The Alaska North Slope is the region of the

U.S. state In the United States, a state is a constituent political entity, of which there are 50. Bound together in a political union, each state holds governmental jurisdiction over a separate and defined geographic territory where it shares its so ...

Alaska Alaska ( ) is a non-contiguous U.S. state on the northwest extremity of North America. Part of the Western United States region, it is one of the two non-contiguous U.S. states, alongside Hawaii. Alaska is also considered to be the north ...

located on the northern slope of the

Brooks Range The Brooks Range (Gwich’in language, Gwich'in: ''Gwazhał'') is a mountain range in far northern North America stretching some from west to east across northern Alaska into Canada's Yukon Territory. Reaching a peak elevation of on Mount Isto, ...

along the coast of two

marginal sea This is a list of seas of the World Ocean, including marginal seas, areas of water, various gulfs, bights, bays, and straits. In many cases it is a matter of tradition for a body of water to be named a sea or a bay, etc., therefore all these ...

s of the

Arctic Ocean The Arctic Ocean is the smallest and shallowest of the world's five oceanic divisions. It spans an area of approximately and is the coldest of the world's oceans. The International Hydrographic Organization (IHO) recognizes it as an ocean, ...

, the

Chukchi Sea The Chukchi Sea (, ), sometimes referred to as the Chuuk Sea, Chukotsk Sea or the Sea of Chukotsk, is a marginal sea of the Arctic Ocean. It is bounded on the west by the Long Strait, off Wrangel Island, and in the east by Point Barrow, Alaska, ...

being on the western side of

Point Barrow Point Barrow or Nuvuk is a headland on the Arctic coast in the U.S. state of Alaska, northeast of Utqiagvik (formerly Barrow). It is the northernmost point of all the territory of the United States, at , south of the North Pole. (The northe ...

, and the

Beaufort Sea The Beaufort Sea ( ; ) is a marginal sea of the Arctic Ocean, located north of the Northwest Territories, Yukon, and Alaska, and west of the Canadian Arctic Archipelago. The sea is named after Sir Francis Beaufort, a Hydrography, hydrographer. T ...

on the eastern. With the exception of the highway connecting Fairbanks to Prudhoe Bay, the region is disconnected from the rest of the Alaskan road system and relies mostly on waterways and small airports for transportation due to the Brooks Range secluding the region from the rest of the state.Alaska Department of Commerce, Community, and Economic Development, Northern Opportunity Alaska's Economic Development Strategy, 2016, at 84 (Alaska 2016). Accessed June 1, 2023. https://www.commerce.alaska.gov/web/portals/0/pub/CEDS/2017-2022-Statewide-CEDS.pdf. The entire Arctic

coastal plain A coastal plain (also coastal plains, coastal lowland, coastal lowlands) is an area of flat, low-lying land adjacent to a sea coast. A fall line commonly marks the border between a coastal plain and an upland area. Formation Coastal plains can f ...

of Alaska with its Arctic coastal tundra has tremendous ecological importance with the densest concentration of birds in the Arctic, along with housing substantial amounts of large mammals such as whales, walrus, seals, caribou, and moose. The region includes the

Arctic National Wildlife Refuge The Arctic National Wildlife Refuge (ANWR, pronounced as “''ANN-warr''”) or Arctic Refuge is a national wildlife refuge in northeastern Alaska, United States, on traditional Inupiaq, Iñupiaq and Gwichʼin, Gwich'in lands. The refuge is of ...

(ANWR) as well as the National Petroleum Reserve–Alaska (NPRA).

Topography

Within the North Slope, only a surface "active layer" of the

tundra In physical geography, a tundra () is a type of biome where tree growth is hindered by frigid temperatures and short growing seasons. There are three regions and associated types of tundra: #Arctic, Arctic, Alpine tundra, Alpine, and #Antarctic ...

thaws each season; most of the soil is permanently frozen year-round. On top of this

permafrost Permafrost () is soil or underwater sediment which continuously remains below for two years or more; the oldest permafrost has been continuously frozen for around 700,000 years. Whilst the shallowest permafrost has a vertical extent of below ...

, water flows out to sea via shallow, braided streams or settles into pools and ponds. Along the bottom of the

Landsat 7 Landsat 7 is the seventh satellite of the Landsat program. Launched on 15 April 1999, 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 ...

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 politically in North Slope Borough, and geographically in the Alaska North Slope basin. On August 12, 2018, a 6.4 magnitude earthquake hit the region, the most powerful recorded for the Alaskan North Slope.

Ecology

The region includes the

. The entire

of Alaska has tremendous ecological importance with the densest concentration of birds in the Arctic.

