MBARI - 2011 Pacific Northwest Expedition

As we steam towards Newport at the end of this most remarkable cruise, it is a good time to reflect on what we have accomplished and to thank the many people who made it possible for us to have learned so much in so short a time.

The ROV team of Knute Brekke, Marco Talkovic, Brian Schaefer, Randy Prickett, and Eric Martin worked miracles to get us back into the water for the final dive on the new lava flow after a string of electrical problems with the ROV. Despite losing much sleep and some of their sense of humor, they persevered and made it happen. Their efforts in helping prepare sushi rolls will also be fondly remembered.

The ship’s crew were called into action for launches at strange times (like the final midnight ROV launch), but also to assist with execution of our back-up plan, which consisted of deploying a 700-pound, wax-tipped rock corer (affectionately known as the “crusher”) off the stern of the ship, also at odd hours and sometimes in light rain. Vinny Nunes, Jason Jordan, and Olin Jordan never flinched. Through it all the engineers kept the ship (and the plumbing!) working, and the bridge smoothly ran the ship through the many course changes during our zig-zag dives or held station for the rock cores, which sometimes were aimed at quite small targets. Patrick Mitts kept us all from losing any pounds while away from home cooking, with great meal after great meal. Our science party, largely of first-time-at sea graduate students, learned fast and are now seasoned and (almost) ready to run their own cruises in the future. Nothing living escaped Linda Kuhnz’s watchful eye when the samples came on board. Our large geology group of Jenny Paduan, Julie Martin, Brian Dreyer, Ryan Portner, John Jamieson, Amy Lange, Andrew Burleigh, Sean Scott, and Kevin Werts cheerfully labeled, processed, described, subsampled, and stowed away a large number of wet, very black rocks (that lacked crystals) and cores, although we will not know what they will tell us for many months. Everyone ran their shifts in the ROV control room and even created a different schedule for the all-night dive. Impressive group that we shall be hearing about in the future as their careers bloom!

If you have been reading our prior web postings, you are aware that on July 28 as we steamed towards Axial Seamount, we received a message from Bill Chadwick of Oregon State University, on board the R/V Atlantis, telling us that there had been an eruption on the seamount in the southern caldera sometime during the last year. We began adjusting our plans to provide as much support as we could without competing with their exploration program. In particular, MBARI’s R/V Zephyr was just arriving at the Endeavour segment of the Juan de Fuca Ridge and about to start mapping with the AUV D. Allan B. We chose to continue with that mapping as planned and began to make the preparations to redirect them to make a repeat map of the Axial caldera during the subsequent leg of their voyage. Our dive plan called for work at Axial, which had been coordinated with Chadwick before the ships left port, and we continued with our planned work at Axial and then elsewhere along the ridge, then returned to add to whatever Chadwick had found out during his dives.

Communications between Chadwick on the Atlantis, the lead of MBARI’s AUV group Hans Thomas on the Zephyr, our mapping software engineer Dave Caress back at MBARI, and the science party on the Western Flyer flew back and forth and the survey was designed to cover the numerous sites where Chadwick had observed or not observed the new flow. The identification of the new flow is not as simple as it sounds since the previous flow in the same area occurred just 13 years ago and both flows look quite similar. The key clue that absolutely confirmed where new lava was located was the numerous instruments that could no longer be found, or were found with the instrument buried and a chain with a float anchored in the new flow. The first AUV mapping mission was run at Axial on August 3rd, and the data were transferred at about 8 p.m. from the Zephyr to the Western Flyer by having a hard drive physically transferred (by paddleboard! - see August 3 log) from one ship to the other. It was a strange and wonderful sight to have 2/3 of MBARI’s fleet side-by-side on the Juan de Fuca Ridge!

Jenny and Julie quickly copied the AUV data and processed and gridded it. Julie calculated a special grid that subtracted our prior mapping data (collected in 2006-2009) from the new data to show where the depths had changed. The AUV data highlight the distribution of the flows from the new eruption because of its 10-centimeter vertical resolution. This helped us design an ROV dive to sample and confirm what the maps were telling us over as much of the flow as possible. The map also clearly showed us that the new AUV map coverage did not quite cover the entire flow as different lobes could be seen exiting the mapped area to the northwest, southeast, and southwest. We needed a second AUV survey to try to cover the entire new flow.

