Wireline Sonic Waveform Data
IODP logging contractor: USIO/LDEO
Hole: U1417E
Expedition: 341
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: DSI (Dipole Sonic Imager)
Recording mode: Monopole P&S and Upper and Lower Dipole (all passes), Cross-Dipole (online and crossline) and Stoneley mode (pass 1).
Remarks about the recording: none.
MONOPOLE P&S MODE: measures compressional and hard-rock shear slowness. The monopole transmitter is excited by a high-frequency pulse, which reproduces conditions similar to previous sonic tools.
UPPER DIPOLE MODE: measures shear wave slowness using firings of the upper dipole transmitter.
LOWER DIPOLE MODE: measures shear wave slowness using firings of the lower dipole transmitter.
CROSS-DIPOLE MODE: uses alternate firings of upper and lower dipole transmitter, thus allowing acquisition of orthogonally polarized data for anisotropy studies.
STONELEY MODE: measures low-frequency Stoneley wave slowness. The monopole transmitter, driven by a low-frequency pulse, generates the Stoneley wave.
The acoustic data are recorded in DLIS format. Each of the eight waveforms generally consists of 512 samples, each recorded every 10 (monopole P&S) and 40 microsec (dipolemodes), at depth intervals of 15.24 cm (6 inches).The original data in DLIS format are first loaded on a Sun system using GeoFrame software. The packed waveform data files are run through a GeoFrame module that applies a gain correction and then converted to ASCII and finally binary format.
Number of columns: 4097
Number of rows: 3757 (downlog)
Number of rows: 3762 (pass 1, monopole, upper and lower dipole, Stoneley modes)
(because of size limits, cross dipole waveforms are split into upper and lower pass 1)
Number of rows: 1794 (lower pass 1, cross dipole mode)
Number of rows: 1971 (upper pass 1, cross dipole mode)
Number of rows: 3358 (pass 2)
The following files have been created:
DSI from FMS/DSI/GPIT/EDTC-B/HNGS (Downlog, drill pipe at ~80 m WSF)
341-U1417E_ldip_d.bin: 0-572.4 m WSF
341-U1417E_mono_d.bin: 0-572.4 m WSF
341-U1417E_udip_d.bin: 0-572.4 m WSF
DSI from FMS/DSI/GPIT/EDTC-B/HNGS (Pass 1, drill pipe at ~82.5 m WSF)
341-U1417E_ldip_p1.bin: 0-573.16 m WSF
341-U1417E_mono_p1.bin: 0-573.16 m WSF
341-U1417E_st_p1.bin: 0-573.16 m WSF
341-U1417E_udip_p1.bin: 0-573.16 m WSF
(because of size limits, cross dipole waveforms are split into upper and lower pass 1)
341-U1417E_cd_ldip_cl_p1u.bin: 0-300 m WSF
341-U1417E_cd_ldip_il_p1u.bin: 0-300 m WSF
341-U1417E_cd_udip_cl_p1u.bin: 0-300 m WSF
341-U1417E_cd_udip_il_p1u.bin: 0-300 m WSF
341-U1417E_cd_ldip_cl_p1l.bin: 300-573.16 m WSF
341-U1417E_cd_ldip_il_p1l.bin: 300-573.16 m WSF
341-U1417E_cd_udip_cl_p1l.bin: 300-573.16 m WSF
341-U1417E_cd_udip_il_p1l.bin: 300-573.16 m WSF
DSI from FMS/DSI/GPIT/EDTC-B/HNGS (Pass 2, drill pipe at ~80 m WSF)
341-U1417E_ldip_p2.bin: -573.16 m WSF
341-U1417E_mono_p2.bin: -573.16 m WSF
341-U1417E_udip_p2.bin: -573.16 m WSF
The sonic waveform files are depth-shifted to the seafloor (-4200 m) but they are not depth-matched to the reference run. Please refer to the 'depth_matches' folder in the hole index page for the depth-matching values and to the "DEPTH SHIFT" section in the standard processing notes for further information.
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.