Alaska North Slope
Encyclopedia
U.S. state
A U.S. state is any one of the 50 federated states of the United States of America that share sovereignty with the federal government. Because of this shared sovereignty, an American is a citizen both of the federal entity and of his or her state of domicile. Four states use the official title of...
of Alaska
Alaska
Alaska is the largest state in the United States by area. It is situated in the northwest extremity of the North American continent, with Canada to the east, the Arctic Ocean to the north, and the Pacific Ocean to the west and south, with Russia further west across the Bering Strait...
located on the northern slope of the Brooks Range
Brooks Range
The Brooks Range is a mountain range in far northern North America. It stretches from west to east across northern Alaska and into Canada's Yukon Territory, a total distance of about 1100 km . The mountains top out at over 2,700 m . The range is believed to be approximately 126 million years old...
along the coast of two marginal sea
Marginal sea
The term marginal sea has differing meanings. In one sense the term is equivalent to territorial waters. In another sense the term indicates a partially enclosed sea adjacent to or widely open to the open ocean, but bounded by submarine ridges...
s of the Arctic Ocean
Arctic Ocean
The Arctic Ocean, located in the Northern Hemisphere and mostly in the Arctic north polar region, is the smallest and shallowest of the world's five major oceanic divisions...
, the Chukchi Sea
Chukchi Sea
Chukchi Sea is a marginal sea of the Arctic Ocean. It is bounded on the west by the De Long Strait, off Wrangel Island, and in the east by Point Barrow, Alaska, beyond which lies the Beaufort Sea. The Bering Strait forms its southernmost limit and connects it to the Bering Sea and the Pacific...
being on the western side of Point Barrow
Point Barrow
Point Barrow or Nuvuk is a headland on the Arctic coast in the U.S. state of Alaska, northeast of Barrow. It is the northernmost point of all the territory of the United States, at...
, and the Beaufort Sea
Beaufort Sea
The Beaufort Sea is a marginal sea of the Arctic Ocean, located north of the Northwest Territories, the Yukon, and Alaska, west of Canada's Arctic islands. The sea is named after hydrographer Sir Francis Beaufort...
on the eastern.
The region contains the National Petroleum Reserve–Alaska
National Petroleum Reserve–Alaska
The National Petroleum Reserve in Alaska is an area of land on the Alaska North Slope owned by the United States federal government and managed by the Department of the Interior, Bureau of Land Management . It lies to the west of the Arctic National Wildlife Refuge, which as a U.S...
, with the bulk of Alaska's known petroleum
Petroleum
Petroleum or crude oil is a naturally occurring, flammable liquid consisting of a complex mixture of hydrocarbons of various molecular weights and other liquid organic compounds, that are found in geologic formations beneath the Earth's surface. Petroleum is recovered mostly through oil drilling...
until the Prudhoe Bay Oil Field
Prudhoe Bay oil field
Prudhoe Bay Oil Field is a large oil field on Alaska's North Slope. It is the largest oil field in both the United States and in North America, covering and originally containing approximately of oil.. BP. August 2006...
was discovered in 1968, as well as the Arctic National Wildlife Refuge
Arctic National Wildlife Refuge
The Arctic National Wildlife Refuge is a national wildlife refuge in northeastern Alaska, United States. It consists of in the Alaska North Slope region. It is the largest National Wildlife Refuge in the country, slightly larger than the Yukon Delta National Wildlife Refuge...
, which itself has been the subject of controversy surrounding the possibility of petroleum drilling within its boundaries. The petroleum extracted from the region is transferred south by means of the Trans-Alaska Pipeline System
Trans-Alaska Pipeline System
The Trans Alaska Pipeline System , includes the Trans Alaska Pipeline, 11 pump stations, several hundred miles of feeder pipelines, and the Valdez Marine Terminal. TAPS is one of the world's largest pipeline systems...
to Valdez
Valdez, Alaska
Valdez is a city in Valdez-Cordova Census Area in the U.S. state of Alaska. According to 2005 Census Bureau estimates, the population of the city is 4,020. The city is one of the most important ports in Alaska. The port of Valdez was named in 1790 after the Spanish naval officer Antonio Valdés y...
on the Pacific Ocean
Pacific Ocean
The Pacific Ocean is the largest of the Earth's oceanic divisions. It extends from the Arctic in the north to the Southern Ocean in the south, bounded by Asia and Australia in the west, and the Americas in the east.At 165.2 million square kilometres in area, this largest division of the World...
.
Within the North Slope, only a surface "active layer" of the tundra
Tundra
In physical geography, tundra is a biome where the tree growth is hindered by low temperatures and short growing seasons. The term tundra comes through Russian тундра from the Kildin Sami word tūndâr "uplands," "treeless mountain tract." There are three types of tundra: Arctic tundra, alpine...
thaws each season; most of the soil is permanently frozen year-round. On top of this permafrost
Permafrost
In geology, permafrost, cryotic soil or permafrost soil is soil at or below the freezing point of water for two or more years. Ice is not always present, as may be in the case of nonporous bedrock, but it frequently occurs and it may be in amounts exceeding the potential hydraulic saturation of...
, water flows to sea via shallow, braided streams
Braided river
A braided river is one of a number of channel types and has a channel that consists of a network of small channels separated by small and often temporary islands called braid bars or, in British usage, aits or eyots. Braided streams occur in rivers with high slope and/or large sediment load...
or settles into pools and ponds. Along the bottom of the Landsat 7
Landsat 7
Landsat 7, launched on April 15, 1999, is the latest satellite of the Landsat program. Landsat 7's primary goal is to refresh the global archive of satellite photos, providing up-to-date and cloud-free images. The Landsat Program is managed and operated by the USGS, and data from Landsat 7 is...
image on the right the rugged terrain of the Brooks Range mountains is snow-covered in places (blue areas) and exposed (pink areas) in others.
Much of the region is located in North Slope Borough
North Slope Borough, Alaska
-National protected areas:* Alaska Maritime National Wildlife Refuge ** Cape Lisburne** Cape Thompson* Arctic National Wildlife Refuge ** Mollie Beattie Wilderness * Gates of the Arctic National Park and Preserve...
.