Alvin Dive 3365


26 February, 1999
Rodey Batiza (transcript), John Sinton (transcript) and Bob Waters

Summary: This dive determined the locations of contacts between the relatively young Aldo-Kihi flow and older lava units near 17° 26'S. On the east side, two older lava units are present, one with slightly more sediment than the other. North of 17° 26'S, the axis is marked by a discontinuous zone of narrow, shallow collapses. Just west of the axis about 200 m north of 17° 26'S, is a relatively extensive zone of diffuse hydrothermal outflow. However, this area appears to be in decline, and one extinct hydrothermal chimney was found there. Biota presently is dominated by serpulids, anemones, dandelions and crabs. One small lava flow, obviously younger than the hydrothermal activity was seen to overlie hydrothermal sediment-coated older lavas and biota.

The western contact of the Aldo-Kihi lava flow was followed for several hundered meters where tongues of younger pillow lava a few meters to several tens of meters across were seen to overlie older lobate and locally pillow lavas. Both the western and eastern contacts of this flow occur within about 500-700 m of the axis in this region.

Aldo Trough (Lake Aldo) was visited during the dive and the site of the Papa Noel cutout left on top of a large pillar during NAUDUR dive 20 was seen. Since implacement on Christmas Day, 1993, a large hydrothermal edifice has grown up just to the south of the pillar and yellow colored hydrothermal sediment now shamelessly coats everything in the vicinity, including Papa Noel. Black smoke was seen to be issuing slowly from around the base of this chimney, but the upper spires appear to no longer be active.

Sample Locations:

1	17° 25.88	113° 11.67	
2	17° 25.68 	113° 11.91
3	17° 25.67	113° 11.97
4	17° 25.91	113° 12.31
5	17° 25.90	113° 12.28
6	17° 25.90	113° 12.52
7	17° 26.21	113° 12.68
8	17° 26.55	113° 12.74

Plots:

  • Navigation (GMT)
  • Navigation (dot cloud)
  • Depth
  • Heading
  • Temperature