This was an OBS program in the Bransfield Strait, Antarctica carried out on two cruises of the Nathaniel B. Palmer. Leg 2 collected OBS data along lines 1 to 5, while Leg 7A finished up the project with Lines 6, 7, 9 and 10. Line 6 was close to the South Sheltland Islands and sets of files were created, one with all shots, and a second subset of shots that form a straight shooting line (_2d_ in the database). The main objective was to examine crustal thinning associated with the active extension in the Bransfield Strait following up on a 1991 MCS seismic program (EW9101). Leg 2 collected OBS data along lines 1 to 5, while Leg 7A finished up the project with Lines 6, 7, 9 and 10.
Chief Scientist:
James A. Austin
Principal Investigators:
James A. Austin (NSF 9814041) Yosio Nakamura (NSF 9814041) Ian W. Dalziel (NSF 9814041) Gail L. Christeson (NSF 9814041)
Data Originating Institution:
Institute for Geophysics, University of Texas at Austin
Scientific References Barker, D. H. N., Christeson, G., Austin, J.A., and Dalziel, I.W.D., 2003, Back-arc basin evolution and cordilleran orogenesis: Insights from new ocean bottom seismograph refraction profiling in Bransfield Strait, Antarctica, Geology, vol. 31, p. 107-110.
Christeson, G.L., Barker, D. H. N., Austin, J.A., and Dalziel, I.W.D., 2003, Deep crustal structure of Bransfield Strait: Initiation of a backarc basin by rift reactivation and propagation, Journal of Geophysical Research, vol. 108, p. 2492, DOI: 10.129/2003JB002468.
Seismic Acquisition Parameters
Receiver Type
Seismometer:OceanBottom
Source Type
undocumented
Acquisition System Name
none
Acquisition System Type
Seismic Navigation System
P-Code GPS
Survey Datum
WGS84
Source to Near Channel (meters)
none
Antenna to Source (meters)
undocumented
Number of Channels Recorded
none
Number of Cables
Number of Channels Each Cable
Channel Length (meters)
none
Cable Length (meters)
Cable Spacing (meters)
Near Channel Number
Cable Receiver Depth (meters)
none
Cable Receiver Depth Recorded
Number Source Arrays
FlipFlop Shooting
Source Array Separation (meters)
Source Volume (cubic inches)
3000
Source Pressure (bars)
138
Source Number
6
Source Depth (meters)
6
Processing System
OBSTool
Shot Control
Shot Interval
Sample Interval (microseconds)
Record Length (seconds)
Compass Birds
Tail Buoy Positioning
Recording Delay
Comments
General Processing Description Standard clock drift corrections, instrument locations and shot positions were placed in the headers. Processing flow and parameters are documented in the SEGY 3200 byte reel headers.
Line start/end dates and times Not applicable or not available.
Related Documents None available
The University of Texas at Austin Institute for Geophysics
Compatible with Firefox 1+ (Solaris, Linux, OSX, Windows), Netscape 7+ (Solaris, OSX), Explorer 5.5+ (Windows)