Once again, emails flew back and forth, a new mapping mission was created by Dave Caress, and Hans Thomas and the Zephyr team were advised that yet another change in plans was coming their way. We were ready with a dive plan for the 6:30 ROV launch the following morning.

However, on August 4th as we descended through 500 meters depth, the lights on the ROV shut off and we had to recover the ROV and set about fixing yet another problem. The ROV crew of Knute, Marco, Brian, Randy, and Eric had already had a tough few days (and nights) as the tether had failed two days earlier only a few hours into the dive, and then an unrelated electrical short had ended the ROV dive after a few hours during the next dive. They had worked what seemed like around the clock to get the ROV ready, only to have another problem (it turned out this one was related to the previous one).

As they once again troubleshot the problem and worked on a fix, we started to sample the distal parts of the different flow lobes using the wax-tipped rock corer. These were targets we were not going to have time to visit with the ROV, but allowed us to get a better distribution of samples.

We dove August 5th, and our cruise log that day tells the story in pictures. In the end, we collected about 20 lava samples and got a look at quite a lot of the new flow, including the channel that fed the largest flow lobe that crosses the entire caldera and ends in a thick ponded flow near the Ashes hydrothermal field. We explored several parts of the fissure system and found the flows close to the vents covered in thick, light colored, fluffy bacterial deposits, which gave way to more colorful yellow and orange hydrothermal sediment farther from the vents. Along the central fissure, and to a lesser degree, the northern fissure, we found abundant low-temperature hydrothermal vents, commonly lined with thick white bacterial mats and venting shimmering water. The lava flow is much larger than one that erupted in 1998, despite not including the distal portions of three flow lobes in our calculations. The second AUV survey will arrive back in Moss Landing next weekend when the Zephyr returns home after six weeks working off Oregon, Washington, Canada, and northern California. Then we will be able to measure the area and volume of the entire flow—unless it flowed even farther than we have guessed and we need to return to map even more distal portions of the flows.

More details of the accomplishments of this leg of the expedition

The spirit of exploration and discovery is alive on the R/V Western Flyer. Too often science is driven by a desire to achieve a specific goal or outcome. Failure to accomplish the goals set out in an initial research proposal could have consequences for future research funding. The pressure to complete experiments, submit manuscripts or complete maps often blinds us from the spirit of spontaneous experimentation and discovery.

The focus on product and results applies to marine geology as much as any other field in science. Research cruises set out with specific tasks set by the scientists to be accomplished: certain areas must be mapped, certain rocks, fluids or animals must be collected. The pressure to complete these tasks often prevents scientists from modifying their original agenda in order to explore an unexpected discovery or occurrence. This has often left me exasperated when opportunities to explore something new were passed over in favour of a planned program. This attitude towards ocean science is one that the scientists and crew aboard the Western Flyer do not embrace.

Many interesting discoveries were made on this cruise, and dive plans and sample programs were altered in order to further explore these new finds. The most significant of these changes was the discovery of a new eruption at Axial Volcano. The significance of this event, and the fact that we had the expertise and exploration tools available on the Western Flyer to further investigate this eruption, meant that we changed several previously-planned dives in order to explore something new.

On another dive, much to my delight, we found a large, previously unknown, hydrothermal mound near the Endeavour vent fields. As this was an unexpected, yet very significant find (due to its size and the fact that mound-like sulfide structures had, up to now, not been documented at the Endeavour Ridge) we spent almost two hours investigating this site, resulting in us having to modify the rest of the dive. While examining this mound, we discovered an oasis of life on an inactive vent chimney. There is currently very little known about the interactions of marine fauna with inactive sulfide deposits, yet these questions are very important today due to the possibility of mining these structures for their valuable metal content. The faunal survey carried out while investigating this dive will provide considerable insight into these interactions.

The oceans are big, deep, dark, and unknown. On every dive on this cruise we discovered something new. If this is not happening on every dive from every research ship, then that spirit of discovery, the reason I do what I do, is dying. To my fellow scientists and crew of the Western Flyer, I say thank you for keeping that spirit alive.