This Leg is sooo Deep and sooo Mooring Leg 4

Leg 4 VISIONS’23 students heading out to sea joined by the Chief Scientist Katie Bigham, Co-Chief Scientist J. Nelson, and RCA technician Andrew Pawley. Credit: M. Elend, University of Washington , V23.
Leg 4 VISIONS students get a tour of the Jason Van. Credit: M. Elend, University of Washington, V23.

Leg 4 began on Thursday, September 7 with 10 excited VISIONS’23 students arriving at the Newport NOAA Dock around 1400 hrs.  The weather was beautiful, and the weather forecast was promising for Leg 4 operations.  Prior to departure, the students spent their time getting familiar with the ship, which at first can seem like a labyrinth of stairways, getting instructions on logging operations in Jason’s control van, and participating in a safety briefing that included their first donning of immersion safety suits. Fondly called “gumby” suits, these red neoprene suits can be life savers in the cold waters of the NE Pacific, but are a bit awkward to get into on your first introduction to them.

A large part of operations during this Leg will focus on recovering and redeploying cabled Deep Profiler moorings that host an instrumented vehicle, which at the Slope Base site traverses up to ~ 2700 m (8858 ft) of ocean water daily. These moorings are a companion to the Shallow Profiler Moorings, which in concert are providing unprecedented, real-time monitoring of ocean environmental conditions throughout the entire water column.

Jason transits through thousands of fingerlings in the nutrient-rich NE Pacific waters of Newport Oregon. Credit: UW/NSF-OOI/WHOI; J2-1548; V23

Leg 4 began with a bang.  The Thompson left the dock at 2000 on September 8 and arrived at the Oregon Offshore site at ~ 0100 on the 9th.  The students gathering on the bow during departure got to witness a striking sunset while the Thompson transited in calm seas underneath the Yaquina Bridge, which rises 133 feet above the entrance to the Yaquina channel that provides access into the NE Pacific ocean. The students were excited to get their first logging opportunity in the Jason control van and watch deck operations for its deployment off the port side of the R/V Thompson.

The vehicle was launched to disconnect the Deep Profiler Mooring from the extension cable at ~ 580 m that provides power and communications to and from shore and to install a recovery beacon on the top float. This site is always great to work at because there is so much abundant sea life in the nutrient-rich waters ~ 48 miles off Newport, Oregon. A beautiful view at the start of the dive included Jason capturing a seal swimming backlit by the sun shining through the oceans’ surface.

Sea lion watching Jason come to the surface. Credit: S. Avetisyan, University of Washington; V23

In deeper waters near the seafloor, sable fish greeted the ROV, so high in abundance that they stirred up the sediment. A beautiful view near the end of the dive included the Jason cameras capturing a seal swimming backlit by the sun shining through the oceans’ surface. 

This operation was quickly followed by a CTD at 0430-0530 to take ocean measurements and fluid samples for follow-on verification of instruments on the mooring.  During this operation, the students learned about the CTD and gained experience sampling fluids from the Niskin bottles that trap fluids at specific depths.

VISIONS’23 clean the Deep Profiler float recovered from the Oregon Offshore site. Credit: M. Elend, University of Washington, V23.

Immediately following the CTD, Jason was back in the water to begin the Deep Profiler Mooring Recovery process, which included attaching a recovery line to the top surface float of the mooring hosting the beacon.  The dive went well and Jason was back on deck before breakfast at 0730.

Unlike several periods during this cruise to date, the weather has been cooperative, allowing deck operations to recover and replace the Deep Profiler (DP) Mooring to proceed rapidly.  After completion of the mooring deployment, another verification CTD will happen, and the Thompson will proceed to Slope Base for some more DP work.