NOAA Ship Ron Brown-Teacher Logbook July 21, 2001

Teacher Logbook - NOAA Ship Ron Brown

A white skate startled scientists in the ROPOS hydro lab during a pressure sensor reading at the southern pillow mound (1723 meters of water). The pillow mound area is located on Axial's south rift zone, about 4 miles south of the main study area in the caldera. During the 1998 eruption, lava formed large pillows in this area, thus the name.

image of NeMO Net camera, click for full size

The NeMO Net 2000 camera had been on the seafloor for one year, and was recovered today. It sent an image of the tubeworm bush (lower left) and temperature readings back to PMEL on a near real-time basis.

image of RAS sampler, click for full size

Susan Lang (center) and Mausmi Mehta (right) prepare the RAS (Remote Access Sampler) for its one- year deployment at Cloud vent, as part of the NeMO Net 2001 experiment.

Jeff Goodrich's Sealog:
North part of caldera above CASM vent field
July 21, 2001

Whew! Only 10 more minutes to go. The pressure reading was almost complete when all of a sudden a huge white skate appeared in the upper part of the monitor. Bill Chadwick panned ROPOS's camera and yelled "Frame Grab, Frame Grab." Susan Merle rushed from her navigation station to the frame grabber and took several shots. "We've got it."

After the reading was complete we had only one more pressure measurement in the middle of the caldera. To get there we followed a fissure where a dike intrusion caused the seafloor to open up and seep molton rock. It looked like a mini submarine Grand Canyon. This 35 hour dive brought us all over the caldera visiting the 1998 lava flow, south rift zone pillow mound, and center of the caldera twice. ROPOS gets around.

With ROPOS safely on deck for maintenance it was time to get back the NeMO Net camera mooring. "I think I see it" deckhand Bill exclaimed. The yellow floats appeared off of the ship's starboard side bobbing up and down with the swells. Twenty minutes later the camera was recovered. It spent a year at Bag City, a vent on the 1998 lava flow, taking pictures and recording temperatures of a tube worm bush. The pictures were transmitted acoustically to a NeMO Net buoy on the surface, via satellite, to PMEL in Seattle. Both the pictures and temperature data were put on the web for all to see. The only problem with the system was that a bacterial ooze grew on the lens clouding the view. Maybe a windshield wiper was needed. Replacing the camera will be the RAS (Remote Access Sampler) at Cloud vent. It has 48 water sample bags and can be programmed to sample on whatever time frame Dave Butterfield wishes. It collects temperature, sulfide, and pH data with probes that will be transmitted to the buoy, via satellite, to PMEL once per week. If an eruptive event were to take place, all of the bottles could be triggered at once. The samples will be retrieved next year and analyzed by almost everyone on board for such things as silica, ammonia, sulfide, pH, alkalinity, magnesium, calcium, cadmium, organic carbon and culturing for DNA. We're conducting a 24-hour test of the sampler at the vent to see how the tidal cycle affects vent chemistry here. After recovering and calibrating it we'll put it on the bottom for good. The real-time data will be available on the NeMO Net web site.