Tuesday, August 16 was our last day at sea for Leg 1. The Thompson left Axial Caldera at 1600 on the 15th to begin the ~22 hr transit back to Newport. All tasks scheduled for Leg 1 were successfully completed, with much thanks to the hard work of the ROPOS team. Of note, these tasks included the very important successful operation of installing the extension cable at Primary Node PN1B, which allowed powering up of the cabled instruments 10 km to the north at Southern Hydrate Ridge (SHR) for the first time in two years. With powering up of the cable, the two novel multibeam sonars at SHR (funded by the University of Bremen, Germany) spun right up and began imaging changes in the seafloor morphology and methane plumes rising ~400 m above the seafloor!
The Shallow Profiler instrumented platforms at Oregon Offshore and Axial Base were turned – the Offshore 200 m parent platform has turned into an underwater "island" hosting beautiful feather stars and a host of other organisms that have found a hard substrate to colonize.
At Axial Seamount, the International Hydrothermal Field was visited again and the novel in-situ hydrothermal fluid and microbial DNA sampler (RAS-PPS) was turned continuing the long-term time series investigation of fluid chemistry and temperature, dissolved gases, and microbial communities over time. Tuesday morning students helped Mitch with the final operations on the RAS/PPS. Data from the instrument, which was first installed in 2014, formed part of the foundation for two additional NSF-funded days to Dr. R. Anderson to study microbes and viruses in this same area using a specialized fluid sampler for follow-on shore-based analyses. Also of note, another 2 days were funded to Dr. W. Wilcock and engineer D. Manalang to install an acoustic net using cabled and uncabled transponders that will allow high resolution measurement of deformation within Axial Caldera and melt migration in real-time. and put the finishing touches on their project presentations as part of the VISIONS experiential learning program. Presentations began at 1300 in the Library and the projects ranged from seismology to microbiology. The students did a great job.
The Thompson arrived in Newport yesterday late Tuesday afternoon (1700). It was a very windy trip into the dock, but the sun was shining brightly. Dinner was served and later that evening all aboard were treated to a mixed jam session provided by APL Engineer Christina, who is a DJ on the side.
This morning things were buzzing as all were working hard to get the equipment from Leg 1 off the ship and to help get the ship ready for Leg 2. Students helped get gear into baskets for transport back to Seattle, and then cleaned their cabins to ready them for occupancy by the Leg 2 students. A very productive morning so far.