448 km on 7 lines in Atlantic Ocean, 120' Fracture Zone

Gravity; Seismic reflection

Multi-channel seismic reflection systems; seismic refraction systems; gravimeters; satellite positioning systems

During summer 1992 OGS, in cooperation with the Istituto di Geologia Marina (CNR), conducted a seismic survey of the Central Atlantic Ocean. The aim of the survey was the investigation of two fracture zones; potential sites for drilling as part of the ODP program. The first site investigated was the area of 120' fracture zone, where a total amount of 450 km of seismic lines was collected to investigate the position of the seismic Moho and the possible presence of low angle faults. The seismic data have been collected with the following sampling parameters: Coverage = 3000 % Sample Rate = 4 ms Shot Interval = 50 m Streamer Length = 3000 m Streamer Depth = 12 m Group Interval = 25 m Number of Groups = 120 Record Length = 17-20 sec Air-Guns: - Total Volume = 80-23 l - Pressure = 140 bar - Depth = 6 m

National Institute of Oceanography and Applied Geophysics - OGS, Division of Geophysics
Borgo Grotta Gigante 42/c
Sgonico (Trieste),

34010
Italy