Super Samplers

A bout of bad weather and rough seas kept Jason dry for two days until conditions improved early this morning. Even though the vehicle was at rest, the science team had plenty to do to keep busy. 

CTD cast

With seas too rough for Jason dives, the science team was still able to map the area with the ship’s multi-beam system and were still able to launch three successful CTD’s (conductivity, temperature, depth), with plenty of sampling equipment attached. 

As mentioned in a previous post, the Plume Team is interested in collecting samples of particles and chemicals from various heights above the vent. With Jason on house arrest, the Plume Team fitted their SUPR (SUspended Particle Rosette) Sampler to the CTD to collect samples from the water column. Atlantis is able to park directly above plume sites thanks to the meticulous mapping done by the Jason team. 

Vent fluid sample

Chip Breier, the lead engineer of the Plume Team’s project, designed and built all of the samplers. There are three instruments, each composed of a 14-channel sampling system and each with a different purpose: the Microbiology Sampler, the Geochemistry Sampler and the Carbon Sampler. Although each collects material in a similar fashion (sucking in fluids through a tube) three separate devices are necessary due to differences in the way each sample is analyzed. For example, to measure carbon, you must combust your sample to measure the carbon dioxide released, so you need a filter able to withstand combustion. On the other hand, you need a carbon-based filter to collect microorganisms, and a polycarbonate (plastic) filter to collect minerals for geochemical measurements. 

Sara Bennett

Sara Bennett, a post-doc at NASA’s Jet Propulsion Lab (JPL), is using a pre-combusted glass filter to measure both solid and dissolved carbon in the plume. She is interested in how carbon is cycled through vent systems and is working with Dr. Max Coleman from JPL who is also onboard. It is important to study the state of carbon as it exits the vent and how carbon is altered through the food chain. “We’re looking at the whole carbon cycle, from abiotic carbon production deep within the crust, to biotic carbon production through chemosynthesis,” said Sarah. “If hydrothermal systems were to exist on Europa, it’s studies like this that may help us to calculate the biomass that may exist” Sarah says. 

Greg Dick

Greg Dick, from the University of Michigan’s Department of Earth and Environmental Sciences Geomicrobiology Lab, is interested in the microbiology associated with vent sites. He will be analyzing the SUPR Sampler’s filters to extract DNA and RNA of these very tiny microbes. “From these samples we can reconstruct the genomes in the organisms, which will tell us what organisms are there, their physiology, how they live and how they get their energy,” said Greg. 

However, enzymes very easily destroy RNA, so the samples must be treated with an enzyme-killer called “RNA later.” It is important to understand the genetics of these microbes, but it is also important to know which genes the microbes are using to survive in these conditions. The RNA tells Greg what genes they are expressing at the moment they were collected. 

Chip optimized the third sampler out of his and Brandy Toner’s interest in the mineralogy of the vent plume and, more specifically, what valance states the minerals are in at different heights above the plume. From this, they can begin to understand how much energy is available for microbes in different parts of the plume. Brandy will take these samples to a synchrotron facility to study them with x-ray spectroscopy. “Because of the way these samples are collected, preserved and analyzed, there is very low impact,” said Brandy. 

Brandy Toner (right)

As you can imagine, the Plume Team brought on board massive amounts of lab equipment dedicated preserving each sample and minimizing exposure to the environment.  So far they’ve collected about 50 samples that are currently preserved at -70º C.

From measuring the microbiology, geochemistry, and carbon from the highest energy source (at the vent) towards the lowest (near the surface) the Plume Team hopes to gain insight of who’s eating what and where, and what that tells us about the bigger picture of life in the ocean This team has been working around the clock and all of their hard work will surely extend our sphere of knowledge about the life and chemistry of the ocean. The Gordon and Betty Moore Foundation are funding their work, and we all look forward to their results!

Underwater Lawncare and Plume Teams

Jason completed a successful third dive yesterday, which was primarily dedicated to mapping Von Damm site using the multi-beam system. Mapping is a very tedious task. The pilots controlling Jason have to drive as straight a line as possible while Jason automatically maintains an altitude of 50 meters above the seafloor terrain.

The Plume Team

They make lines 400 meters long and take measurements continuously along lines spaced at 50-meter intervals over the whole site, taking care to ensure there are no gaps. The process is like mowing a lawn—one that can take 12 hours or more finish. It is important for these sites to be thoroughly mapped, as previous maps of this area are inaccurate and at a lower resolution. In addition, the high-resolution images can reveal new, never before seen vents and can be used to create a mosaic image of the entire site.

