Keck Expedition 2004
August 6, 2004 Day 8
Update for Friday August 6, 2004 (by Debra Stakes)
It’s been a beautiful day on the Explorer Plate. We arrive here sometime during the night, to a spot picked out on a map during a Neptune Science Planning meeting last May. This is a dot on a map that marks an even more remote location on the seafloor. The coordinates say it all: 49 degrees 30 minutes north, 129 degrees 00 minutes west. A cross line on the lat-long grid that puts the broadband seismometer north of the Nootka Transform zone of seismicity. As far as we know no one has been to this particular postage stamp of seafloor before. The attraction that brings us to this obscure location is that it adds to the azimuthal coverage of the global seismic network and complements the on-shore seismic network in Canada.
Because we worked so late last night, the elevator did not get launched until after lunch. The morning jobs kept everyone busy: putting batteries into glass spheres, doing a final check on the logger before it is placed into its sphere, then assembling the electronics module or RIN. All the electronics are checked and then checked again. Just sealing the glass spheres is a scripted ceremony with butyl rubber, wide black tape, and special lube goo on the vacuum purge port. Cables must all be fastened in place with tie wraps. The RIN and large PVC caisson (see Mike Conway standing inside of the caission) must each be lifted onto the elevator using the small deck crane. Mike Conway filled the bead hopper during the night before and now worries over all of the clever tie-downs that must keep the elevator items secure for the descent but still permit the ROV manipulator to untie them on the seafloor. Paul spends the morning trouble-shooting the serial connection that allows the vehicle to communicate with the instruments. At the Nootka installation on Wednesday, this critical communication link was difficult to establish. Finally the broadband sensor was placed into the ROV drawer and a final time check was done before the launch.
The mood on the ship is almost jovial. Styrofoam cups are decorated in creative motifs and then sent to the seafloor to be crushed by 245 atm (~3600 pounds of pressure per square inch) at depth, a souvenir of the hostile nature of our working environment. In the photograph you can see the original size of the cups before their round trip journey on the ROV. By dinnertime, the ROV is just beginning to unload the elevator. People scramble to the mess deck to enjoy the food cooked by Derek, the Western Flyer Chef extraordinaire. There is a birthday to celebrate. There is sunshine and fresh air to sit out in on the chairs, mesmerized by the empty blue ocean all around. In the control room, the few people left behind watch the caisson brought over to be pushed into the red-brown abyssal ooze of the center of the Explorer Plate. Hours later, the electronics module is unloaded and the sensor is carried over to be connected. By this time everyone has reassembled in the control room to watch the ROV go about its final tasks in establishing this pioneering seismic station of the Explorer Plate. Once the connections and sensor are tested in place, everything is shut down until tomorrow and the ROV is recovered. Everyone is looking forward to a movie and a good night’s sleep.
Here you can see the caisson being pushed into the abyssal ooze.
The sensor is being carried over to be connected.
All the connections and sensors are being tested.