Borehole Seismic Data
IODP logging contractor: USIO/LDEO
Location: Gulf of Alaska (NE Pacific Ocean)
Latitude: 56°57.5888' N
Longitude: 147° 6.5983' W
Logging date: June 22, 2013
Sea floor depth (driller's): 4199.5 m DRF
Sea floor depth (logger's): 4200 m WRF
Total penetration: 4909 m DRF (709.5 m DSF)
Total core recovered: 146.92 m (42.1 % of 348.7 m; several drilled-down intervals)
Oldest sediment recovered: ~5 Ma at 400 m DSF
Lithologies: Mud, iceberg-rafted diamict, coarse-grained interval dominated by gravity flows alternate with mud, siltstone and sandstone.
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.
Despite the unstable hole dconditions, good shots were obined at two stations ( 4411.9 and 4411.3 m WRF). 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).
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:
E-mail: Gilles Guerin
E-mail: Cristina Broglia