Science Report:
ROPOS dive 554 completed the Imagenex survey that was started on dive 546 at the southern end of the 1998 eruptive area. At this location, 4 miles south of Marker 33, a mound of pillow lavas was erupted which piled up to a thickness of 25 meters in places, enough of a depth difference to be detected in before-and-after bathymetric surveys. After collecting the Imagenex data, a geologic traverse was made on the bottom to examine some of the features revealed during the first part of the survey. ROPOS visited the large 1998 eruptive fissure to the north of the pillow mound which was 20 meters wide and 3 meters deep, and collapse pits in the middle of the flow with spectacular drain-out features in them (photo right).

After the dive we recovered the acoustic transponders that allowed us to navigate ROPOS in that southern area. Next, we transited up to Axial's north rift zone for the first time during NeMO 2000 (the 1998 eruption was on Axial's south rift zone) and we lowered four extensometer instruments to the seafloor in an elevator mooring. ROPOS then positioned the instruments across the rift zone during dive 555, where they will precisely measure the distance across the rift over the next year. These same instruments measured deformation at this site due to the 1998 eruption.

We're hoping to get two more dives in before we have to leave Axial early Monday morning.