Monterey Bay Aquarium Research Institute
2009 Pacific Northwest Expedition


Leg 3 - Gas Hydrates
Chief Scientist - Charlie Paull
August 2 - 12, 2009

Autonomous underwater vehicle (AUV) mapping and remotely operated vehicle (ROV) diving operations will be focused on investigating known gas vents, chemosynthetic biological communities (CBC), and gas hydrate bearing sites along the North American margin. The plans for the expedition involve collecting a series of AUV mapping surveys from the R/V Zephyr at four sites. This data will then be used to direct ROV Doc Ricketts dives to ground truth the mapping surveys and to help direct the design of other experiments and installations. Among the sites to be included are the two summits of Hydrate Ridge (Oregon), Bullseye Vent (Canada), and Barkley Canyon (Canada). These sites continue to be targets for exploration and experimentation by researchers at MBARI and many other institutions.

The installation of a seafloor observatory to monitor natural variations in gas and gas hydrate dynamics and to conduct perturbation experiments remains one of the most supported concepts within the various Ocean Observing Initiative efforts. Bullseye Vent and Barkley Canyon are both sites for the planned installation of gas hydrate observatories, as part of NEPTUNE Canada. The other candidate for a cable-connected system is Hydrate Ridge. While an initial deployment of instruments is planned for NEPTUNE Canada in 2009, detailed high-resolution mapping is still lacking in parts of these areas and is necessary for the long-term planning for expansion of hydrate observatory infrastructure. This can be best (and perhaps only) provided with a system like the MBARI mapping AUV.

A particular focus of this expedition is the nature and origin of the micro-topography associated with these gas-rich seafloor environments. Visual observations in many such environments have already shown that the seafloor where CBCs are on the surface and gas hydrate are believed to be in the near subsurface is commonly associated with seafloor blisters or mounds of various sizes, shallow depressions (e.g., approximately three meters wide and one meter deep), as well as an occasional small up-turned ridge of truncated strata. The origin of this topography remains unexplained, yet is potentially critical for assessing the extent to which gas hydrates are geo-hazards and to understand how gas hydrates may shape the seafloor. Moreover, up-to-date maps that document these features do not exist, largely because of the limitations of previously available surveying tools. We are interested in documenting these features and evaluating possible processes that may play a role in creating these features. The area around these vents may be experiencing seafloor modification because of gas hydrate growth. Subsurface gas hydrate formation may inflate the seafloor producing pingo-like features that range from 1 to 10 meters in height and width.

Day 11 - Behind the scenes on the Western Flyer
August 12, 2009

We’re cruising southward today at about 10 knots, with a smooth sea and light winds. Aside from the spitting rain, it’s a pretty nice day to be at sea in the Pacific Northwest...

Day 10 - Pushing our luck at Bubbly Gulch
August 11, 2009

This morning we made our last ROV dive of the cruise. We knew we had to begin steaming south by 11:30 a.m., but Charlie wanted to fit in one more dive. His slogan for this dive was “Go for the gas.”...

Day 9 - Visiting old haunts and discovering new ones
August 10, 2009

We had another long two-dive day today, but now the wind is dead calm, the seas are small, and best of yet, we can actually see the sun as it’s setting...

Day 8 - Sleuthing our way around
August 9, 2009

Geology is like detective work. You make an initial guess about who dunnit, but the hard part is finding conclusive evidence...

Day 7 - Just the same old stuff (whale skeletons and underwater gas eruptions)
August 8, 2009

Chief scientist Charlie Paull inspects an elaborate array of syringes we used to extract fluids from ....

Day 6 - A tale of two dives
August 7, 2009

No less than eight people swarm around ROV Doc Ricketts during one of our quick “pit stops” between dives. Since the ROV can only carry five vibracores (the vertical aluminum tubes on the right side of the image), we often come up to the surface ....

Day 5 - A hole in the bottom of the sea
August 6, 2009

We spent all day today exploring a hole in the bottom of the sea. It wasn’t a very deep hole—only about eight meters (25 feet) deeper than the surrounding seafloor. It wasn’t even a very large hole—just an irregular rectangle about 250 meters long and 60 meters across. But on our high-resolution sonar images, it appears as a very distinctive and somewhat mysterious-looking feature...

Day 4 - Oil and gas and mud, oh my!
August 5, 2009

As I write this, my jeans are dappled with splotches of congealing brown ooze, which smells somewhat like kerosene. We just finished processing the vibracores we collected during today’s dive. It was a messy business. Today’s dive site, Barkley Canyon, is famous among geochemists because it is one of the few well-known places where methane hydrates are exposed right at the seafloor...

Day 3 - Getting from here to there
August 4, 2009

We spent today motoring at a leisurely pace up the coast of Oregon and Washington, heading toward a spot about 96 kilometers (60 miles) off Vancouver Island. Our world has become a rolling gray sea and flat gray sky, with a few sea birds and fishing boats for variation. We haven’t seen the coast, but we figure that somewhere over there it must have been a normal Tuesday...

