Seafloor lava flows
Day 6: A very interesting place August 1, 2011
Location: Endeavour Ridge We're finishing up the last dive at the Endeavour segment for this leg. It is very cool to actually see the physical settings in which the rocks we are analyzing reside. When I began my Master's project on the geochemistry of Endeavour basalts, I had no intentions of coming out to sea to view the study area. Now I have seen that Endeavour is a very interesting place: near-vertical cliffs along fault scarps, all kinds of hydrothermal activity and deposits, and variable rock types and flow morphologies. Before coming out here, I often imagined how interesting and exciting it would be to walk around on the ocean floor at Endeavour. After seeing the terrain, I realize it would be almost impossible to walk around on the seafloor due to the dramatic relief on fault scarps and lava flows themselves. Some pillows are very large, and some are completely collapsed. If a person were able to walk around down there, one might expect pillows to just cave in from walking on them. One of the most exciting things on this cruise (besides the dives themselves) is processing the newly acquired samples from a day’s dive. It almost reminds me of fishing for crab in the Puget Sound. When you go out to pick up your crab pots, it is always exciting to see the day’s catch. I experience a similar feeling when the ROV is coming back up to the surface. I just can’t wait to see and examine samples. When the ROV reaches the surface and samples begin to come out, I become very anxious and excited to see what kinds of samples were acquired. All samples collected can be seen during the dive with the cameras, but it is not the same as actually holding the samples in your hands, trying to think about the fact that these samples came from the bottom of the ocean! Probably the most exciting discovery during the three days of Endeavour diving was an enormous inactive hydrothermal mound. It may be the biggest hydrothermal deposit discovered since the TAG field on the Mid-Atlantic Ridge. At the top of the mound, an incredible diversity of fauna was observed. It appears that hydrothermal chimneys can still support plenty of life after the vents become inactive. — Sean Scott 
Approaching the top of a chimney on an enormous (30-meter-high!), now inactive, hydrothermal mound.
Multiple species of deep-sea corals and sponges host hundreds of smaller animals like nudibranchs (sea slugs), crustaceans, worms, and snails—as beautiful as any coral reef! 
A hornito is a cone-shaped formation that occurs when lava erupts through an opening in the cooled surface of a flow. This forty-meter-high hornito of elongate pillow lava has spatter at the top. This demonstrates that mildly explosive (Strombolian) eruptions can produce pillows. Brittle stars are about 10 cm for scale. 
Pillow lava drapes over the vertical wall of a fault scarp. Did the pillow flow erupt after the fault formed, or are these pillows older than the faulting events, and they somehow survived the forces pulling the flow apart? Even though I was sitting a couple of feet from four, different, large, high-definition screens and the camera was zoomed all the way in, I still found myself leaning forward to get a closer look. We were hovering at the top of a 16-meter-high inactive hydrothermal chimney with an abundance of very colourful (yes, I am using the Queen’s English since we are in Canadian waters) corals and other deep-marine life. The rocks were also vibrant with bright orange, red, and yellow colours. Veils of black “smoke” drifted by from a vent somewhere in the distance. Rock that we collected fell into the submersible’s sample box with trails of sparkling metallic luster. It was beautiful. — Ryan Portner 
The ROV pilot and scientist sit side-by-side in the ROV control room, watching the collection of a sulfide sample on the ROV’s HD video camera (center monitors). Other sensor, controller, and camera feeds are shown on other monitors around the control room, and also in most rooms on the ship so everyone can participate in the dive. 
Dave Clague and John Jamieson are watching the ROV camera feed (probably the collection of a sulfide sample) in the ROV control room.
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Track the ship
Equipment
 R/V Western FlyerThe 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 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.
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 the ROV'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 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.
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.
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.
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.
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.
Canvas bags on a T-handle for collecting gravel or other materials that fall out of a push-core.
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.
Vibracoring is a common technique used to obtain samples from water-saturated sediment. These corers work by attaching a motor that induces high frequency vibrations in the core liner that in turn liquefies the sediment directly around the core cutter, enabling it to pass through the sediment with little resistance. Crew
R/V Western Flyer
ROV Doc Ricketts
Research Team
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 works with Dave Clague in the Submarine Volcanism project, processing the high-resolution MBARI Mapping AUV data and interpreting the maps using ROV observations and samples from our research sites. On this cruise, she will 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. 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.
