Reflection seismic, magnetic, gravimetric survey of the South Pacific Ocean, Antarctica (Summer 1988-89, 89-90, 90-91)

During the Antarctic summers from 1988 - 1989 to 1990 - 1991, the
Osservatorio Geofisico Sperimentale realized a geophysical survey in
the Ross Sea, making use of the Research Vessel OGS - Explora,
collecting magnetic, gravimetric and seismic data. This research has
been carried out in the context of the Nation Research Program in
Antarctic (PNRA), coordinated by the Italian ENEA, under the auspices
of the Italian Ministry for Scientific and Technological Research.

The parameters for the different campaign are:

Summer 1988 - 1989:

The first part of the survey has been dedicated to the area of the
Balleny Island in South Pacific Ocean, where 3,053 km of profiles have
been collected. The data have been collected with the following
parameters:

Coverage 3000%
Record Length 14 sec
Sample Rate 4 ms
Shot Interval 50 m
Streamer Length 3000 m
Streamer Depth 12 m
Number of Groups 120
Group Interval 25 m
Air-Guns:
- Total Volume 45.16 1
- Pressure 140 bar
- Depth 6 m

Summer 1989-90:

in cooperation with the United Geological Survey (USGS) the second
part of the survey has been dedicated to the South Pacific Ocean
(Balleny Island area), where 1,280 km of profiles have been collected
by using. the following parameters:

Coverage 3000%
Record Lengtht 14 sec
Sample Rate 4 ms
Shot Interval 50 m
Streamer Length 3000 m
Streamer Depth 12 m
Number of Groups 120
Group Interval 25 m
Air-Guns:
- Total Volume 45.16 1
- Pressure 140 bar
- Depth 6 m

December 1990, January, February and March 1991:

The survey interested mainly three different areas: the South Pacific
Ocean,, the Ross Sea and the Weddell Sea. The program in the South
Pacific Ocean is the continuation of the research performed in the
previous years on the triple joint between the Antarctic, Pacific and
Indian Plates. During the present survey about 1,930 km of seismic
reflection and gravity data have been collected along 7 lines in this
area with the following parameters:

Coverage 3000%
Record Length 14 sec
Sample Rate 4 ms
Shot Interval 50 m
Streamer Length 3000 m
Streamer Depth 12 m
Number of Groups 120
Group Interval 25 m
Air-Guns:
- Total Volume 45.16 1
- Pressure 140 bar
- Depth 6 m

Source Name:Research Vessel > OGS-Explora
Sensor Name:ASTR1>Analogic streamer, Prakla
Sensor Name:MSREC1>Multichannel seismic recorder,Sercel 358
Sensor Name:BGV2>Gravimetric Bodenseewerk, KSS31
Sensor Name:GMG1>Magnetometer Geometrics, G801-803