Monterey Bay Aquarium Research Institute
2009 Pacific Northwest Expedition


Leg 5 Logbook - Submarine Volcanism II
Day 5 — 1986 lava flow
September 2, 2009

Latitude 45 degrees 01.48 minutes N
Longitude 130 degrees 10.55 minutes W

Today's dive explored several exposures of a lava flow that erupted in 1986 on the northern Cleft Segment of the Juan de Fuca Ridge, the first eruption to be detected at a mid-ocean ridge. A "mega-plume" that was rich in helium, more turbid, and slightly warmer than the ambient seawater temperature was found in the water column that year. Fresh lava was identified from towed camera work and submersible dives a few years later, and was inferred to have been the cause of the water column anomaly. Our AUV maps show very clearly what we suspect to be young vs. old flows: young flows have no fractures, and older flows are sliced and diced by tectonic spreading. We dove with the ROV today to collect lava samples and biotransects, and to verify our interpretations of the flow boundaries on the maps. Indeed, the young flow was lightly sedimented and unfractured, had fewer animals on it, and still had traces of hydrothermal staining. Old flows had deep fractures, down-dropped faulted valleys, and lots of sediment and animals. Our map also showed structures similar to the hydrothermal vents at Axial and Endeavour, and we found four sulfide chimneys up to 15 meters tall, but none were actively venting hot water any more.

—Jenny Paduan

Small gorgonian fans hang from the underside of drained lobate pillow lavas. The red dots are from lasers used to assist scientists with measuring objects on the seafloor.

Very top of a 15 meter tall inactive sulfide chimney. We think it looks like a cartoon stegasaurus.

Today, a rarely seen bit of deep-sea predation! The asteroid Evoplosoma feeding on a bamboo coral colony (family Isididae)! As I had mentioned in an earlier post, Evoplosoma is known from less then a dozen specimens and next to nothing is known about its biology. But today—a critical observation! We watched the sea star climbing up the stalk of the coral with its stomach extended out over the fleshy colonies of the coral, digesting them and leaving behind a bare, empty “bamboo-like” skeleton on the coral (which is where it gets its common name).

Evoplosoma is related to a larger subfamily of sea stars, the Hippasterinae, which includes the genus Hippasteria, an animal also known as the “spiny star” or the “horse star”. In some regions, such as around the Aleutian Islands, Hippasteria is one of the primary predators of deep-sea corals. I am in the process of publishing new species of these sea stars and reviewing all the members of this group and it turns out that all of them feed on deep-sea corals!

Why is this important? At present, the conservation of deep-sea corals is a big priority in marine conservation. Deep-sea coral reefs are important fish habitats and are threatened by climate change and destructive fishing practices. Understanding the ecology and the different kinds of species that inhabit these systems is a critical step towards helping conserve them. One only has to think about the removal of otters and the effect on abalone and sea urchins to realize how important different players are in marine ecosystems. How many of these corals do these sea stars eat? What effect do they have on coral populations? How important are these sea stars to coral ecology and coral evolution?

—Chris Mah

Large star (Evoplosoma, 18 centimeters across) eating a bamboo coral (Isididae).

Chief Pilot Mark Talkovic working the master (foreground) for the manipulator arm to put a sample in the drawer of the ROV.

Levin inspecting a rock in the lab.

Gill and Soureya taping end caps on a push-core (the blue is a piece of foam used as a spacer). We'll sieve the forams from the bottom layer back on shore.

Three crew members in the small boat.

Gathering clouds of a storm headed our way.

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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.