Marine seismic survey area: Antarctic Ocean - Reflection seismic data
Refraction seismic data
(1) Weddel Sea | (2) Ross Sea |
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BGR78 (Explora) 1978 | BGR80 (Explora) 1980 |
BGR96 (Ak. Nemchinov) 1996 | |
ANT.IV (Polarstern) 1986 | |
ANT.VIII (Polarstern) 1990 |
Source: BGR
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Cruise BGR78 1978
Vessel Explora
Weddel Sea
Total length of lines | |
Sampling rate | 4 ms |
Record length | 6 000 ms |
Streamer | digital - 48 channels |
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Cruise BGR96 1996
Vessel Akademik Nemchinov
Weddel Sea
Total length of lines | |
Sampling rate | 4 ms |
Record length | 14 000 ms |
Streamer |
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Cruise ANT.IV/3 1986
Vessel Polarstern
Weddel Sea
Total length of lines | |
Sampling rate | 4 ms |
Record length | 10 000 ms |
Streamer | digital - 48 channels |
Summary
On the "F.S. POLARSTERN" cruise ANT-IV/3 (6th December, 1985 - 13th March, 1986) multichannel seismic measurements were carried out in parallel with magnetic and gravimetric measurements on 33 lines with a total length of 6,263 km . 3,350 km of the multichannel seismic lines have been processed aboard. The geophysical studies were designed to investigate the structure and geological development of the Weddell Sea continental margin from meridians zero to 60°W, and to define suitable and safe drilling locations for Leg 113 of the Ocean Drilling Program.
The main results of the geophysical studies are:
- the discovery of an approximately N50°E trending failed drift basin, following the trend of a negative magnetic anomaly and a positive gravity anomaly; - the discovery of two extensive wedge-shaped and symmetric basement units around a failed drift basin between longitudes 40°W and 20°W. The seismic characteristics, i.e. seismic velocities of > 4 km/s and an internally divergent pattern of reflectors suggest that both wedges are formed from extrusive/intrusive volcanic rocks;
- the confirmation of a major plate tectonic boundary trending approximately N80°E to N60°E, i.e. the EXPLORA-ANDENES escarpment;
- the confirmation of a glaciogenic progradational wedge beneath the shelf of the Weddell Sea Embayment, made up of several thousand metres of sediments;
- the definition of 13 suitable and safe drilling locations for ODP-Leg 113.
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Cruise ANT.VIII 1990
Vessel Polarstern
Weddel Sea
Total length of lines | |
Sampling rate | 4 ms |
Record length | 12 000 ms |
Streamer | digital - 48 channels |
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Cruise BGR80 1980
Vessel Explora
Ross Sea
Total length of lines | |
Sampling rate | 4 ms |
Record length | 10 000 ms |
Streamer | digital - 48 channels |
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