Dave writes: For our final dive, we moved to Taney Seamount C, the third one from the western end. This seamount and seamount D are similar in being nearly circular with one or more calderas in their centers, plus one on their eastern flank that makes them look somewhat like a donut with one bite taken. We wanted to sample the lavas exposed on all three of the concentric nested caldera walls of Taney C, and planned a dive to accomplish that goal despite having to make a long traverse between walls across the flat and rather uninteresting floor of the largest caldera. Indeed, the scenery there was constant Mn-crusted volcanic sandstones, probably generated when the calderas collapsed, outcropping between thin ponds of loose sediment covered with Mn-nodules.
Once again, we started the day with a series of pushcores to determine the infauna—those animals that live within the sediment. We collected two more long cores for paleoclimate study, one about 1.15 meters long and the other about 1.35 meters long. These cores are the longest taken by an ROV without a special vibracoring device mounted on the vehicle. (We chose not to use the vibracoring system because it hinders our ability to collect the wide range of sample types for the multidisciplinary nature of our dives.) The biologists collected numerous specimens, mainly of urchins, gastropods, and sea stars, but also a large white anemone. Once again, we observed a toad fish—this one much larger than the one collected for DNA analysis yesterday. And once again, bio-transects were collected to quantify the animal populations and abundances during the dive. We managed to collect 40 rock samples from all three caldera walls, and found that the oldest, largest caldera was flanked by deposits, several meters thick, of fragmental volcanic sands and finer grained light-colored ash-like rocks.
The dive included spectacular scenery. Ascending the tallest caldera wall, we encountered an active talus slope with huge angular lava unencumbered by manganese crusts, so very easy to collect. Above that was a sheer cliff of truncated bulbous and lobate pillow flows. It had shed the talus recently enough that it, too, had little manganese, so was recognizable as well as collectable. The rose-like pattern in the photo is from radial jointing that occurred as a bulbous lava pillow cooled and shrank. The pillow was truncated by the caldera collapse and subsequent instability of the cliff face.
At the very top of the outer caldera was a thick, layered unit of volcanic fragmental material, deposited after the caldera collapsed. Here it provides substrate for purple and white sponges, a stalked crinoid, and large brisingid star.
Sarah writes: Little work has been done on soft-sediment habitats on seamounts, with much attention being paid to the larger, eye-catching organisms on hard bottom areas like sponges and corals. In order to describe the seamount community as a whole and understand how it may be different than similar habitat on the continental shelf, we are trying to figure out what organisms live in the soft-sediment areas as well. Marine sediments (even in the deep sea) are typically full of tiny organisms that are difficult to see without the help of a microscope. Small worms are usually the dominant members of the sediment community (many are relatives of the Liberace worm we collected; see August 11 log).
We plan to sort through most of the sediment cores under a microscope to look for critters. We will also send some samples to a colleague who will use a new method of gene sequencing that allows her to count the numbers of species in the mud without having to identify them the traditional way. But out here we have been surprised that our preliminary observations of the sediment community have turned up very little. Even on the deeper abyssal plain where food is very scarce we tend to find more life in the sediments. so we will also be freezing some sediment to take back to the lab and measure the amount of food available here. Since these organisms live in the absence of light, they rely on the sinking of food particles from above, but out here away from coastal areas, and in very deep water, very little food reaches the bottom and can thus be expected to be limiting for deposit-feeding organisms.
Craig, Sarah, and Lonny sieving push cores of sediment in the lab.
Justine writes: As we near the end of our expedition, I feel I should somehow summarize my first experience at sea. The first couple of hours were full of the excitement of setting out, but I gradually began to feel dizzy and by lunchtime was decidedly nauseous. It was too late to take the Dramamine I brought. I spent some time on deck getting fresh air and was well taken care of. Water, saltine crackers, and a whale sighting helped to some degree. Back inside, I slept until dinner, ate very little and returned to the sanctuary of my bed, hoping the following day would be easier.
The first dive was an incredible experience. We were viewing rocks and life 3000 meters below in high definition. The highlight of the dive came at the end: a flame-orange octopus, which was made all the more stunning by the sheer blackness of the sea around it. The next morning brought with it hard winds and strong waves, and we kept Doc Ricketts aboard. I was still feeling under the weather, so I gave up on reading and went back to bed. I slept through lunch and skipped dinner, finally rallying later that night for some cards and Scrabble.
