This past few days since leaving port have been quite busy. Following an ~ 22 hour transit to the base of Axial Seamount, the R/V Thompson arrived on site at 17:30 (Pacific local) to begin work at the Shallow Profiler Mooring. Prior to a series of three Jason dives, a CTD cast was conducted to collect ocean water for follow-on shore-based verification of environmental data collected with the 18 instruments on the mooring over this past year.
The Shallow Profiler Moorings, are the most advanced in the oceans, collecting real-time data at ~ 200 m water depth from instruments on a stationary platform (the Platform Interface Assembly) and on a winched, instrumented “science pod,” which has made over 3,000 profiles from ~ 200 m to ~ 5 m beneath the oceans’ surface during this past year. Because the moorings are cabled, a wealth of engineering and environmental data are streamed to shore in real-time at the speed of light. In concert, these instruments provide information on ocean acidification, biological productivity, currents, water temperature and oxygen concentrations, as well as many other parameters including digital still imagery of the life that lives at these depths. A smart mission execution program, developed by APL engineer Eric McRae, uses data from the instruments to know when it is safe for the science pod to go near the oceans’ surface. When the ocean waves are too large, the science pod knows to “keep its’ head down” deeper beneath the turbulent waves, and during nicer days it rises to just below the surface. A light sensor on the science pod lets us know when the sun is shining out at Axial – over 300 miles offshore. Everyone onboard was excited to get the first series of Jason dives underway – we have been preparing a year for this event!
During the transit, the VISIONS’s students were trained in the Jason control van on how to enter myriad metadata information and how to collect 4K video and digital still images, which in concert are critical to our mission.
The first Jason dive (J2-1339) imaged the mooring in detail to see how it fared over the past year, and then disconnected and recovered the PIA, latched beneath the vehicle’s underbelly. A swarm of beautiful salps greeted the vehicle as it surveyed the platform. We have not seen such an aggregation of these amazing organisms before at Axial Seamount. The students were enthralled by the ROV operations and the “mission control-like” atmosphere within the Jason operations van.
The second Jason dive (J2-1340) installed a newly refurbished PIA, and recovered the Science Pod from the 12 ft- across, 7,000 lb platform. The final dive at the platform, installed the refurbished Science Pod and then surveyed the platform again in detail. The 200 m deep platform was installed in 2014, and it has become a blue water island for a variety of animals to colonize and to aggregate, such as the salps this year.
The work at Axial Base ended with a deep dive to 2600 m water depth (8530 feet) to recover and redeploy a junction box (small cabled substation) that provides power and communication to the Shallow and Deep Profiler moorings at this site, as well as an array for seafloor instruments.
The students have now gotten their “sea legs” and are adjusting to working in the wee hours of the mooring – operations run 24/7 on the R/V Thompson. They are discovering that life at sea onboard a global class research ship is amazing.