Keck Expedition 2004
August 1, 2004 Day 3
We arrived at KEMO at 7 am, but unfortunately the seas are too rough to launch the vehicle. The pilots want to be sure that our precious seismometer cargo does not get damaged or dropped during the launch or the recovery. So we wait, eat lunch, nap, and wait some more. Finally the new datalogger gets loaded into the drawer of the ROV (See Mike Conway loading the equipment into the drawer) and the batteries for the leveling mechanism are placed into the seismic sensor package. These batteries power LED’s that flash on when the sensor is properly oriented so the pilots can visually level the sensor in the borehole.
Using the pings from the Homerpro beacon, we locate the KEMO site within moments of landing on the seafloor. First the old system is removed and set to one side, then the new logger is cut free from the ROV(you can see the manipulator cutting the line) and put into place. Then the seismic sensor is inserted into the borehole, an operation that apparently lures many giant crabs to the spot. We hypothesize that they think we are some great whale carcass or something and they are especially drawn to the seismic sensor package. They seem to want to help level it for us which would have been a great asset. When we left they were still inspecting the sensor package to see if anything was edible (they are getting a pretty good look at the package). Hmmm…I wonder if these crabs would be a problem for observatory installations?? In this image you can see the epoxy plug that seals the LED’s. Placing the seismometers into the rocky substrate on the bottom creates the optimum coupling for accurately recording the smallest earthquakes. The KEMO site is right on the Endeavour spreading axis just north of the Mothra hydrothermal vent field visited by Tiburon in 2002 (Here you can see Mothra and you can find out more information about the 2002 expedition here), and thus is perfectly positioned to capture both hydrothermal or volcanic-tectonic events and volcanic tremor episodes.
The pilots devise a strategy to carry the used logger and batteries to the surface. We all keep our fingers crossed. Will the clock still be running? This is critical because only the precise timing provided by the on-board quartz clocks can correlate all of the events across the array. Will the logger still be running? Will there be data or did something leak and destroy our hard drives? We pace silently like expectant parents and eat distractedly watching for the ROV to surface. Finally vehicle and logger clear the moonpool.
As soon as the ROV arrives on deck, Paul and Tony carry it into the laboratory to check that the system is running . It is (we all breath). The clock is running and the time drift is measured (we all smile). The data disks are full (we dare to be optimistic). Andrew begins to download the disks (we are successful!!). By tomorrow we should have some data to show. The day ends well and we look forward to recovering the Endeavour broadband logger tomorrow.