Permafrost beneath the Beaufort Sea: near Prudhoe Bay, Alaska
Nine holes were drilled and 27 sites were probed with a cone penetrometer. The deepest drill hole was 65.I m below the seabed, while a depth of 14.1 m was reached with the cone penetrometer. Engineering and chemical properties were determined from core samples and point penetration resistance data were obtained with the penetrometer. Thermal profiles were acquired at both the drill and probe sites. Temperatures below 0/sup 0/C were observed in all the drill and penetrometer holes logged, although frozen sediments were encountered only occasionally. Seasonally frozen sediments were observed near the seabed at each site. The degree of ice bonding, or strength, could be related to seabed temperature and was greatest in shallow water (<2 m). The penetrometer resistance and thermal data indicated that deeper ice-bonded sediments occur, for example approximately 12.7 m below the seabed in 2 m of water off the Sagavanirktok delta. Of eight holes drilled offshore, it appeared that four encountered bonded permafrost. In general, the position of the ice-bonded permafrost interface was extremely irregular. The depth below the seabed to this interface at various distances from shore along the line studied was 28.8 m at 1 km, 65.1 m at 3.5 km, 44.1 m at 6.8 km, and 29.5 m at 17.2 km. Shallow, overconsolidated marine sediments were found in the upper fine-grained section at all of the drill sites investigated; the degree of overconsolidation varied considerably among the sites. This fine-grained section was up to 10 m thick and covered sands and coarse gravels.
- Research Organization:
- Army Cold Regions Research and Engineering Lab., Hanover, NH
- OSTI ID:
- 6446856
- Journal Information:
- J. Energy Resour. Technol.; (United States), Journal Name: J. Energy Resour. Technol.; (United States) Vol. 102:1; ISSN JERTD
- Country of Publication:
- United States
- Language:
- English
Similar Records
Geothermal studies in Alaska: Conditions at Prudhoe Bay