Keck Expedition 2004
August 1, 2004 Day 3
August
1 update (by Debra Stakes)
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.