Mixing Zephyr Program
Dive 2939

Port Observer: McLaughlin
Starboard Observer: Davis
Pilot: Hickey
Date: 6/18/95

Summary

Dive Objectives: The goals of the last dive are

Fluid sample from all missed opportunities during the dive program, if possible, and in this order: Hulk, Crypto, TP, Lobo, Dudley, Cantilever

Niskin bottles over Tara

Check out giant? tube worms at 5108,6186 (5112,6187 - 5142,6192)

Summary: Launch Site - X =5150 Y= 6450 47° 57.007 N 129°05.739 W

We landed approximately 100m east of Hulk at the northern end of the Main Endeavour Field. We then proceeded to Hulk to begin collecting water samples.

At Hulk we filled two major sample bottles (MS-5, MS-6) and one gas tight bottle (GT-6) from the black smoker next to marker 8F. The temperature measured with ALVIN's high temp probe was 334 degC. We then proceeded south towards Crypto. We flew past Crypto to TP and backtracked to Crypto.

At Crypto we filled two major sample bottles (MS-10, MS-9) and one gas tight bottle (GT-7) from a black smoker. We deployed small marker BG at this location. The temperature measured with ALVIN's high temp probe was 321.8 degC. We then proceeded to TP to look for marker L. We were unable to find marker

so we chose a black smoker on the West side of TP where L was supposed to be.

We filled two major sample bottles (MS-14, MS-11) and one gas tight (GT-4) using the manifold sampler (Man 1,2 and 5). We deployed small marker BE at this location. The temperature measured with the manifold temp probe was 337.1 - 337.4 degC. The data file was saved as alv2939a. We then proceeded to Dante to look for the putative Riftia worms reported by Blee on dive 2938. We located the clump of worms and decided they were not Riftia but obtained some video of them. After this we headed to Lobo to continue water sampling. We filled two

major samplers (MS-13, MS-15) and one gas tight (GT-3) using the manifold at black smoker south of marker V. We also observed a rectangular marker with two orange stripes next to the smoker. We deployed small marker BD at this location. The temperature measured with the manifold temp probe was 351 degC.

We collected a piece of sulfide chimney from here and inserted the Peek tubing sampler into the black smoker to see if it would melt. Next we proceeded to Dudley to sample the B9 flange. When we got to Dudley, Pat determined that the J-hook had been deployed in a different flange than the one Marv had chosen.

We received instructions from the ship to sample the correct flange and redeploy the J-hook. We filled one major sample bottle (MS-4) and one gas-tight (GT-2) with the flange fluid. The temperature measured with

ALVIN's high temp probe was 306 degC. We then moved the J-hook from a flange slightly

to the left and about .5 m above marker B9 to a flange slightly to the right and about 1-1.5 m above marker B9. At this point, the starboard relay died and Pat had no power to the starboard side of the sub and the dive had to be ended early.