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.
Julie works with the submarine volcanism group, where she currently produces high resolution maps of the seafloor that are used to identify geologic features along submarine ridges and seamounts. Her research interests also include modeling of volcanic ash from sub-aerial, large-scale explosive eruptions.
Ryan's work with the submarine volcanism project primarily focuses on the formation and distribution of volcaniclastic deposits on active and extinct seamounts and mid-ocean ridges. By categorizing the diversity in these deposits with respect to volcanic landforms he hopes to better understand the underlying controls on explosive vs. non-explosive deep marine eruptions. His background research on deep-marine gravity flow deposits preserved in sedimentary-volcanic successions exposed on land lends a comparable platform to study similar deposits of the modern oceans.
Brian is an isotope geologist in the Institute of Marine Sciences at UC Santa Cruz where he studies the recent magmagenesis and petrology of the Juan de Fuca Ridge. His interest in the petrology of mid-ocean ridges began during his postdoctoral fellowship with MBARI's Submarine Volcanism Group; there, he utilized uranium-series disequilibria within individual lavas of Axial Seamount to clarify eruption and petrogenetic timescales. At mid-ocean ridge systems globally, Brian is interested in a) how variability in lava morphology, geochemistry, and petrology reflect deeper mantle-melting and magmatic processes and their complex interplay with tectonism and b) improving the chronological framework of the ridge magmatic plumbing systems. Brian received his B.S. in Geology from Cal State East Bay in 2000 and PhD in Earth and Planetary Science from Washington University in St. Louis in 2007. When not on the Western Flyer this summer, Brian defends the left side of the infield for the Surfing Squirrels, MBARI's coed softball team.
Andrew received his bachelors in geology at Oregon State University in 2011 and is currently a graduate student at Oregon State University. His research focuses on the geochemistry of plagioclase ultraphyric basalt from mid ocean ridges to investigate how and why they form. Particularly, he is interested in using major and trace element variations in mineral phases to better understand magma chamber processes that modify melts in residence and transit prior to eruption.
John's research interests focus on sulfide deposits that form on the seafloor as a result of venting of hydrothermal fluids. In particular, he uses radioactive isotopes to determine the ages of sulfide deposits in order to better understand the history of a vent field, as well as the rates at which sulfide accumulates along ocean ridges. John also studies the mineralogy and trace element geochemistry of seafloor sulfides, in order to better understand the tectonic controls on massive sulfide formation. The broad aim of this research is to constrain the impact of hydrothermal activity on the metal and sulfur budgets of the ocean and evaluate the geo-economic viability of seafloor massive sulfides as a source of copper, zinc, gold and silver.
Amy received her bachelors in geology from Hanover College in 2008 and is currently a Ph.D. student at Oregon State University. Recently she has been working on the geochemistry of plagioclase ultra-phyric basalts from mid-ocean ridges globally to understand why they erupt and what information they can tell us about crustal magma chamber processes. Her research uses trace element and isotopic microanalyses of mineral phases to unravel the pre-eruptive history of magmas. This is Amy's first cruise and she is excited to actively participate in ocean research!
Sean received his B.S. degree in geology from Central Washington University in 2009 and is currently pursuing his M.S. degree at New Mexico State University. Sean is presently working on uranium series geochemistry of Endeavour basalts to evaluate spreading dynamics and chemical variation through time. Never did he think that he would have the opportunity to go on a research cruise with MBARI to his thesis area, and he is absolutely ecstatic about this trip!
Kevin graduated from Texas Tech University with a bachelor's degree in geology. He is currently working towards his M.S. degree with Dr. Michael Perfit at the University of Florida. Kevin's research focuses on the phase chemistry of evolved mid ocean ridge lavas from the Cleft segment of the Juan de Fuca Ridge. He is using phase chemistry to better understand the processes of differentiation that produced such evolved lavas at this mid ocean ridge. |
