The Alaska North Slope (
Iñupiaq: ''Siḷaliñiq'') 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 sover ...
of
Alaska
Alaska ( ; russian: Аляска, Alyaska; ale, Alax̂sxax̂; ; ems, Alas'kaaq; Yup'ik: ''Alaskaq''; tli, Anáaski) is a state located in the Western United States on the northwest extremity of North America. A semi-exclave of the U.S., ...
located on the northern slope of the
Brooks Range
The Brooks Range ( 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, the range is believ ...
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.
Terminology
* Ocean – the four to seven largest named bodies of water in the World Ocean, all of which have "Ocean ...
s of the
Arctic Ocean
The Arctic Ocean is the smallest and shallowest of the world's five major oceans. It spans an area of approximately and is known as the coldest of all the oceans. The International Hydrographic Organization (IHO) recognizes it as an ocean, a ...
, the
Chukchi Sea
Chukchi Sea ( rus, Чуко́тское мо́ре, r=Chukotskoye more, p=tɕʊˈkotskəjə ˈmorʲɪ), 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 b ...
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 Utqiaġvik (formerly Barrow). It is the northernmost point of all the territory of the United States, at , south of the North Pole. (The nor ...
, and the
Beaufort Sea
The Beaufort Sea (; french: Mer de Beaufort, Iñupiaq: ''Taġiuq'') is a marginal sea of the Arctic Ocean, located north of the Northwest Territories, the Yukon, and Alaska, and west of Canada's Arctic islands. The sea is named after Sir Fr ...
on the eastern.
Petroleum resources
The Alaska North Slope region includes the
National Petroleum Reserve–Alaska
The National Petroleum Reserve in Alaska (NPRA) 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 (BLM). It lies to the west of the ...
, with the bulk of Alaska's known
petroleum
Petroleum, also known as crude oil, or simply oil, is a naturally occurring yellowish-black liquid mixture of mainly hydrocarbons, and is found in geological formations. The name ''petroleum'' covers both naturally occurring unprocessed crud ...
until the
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 North America, covering and originally containing approximately of oil. was discovered in 1968, followed by the
Kuparuk River oil field
The Kuparuk River Oil Field, or Kuparuk, located in North Slope Borough, Alaska, United States, is the second largest oil field in North America by area. It produces approximately of oil and is estimated to have of recoverable oil reserves. It ...
in 1969. The region also includes the
Arctic National Wildlife Refuge
The Arctic National Wildlife Refuge (ANWR or Arctic Refuge) is a national wildlife refuge in northeastern Alaska, United States on traditional Gwich'in lands. It consists of in the Alaska North Slope region. It is the largest national wildli ...
, 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
The Trans-Alaska Pipeline System (TAPS) is an oil transportation system spanning Alaska, including the trans-Alaska crude-oil pipeline, 11 pump stations, several hundred miles of feeder pipelines, and the Valdez Marine Terminal. TAPS is one of ...
to
Valdez on the
Pacific Ocean
The Pacific Ocean is the largest and deepest of Earth's five oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean (or, depending on definition, to Antarctica) in the south, and is bounded by the continen ...
.
Under the North Slope is an ancient seabed, which is the source of the oil. 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 ( ik, Utqiaġvik; , , formerly known as Barrow ()) is the borough seat and largest city of the North Slope Borough in the U.S. state of Alaska. Located north of the Arctic Circle, it is one of the northernmost cities and towns in the ...
to a point just west of the Arctic National Wildlife Refuge.
The Arctic Alaska Petroleum Province, encompassing all the lands and adjacent Continental Shelf areas north of the Brooks Range-Herald arch (see map) were estimated by the USGS in 2005 to hold more than 50 billion bbl of oil
An oil is any nonpolar chemical substance that is composed primarily of hydrocarbons and is hydrophobic (does not mix with water) & lipophilic (mixes with other oils). Oils are usually flammable and surface active. Most oils are unsaturated ...
and natural-gas
Natural gas (also called fossil gas or simply gas) is a naturally occurring mixture of gaseous hydrocarbons consisting primarily of methane in addition to various smaller amounts of other higher alkanes. Low levels of trace gases like carbon di ...
liquids and 227 trillion cubic feet of gas.[
The ]source rock
In petroleum geology, source rock is rock which has generated hydrocarbons or which could generate hydrocarbons. Source rocks are one of the necessary elements of a working petroleum system. They are organic-rich sediments that may have been depos ...
