Use of Side-Looking Airborne Radar to Determine Lake Depth on the Alaskan North Slope

• Main Authors: Sellmann,P., Weeks,W. F., Campbell,W. J.
• Other Authors: COLD REGIONS RESEARCH AND ENGINEERING LAB HANOVER N H
• Format: Text
• Language: English
• Published: 1975
• Subjects: Hydrology; Limnology and Potamology; Snow; Ice and Permafrost; *ALASKA; *ICE; *LAKES; THICKNESS; COASTAL REGIONS; AIRBORNE; RADAR IMAGES; DEPTH; FRESH WATER; CLASSIFICATION; SIDE LOOKING RADAR; BRACKISH WATER; Ice cover; Remote sensing; Lake ice; Ice Lakes; Barrow; Ice; north slope; permafrost; Tundra; Alaska
• Online Access: http://www.dtic.mil/docs/citations/ADA011249; http://oai.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=ADA011249

Side-looking airborne radar (SLAR) imagery obtained in April-May 1974 from the North Slope of Alaska between Barrow and Harrison Bay indicates that tundra lakes can be separated into two classes based on the strength of the radar returns. Correlations between the areal patterns of the returns, limited ground observations on lake depths, and information obtained from ERTS imagery strongly suggest that freshwater lakes giving weak returns are frozen completely to the bottom while lakes giving strong returns are not. Brackish lakes also give weak returns even when they are not completely frozen. This is presumably the result of the brine present in the lower portion of the ice cover limiting the penetration of the X-band radiation into the ice. Although the physical cause of the differences in radar backscatter has not been identified, several possibilities are discussed. The ability to rapidly and easily separate the tundra lakes into these two classes via SLAR should be useful in a wide variety of different problems.