HOT-26: Chief Scientist Report

Chief Scientist: C. WINN

Personnel List

C. Winn, Chief Scientist
D. Hebel
R. Letelier
J. Dore
T. Houlihan
J. Snyder
M. Rosen
S. Kennan
T. Shinoda
M. Cremer


Cruise schedule

We departed Snug Harbor at 9 am Monday the sixth of May.  We spent
approximately 4 hours at Kahe point, about a hour longer than usual,in
order to try the new CTD deployment system.   We returned to Snug on
May 10 at 1700.  The return trip was unusual because we rounded the
south end of Oahu.  This course saved us about two hours of transit
time because the sediment traps drifted about 25 miles east of station
ALOHA.

Sampling

All WOCE and GOFS chemical sampling was completed on HOT-26.  The WOCE
deep cast was obtained and both the sediment trap and primary
production experiments were completed.  However, the WOCE 36 hour burst
sampling was not completed as planned.  Although, CTD casts were
collected over the entire period spent at station ALOHA, CTD casts were
not obtained on three hour intervals over a contiguous 36 hour period.
The WOCE 36 hour burst sampling was not obtained, primarily because of
weather.  To a lessor extent, the extra time required to deploy the CTD
contributed the failure to obtain the 36 hour CTD burst sampling.

CTD operations

Approximately 215 meters of hydrowire was cut off of the top of the
spool after leaving Kahe Point.  The CTD cart and tail-weight was used
for all CTD deployments.   The new tail-weight deployment system proved
very effective in reducing the CTD motion during recovery.  We attached
some wooden braces on the cart in order to prevent the CTD from moving
on the cart.  The ship's roll tended to move the rosette off of the
center of the cart between deployments.  CTD operations were slowed
significantly until we installed the wooden braces on the cart.  CTD
operations were halted for approximately 12 hours on Wednesday the 8th
due to rough seas (i.e., 10 to 12 foot seas and 25 to 30 knot winds).

Sediment traps

The captain and crew of the Alpha Helix deployed the sediment traps
under Marcs direction.  There were no significant problems in spite of
a very wet back deck.  The crew recovered the array under my
direction.  Again, there were no significant problems.  The sediment
trap operations were done on the starboard side on HOT-26, in an
attempt to decrease the crane whip.  Although the starboard deployment
was an improvement, the recovery of the sediment trap spar buoy was a
problem again on HOT-26.  We may want to replace the large GOFS spar
buoy with a smaller one on the remaining Alpha Helix cruises.

The sediment trap crosses at all four depths slipped on this cruise.
At all depths except 500 meters the crosses were prevented from moving
significantly downward by the hose clamp used to stabilize the
crosses.  The 500 meter cross slipped all the way down to the tail
weight.  This was reported to have happened on both of the previous
Alpha Helix cruises.

Marc Rosen Injury

Marc injured his lower back while setting up the primary production
array on Wednesday morning.  According to Marc the injury occurred
while he was bending over.  He was not lifting or carrying anything at
the time.  Marc spent about 24 hours lying down, and at Marc's request,
was given some pain medication after Captain Callahan spoke with his
medical service in Alaska.  Marc did not participate in any more deck
work on HOT-26, and reported that he had largely recovered by Friday
afternoon.