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 petroleum-bearing formations of low permeability, often shale or tight sandstone.
Economic production from ...
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 some a ...
– 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."
Ira Harkey
Ira B. Harkey Jr. (January 15, 1918 – October 8, 2006) was an American writer, professor of journalism, and editor and publisher of the ''Pascagoula Chronicle-Star'' in Mississippi from 1951 to 1963. Harkey was awarded the Pulitzer Prize f ...
quotes Noel Wien Noel Wien (June 8, 1899July 19, 1977) was an American pioneer aviator. He was the founder of Wien Alaska Airways.
Biography
Wien was born in Lake Nebagamon, Wisconsin, but the family moved to a homestead in 1905, to a place now called Cook, Minne ...
as stating that in the 1920s, "To keep warm and to cook with, the Eskimo
Eskimo () is an exonym used to refer to two closely related Indigenous peoples: the Inuit (including the Alaska Native Iñupiat, the Greenlandic Inuit, and the Canadian Inuit) and the Yupik peoples, Yupik (or Siberian Yupik, Yuit) of eastern Si ...
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."
Alaska North Slope (ANS) crude production
Alaska North Slope (ANS) is a more expensive waterborne crude. Since 1987, Alaska North Slope (ANS) crude production has been in decline.
Topography
Within the North Slope, only a surface "active layer" of the tundra
In physical geography, tundra () is a type of biome where tree growth is hindered by frigid temperatures and short growing seasons. The term ''tundra'' comes through Russian (') from the Kildin Sámi word (') meaning "uplands", "treeless moun ...
thaws each season; most of the soil is permanently frozen year-round. On top of this permafrost
Permafrost is ground that continuously remains below 0 °C (32 °F) for two or more years, located on land or under the ocean. Most common in the Northern Hemisphere, around 15% of the Northern Hemisphere or 11% of the global surface ...
, water flows to sea via shallow, braided streams or settles into pools and ponds.[ Along the bottom of the Landsat 7 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
The North Slope Borough is the northernmost borough in the US state of Alaska and thus, the northernmost county or equivalent of the United States as a whole. As of the 2020 census, the population was 11,031. The borough seat and largest city i ...
, and geographically in the Alaska North Slope basin.
On August 12, 2018, a 6.3 magnitude earthquake hit the region, the most powerful recorded for the Alaskan North Slope.
See also
* Arctic Alaska-Chukotka terrane
The Arctic Alaska-Chukotka terrane (AAC) is a microcontinent that today encompasses the North Slope, Brooks Range, and Seward Peninsula of northern Alaska; the Chukotka Peninsula, New Siberia Islands, and Wrangel Island in eastern Siberia; and ...
* Arctic coastal tundra
The Arctic coastal tundra is an ecoregion of the far north of North America, an important breeding ground for a great deal of wildlife.
Setting
This ecoregion is located on the north coast of Alaska, and includes the east coast plain of Banks Is ...
* Arctic foothills tundra
* BP#1993–1995: Hazardous substance dumping
* Mount Elbert Gas Hydrate Site
* North Slope Borough
The North Slope Borough is the northernmost borough in the US state of Alaska and thus, the northernmost county or equivalent of the United States as a whole. As of the 2020 census, the population was 11,031. The borough seat and largest city i ...
References
External links
DOE report on North Slope Oil and Gas
northslope.org
North Slope Science Initiative official website
*
{{Authority control
Beaufort Sea
Brooks Range
Chukchi Sea
Geography of North Slope Borough, Alaska
Inuit territories
Regions of Alaska