Mixing Zephyr Program
Dive 3005

Port Observer: Squyres
Starboard Observer: McDuff
Pilot: Heintz
Date: 9/25/95

Summary

Dive Objectives: Overall objectives of dive were (1) Temperature and water sampling at Puffer at three different times during the tidal cycle, (2) Mesotech coverage, (3) Niskin sampling at 75 and 200 meters off the bottom above Bastille, and

(4) searching for potential extinct sulfide structures between planned touchdown point at 5075, 6025 and Puffer.

Dive Summary: (1) Temperature and water samples were obtained at Puffer at three times, as planned. Temperatures were obtained were 376.3 deg at about 1103, 365.7 at 1316, and 373.6 at 1457. The first of these was a solid, repeatable measurement; i.e., repeated placement of the temperature probe in the same position gave the same result. The second time, the temperature appeared more variable and it was more difficult to repeat the measurement. The third one is somewhat suspect, because part of the structure was knocked off during the sampling, changing the geometry of the vent. Water samples were obtained on these three visits to Puffer, as follows:

1103-1114: Outer and inner port majors, port gas-tight

1323 Starboard inner major

1327 Starboard outer major

1331 Starboard gas-tight

1430 Two majors (number 4 and one other; unable to hear which one it was due to noise in sphere)

1452 Gas-tight, 6 black stripes and 1 yellow stripe

1453 Gas-tight, 5 black stripes

1454 Gas-tight, 2 black stripes

1459 Pair of majors (10 and 6)

1504 Gas-tight 7

(2) Mesotech coverage was obtained, almost as planned. See Mesotech data for coverage details. Data were obtained in three segments, after each visit to Puffer. The second segment was cut short by a message from the surface at 1404 that the dive could be terminated early due to weather. When we received that message we decided to terminate that Mesotech run at that point and return to Puffer, since the Puffer measurements had the highest priority. Once the third set of measurements at Puffer were obtained, we returned to taking Mesotech data, and continued that until out of power.

(3) Niskin samples were obtained as follows:

1536 X=4861, Y=6024, depth=2104 (Red)

1540 X=4871, Y=5998, depth =2000 (Yellow); depth=1988 (Blue)

(4) During the initial traverse from the touchdown point to Puffer, no sulfide structures were observed, only basalt and minor amounts of sediment.