected by the ice floes indicate fairly calm weather.
The Arctic National Wildlife Refuge (often abbreviated to ANWR) was
established by President Eisenhower in 1960, and is the largest wildlife
refuge in the United States. Animals of the Refuge include the
130,000-member Porcupine caribou herd, 180 species of birds from four
continents, wolves, wolverine, polar and grizzly bears, muskoxen, foxes,
and over 40 species of coastal and freshwater fish. Although most of
ANWR was designated as wilderness in 1980, the area along the coastal
plain was set aside so that the oil and gas reserves beneath the tundra
could be studied. Drilling remains a topic of contention, and an energy
bill allowing North Slope oil development to extend onto the coastal
plain of the Refuge was approved by the US House of Representatives on
August 2, 2001.
The Refuge encompasses an impressive variety of arctic and subarctic
ecosystems, including coastal lagoons, barrier islands, arctic tundra,
and mountainous terrain. Of all these, the arctic tundra is the
landscape judged most important for wildlife. From the coast inland to
an average of 30-60 kilometers, arctic tundra dominates the coastal
plain, until reaching the foothills of the Brooks Mountain Range.
Beneath the tundra, a layer of permafrost reaches an average depth of
600 meters, restricting water drainage through the soil, and increasing
the sensitivity of tundra vegetation to disturbance. Precipitation is
scarce (less than 16 centimeters per year) and the small amount of melt
water or rain that soaks into the tundra remains near the surface. This
is why the coastal plain can be classified as a wetland.
The western boundary of the Refuge is marked by the Canning River,
about halfway between the center and left-hand side of the image, and
the eastern boundary is near the right-hand edge at the US/Canadian
border. The two permanent human settlements within the image area are
Kaktovic near the tip of the large rounded peninsula, and Arctic Village
south of the Brooks Range near the southern Refuge boundary. The area
represented by the image is approximately 380 kilometers x 540