Seismic reflection and refraction surveys in Arctic waters (project ARCTIC'91)

The seismic reflection survey was carried out in order: a) obtain a profile across the Eurasia Basin for mapping the first order sediment distribution and its seismic stratigraphy above oceanic crust of known age, b) investigate the sediment cover and the crustal structure of the Lomonosov Ridge to elucidate its subsidence history, c) determine the extent of a sediment cover and the nature of basement on the marginal plateaus Morris Jesup and Yermak d) obtain further data on the thickness of the oceanic crust to evaluate any dependence of crustal thickness at very slow spreading mid ocean ridges.

Shot interval was 25 m to 30 m for reflection and 70 m to 150 m for the refraction seismic data. The following instruments were used: 100 m and 500 m (24 channel) long streamers, 6 l and 24 l airgun array., sonobuoys, 6-channel Reftek station with 3 component seismeters, geophone arrays and 2 hydrophones. The geographical coverage is as follows: - 200 km of single-channel and 1500 km of multi-channel seismic reflection data covering the Amundsen Basin, the Lomonosov Ridge, the Gakkel Ridge, the Morris Jesup Rise, the Nansen Basin and the Yermak Plateau. - 60 km of seismic refraction data on Lomonosov Ridge and Gakkel Ridge.