October 25, 2001
Dive Report 3719
Pilot: Pat Hickey
Port Observer: Peggy ODay
Stbd Observer: Becky Gast
Primary objectives: Deploy Autonomous Larval Sampler (ALS)
and crab trap. Collect hot Alvinella. Chimney collections
with Sipper and temperature readings. Basalt collection.
Dive Start: 14:00
Video Start: 15:30
On Bottom: 15:33 at a depth of 2479m
Dive End: ~19:40
- At ~15:40 GMT the ALS was located and moved to basalt near Riftia
patch at Q vent (4462/78837 heading 300). The hoses were released to
hang down from the sampler; the one with only one tube hangs a bit longer
and goes down a bit of a slope (see video).
- Deployed crab trap in rust-colored Riftia bed near the ALS
(4468/78842;16:05). Returned to pick this trap up at the end of the
dive (19:29) and 5 crabs were recovered.
- Went to M vent (16:11) to look for area where chimney was knocked
off on first day of diving interested in seeing if there was
a new chimney growing and determine whether we could use the snatcher
on it (4448/78950; 16:23 for start on video). No new chimney was growing,
so a different one was selected for a grab with the manipulator. The
one selected was a vigorous black smoker. Temperature 353°C before
catch, Sipper samples taken (#8 may have been bad, #9 was sipped at
16:39), temperature was 362°C after chimney collection. Sipper temp
probe wasnt working, so we used High temp probe. Collected chimney
went into large biobox and broke into several pieces nice pyrite.
Note: the Sipper may have been damaged at this site when it accidentally
sucked the extremely hot water.
- Moved around to the other side of the same chimney spire at M vent
(2589?/78975; heading 117) to select smaller chimney for snatcher attempt.
Tried to get temperature but chimney started to break off. At 16:45
we triggered the snatcher, but didnt recover a chimney because
the apparatus didnt close completely. The temperature at this
chimney was about 100°C, but the measurement may not have been accurate.
- Moved to Robins Nest/Roost near M vent to collect Alvinellids
(4437/78946; 199 heading; 16:57). Began taking temperatures and Sipper
samples: Sipper #10 was in 55-60° C clump it misfired so
#11 was used (17:07); Sipper #12 was in 80-90°C clump (17:11); Sipper
#1 was in ~40°C clump (17:15); Sipper #2 was at 90° C (17:18),
followed by #3 and #4 in the same place (temperature was actually taken
after the #4 sipper sample). Alvinellids were collected for the cold
small biobox first (17:50), then for the ambient/warm front chamber
of the large biobox (17:54). It was very difficult to determine how
many worms were in the boxes because of floating biological debris.
We noticed that the worms were crawling into crevices on the recently
scraped rock, so we took temperature readings that ranged from 70
200° C depending upon location of the probe (deeper into the crevice
became hotter). The #5 Sipper sample was taken (18:07) next to a worm
in one of these crevices (very cute). Note: Digital stills were taken
for all of these samples, in the order written, except #3. There are
three images associated with each sample one wide angle, two
zoom. Take notice of the pattern in order to determine which images
go with each Sipper sample. 3 Chip video was taken at 17:36 of Alvinellids
in tubes and after collection. Digital stills were taken of Robins
Nest site as well.
Note: video was changed at 17:34.
- Collection of second chimney at M vent (18:11; 4444/78953, heading
135). Temperature of 310°C (18:14), chimney grabbed at 18:16 and
placed in back of large biobox with other chimney. Sipper samples #6
and #7 taken at 18:30 and 18:32.
- Went in search of glassy basalt (~18:45) 4450/78868, heading 50. Collected
several pieces into Rock box, pulled pin, then went back and collected
another large piece that was placed into the milk crate (18:51). Had
to readjust ballast due to heavy rocks and the consumption of lunch.
- Went collecting crabs for slurp gun, and at 19:18 had to stop and
investigate battery imbalance problem.
- Notified top lab that we would be up in about 20 minutes and went
back to Q vent to retrieve the crab trap (19:29). After collecting the
trap, the manipulator arm was placed on top of the cold biobox, we dropped
the weights and began to surface.