Day four was better, and each successive day got better still. Each dive had at least one new and/or exciting critter to marvel over. So even though I was convinced on the second day that I would never go on another long cruise again, the third day I decided I would not be on one any time soon but might consider it in the future, and by day four I could actually imagine myself going out to sea again one day. Despite an uncomfortable feeling of confinement and isolation, spending multiple days out at sea is quite an enjoyable experience. In addition to the thrill of just being on the ocean immersed in science, the particular experience of this ship has been excellent as well. The scientists and the crew are all exceptional people, the food is terrific (as far as meals go, we have definitely been spoiled), and there is something oddly satisfying in sharing a name with our ROV.
Next time I’ll take the Dramamine before I board the ship.
Just out of view in the control room photo is the GIS station for tracking and annotating the progress of the dive with real-time GIS on top of our bathymetry maps. Justine is also logging our samples the old-fashioned way as a back-up.
The R/V Western Flyer is a small water-plane area twin hull (SWATH) oceanographic research vessel measuring 35.6 meters long and 16.2 meters wide. It was designed and constructed for MBARI to serve as the support vessel for ROV operations. Her missions include the Monterey Bay as well as extended cruises to Hawaii, Gulf of California, and the Pacific Northwest.
ROV Doc Ricketts
ROV Doc Ricketts is MBARI's next generation ROV. The system breaks new ground in providing an integrated unmanned submersible research platform, with many powerful features providing efficient, reliable and precise sampling and data collection in a wide range of missions.
R/V Zephyr is the primary support vessel for MBARI's autonomous underwater vehicle (AUV) program. This 26-meter vessel is also used to maintain environmental moorings, collect time-series data along the California Current, and support scuba divers as they study near-shore habitats.
AUV D. Allan B.
The MBARI mapping AUV is a torpedo-shaped vehicle equipped with four mapping sonars that operate simultaneously during a mission. The multibeam sonar produces high-resolution bathymetry (analogous to topography on land), the sidescan sonars produce imagery based on the intensity of the sound energy's reflections, and the subbottom profiler penetrates sediments on the seafloor, allowing the detection of layers within the sediments, faults, and depth to the basement rock.
A push core looks like a clear plastic tube with a rubber handle on one end. Just as its name implies, the push core is pushed down into loose sediment using ROV Doc Ricketts' manipulator arm. As the sediment fills up the core, water exits out the top through one-way valves. When the core is pulled up again, these valves close, which (most of the time) keeps the sediment from sliding out of the core tube. When we bring these cores back to the surface, we typically look for living animals and organic material in the sediments.
The box fits in a partition in the sample drawer. It is shown open, with an animal being placed into it by the ROV's manipulator. When the lid is closed, the box will hold water to protect the animals inside.
Sample drawer with partitions
The benthic toolsled is attached to the bottom of the ROV for our geology dives. Its components are the manipulator arm and the sample drawer. The sample drawer is shown open on deck, full of rocks. Normally it is closed when the vehicle is operating and is opened only when a sample needs to be stowed. Partitions in the drawer help us keep the rocks in order. The rocks often look alike, but the conditions and chemistries of the eruptions are different so it is important that we know where each came from.
Canvas bags on a T-handle for collecting gravel or other materials that fall out of a push-core.
Senior Scientist, MBARI
Dave's research interests are nearly all related to the formation and degradation of oceanic volcanoes, particularly Hawaiian volcanoes, mid-ocean ridges, and isolated seamounts. Topics of interest include: compositions of mantle sources for basaltic magmas and conditions of melting; volatile and rare-gas components in basaltic magmas and their degassing history; chronostratigraphic studies of eruption sequence and evolution of lava chemistry during volcano growth; subsidence of ocean volcanoes and its related crustal flexure, plate deformation, and magmatic activity; geologic setting of hydrothermal activity; origin of isolated seamounts; and monitoring of magmatic, tectonic, and hydrothermal activity at submarine and subaerial volcanoes.
Senior Research Technician, MBARI
Jenny works with Dave Clague in the Submarine Volcanism project. On this expedition, Jenny will be in charge of the GIS work, including use of the recently acquired, high-resolution MBARI mapping AUV data of our dive site. She will also stand watch in the ROV control room, help with rock and sediment sample workup and curation once the vehicle is on deck, and coordinate these cruise logs. She is now quite solidly a marine geologist, but her degrees are in biochemistry (Smith College) and biological oceanography (Oregon State University). She is thankful for the opportunities that have led her to study volcanoes, and loves being involved with the research and going to sea. She looks forward to discovering more about how the Earth works.
Biologist, Video Lab Technician, MBARI
Lonny received a B.S. in Marine & Coastal Ecology from California State University, Monterey Bay, and an M.S. from Moss Landing Marine Laboratories. His thesis work at MLML described the biological communities found at three seamounts off the coast of California. On this cruise, Lonny will be in charge of biological sample collection and processing and video data management. This work entails identifying unique biological and geological features that will be seen during the dive, while using MBARI-designed software to log the observations. He will also be preserving and organizing many of the biological samples collected during the cruise, preparing them for identification and further analysis by MBARI scientists and research collaborators.
