April 14-15: Mooring Swaps and Shelf Surveys Continue

Calm seas and light winds supported two efficient days of operations aboard the R/V Neil Armstrong as the Pioneer 21 Leg 2 team completed major mooring work and regional surveys.

On April 14, the Southern Offshore Profiler Mooring (SOPM-2) was deployed successfully after an early morning setup. Post-deployment checks confirmed all systems were in good condition. The team then recovered the heavily biofouled SOPM-1 buoy, complete with a fisherman dock line attached, before continuing with the SEPM-1 anchor recovery and deck reorganization.

The rest of the day was spent cleaning gear, assembling the NOPM-2 mooring, and conducting an alongshore CTD survey between the Southern and Northern Offshore sites. Evening operations included shipboard meteorological and EK80 surveys near the NOSM-2 site.

April 15 followed a nearly identical schedule. The Northern Offshore Profiler Mooring (NOPM-2) was deployed early, followed by a CTD cast and recovery of NOPM-1 after lunch. Mooring operations were once again executed with precision, highlighting strong coordination among the ship’s crew, science party, and deck team.

In the afternoon, work shifted to cleaning recovered gear and building NEPM-2. An ADCP survey was conducted in a counterclockwise circuit (NO–CN–SO–NO), concluding with another overnight meteorological survey at NO.

With NEPM deployment set for April 16, the team remains on track and continues to maintain the high standard of execution expected on OOI mooring cruises.

(c): Nikki Arm, WHOI