Diving Begins Along the Cascadia Margin

This morning at 1000 the R/V Atlantis departed for the Oregon Offshore site to conduct a series of dives focused on turning two instrumented platforms on the Shallow Profiler Mooring at this site. These state-of-the-art moorings, hosting a diverse array of up to 18 instruments, are true workhorses for the Regional Cabled Array. The shallow profiler science pods have made >35,000 profiles from 200 m water depth to near the oceans’ surface since their installation in 2014. During these profiles they make continuous measurements of key environmental ocean parameters – e.g. pH. CO2, nutrients, biological productivity, mammal vocalizations, temperature, and dissolved oxygen etc.

VISIONS’19 students don survival suits during the Leg 2 Safety meeting. Credit. M. Elend, University of Washington, V19.

During the transit out to the Offshore site, the day was filled with Safety briefings where VISIONS19’ students got to practice donning emergency survival suits and were mentored in CTD operations. For most, this is there first time at sea and they had the pleasure of experiencing a gently rolling ship for ~ 5 hrs as the ship steamed towards our worksite The engineers and scientists onboard conducted final instrument testing and installation of sensors onto the platforms to be deployed.

Co-Chief Scientist, Orest Kawka, mentors Leg 2 VISIONS’19 students in sampling of ocean water from the CTD. Credit. M. Elend, University of Washington.

In concert, the ROV Jason team also conducted final testing of the vehicle.

The Atlantis arrived on site at 1400 and the students got to apply their newly gained knowledge about CTD operations helping launch the CTD-Rosette system, be in the control room for the CTD, and then help with sampling the ocean water collected. A variety of samples are collected for verification of sensor data through fluid analyses on the ship and onshore.

Jason just about to begin its descent on the first dive of the Cabled Array 2019 cruise. Credit. M. Elend, University of Washington, V19.

There was much anticipation and excitement as the ROV Jason entered the water for the first time at ~1640. RCA scientists, engineers and students anxiously awaited the first glimpse of the shallow profiler mooring. The dive went extremely well – recovering the instrumented platform (PIA – platform interface assembly) within 3 hrs. Within about 20-30 minutes the vehicle was back in the water to install a refurbished PIA replacement that was latched beneath Jason for the descent and to recover the winched shallow profiler (SciP).  We have one more dive at this site to recover the SciP, and then the R/V Atlantis will transit to Slope Base.