Underway Geophysics
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Table of Contents
- 1 Overview
- 1.1 Instruments
- 1.1.1 Seismic Sound Sources
- 1.1.2 Bathymetry
- 1.1.3 Navigation
- 1.1.4 Magnetics
- 1.2 Bathymetry
- 1.3 Magnetometer
- 1.4 Navigation
- 1.5 Archived
- 1.1 Instruments
Illustration of underway geophysical data acquisition during Expedition 324 (Kang et al., 2010, doi:10.2204/iodp.proc.324.108.2010).
Overview
The primary function of the Underway Geophysics lab is to acquire navigation and bathymetric (3.5 and 12 kHz) data, and provide and maintain the sound sources used for check shots and vertical seismic profile experiments. In addition to their scientific uses, geophysical data are used to ensure the drilling safety of the ship by confirming site positions and identifying potentially dangerous seafloor and subseafloor characteristics. The lab also supports downhole vertical seismic profiling and can collect magnetic data while underway.
Instruments
Seismic Sound Sources
Sercel 210 in3Â GI Gun pneumatic sound source: configurable to "True GI Mode" and up to 255 total in3; used as a sound source for downhole logging operations and towed seismic surveys
Sercel G. Gun Parallel Cluster pneumatic sound source: the cluster is composed of two 250 in3Â G. Guns separated by 1 meter; used as a sound source for downhole logging operations
Bathymetry
Knudsen Sounder Suite for CHIRP 3260 Sub-bottom Profiler using (i) 3.5 kHz frequency obtained with a 12 x TR-109 transducer array driven by a 10 kW power amplifier; (ii) 12 kHz frequency obtained with an EDO-323C transducer
Transducers are housed in the forward sonar dome
Navigation
Integrated navigation software: EIVA NaviPac and Helmsman; in-house Site Fix LabVIEW application
Two Trimble SPS356 GNSS Modular Receiver with Trimble GA530 antenna (GA830 also available)
Magnetics
Marine Magnetics SeaSpy M-SS1001 Towed Magnetometer
Bathymetry
Magnetometer
Navigation
JRNav Google Earth_v. 375
JRData Server_378T
Site Fix_OldNew  Merged
Archived
Winfrog User Guide_378T
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