National Evolutionary Synthesis Center
Craig has conducted deep-sea research for 11 years and published over 30 papers in the area. Participation in dozens of expeditions has taken him to the Antarctic and the most remote regions of the Pacific and Atlantic. Craig's research focuses on the ecological and evolutionary drivers of marine invertebrate biodiversity and body size. He is the author and editor of Deep-Sea News, a popular deep-sea themed blog and rated as the number one ocean blog on the web, and his writing has been featured in Cosmos, Science Illustrated, and Open Lab: The Best Science Writing on the Web.
John studies large caldera-forming volcanoes and their eruptions—termed supervolcanoes and super-eruptions by the popular media—which have global impact. The underlying causes of these large eruptions remain enigmatic. John also studies volcano degassing, which can result in severe local, regional, and global impacts. Understanding the subterranean pathways through which volcanic gas is transported allows insight into the subsurface structure of volcanoes, and can also aid in eruption forecasting and better understanding magmatic-hydrothermal ore deposits. John's interest in this cruise lies in better understanding caldera development in marine environments in relation to underlying magmatic processes. John has been chair of the McGill Earth and Planetary Sciences Department from 2006 to 2010 and executive editor of the Bulletin of Volcanology from 2003 to 2010.
Summer Intern, MBARI
Currently Isobel is an MBARI summer intern working with the Submarine Volcanism Group looking at how crust is built at intermediate-spreading mid-ocean ridges and how melts are supplied to seafloor eruptions. Isobel is also a second year Ph.D. student at Durham University in the U.K. At home she uses physical volcanology and geochemistry to study how huge volcanic edifices (called Axial Volcanic Ridges) are being built on the Mid-Atlantic Ridge. This will be Isobel's second research cruise and she can't wait to go to sea again!
Postdoctoral Fellow, MBARI
Ryan recently completed his Ph.D. at Macquarie University in Sydney, Australia, working on volcaniclastic and sedimentary rocks of the Macquarie Island ophiolite. His interests mainly focus on subaqueous mass gravity flows and their relationships to tectonic and volcanic controls. By identifying these relationships and implementing provenance and geochemical techniques, insight into the petrogenetic history of igneous and metamorphic source terrains is sought out. Soon to start a postdoctoral fellowship at MBARI, Ryan will examine the modes of volcaniclastic particle transport and dispersal from deep-sea eruptions, and their record of eruptive and magmatic controls.
University of Quebec, Chicoutimi
Lucas Brião Koth finished his bachelor's degree in geology at the University of Brasília, Brazil, in 2008 and currently is working toward his master's degree at the University of Quebec, Chicoutimi. His research is focused on the relationship between dykes, synvolcanic faults, and mineralization associated with an Archean subaqueous volcanic center. His participation in this cruise will be complementary to his studies and is also a great opportunity to look at modern submarine volcanism and better understand the genesis of volcanic massive sulfide deposits (VMS) associated with these geological environments.
Assistant Professor of Marine Biology
University of Alaska
Sarah has a B.A. in marine biology from University of California, Santa Cruz, an M.S. from San Francisco State University, and a Ph.D. in biological oceanography from the University of Hawaii. Her research focuses on the biology and ecology of benthic invertebrates, particularly in polar and deep-sea environments. She is especially interested in the growth, reproduction and dispersal of benthic invertebrates, and uses a variety of research tools including genetic techniques. On this expedition, Sarah is working with Craig McClain to conduct biological investigations on the fauna encountered on seamounts. Their goal is to determine the number of invertebrate species found at various depths on seamounts, and investigate whether (and why) seamounts are home to unique and/or more diverse invertebrate communities than other seafloor habitats. Sarah will also be collecting specimens for use in genetic studies to look at patterns of gene flow on seamounts, which will provide clues to tell us whether seamount act like isloated island habitats, or whether tiny invertebrate larvae are able to move between seamounts and the mainland.
Graduate Student, McGill University
Jason graduated in 2010 with an H B.S. in geology from the University of Toronto and is a M.S. student at McGill University, Montreal. His research focus will be oriented on the geology and petrology of the Taney Seamounts. His research interests are the physical, chemical and geodynamic processes that govern volcanism.
Justine recently received her bachelor of science degree in biology from Duke University, where she worked for Craig McClain at the National Evolutionary Synthesis Center. She will be entering the marine biology graduate program at the University of California, Santa Cruz, in the fall with plans to pursue a career in marine conservation biology.