Borehole Seismic Data
Science operator: Texas A&M University
Hole: U1471E
Expedition: 359
Location: Maldive Archipelago (central equatorial N Indian Ocean)
Latitude: 4° 45.9829' N
Longitude: 73° 8.0929' E
Logging date: November 25, 2015
Sea floor depth (driller's): 430.3 m DRF
Sea floor depth (logger's): 430.5 m WRF (HRLA/MSS/APS/HLDS/EDTC/HNGS Main Run)
Total penetration: 1434 m DRF (1003.7 m DSF)
Total core recovered: 171.54 m (42.1 % of cored section)
Oldest sediment recovered:
Lithology: Lithified foraminifer-rich packstone and wackestone.
SEISMIC TOOL USED: VSI (Versatile
Seismic Imager)
The logging data
was recorded by Schlumberger in LDF/DLIS format. All processing, including first
arrival picking and stacking, was performed by Schlumberger during
Expedition 359. The data was then
converted into SEGY format at USIO/LDEO, using tcode developed in house.
The VSI string hung up at about 1042 m WRF,which corresponded to one of the narrow readings on the caliper log from the previous run. Since all attempts to pass the bridge failed, 30 shots in 5 stations were acquired above that depth. Proper anchoring of the tool was made difficult by the large hole diameter and by the rapidly degrading hole conditions.
Stacks are
generally calculated with at least nine good traces.
All the data in
the SEGY files are sorted shot by shot (i.e. chronologically).
Additional information about the drilling and logging operations can be found in the Operations and Downhole Measurements sections of the expedition report, Proceedings of the International Ocean Discovery Program, Expedition 359. For further questions about the logs, if the hole is still under moratorium please contact the staff scientist of the expedition.
After the moratorium period you may direct your questions to:
Cristina Broglia
Phone: 845-365-8343
Fax: 845-365-3182
E-mail: Cristina Broglia
Gilles Guerin
phone: 845-365-8671
fax: 845-365-3182
E-mail: Gilles Guerin