Monterey Bay Aquarium Research Institute
2009 Pacific Northwest Expedition


Leg 5 Logbook - Submarine Volcanism II
Day 3 — CoAxial site on the Juan de Fuca Ridge
August 31, 2009

Latitude 46 degrees 31.33 minutes N
Longitude 129 degrees 33.21 minutes W

We did our second dive at the CoAxial site on the Juan de Fuca Ridge today. This small region was the location of two separate eruptions in the 1980s and 1990s. The first eruption occurred before sonar detection of underwater earthquakes was available to the scientific community, and was detected using bathymetric differences between two surveys, one in 1982 and the second in 1991. The eruption that formed this pillow ridge occurred between those two surveys. The later eruption took place in 1993 and formed a similar and parallel pillow ridge slightly west of the earlier eruption. Our dives yesterday and today were designed to visit these two pillow ridges to determine changes that have taken place since they formed, and since our last surveys in 2005. One of the primary things we did was to take close-up video of the bottom so that we can quantify the populations of animals on the flows, including who lives there and how abundant they are. We can compare these data to similar surveys done four years ago and at other flows of known ages to assess changes over time.

We also have been collecting lava samples from some of the older flows in the region, along with short push-cores of the overlying sediment, to determine their ages. We do this by selecting the shells of microscopic planktonic animals that use calcium carbonate to make their shells and date them using radiocarbon. This procedure yields a minimum age for the underlying lava flow. Combining these ages with the overlapping relations we can see at the margins of flows (which flow is on top of which other flow), we can construct a rough time framework for many of the lava flows in the region. This is essentially the same procedure that is used to determine lava flow sequences and recurrence intervals on land, except that the flows are usually dated using radiocarbon of charcoal that formed beneath the flow as vegetation was covered. Today, we managed to find four flows with thick enough sediment cover to sample, so we should add four more ages to the three we had obtained during a dive in 2005. For comparison, the lava sequences on entire young volcanoes on land are commonly constrained by less than a dozen radiocarbon ages. Here at CoAxial, the seven radiocarbon and two historic ages, as well as numerous field relations of relative ages of adjacent flows, will constrain the sequence of eruptions. A major factor in being able to apply these techniques to undersea volcanoes is having very detailed maps, such as those generated by the MBARI mapping AUV. These maps have guided our dives, and we have also used the dives to better locate the maps for future work.

Along the way, we also managed to sample a number of the animals we see in the video, so they can be identified by taxonomic experts. But I will leave that to the biologists to tell you about.

—Dave Clague

Voluminous sheet flow from an older eruption, which is more sedimented and populated than the more recent lava flows in the area. Here a large white sponge has grown into the folds of a lava whorl, which was an eddy in the flow.

A brisingid star clings to a wall of truncated pillows in a fracture that was large enough to see in the AUV map. Large fractures slicing and dicing the terrain indicate that a flow is old; young flows do not yet have these fractures through them. The tectonic plates are continally spreading apart at mid-ocean ridges, which eventually will cause new eruptions to fill the gap and create new ocean crust.

Rust-colored hydrothermal stains in cracks of a lava pillow mound are another indication that this is a recent flow. The stain will weather away over time.

The lava pillows at CoAxial tend to be more decorated with small pillow buds than those at Axial Volcano. These are formed when the larger lava pillow pressurizes and cracks open, allowing small dribbles of fluid lava to leak out. The pillow buds are convenient samples to collect, as they are easily gripped by the manipulator.

Haystack of pillow buds. This small mound formed over an eruptive vent that slowly squeezed lava up and out, somewhat analogous to a small spatter vent on land.

We found some very unusual animals today. One is a deep-sea coral that looks quite familiar, but has a branching character that is different from others we've seen. Is this a new species or just a variant of the one we know? If we were exploring the Great Barrier Reef or the Monterey rocky reefs, we'd look through a field guide with pictures to match them with a name. Most shallow water areas are well-known, but we study animals that live so deep that there are no field guides to refer to—except our own. MBARI has been exploring the deep sea since 1988 and we video each and every ROV dive. Over the years we've catalogued everything we see and we've racked up three million observations so far. We get help from taxonomic experts around the world who specialize in each group of animals and sort out these mysteries as they arrive. Having someone like Chris Mah aboard is amazing. He is identifiying the deep-living sea stars we're seeing and will be able to tell us if we have collected some new species—always a very exciting event.

—Linda Kuhnz

Unusual deep sea coral at 2,453 meters.

Craig prepares to pick a small brittle star (ophiuroid) from the surface of a push core.

"Backstays of the sun."

Soureya measuring and describing the rock samples after the dive.

Red sky at night, sailor's delight!

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Leg 5
 Equipment

R/V Western Flyer

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

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.

Push cores

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 Tiburon's 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.

Niskin bottles

Niskin bottles are used to collect water samples as well as the tiny bacteria and plankton in that volume. The caps at both ends are open until the bottles are tripped, when the caps snap closed.


Biobox

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.


Rock crusher

This device is used to collect volcanic glass fragments from the surface of a flow. It is made of about 450kg of lead and steel and is launched over the stern of the ship on a wire. Fragments of rock that break off of the lava flow on impact are trapped in wax-tipped cones mounted around the crusher. The wax is melted in the lab to liberate the rock particles for analysis.

