Monterey Bay Aquarium Research Institute

 


Seafloor lava flows
Day 11: Cruise finale
August 6, 2011

Location: Transit to Newport
Latitude: 44° 37.48' N
Longitude: 124° W

Map showing our dive sites (purple dots) from Leg 1 as well as Leg 2.

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!

The science party assembled next to the ROV Doc Ricketts in the moon pool area of the ship.

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.

—David Clague

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.

—John Jamieson


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Leg 2
 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 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

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.

Vibracores

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

George Gunther
Master


 

Lance Wardle
Chief Engineer


 

Andrew McKee
First Mate


 

Paul Tucker
First Engineer


 

Olin Jordan
Oiler


 

Vincent Nunes
Bosun


 

Dan Chamberlain
Electronics Officer


 

Patrick Mitts
Steward


 

ROV Doc Ricketts

Knute Brekke
Chief ROV Pilot


 

Mark Talkovic
Senior ROV Pilot


 

Randy Prickett
Senior ROV Pilot


 

Bryan Schaefer
ROV Pilot/Technician


 

Eric Martin
ROV Pilot/Technician


 

 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, 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 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.

Julie Martin
Senior Research Technician
MBARI

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 Portner
Postdoctoral Fellow
MBARI

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 Dreyer
Institute of Marine Sciences
UC Santa Cruz

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 Burleigh
Oregon State University

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 Jamieson
University of Ottawa

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 Lange
Oregon State University

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 Scott
New Mexico State University

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 Werts
University of Florida

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.