Alvin Dive 3362

26 February, 1999
Cindy Van Dover (transcript, Eric Bergmanis (transcript), Dudley Foster

This dive began with a ½ h geology transect with sampling, beginning west of the axis to cross a contact en route to the ARGO-Rehu Marka site. At this Rehu-Marka site, there is evidence of a greatly declining vent system, with dead serpulids, dead mussels but still with extensive anemone beds. From the Rehu-Marka waypoint, we headed approximately 010 to Mkr 24 where we found diffuse flow and live mussels in discrete patches among more extensive patches of dead and dying mussels in cracks. We attempted 3 pot samples in patches of 100% live mussels (2 of which worked) and we filled one box with a scooped sample of 100% live mussels for a comparison of these two sampling methods (x = 1180, y = 243, z = 2581). Maximum temperature in the mussel patch was 9.5C. We selected a second site for mussel sampling, about 110 m NW of the first sample, within this same field (x = 1149, y = 276, z = 2581). Maximum temperature within the patch sampled was 5.5C. We collected 3 pots here plus one box sample (but the box sample contains mussels by one's and two's rather than scoops). Although there were 2 mussel boxes remaining, the loss of the scoop made it doubtful that filling these would be a very satisfactory use of dive time. Given that another dive would be made in this area, the decision was made at 1330 h to divert an additional 1.5 hr of the dive to geology, with perhaps a trade for some bio samples in this area on a subsequent geology dive.


Sample Locations:



  • Navigation Plot (GMT)
  • Navigation Plot (dot cloud)
  • Depth + Altitude
  • Heading
  • Temperature