Day 2 - An eventful first dive
August 3, 2009

The day started out like most days on the Oregon coast—calm and foggy. At 9:00 a.m. sharp, we left the dock and steamed out the entrance channel, passing underneath the picturesque span of the Yaquina Bay Bridge. Both ship’s crew and science crew took photos, talking of past and future journeys, and thinking of our friends and family on shore...

Day 1 - Getting ready to go to sea
August 2, 2009

It’s been a day of continuous, if not quite feverish activity, and we haven’t even put out to sea yet. At around 9 AM this morning, the science crew assembled on board the Western Flyer—eleven scientists from eight different research institutions, flying and driving to Newport, Oregon from all over North America...




Leg 3
 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.

Benthic elevator

The benthic elevator allows us to carry more than the ROV itself can carry. Loaded with sediment enrichers, it is deployed from the ship before the dive and free-falls to the bottom where the ROV pulls the equipment from the elevator for use. After the ROV is recovered, the elevator anchor's acoustic release is triggered from the ship, and the elevator freely ascends to the surface and is recovered.

Niskin bottles

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


Heat flow 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

Charlie Paull
Senior Scientist, MBARI

Charlie Paull has been a marine geologist and geochemical stratigrapher at MBARI since January 1999. The central theme of Charlie's work involves investigating the fluxes of fluids and gases through continental margins. Over the past decade his primary focus has been gas hydrate research on the Blake Ridge gas hydrate field on the continental rise off of southeastern North America. Assessing the global distribution of gas hydrate and interstitial gas is a continuing interest as well as the development of new techniques to detect the presence of gas hydrate in marine sediments. Charlie's other ongoing work is focused on the geology associated with seafloor seepage sites, including investigating the deposits associated with chemosynthetic communities, determining the processes that occur at the methane-sulfate boundary, and understanding the origin of pockmarks and other potential seafloor fluid venting sites.

Bill Ussler
Senior Research Specialist, MBARI

During expeditions, Bill Ussler is primarily responsibility for the operation of the custom-built, portable chemistry lab van which contains a complete analytical laboratory for the analysis of the fluids and gases contained in marine sediments. Along with colleague Charlie Paull, Bill studies how methane (natural gas) forms and moves within seafloor sediments.

Michael Riedel
Research Scientist
Natural Resources Canada - Geological Survey of Canada

Michael Riedel was part of an international team of scientists supported by the Integrated Ocean Drilling Program (IODP) which completed a unique research expedition in 2005 aimed at recovering samples of gas hydrate, an ice-like substance hidden beneath the seafloor off Canada's western coast. As IODP Expedition 311's co-chief scientist, Michael explored his interest in gas hydrate; he believes such deposits have played an important role in ancient global climate change.

Ross Chapman
Professor, University of Victoria

Ross's research interests are in seismo-acoustic propagation, with specific application to the study of marine gas hydrates, and development and application of acoustic inverse methods for estimation of geophysical properties of the ocean bottom and for source localization. (Note: At the last minute Ross was unable to participate in the cruise, although he did attend the initial science meeting before the ship left the dock.)

Mary McGann
Geologist, United States Geological Survey

As a member of the USGS Coastal and Marine Geology Program, Mary McGann's professional interests include: foraminiferal and pollen biostratigraphy, paleoecology and biogeography; sedimentary paleoenvironment mapping, quaternary paleoclimatology; and AMS C-14 chronostratigraphy.

Laura Lapham
Postdoctoral Researcher, National Energy Technology Lab, U.S. Department of Energy

Laura's research is concentrated on studying methane cycling at cold seeps, biogeochemcial cycling of methane and sulfer in deep sea sediments, development of deep sea instrumentation to collect novel samples, stable isotope geochemistry, modeling of biogeochemical processes and temporal variability of dissolved methane concentrations. The focus of her research has been mainly on gas hydrate environments, but she is also interested in other systems that relate to the carbon cycle. Her research seeks to understand how methane is distributed between different pools, e.g. dissolved or hydrate phases, and also to understand how local biogeochemical processes affect this methane, mostly through anaerobic methane oxidation.

Kim Fulton-Bennett
Communications Associate, MBARI

Kim helps people outside of the institute to understand MBARI's research and development efforts. He does this by writing news releases and articles about MBARI research, as well as by helping members of the press who want to write their own articles or create video stories about MBARI. His academic background is in marine geology, environmental planning, and science writing.

Yirang Cho
Student, University of California, Davis

Yirang is an undergraduate at UC Davis in Environmental Studies and Ecological Engineering. She is an exchange student from Korea University who is interested in methane hydrates as an alternative energy source and in the ecological communities around methane seeps. She is very happy to have the opportunity to go on this cruise.


Tess Menotti
Graduate Student, Stanford University

 


Craig Joseph
US Department of Energy
Graduate Student, Oregon State University