Seismic reflection and refraction data acquired in Canada Basin, Northwind Ridge and Northwind Basin, Arctic Ocean in 1988, 1992 and 1993

Seismic reflection and refraction data were collected in generally ice-covered
waters of the Canada Basin and the eastern part of the Chukchi Continental
Borderland of the Amerasia Basin, Arctic Ocean, during the late summers of
1988, 1992, and 1993. The data were acquired from a Polar class icebreaker, the
U.S. Coast Guard Cutter Polar Star, using a seismic reflection system designed
by the U.S. Geological Survey (USGS). The northernmost data extend to 78° 48' N
latitude.

In 1988, 155 km of reflection data were acquired with a prototype system
consisting of a single 195 cubic inch air gun seismic source and a two-channel
hydrophone streamer with a 150-m active section. In 1992 and 1993, 500 and
1,900 km, respectively, of seismic reflection profile data were acquired with
an improved six air gun, 674 to 1303 cubic inch tuned seismic source array and
the same two-channel streamer. In 1993, a 12-channel streamer with a 150-m
active section was used to record five of the reflection lines and one line was
acquired using a three air gun, 3,000 cubic inch source. All data were recorded
with a DFS-V digital seismic recorder. Processed sections feature high quality
vertical incidence images to more than 6 km of sub-bottom penetration in the
Canada Basin.

Refraction data were acquired with U.S. Navy sonobuoys recorded simultaneously
with the seismic reflection profiles. In 1988 eight refraction profiles were
recorded with the single air gun, and in 1992 and 1993 a total of 47 refraction
profiles were recorded with the six air gun array. The sonobuoy refraction
records, with offsets up to 35 km, provide acoustic velocity information to
complement the short-offset reflection data.

The report includes trackline maps showing the location of the data, as well as
both digital data files (SEG-Y) and images of all of the profiles.

[Summary provided by the USGS.]