Petroleum resources

Under the North Slope is an ancient seabed, which now contains large amounts of

petroleum Petroleum, also known as crude oil or simply oil, is a naturally occurring, yellowish-black liquid chemical mixture found in geological formations, consisting mainly of hydrocarbons. The term ''petroleum'' refers both to naturally occurring un ...

. Within the North Slope, there is a geological feature called the Barrow Arch — a belt of the kind of rock known to be able to serve as a trap for oil. It runs from the city of

Utqiaġvik Utqiagvik ( ; , ), formerly known as Barrow ( ), is the borough seat and largest city of the North Slope Borough, Alaska, North Slope Borough in the U.S. state of Alaska. Located north of the Arctic Circle, it is one of the List of northernmost ...

to a point just west of the Arctic National Wildlife Refuge. Ira Harkey quotes Noel Wien as stating that in the 1920s, "To keep warm and to cook with, the

Eskimo ''Eskimo'' () is a controversial Endonym and exonym, exonym that refers to two closely related Indigenous peoples: Inuit (including the Alaska Native Iñupiat, the Canadian Inuit, and the Greenlandic Inuit) and the Yupik peoples, Yupik (or Sibe ...

was burning hunks of dark stuff he just picked up on the ground all around his tent. This was oil from seepage under the tundra. The Eskimos had always known about the oil, long before there was any drilling for it." The North Slope region includes the National Petroleum Reserve–Alaska (NPRA), which was established by President

Warren G. Harding Warren Gamaliel Harding (November 2, 1865 – August 2, 1923) was the 29th president of the United States, serving from 1921 until his death in 1923. A member of the Republican Party (United States), Republican Party, he was one of the most ...

in 1923 as an oil supply for the US Navy, though the presence of oil in the region had been known by American whalers for some time. It constituted the bulk of Alaska's known

until the Prudhoe Bay Oil Field was discovered (outside the NPRA) in 1968, followed by the Kuparuk River oil field in 1969. The petroleum extracted from the region is transferred south by means of the

Trans-Alaska Pipeline System The Trans-Alaska Pipeline System (TAPS) is an oil transportation system spanning Alaska, including the trans-Alaska crude-oil pipeline, 12 pump stations, several hundred miles of feeder pipelines, and the Valdez Marine Terminal. TAPS is one o ...

to Valdez on the

Pacific Ocean The Pacific Ocean is the largest and deepest of Earth's five Borders of the oceans, oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean, or, depending on the definition, to Antarctica in the south, and is ...

. In 2005 the USGS estimated that the Arctic Alaska Petroleum Province, encompassing all the lands and adjacent Continental Shelf areas north of the Brooks Range-Herald arch (see map) held more than 50 billion bbl of oil and natural-gas liquids and 227 trillion cubic feet of gas. The

source rock In petroleum geology, source rock is a sedimentary rock which has generated hydrocarbons or which has the potential to generate hydrocarbons. Source rocks are one of the necessary elements of a working petroleum system. They are organic-rich sedim ...

for the Prudhoe Bay Oil Field and neighboring reserves is also a potential source for unconventional

tight oil Tight oil (also known as shale oil, shale-hosted oil or light tight oil, abbreviated LTO) is light crude oil contained in Unconventional (oil & gas) reservoir, unconventional petroleum-bearing formations of low Permeability (earth sciences), perme ...

and

shale gas Shale gas is an unconventional natural gas that is found trapped within shale formations. Since the 1990s, a combination of horizontal drilling and hydraulic fracturing has made large volumes of shale gas more economical to produce, and ...

– possibly containing "up to 2 billion barrels of technically recoverable oil and up to 80 trillion cubic feet of natural gas, according to a 2012 U.S. Geological Survey report." Alaska North Slope (ANS) is a more expensive waterborne crude oil. Since 1987, Alaska North Slope (ANS) crude production has been in decline. As of 2020, the

U.S. Geological Survey The United States Geological Survey (USGS), founded as the Geological Survey, is an agency of the U.S. Department of the Interior whose work spans the disciplines of biology, geography, geology, and hydrology. The agency was founded on March ...

estimated 3.6 billion barrels of oil and 8.9 trillion cubic feet of natural gas in Mississippian through

Paleogene The Paleogene Period ( ; also spelled Palaeogene or Palæogene) is a geologic period and system that spans 43 million years from the end of the Cretaceous Period Ma (million years ago) to the beginning of the Neogene Period Ma. It is the fir ...

strata in the central North Slope of Alaska, which are undiscovered and technically recoverable.

References

External links

DOE report on North Slope Oil and Gas

northslope.org
North Slope Science Initiative official website * {{Coord, 69.0578758, -152.8628274, region:US-AK, display=title Beaufort Sea Brooks Range Chukchi Sea Geography of North Slope Borough, Alaska Inuit territories Regions of Alaska

Topography

Ecology

Petroleum resources

See also

References

External links