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: July 7-9, 2013

Sea floor depth (driller's): 3678 m DRF

Sea floor depth (logger's): 3677.5 m WRF (MSS/HRLA/HLDS/HNGS/EDTC-B uplog)

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


Cristina Broglia

Phone: 845-365-8343

Fax: 845-365-3182

E-mail: Cristina Broglia