Borehole Seismic Data
IODP logging
contractor: USIO/LDEO
Hole: U1418F
Expedition:
341
Location: Gulf of Alaska (NE Pacific Ocean)
Latitude: 58°46.5883' N
Longitude: 144° 29.5986' W
Logging date:
Sea floor
depth (driller's):
3678 m DRF
Sea floor
depth (logger's):
3677.5 m WRF
Total
penetration: 4626.2 m DRF (948.7 m DSF)
Total core
recovered: 495.2 m (71.9% of 688.7 m; several drilled-down intervals)
Oldest
sediment recovered:
~1 Ma at 645 m DSF
Lithologies: Mud, interbedded mud and silt, diamict, diatom/biosiliceous ooze, calcareous mud, volcanic ash, volcaniclastic mud and sand
TOOL USED: VSI (Versatile
Seismic Imager)
The logging data
was recorded by Schlumberger in LDF format. All processing, including first
arrival picking and stacking, was performed by Schlumberger during
Expedition 341. The data was then
converted into SEGY format at USIO/LDEO, using code developed in house.
Several bridges were encountered dueing the tool descent in the hole. Various stations were attempted between 3896.6 and 3847.1 m WRF, but not a single shot was good due to poor anchoring of the tool to the borehole wall.
All the data in
the SEGY files are sorted shot by shot (i.e. chronologically).
A schematic design of the geometry of the VSI tool is in the Documents section of the hole index page.
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 Integrated Drilling Program, Expedition 341.
For further questions about the logs, please contact:
Gilles Guerin
phone: 845-365-8671
fax: 845-365-3182
E-mail: Gilles Guerin
Phone: 845-365-8343
Fax: 845-365-3182
E-mail: Cristina Broglia