thumb|450px|A map of northern Alaska; the dotted line shows the southern boundary of the North Slope. The National Petroleum Reserve–Alaska is to the West, the Arctic National Wildlife Refuge to the east, and Prudhoe Bay is between them.

The Alaska North Slope or Alaska Arctic Slope () is the region of the U.S. state of Alaska located on the northern slope of the Brooks Range along the coast of two marginal seas of the Arctic Ocean, the Chukchi Sea being on the western side of Point Barrow, and the Beaufort Sea 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.

The entire Arctic coastal plain 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.

Ecology

The region includes the Arctic National Wildlife Refuge. The entire coastal plain of Alaska has tremendous ecological importance, with the densest concentration of birds in the Arctic.

Petroleum resources

thumb|Map from the US Bureau of Land Management showing structures that create the oil fields in Alaska

thumb|North Slope geologic cross section

thumb|[[Geophysical Service Inc. seismic exploration crew, Deadhorse, Alaska, 1981]]

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

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.

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 estimated 3.6 billion barrels of oil and 8.9 trillion cubic feet of natural gas in Mississippian through Paleogene strata in the central North Slope of Alaska, which are undiscovered and technically recoverable.

See also

  • Arctic Alaska-Chukotka terrane
  • Arctic coastal tundra
  • Arctic foothills tundra
  • BP hazardous substance dumping
  • Mount Elbert Gas Hydrate Site
  • North Slope Borough
  • Project Chariot

References

  • DOE report on North Slope Oil and Gas
  • northslope.org, North Slope Science Initiative official website