Borehole Seismic Data
ODP logging contractor: LDEO-BRG
Location: Hydrate Ridge - Cascadia Margin (NE Pacific)
Latitude: 44° 34.1166' N
Longitude: 125° 9.0025' W
Logging date: August 25-27, 2002
Water depth (as seen on logs): 806.5 mbrf
Total penetration: 180 mbsf
Total core recovered: 70.1 m (91 %)
TOOL USED: VSI (Versatile Seismic Imager) and QSST (Inline Checkshot Tool).
The logging data was recorded by Schlumberger in DLIS format. Check shots with the in-line check shot tool (QSST) were acquired at the base of the hole after the repeat run (DIT/APS/HLDT/HNGS/QSST/TAP). Zero-offset VSP stations were taken with the VSI at 5 m intervals between 83 and 173 mbsf. Walk-away VSP surveys along E-W and N-S lines were made with stations at 91, 138, and 172 mbsf.
All processing, including first arrival picking and stacking, was performed by Schlumberger during Leg 204. The data was then converted into SEGY format at the Borehole Research Group of the Lamont-Doherty Earth Observatory, using the SEGY Save module in GeoFrame.
Stacks are generally calculated with at least seven good traces.
All the data in the SEGY files are sorted shot by shot (i.e. chronologically).
E-mail: Gilles Guerin
E-mail: Cristina Broglia