Mixing Zephyr Program
Dive 2997

Port Observer: Butterfield
Starboard Observer: Summit
Pilot: Hickey
Date: 9/17/95

Summary

Dive Goals: The main objectives of this dive included the recovery of both the time lapse camera at Cannaport and the J-hook at Cantilever, additional characterization of the Bastille complex via water sampling and thermocouple measurements, and to further increase geomorphologic and geologic characterization of Peanut and the Main Endeavour vent Field by detailed video and Mesotech surveys, respectively.

Dive Summary: ALVIN touched bottom northeast of S&M [x5127 y6057] on pillow basalts. We drove on a heading of 252° until we crossed the large fissure that runs beside the South Main Field, at which point we followed the fissure south to the STOP sign [x4929 y6010] below S&M. Crossing south of S&M we moved towards Cannaport, passing markers CM, AH, and a marker that was presumably AS. The camera at Cannaport was heavily encrusted by limpets and gelatinous material but was released uneventfully at 1019 [bad fixes, d2197].
t Cannaport we sampled gas tight #2 [1043h, high T 343 degC] at marker AP (the smoker at which the camera was aimed). The bolts on the discrete gas tights and majors were improperly adjusted and could not be triggered with the ram on the port arm, so all discrete samples were taken with the starboard arm. We then searched for a site to sample on Bastille near marker AM--many orifices to choose from. A chunk of chimney from one fruitless excavation made it into the basket at 1054h. We sampled an apparently puffing vent below a tight group of three smokers [x4865 y5984, d2194, h025, a4]. The ALVIN high temperature probe quit working and all further temperatures were measured through the manifold. Manifold temp=375 degC, port gas tight [1122h], port major [1124h], port inner major [1128h], gas tight #7 [1137h]. At Bastille we sampled directly above marker AD in a cloud of floc and smoke [x4870 y5997, d2190, h219, a2]. Manifold temp=355 degC, starboard inner major [1216h], gas tight #5 [1225h], yellow discrete major [1230h]. Noticed that the forward Niskin tripped sometime during the sampling at Bastille. Began video survey of Peanut, which had grown a large spire [8m] in comparison to the 1991 maps. We sampled an unmarked site at Peanut at the base of the large new spire [x4840 y5996, d2192, h164-141, a2]. Manifold temp=350.7 degC, discrete major #4 (purple) [1302h], discrete major #10 [1305h], gas tight #6 [1309h]. At Cantilever, close-up video of the refractive index probe and manifold samples from the flange pool were taken before disturbing the J-hook. The refractive index probe had concretions at the pool interface, and the J-hook stem was covered with gelatinous goo similar to that on the camera. [bad fix, d2193, h156] Manifold temp=359 degC, starboard gas tight [1325h], starboard major [1327h]. The J-hook was recovered and what was left of the refractive index probe. In the excitement of the moment we forgot to change videotapes until 1349h (about 15 minutes lost). Began Mesotech line at [x4904 y5902] and flew along the large fissure at h020. Ended line and tripped remaining Niskins in plume over Dante at 1404h [x4967 y6146, d2164]. Ran a line south along talus slope from [x4864 y6195] to [x4862 y5939]. Drove a final line that was meant to be up the center of the South MEF but instead was a repeat of the initial Mesotech line. At 14:38 the weights were dropped.