Logbook: September 6, 2006

NeMO 2006 Cruise Summary Web Report

Chief Scientist Dave Butterfield directs a dive with ROPOS pilots Keith Tamburri and Dan Cormany in the control room. (click image for larger view)

The NeMO 2006 expedition is the eighth in the string of submersible cruises that started in 1998 when the PMEL VENTS Program began a multi-year seafloor volcano observatory. With the exception of 2005, every cruise has involved the remotely operated vehicle ROPOS, as well as water column hydrothermal plume measurements and a heavy emphasis on seafloor instrumentation. This year, we also added a second, highly capable mapping vehicle, the D. Allen B. autonomous underwater vehicle from MBARI. The University of Victoria provided NSERC funding for four days of ROPOS operations and NOAA/PMEL provided the funding for the ship and the remaining ROPOS time.

It was an exciting and productive two weeks of oceanographic science. Time-series water and microbial DNA samplers were recovered and deployed at the Endeavour Integrated Studies Site and also deployed at Axial Volcano for another year of weekly monitoring to detect responses to volcanic or tectonic events. Initial results show a surprisingly large change over the past year at one site in the Mothra vent field at Endeavour. Throughout the cruise, we collected a large and varied set of water column, vent fluid, rock, sediment, vent fauna, and microbial DNA samples, including adapting a pump system to take very large volume DNA samples in a very short time. We recovered temperature recorders from warm and hot vents around the caldera, deployed more temperature recorders, recovered a Volcanic System Monitor (or “Rumble-ometer”) using the ROPOS heavy lift capability, deployed 4 ocean bottom hydrophones to detect seismic/volcanic events, successfully deployed a new autonomous hydrophone (Que-phone), and made a series of high-precision pressure measurements to determine that Axial Volcano is still inflating with magma from below. We sampled hydrothermal vents from most of the known vent areas, discovered a new diffuse vent field, and finished our ROPOS operations by finding the largest active sulfide chimney yet seen at Axial (13-meter high “El Guapo”).

The entire ship went through a nerve-wracking experience when the AUV unexpectedly ran out of tracking range near the beginning of its first dive. It became the mission of the ship to find the AUV with a logically planned search pattern. I have never seen so many people on the bridge for such a long time, and it was a very happy moment for those who were still awake when the AUV was recovered. A very long ROPOS dive began the next morning and by the time it was over, the AUV team was well on the way to getting back in the water.

The scientific staff for NeMO 2006 included Keith Tamburri and his team of 5 engineers (Vincent Auger, Steve Bucklew, Dan Cormany, Reuben Mills, and Dean Steinke) who kept ROPOS operating beyond the expectations of the scientists on board. ROPOS was diving within 90 minutes of arriving at Endeavour, our first area of operations, carried out a long dive the following day, then a record-breaking 53 hour dive at Axial, followed by 12-hour dives every day. The new launching system, fiber-optic data telemetry and ultra-short baseline navigation system mean better performance over an increased range of weather conditions. The performance of the ROPOS team and vehicle was as close to flawless as you can get. The whole science team really appreciates the efforts of the ROPOS team to make our program work.

There were 6 scientists and engineers from MBARI on board to plan missions, operate the AUV, and produce maps from the data collected. Volcanologist David Clague, in collaboration with Bill Chadwick of PMEL, developed the mapping strategy and priorities. The entire AUV group (Dave Caress, Hans Thomas, Doug Conlin, Jenny Paduan, and Paul Tucker) performed with great confidence and tenacity in spite of adverse developments. In the end, we had five full nights of mapping, and the results are absolutely spectacular. The maps are simply the best seafloor bathymetric maps that any of us have ever seen. Having the maps available shortly after the AUV missions were completed allowed us to use them during the ROPOS dives to see where we were going and find features that are invisible on previous maps. For example, the plan for our last ROPOS dive with the fluid sampler on board was to sample multiple vent sites in the south and southeastern parts of the caldera, and especially to find sulfide chimneys that were briefly glimpsed at the end of a ROPOS dive in 2004. We could actually see the sulfide structures on the AUV map, so we knew exactly where to look for the big chimneys. The combination of ROPOS observations and sampling with high-precision AUV mapping allows “ground-truthing” to help interpret the maps and can help to target exploratory dives.

NeMO 2006 had a talented, energetic, and congenial group of scientists and technicians on board to keep the science moving 24 hours a day by standing watch during ROV dives, dealing with instruments, and collecting and processing samples. The chemistry team was large this year, with Nathan Buck, Geoff Lebon, Leigh Evans, Andrew Opatkiewicz (also doubling as a microbiologist), Pamela Maynard, and Francoise Labonte all pitching in. The biologists included Angela Kouris (ecology of blue mats), Jonathan Rose (vent fauna), Raphaelle Dancette (Marine Protected Area study), and Sheryl Bolton (microbiology). The Marine Geology team included Bill Chadwick, Scott Nooner, Emily Laity, and Susan Merle, who was also our data czar. Bill and Susan made the web site happen with the help of Andra Bobbitt back in Newport. Engineers Jon Bumgardner and John Shanley took care of all moored instrument recoveries and deployments, and Haru Matsumoto handled the OBH surveys and Que-phone deployment. Special thanks to Bill Chadwick for his wise counsel before and throughout the cruise. We had critical shore help from Mike Hopkins, Sharon Walker, Alan Hilton, Chris Meinig, Dan Schwartz, and Mr. Tamburri of Vancouver. Captain Al McClenaghan and the entire crew of the Thompson were utterly competent and professional and a pleasure to work with.

A good research cruise consists of a well-designed plan that meets a series of unpredictable problems that have to be solved. A missing buoy was a problem that we could not solve, but we took on all the others. It is remarkable how unselfishly the entire science group and the crew of the Thompson rallied to make the cruise a success. This is a really great group of people.

Dave Butterfield
NeMO 2006 Chief Scientist