| EM122 Water Column Sonar Data Collected During AT26-02 |
| Cascadia Initiative Year 3, LEG 3 (At26-02, EM122). Recover 30 Lamont Doherty Earth
Observatory Ocean-bottom Seismometers (OBSs) of 3 different types: ?10 TRM shallow-water
OBSs with Trillium compact 3-component absolute pressure gauge installed at depths
from 200-1000m (nominal). Recovered using remotely operated vehicle Jason. ?10 Trawl-Resistant
Mount (TRM) shallow-water OBS with Trillium compact 3-component seismometer, absolute
pressure gauge (APG), acoustic release/pop-up buoy with Jason backup. ?10 LDEO deep
water OBSs with APG. Recover by sending an acoustic release command to drop the anchor.
OBS then floats to the surface a nominal rate of 50m/min. Referred to as LDEO-DW below.
?Iftime allows, discover and recover 2 Woods Hole Oceanographic Institution deep water
OBSs. Additional Activities: Acquire swath bathymetry, including water column data,
in transit between all stations and port. Acquire other underway data (e.g. meterology,
acoustic doppler current profiler). |
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