On the tail end of the dive, a group of scientists dubbed the Plume Team (left to right: Chip Breier, Greg Dick, Sarah Bennett, and Brandy Toner) were given precious dive time to collect samples of vent fluids from different heights in the hot plume of particles and fluids that originate from the vent. The samples that the team gets are collected in a novel way, and the team has been putting in incredible hours around the clock, building their own equipment.

Jason sampling the plume

All of their hard work has paid off and their sampling equipment performed magnificently. Right now, the Plume Team’s equipment is on Jason’s fourth dive, which launched yesterday at 4:30 p.m. Another session of mapping is on Jason’s plate, but this time the vehicle will move to just 20 meters above the seabed to create more detailed maps. After the mapping is finished (around 6:00 a.m.) the Plume Team will be collecting samples again at various heights above the vents. The data that the Plume Team collects will permit them to study the different minerals and microbiology in the water, which is important for understanding biogeochemistry (the interaction between life, geology, and chemistry) in the ocean. The science that the Plume Team is interested in will be the subject of a later post, so stay tuned.

The Plume Team received support
from the Gordon and Betty Moore Foundation

In other exciting news, we spotted a waterspout around 11:00 a.m. yesterday.  






Why is the Mid-Cayman Rise so important? (Continued from previous post)

As I mentioned earlier, the Mid-Cayman Rise is a spreading center, much like the Mid-Atlantic Ridge, which is responsible for pushing the Americas apart from Africa and Europe. However, the Mid-Atlantic Ridge spreads at a rate of 25 to 35 millimeters a year (the rate that your fingernails grow), but the ultra-slow spreading center at the Mid-Cayman Rise spreads at just 12 millimeters per year. Geology reveals that rocks normally get older as one moves away from a spreading center (and active venting). Strangely, this is not entirely correct with ultra-slow spreading centers.

The slab-pull process (Wiki Commons)

There are two ways that plates are thought to spread: ridge-push and slab-pull. An example of spreading due to the ridge-push process is the mid-Atlantic ridge, where new sea floor is erupting from the mantle is pushing plates apart. It is thought the Mid-Cayman rise is spreading by the slab-pull process.

Close to spreading centers, where new sea floor is erupting and the plate is young, the tectonic plate is hot and less dense (or lighter). As you move away and get into the older, cooler sections of the plate, it gets denser (heavier). As the plate gets denser it begins to sink into the mantle, also known as subduction.

It is thought that the other end member of the Cayman plate (the old, cool, and dense part) is subducting underneath the American plate, pulling the rest of plate along with it. This still creates new sea floor, however it’s not of new crust, but of old crust (ultra mafic) being pulled out from deep underneath.

Think of the plates as stack of books that have fallen over and that the orange book is the Cayman Plate. Now imagine what happens when I drag the orange book out, which is analogous to the way the the subducting end of the plate is dragging the rest of the plate along. I am still creating more ‘orange book’ sea floor but it is not fresh. Scientists call this type of spreading amagmatic spreading (not volcanically active).

Scientists long thought that hydrothermal vents would not be present at these non-volcanic ultra-slow spreading centers because there is no fresh volcanic heat source near the seafloor. However, Dr. Chris German and others had a hunch that there might be vents there and sure enough there are! It is still unclear how exactly these vents exist here, but theories suggest that perhaps the rising plate makes becomes thinner. When the plate is thinner it is physically closer to the hot mantle below, and cracks could easily form creating a path for seawater to penetrate to depths where heat in the Earth causes it to re-circulate, creating hydrothermal activity on the surface.

First Dives a Success

Dive #1 Complete

January 9 marked Jason’s first dive of the expedition. The vehicle descended to 2300 meters to reach our first target, the Von Damm vent site, which is the shallower of the two planned locations. Shortly after reaching the seafloor, the vehicle began heading towards the vents.

Tubeworm goes under the microscope

Along the way, the science team instructed the pilot to collect samples of interest. With its two strong robotic arms, Jason was able to break off and collect several samples of rock and pieces of the vent. Jason’s arms are also dexterous enough that they gently collected five tubeworms, a clam, and a sea cucumber and placed them in a tub on the front of the vehicle called the bio box.

