Mixing Zephyr Program
Dive 2931

Port Observer: Delaney
Starboard Observer: Robigou
Pilot: Hickey
Date: 6/5/95

Summary

Dive Objectives: Exploration dive to the north of High Rise to a water column anomaly identified during the previous nights of CTD Tow-Yo work. Hopefully discovery of new vent field.

Launching target 6320, 9018

3 main targets from water column work: 6560, 9758 / 6794, 10277 / 5946,9573

Summary: Checking navigation and old net versus new net recrunched by C. Parker depth 1050m. Ranging on transponders 11.5, 11, 9.5, 7.5. On bottom at 9:37. Plan for the day is to start in the valley, then travel west toward the wall and find the first anomaly, then travel west toward the second anomaly and finally if time left, go to the third anomaly which is even further north and also the landslide deposit just east of the volcano summit.

Traveling west to the wall. Collected basaltic sample from valley floor. Nice fresh glassy rim for sampling glass 5977, 8922, 2167, 3, 292

Traveling describing the geology and following SONAR map. All detailed observations are in dive narrative (from 9:45 to 11:11).

We then arrived at a tubeworm patch on a N-S basaltic pillow ridge (5878, 9562, 2131, 8, 306). Temperature inside tubeworm patch 14, 12, 8C. Temperature at the surface of the worms 5°C

Sampling temperature on another tubeworm clump on this tubeworm covered ridge. 12.6°C in diffuse flow with tubeworms (small-young) and limpets 2121, 8, 307. GT yellow 5878, 9563, 2131, 8, 312. Major yellow 5877, 9561, 2131, 8, 273. Deploying marker AC 5m south of tubeworm patch sampled 5879, 9557, 2133, 7, 269

Traveling north (see dive narrative for observations. At 11:51, Arriving at new tubeworm patch 5882, 9735, 2127, 4, 180 temperature in tubeworms 24.4C max. Temperature in tubeworms and diffuse flow 29.8C 5882, 9735, 2127, 5, 197. Sampling GT purple 5882, 9735, 2127, 4, 174 and Major red 5884, 9738, 2127, 4, 185. Deploying marker AK 5884, 9737, 2127, 5, 185. Finally we sampled of tubeworms in bio-box. Finally documenting area with 3-chip.

Traveling north (dive narrative) we arrive at First area with sulfides and tubeworms. It seems we have reached a field this time rather than an isolated “seep” of diffuse flow. 6685, 9843, 2156, 9, 312 In the field hunting for something good. And at 6685, 9843, 2144, 14, 055 sulfide structure with rather weak looking flanges and one smoker. Working on documenting this structure in this NEW vent field. Black smoker Temperature measurements 323.9C max on smoker 6685, 9843, 2144, 14, 191. Major purple. Deploying marker AF. GT blue. Major blue #10. GT red did not hear trigger! Work on flange temperature in pool 322.1C max

Temperature on flange 28.1C, edge of the flange 70C, top of flange 0.5-0.6°c. Inside "red" community of palm worms 7°C. Flange pool 306.4C. 2146, 13, 153 flange is 80 cm wide and sticks away from sulfide wall 80 cm. Documenting flange with video. Documenting area from which flange piece was removed

14:15 On the way up triggering 2 Niskins: Red Niskin 2143, 15, 172 and Orange Niskin 2136, 22, 189.