45° 51.8' N, 130° 00.2' W
Air temperature 60° F, 1500 PST
Science Report
At
1000 PST the Thompson arrived at Axial caldera. The first task was to
deploy the Ocean Bottom Hydrophone (OBH) over the side of the ship. Next
the ship steamed south 8 kilometers to the Southern Pillow Mound area,
where ROPOS was deployed for its first NeMO 2003 dive. The main task of
dive R734 will be to make 3 transects from the Southern Pillow Mound area
to the center of the caldera, taking pressure sensor readings at 5 benchmarks
on each transect. The purpose of the measurements is to see whether or
not the volcano is inflating with magma and building up to its next eruption.
Left to right: Frank Spetla, Jon Shanley,
and Terence Singerline prepare to deploy the Ocean Bottom Hydrophone
(OBH). The hydrophone is the white cylinder in the foreground. .
Teacher's Report
Bill Hanshumaker, Educator at Sea
The
morning dawned clear and calm, after steaming overnight through choppy
seas. Following breakfast we had a brief science team meeting to update
the deployment and recovery schedule. The first device deployed was an
Ocean Bottom Hydrophone (OBH). It is secured to a weight in approximately
1500 meters of water. The OBH is used to listen to the sounds of underwater
volcanoes and earthquakes. It will be collecting data over the next two
weeks and we will recover it before returning to shore. To recover the
OBH, scientists on the Thompson send down an acoustic signal that triggers
the weight's release from the instrument package. Once released from the
weight, glass floats protected by yellow "hard-hats" raise the
OBH to the surface for recovery. Technicians and researchers were actively
preparing the ROPOS for its first dive. Antifreeze and other fluids were
added to help protect the hydraulics and electrical systems from the pressure
of the ocean bottom.
Gitai Yahel, studying at University of Victoria,
attaches bottles to the suction sampler before the first ROPOS dive.
.
Researchers
added collection bottles to the suction sampler, enabling multiple samples
to be collected without returning to the surface. Equipment failure could
result in missed opportunities for data collection and new discoveries.
ROPOS was deployed at 1300 hours for a descent to 1700 meters. It is scheduled
to be submerged for approximately 40 hours.
My
ship board training continues. I am scheduled to stand watch from 2000
to 2400, but will be assisting in the control room during the entire dive.
My primary responsibilities include tracking and logging the videos captured
by ROPOS. It is only through the completion of meticulous records that
the physical environment can be correlated to the collection activities
and specific samples. I will be sitting in a dark room looking at numerous
monitors, simultaneously logging several videos. This wasn't exactly in
my image of being "at sea".