The Regional Cabled Array cruise AT42-12 (May 30-July 12, 2019) was highly successful with the completion of all tasks scheduled for the annual maintenance and operations expedition. The cruise was extremely complex and required highly detailed logistics and personnel planning. Over 53 days, sixteen 48-ft trailers, and six 16-ft flatbed trucks moved 166 tons of RCA equipment to and from the Seattle, WA and Newport, OR. Onboard staffing during the four legs included 52 personnel with 13 students, six non-OOI PI’s-technicians from four institutions and one member from industry. In addition, Susan Casey, a New York Times bestselling author (i.e. The WAVE, the Devils Teeth, and Voices of the Ocean) participated on Leg 4.
As part of the NSF Oceans Month, a 1-hour Facebook live interactive broadcast was conducted, including live streaming of imagery from Jason working at Southern Hydrate Ridge and a period for questions and answers.
There were 58 Jason Dives ( J2-1144 – J2-1201); only three were aborted. The vehicle worked extremely well with very short turn-arounds and the team was highly efficient in installation and recovery of instruments/infrastructure. The Atlantis crew also provided exceptional support. The RCA team gives a big shout out to both Jason and the Atlantis for jobs well done and to contributing to this highly successful cruise. Other highlights from the cruise include:
- The successful recovery and reinstallation of the Axial Base Shallow Profiler Mooring;
- A record of 20 Jason dives in five days during Leg 2;
- Turning of 6 platforms on the Shallow Profiler Moorings;
- Turning of 3 Deep Profiler Vehicles;
- Turning of two Benthic Experiment Packages and two secondary Junction Boxes
- Installation of 113 RCA instruments;
- Recovery of 100 RCA instruments;
- A record number of cabled RCA instruments (131) are operational (as well as all 10 cabled PI instruments);
- All Shallow and Deep Profiler vehicles are conducting their missions;
The cruise included nine days for the installation and recovery of PI instruments:
- The installation of an NSF-funded A-0-A high resolution, self-calibrating pressures sensor, Central Caldera, Axial Seamount (Wilcock, University of Washington) (1);
- The recovery, repair and reinstallation of the NSF-funded COVIS multibeam sonar for hydrothermal plume imaging at the ASHES hydrothermal field, Axial Seamount (Bemis, Rutgers University); Bemis also conducted a several hour thermal and video survey of the field (3);
- Installation of an NSF-funded uncabled thermistor array at the ASHES hydrothermal field, Axial Seamount (Bemis, Rutgers University); and recovery of three other arrays;
- The turning of an NSF-funded CTD at the ASHES hydrothermal field, Axial Seamount (Chadwick, OSU) (1);
- The recovery of an ONR-funded uncabled Benthic Observatory Platform from the Oregon Offshore site (Reimers-OSU) and associated sediment sampling (1);
- The installation of an ONR-funded uncabled Benthic Observatory Platform at Southern Hydrate Ridge (Reimers-OSU and Girguis – Harvard) and associated sediment sampling (1);
- The recovery, repair, and reinstallation of a University of Bremen-Germany-funded cabled overview multibeam sonar for imaging of all methane plumes at Southern Hydrate Ridge (Bohrmann and Marcon, University of Bremen) – its range is now extended from 200 to 700 m (1);
- The installation of a University of Bremen-Germany-funded cabled 4K camera at Southern Hydrate Ridge (Bohrmann and Marcon, University of Bremen).