Benthic toolsled/
Manipulator arm/
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.

Glass suction sampler

This equipment is used to vacuum glass particles and larval animals from cracks and crevices. The carousel of small plastic jars fitted with wire mesh will be mounted in the benthic toolsled. The hose will be held by the ROV's manipulator and a suction will be drawn by the pump.

Sediment scoops

Canvas bags on a T-handle for collecting gravel or other materials that fall out of a push-core.


Temperature probe

Held by the ROV's manipulator, the wire on the right is placed into the fluid emitted from a hydrothermal vent to record the temperature.


 Research Team

David Clague
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.

Jenny Paduan
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 sites. She will also stand watches 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 for our group's two legs of the expedition. 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.

Brian Dreyer
Science Postdoctoral Fellow, MBARI

Brian completed his Ph.D. in igneous geochemistry at Washington University in Saint Louis in 2007 and has since been working in MBARI's Submarine Volcanism Group. Brian applies the principles of isotope geochemistry to young samples of volcanic rocks to gain insight into aspects of magmatism. Much of his postdoctoral work focuses on eruption and petrogenetic timescales of Axial Seamount, the most volcanically active portion of the Juan de Fuca Ridge. His other research interests include geochemistry of the Earth's mantle, magmatic interaction between oceanic spreading centers and hotspots, and exploiting the systematics of rare isotope species to quantify material flux through subduction zones.

Craig McClain
Assistant Director of Science, 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 popular writing has been featured in Cosmos, Science Illustrated, and Open Lab: The Best Science Writing on the Web.


Linda Kuhnz
Senior Research Technician, MBARI

Linda specializes in the ecology of small animals that live in marine sediments (macrofauna), and larger invertebrates and fishes that live on the seafloor or just above it (megafauna). She conducts habitat characterization studies in benthic (seafloor) ecosystems using underwater video and by collecting deep-sea animals. She hopes to find some new and interesting animals in the unique habitats we are visiting on this cruise.

Ángel Puga-Bernabéu
Postdoctoral Fellow, University of Sydney

Angel is a carbonate sedimentologist specialist in non-tropical carbonate sediments. His current research, however, is focused on the tropical realm. He is working on drowned reefs from Hawaii, studying their morphology and structure, sedimentary facies and stratigraphical successions in order to attempt to constraint eustatic sea-level changes, subsidence rates, drowning times, carbonate accretion rates, and paleobathymetry. In this expedition Angel hopes to learn basic skills in marine geology that could help him to better understand the data he works with in his current research.

Julio Harvey
Research Technician, MBARI

Julio is a molecular ecologist and evolutionary biologist currently working on the population genetics of various deep-sea invertebrate species in Bob Vrijenhoek's laboratory. Julio is also developing molecular probes capable of detecting a variety of marine invertebrate larvae and other microorganisms from environmental seawater samples as part of the Environmental Sample Processor project.

Chris Mah
Research Collaborator, Smithsonian Institution

Chris specializes in the evolution, systematics, and taxonomy of echinoderms, specifically asteroids (starfish or sea stars). His research emphasizes cold-water species, including those living in the deep sea and at high-latitudes (Antarctica and the Arctic). He has identified starfish species for National Geographic, the National Marine Fisheries Service, and MBARI, as well as organizations in France, Australia, Palau, and New Zealand. He has been on many deep-sea cruises, including submersible work in the Bahamas and Hawaii as well as more conventional scientific cruises in Antarctica, Alaska, as well as off Monterey, California. He is also the author of the Echinoblog, an echinoderm-themed blog. This will be his first trip on the Western Flyer.

Soureya Becker
Graduate Student

Soureya recently received her bachelor's degree in general geology in Munich. She gained field experience related to volcanology during a campaign to Colima volcano in Mexico, where she looked at pyroclastic flow and block-and-ash flow deposits, did detailed stratigraphic logs, and performed density measurements in the field. She also participated in a field trip to Etna, Vulcano, Lipari, and Stromboli volcanoes where she was shown the different aspects of Italian volcanism. After these terrestrial experiences she is now looking forward to discovering more about submarine volcanism. She will benefit greatly from participating in this cruise, as it is highly complementary to her university education.

Levin Castillo
Student, University of Quebec, Chicoutimi

Levin Castillo-Guimond finished a BSc-Honour's degree in Earth Sciences at University of Quebec in Chicoutimi (UQAC-2009). His prime interest was on the physical volcanology of Archean mafic and felsic submarine successions, as they are often associated with volcanic massive sulfide deposits (VMS). In addition, to better understand large-scale caldera evolution and pyroclastic processes, Levin participated on a field trip in autumn 2007 on the island of Tenerife (Canary Islands). In summer 2009 he worked for an exploration focusing on gold and uranium deposits.

Gillian Clague

Gillian recently received her BSc-Honours degree in Marine Biology in Brisbane, Australia. She gained diving field experience while observing fish behavior on the Great Barrier Reef. On previous research cruises, she has assisted in the processing of collected organisms and in the collection and analysis of underwater video to identify the benthic life present on flows over an age series. On this cruise, she will assist in the collection of underwater video and hydrothermal clams and tubeworms, and aims to gain a better understanding of the diversity of animals living at these sites.