The Little Hercules ROV shines its lights on active hydrothermal venting at Kawio Barat submarine volcano.

The Little Hercules ROV shines its lights on active hydrothermal venting at Kawio Barat submarine volcano. Image courtesy of the NOAA Office of Ocean Exploration and Research, INDEX-SATAL 2010. Download larger version (jpg, 2.9 MB).

Dive 7: Hydrothermal Venting
July 30, 2010
Latitude: 4d 40.579849' N
Longitude: 125d 05.240244' E

Dive number 7 of Leg 3 took place at Kawio Barat submarine volcano. The ROV descended 1925 meters, arriving above the wall vents discovered on dive 2 of cruise leg 2. This return dive to Kawio Barat was an effort to relocate and characterize more extensively the characteristics and fauna of this area. We observed white bacterial mats on rocks. The area below the vents presented an accumulation of black, yellow and green sulfur flows. Diffuse venting was also observed adjacent to the main smoker vents. Dense barnacle colonization of rocks on the summit crest above the sulfur vents was observed, likely fed by diffuse venting. Volcaniclastic sediments were abundant elsewhere. The lithology was dominated by volcanic rock with sulphide and manganese content. Volcanic sediments with well-oxidized surfaces were observed as we moved east. As we kept progressing laterally the slope became less sedimented and yellow patches of very light and fluffy orange/yellow material were observed – possibly iron-rich microbial mats and/or native sulfur. Clam fields were also found in this area, most of which appeared to be dead.