Arctic Sea Ice Thickness Profiles from 1976 Submarine Sonar

Arctic sea ice thickness profiles were collected by the USS Gurnard submarine using upward-looking sonar in the Beaufort Sea from April 7 to 10, 1976. This raw dataset covers three transects totaling 777 nautical miles, with ice draft measurements recorded in feet. The National Snow and Ice Data Center (NSIDC) provides this historical data for preservation, accompanied by scanned background documents.

Use Cases

• Analyzing historical sea ice thickness distribution along specific 1976 transects in the Beaufort Sea.
• Calibrating or validating ice draft models using raw sonar measurements recorded in feet.
• Investigating the structure of Arctic pack ice from upward-looking sonar profiles.
• Supporting paleoclimatology studies by providing a baseline ice condition snapshot from the 1970s.

Strengths

• Provides a unique historical record from a specific U.S. Navy submarine mission in April 1976.
• Covers a substantial spatial extent with three transects totaling 777 nautical miles.
• Includes supporting scanned PDF documents (AIDJEX_ULS_background.pdf, AIDJEX_ULS_format.pdf) for context.

Limitations

• Data is in a raw, unformatted ASCII text file with unknown column structure and unclear measurement frequency.
• Conflicting metadata exists for the 'last updated' field (2026-03 13 vs. 1976-04-10).
• Specific header fields beyond likely latitude and longitude are unknown, requiring caution and expert interpretation.

Provenance

Source

U.S. Navy submarine USS Gurnard (SSN-662), collected for the AIDJEX Main Experiment.

Collection Method

Upward Looking Sonar (ULS) profiles of the underside of Arctic pack ice.

Time Range

1976.04.07 - 1976.04.10

Freshness

2026-03-13 18:03:39.669329

Geography

Beaufort Sea, Arctic Ocean, AIDJEX Main Experiment area.