End of Leg 7

September 30, 2014

The sensor pod of the cabled coastal surface-piercing profiler (cCSPP) floating freely in the water column after being released from the deployment cradle on the profiler base. Once powered up, the sensor pod will move up and down in the water column at least 4 times per day, taking samples continuously using the onboard CTD, oxygen, fluorometer, nitrate, AC-S, PAR sensor, spectral irradiance, and 3D water velocity sensors. Photo Credit: NSF/UW/CSSF, Dive R1801, V14

ROPOS using the starboard manipulator to pull the release that allowed the sensor pod of the cabled coastal surface-piercing profiler (cCSPP) to swing upwards and float freely in the water. The cCSPP was delivered to the seafloor and placed roughly 12 meters due East of the medium-powered junction box MJ01C at the Oregon Shelf site, in 79 meters of water. Photo Credit: NSF/UW/CSSF, Dive R1801, V14

An orange anemone clinging to the hydrophone cable at the Oregon Shelf site. The hydrophone was only deployed roughly a week before, so this anemone found the hard substrate and attached itself fairly quickly. Photo Credit: NSF/UW/CSSF, Dive R1801, V14

A lingcod and two anemones attached to the Oregon Shelf hydrophone cable. Photo Credit: NSF/UW/CSSF, Dive R1801, V14

A lingcod resting on the seafloor next to the hydrophone cable at the Oregon Shelf (80m) site. Photo Credit: NSF/UW/CSSF, Dive R1801, V14

The hydrophone (an underwater microphone) connected to the Benthic Experiment Package (BEP) at the Oregon Shelf site, in 80 meters of water. Photo Credit: NSF/UW/CSSF, Dive R1801, V14

All cruises must eventually end. And this VISIONS ’14 cruise, which has gone on for 3 months and deployed hundreds of instruments, came to a triumphant end with the textbook deployment of a cabled coastal surface-piercing profiler (cCSPP) at the Oregon Shelf site, in 79 meters of water.

The cCSPP was transported from Corvallis to Newport on the morning of Monday, September 29th, and loaded onto the Thompson. The platform and sensor pod were assembled and prepped onboard, and the Thompson left Newport at 1600 PDT, headed for the Oregon Shelf site (80 meters water depth). We arrived on site at 1800 PDT and ROPOS was in the water with the cCSPP by 1830. Visibility at the Oregon Shelf site was extremely good compared to recent visits, and the dive went super quickly and was a complete success. The cCSPP was placed ~12 meters due East of medium-powered junction box MJ01C, plugged into the node, and the sensor pod was released from the profiler base at 1923 PDT.

Once powered up (in about a week), the sensor pod will move up and down in the water column at least 4 times per day, taking samples continuously using the onboard CTD, oxygen, fluorometer, nitrate, AC-S, PAR sensor, spectral irradiance, and 3D water velocity sensors. This is a novel technology, and will provide a high-resolution water column profiles at the Oregon Shelf site that can be compared to profiles at the other OOI sites, and allow us to track daily, weekly, monthly, seasonal, and multi-year trends and changes in many oceanographic parameters.

We conducted a brief survey of the site afterwards, and noticed some significant scouring around the base of the BEP (indicating recent, strong water current activity at the site). ROPOS then tripped 4 Niskin bottles next to the BEP to collect water at the site for instrument validation purposes, and returned to the surface. After ROPOS was back on deck and secured, CTD casts were conducted at the same site for several hours to characterize the water column, followed by additional water sampling. Leg 7 will end when the Thompson returns to Newport at 1000 PDT on September 30th, less than 24 hours after we left.

The Thompson will then steam out of Newport this afternoon for a non-OOI cruise, and then return to Seattle. Congratulations to all members of the OOI team at UW and Oregon State, and thanks to the crew of the R/V Thomas G. Thompson and the ROPOS team from the Canadian Scientific Submersible Facility (CSSF).