Among the greatest uncertainties in future energy supply is the amount of oil and gas yet to be found in the Arctic. Using a probabilistic geology-based methodology, the U.S. Geological Survey has assessed the area north of the Arctic Circle. The Circum-Arctic Resource Appraisal (CARA) consists of three parts:

  1. Mapping the sedimentary sequences of the Arctic (Grantz and others 2009),

  2. Geologically based estimation of undiscovered technically recoverable petroleum (Gautier and others 2009, discussed in this presentation) and

  3. Economic appraisal of the cost of delivering the undiscovered resources to major markets (also reported at this conference by White and others).

We estimate that about 30% of the world's undiscovered gas and about 13% of the world's undiscovered oil may be present in the Arctic, mostly offshore under less than 500m of water. Billion BOE-plus accumulations of gas and oil are predicted at a 50% probability in the Kara Sea, Barents Sea, offshore East and West Greenland, Canada, and Alaska. On a BOE basis, undiscovered natural gas is three times more abundant than oil in the Arctic and is concentrated in Russian territory. Oil resources, while critically important to the interests of Arctic countries, are probably not sufficient to significantly shift the current geographic patterns of world oil production.


The U.S. Geological Survey (USGS) has completed an assessment of the yet-to-find, technically recoverable petroleum in the Arctic. The Circum-Arctic Resource Appraisal (CARA) provides probabilistic estimates of the numbers, sizes, and aggregate volumes of oil, gas, and natural gas liquids in undiscovered accumulations (Gautier et al. 2009). Most discoveries will probably be made on the continental shelves, under less than 500 meters of water.

The CARA is a geologically study of the potential for new discoveries of conventional oil and/or gas in accumulations larger than 50 million barrels of oil or 300 billion cubic feet of natural gas north of the Arctic Circle. So-called unconventional resources such as coal bed methane, heavy oil and bitumen, and gas hydrates were not included in the study.

Before the assessment could be conducted, it was necessary to compile a consistent map of the sedimentary basins of the Arctic, delineated according to geologic age, tectonic history, thickness of sedimentary strata, and structural style (Grantz et al. 2009). Using the new map, the Arctic was subdivided into 69 geologically defined subsets called Assessment Units (AUs); the AU boundaries are available as digital shape files online (USGS 2009).

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