13 September, 1997
When I boarded the Louis I thought it odd to see a number of large metal wheels from a railroad car lashed on the forward deck. Today I began to understand their purpose. They are the expendable anchors for the moorings that will be deployed in the Beaufort Sea. Humfrey, Peter, Paul, and Dave, from the Institute of Ocean Sciences are attempting to find, recover, and redeploy six underwater experiments that have been remotely recording data from the ocean bottom since April 1995. Their battery-operated equipment acoustically measures ice thickness and water velocity storing the data in its onboard computer. When downloaded, these data will be used to determine if the volume of ice in the Arctic is decreasing, refine models which predict how the planet will respond to global warming, and aid in the design of oil platforms constructed to exploit the natural resources in the higher latitudes.
Locating the moorings under the ice is presenting a major problem. When they were deployed, a global positioning system, using a net work of US military satellites, identified their location. If the government didn't scramble the satellite signals to guard against guided missile attack, the ship could return to within a meter of the mooring. Instead, we found the approximate site and then a hydrophone was lowered over the side to listen for a signal from the mooring. If located, it would be released from it anchor electronically and buoys could carry it to the surface.
After searching for several hours the mooring was located, under a multiyear ice pack! Since so much science still needs to be completed before the end of the cruise, the decision was made to move on to the next station, deploy a new mooring, and return for a second attempt at retrieval in the morning.
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