Mixing Zephyr Program
Dive 2938

Port Observer: Delaney
Starboard Observer: Paradis
Pilot: Williams
Date: 6/17/95

Summary

Dive Objectives: 1) Deploy Sea water Battery near Dudley.

2) Deploy J-hook at Dudley.

3) Go to elevator to retrieve camera and t-probe.

4) Go to Grotto via pass between Dante and Dudley to deploy camera.

5) Collect fluid samples at Dante.

6) Geological survey/sonar map check-up.

Summary:Elevator Deployment The morning of the dive was characterized by intermittent rain with 13 knots wind and a 6 - 8 foot swell. Due to the large number of instrument deployments desired for this dive, an elevator was equipped with the camera and temperature probe. It was deployed from the deck at 07:15 at 5150 6200. J-hook Deployment The sub landed at 5071 6075, which was NW of Dudley. After sitting at this spot long enough for Blee to obtain neutral buoyancy and a good navigation fix, we headed towards Dudley to deploy the J-hook. We found the markers B9 and AA and immediately found the previously surveyed flange. At 10:25 the deployment was complete and Blee relayed to us his reservations about trying to sample the flange pool with the manifold for fear of disturbing the j-hook arrangement, which appeared to be ideal. No sampling attempt was

made. The 3-chip camera was utilized to document the j-hook orientation. A general perspective view was obtained as well as close ups of the sensors in the pool. Sea Water Battery Deploymentt The sea water battery was deployed at 10:54 between Dudley and Dante (4941 6143) on lobate sheet flow with light dusting of brown sediment. The angle of the battery was estimated at less than 5 degrees off from level and

appeared stable for long term deployment. Deployment of Camera and T-probe The elevator was found at 5190 6010. While searching the nominal x y location for the elevator, John Delaney observed the camera lights flashing on and off. Nobody observed the strobe flashing on the elevator apparatus. The T-probe was easily and quickly removed from the elevator, but the pull-pin for the camera was situated on the opposite side from the pull-pin for the t-probe. Therefore it was necessary to reorient the sub to get the camera. This attempt resulted in a large prop wash generated sediment cloud. Blee found it necessary to move the elevator with the camera on it to an area free of turbidity. This was accomplished, the camera put on the basket, and the elevator sent to the surface (after much coercion from the manipulator). We headed to Grotto which was 237 meters away and found the marker BA (4937 6152), which was the previously surveyed site for the camera and t-probe. Both instruments were deftly deployed by 12:31 and will document the activity of a vigorously venting black smoker. Fluid Sampling at Dante We moved over to the east to Dante and found the marker A6 (4981 6177). Black smokers were visible up and down the large Dante edifice, but a smoker that was approachable for sampling with the manifold was needed. Blee found a good smoker to sample and after some initial problems with the manifold computer, we obtained 2 gas tight samples and 4 major samples from the same orifice(13:41 - 13:48). The ALVIN high temperature probe had a maximum reading of 346.4C. Geological Survey The remainder of the dive was dedicated to a geological survey to attempt to identify features that are evident on side scan sonar images. Our first goal was not accomplished, which was to fly across the graben to the east talus slope edge and follow it northward to a prominent rise, possibly a volcanic cone or an old sulfide structure. We made it across to the edge of the talus slope and ran out of power. Our ascent began at 14:41.