August 14: Since the exciting and successful powering up of the two short-period seismometers, thermistor array, and HD camera that comprise the ASHES secondary infrastructure…and the live streaming of video and seismic information onto the Internet, the past coupled days have flown by. The team has been extremely busy preparing for the last few dives of the VISIONS’13 expedition, examining engineering and science data from the sensors deployed, working up reports from the prior dives, and making sure that all data are backed up and well organized. The students have helped in collection of multiple samples collected with the CTD and they are busily working on their projects.
Subsequent to the full testing of the Secondary Infrastructure at the ASHES hydrothermal field, yesterday we had weather blow in with winds up to almost 40 knots. The storms out here are amazing in their own way, creating beautiful chaotic seas that rock the boat, and send spray flying into the air and waves onto the fantail, but this weather is not kind to ROPOS. Hence we were on a weather hold until yesterday morning (August 14).
What a difference a day makes, however! Today (August 15) we awoke to a beautiful, slightly blustery, blue-sky day with stellar blue water and a visitation by a Mola mola fish. With this welcome change, ROPOS dove to the Central Caldera site and conducted a test of the > 4 km extension cable that crosses the caldera to Primary Node PN3B. This cable had a couple of hockles (or kinks) in it, and so the signal was compromised and needed retesting. ROPOS plugged into the cable and tested the fibers and, although additional work will need to be conducted on shore to finalize a solution, this cable may be operational for next year’s deployment with some modifications perhaps to some of the other secondary infrastructure.
Out of the ~22,000 m of cable laid during this cruise, this is the only cable with an issue, and one that looks solvable. The team has worked very, very hard to make this happen, and we took tremendous joy in watching the HD imagery and seismic data streamed live. We cannot wait until next year when over 100 sensors of 33 different types will be connected to the Internet (stay tuned for VISIONS’14!) as part of the cabled component of NSF’s Ocean Observatories Initiative.
The day ended with a dive in the International District Hydrothermal Field that always fills us with awe. Here, the vent El Guapo rises > 50 ft above the surrounding seafloor with jetting fluids reminiscent of fire issuing from its summit. During the dive, ROPOS recovered a temperature-resistivity sensor deployed in the 270°C black smoker chimney called Escargot. This instrument has been collecting temperature and compositional (chlorinity) data on the vent fluids issuing from this structure for a couple weeks, and it will be exciting to see the results. ROPOS placed a new, battery-powered temperature probe in the same orifice that the resistivity probe was in. This probe will be collected next year. ROPOS also took a sample of the vent fluid at El Guapo, as well as at the anhydrite chimney called Diva, and retrieved another temperature sensor from the small chimney called Pagoda. The night will be a late one for many as the samples are processed, data are downloaded, and preparations are made for the dive that will start ~ 2 am. But right now it is a beautiful star-filled night, and we see our neighbor ship, the Western Flyer from the Monterey Bay Aquarium Research Institute, as a light on the horizon. Its now 1 am, on the 15th…we dive again soon.