Because this site is so unique, energy levels in the ROV van were high. After Jason surfaced, the science team quickly retrieved their samples and began analyzing them. It was an incredible experience to be present as Jason returned with samples from the Mid-Cayman rise, home to the deepest hydrothermal vents ever discovered.


Dive #2 Underway

Jason dives to Piccard

After our success at Von Damm, Atlantis headed for the second target, the Piccard site, about an hour away. Jason's second dive went off without a hitch, beginning just after midnight. Check out the eerie color in the water as Jason began its three hour, 5000 meter journey to the deeper of the two sites.

The images from Piccard were breathtaking, with black smokers sending a whirlwind of mineral-rich fluid into the dark water. Everyone in the van was mesmerized by the images on the monitors, even if they had seen hydrothermal vents many times before.

Microbial mats

During the dive, we saw strange yelloworange and white mats—what looked like fur on rocks was actually strings of microbes! Jason also broke off a piece of the vent to bring up to the surface at around midnight tonight.  

History of the Cayman Rise 

I was curious as to why this particular site is of such scientific interest, so I sat down for an interview with Dr. Chris German, the PI (Principle Investigator) of this expedition. He filled me in on the history of exploration of the Cayman Rise and why he is so interested in studying it.

In 1976, Bob Ballard, a geologist then working at Woods Hole Oceanographic Institution, became the first person to investigate the seafloor at the Mid-Cayman Rise. The vents had not yet been discovered, and he used Alvin, the famous submersible, to explore the area. However, this ridge reaches depths of 5000 meters or more and Alvin can only reach a depth of 4500 meters. Ballard’s team also brought along Trieste, a bathyscaphe capable of diving to greater depths, which they used to reach deeper parts of the ridge. “This was the only time that anyone has been down there and seen it with their own eyes” Chris said.

However, because Trieste could only go up and down, they had to tow a camera system called ARGO over the seafloor to get the first confirmation that there were lava flows down there. “Thirty-five years later we get the first chance to come back with the latest WHOI technology and study cool new vents that were probably actively here all along.” Chris said.

Seafloor spreading (USGS)

In 1968, a man named Carl Bowin had also been involved with researching the Mid Cayman Rise. Bowin was one of the first proponents of the geologic concept of sea floor spreading (http://en.wikipedia.org/wiki/Seafloor_spreading). Chris remembered first meeting Carl Bowin. “I met him when I first moved to Woods Hole in 2005,” he said. “He introduced himself as the first person that ever took a computer to sea. It was at the time when they were still referring to plate tectonics as being ‘just a theory’ and that the Mid-Cayman Rise should be a spreading center, which lead Bob Ballard to come to this site and study it as a mid-ocean ridge.”

Multibeam bathymetry

With the perspective that this site may be a spreading center, Ballard and his team made more detailed maps using a technique called multibeam bathymetry. Multibeam bathymetry measures depth by sending sound waves down and recording the time it takes for them to bounce off the seafloor and return to the surface, similar to how a bat uses echolocation. 

When Trieste descended on the site, the scientists inside took photographs, but their ability to explore was limited, as Trieste couldn’t move around like Alvin or Jason. Despite this minimal data, the scientific team knew there was volcanic basalt in the deep parts of this ridge, confirming suspicions that, indeed, the Cayman Rise was a spreading center.

Want to find out why this particular site is so important to study? Stay tuned!

On Site and On Target

We reached our destination last night (January 8) at 9:45 p.m. Since we are in the deep ocean, anchors can't reach the sea floor, so the ship relies on thrusters—one in the bow plus the stern propellers, which can rotate through 360 degrees—to remain relatively stationary. These maintain our position to within a close distance of our target over the seafloor at all times.

Chip Breier working late.

 Right now we are floating above the Mid-Cayman Rise (see Where Is Atlantis?, upper right on this page) and everyone began testing their equipment last night.  

A CTD (conductivity, temperature, depth gauge) was lowered to a depth of 2000 meters last  night, along with other collection instruments that were being tested for the first time. The team members who were working on these new instruments were up well into the night, and finally got some rest at 8:00 this morning!  

Today our ROV Jason was to dive at noon, but due to technical difficulties the dive was pushed back a few hours. Around 4:30 p.m., Jason reached the sea floor and everything is going smoothly. So far, the vehicle has sent back images of some interesting, highly weathered rock outcrops, a few fish and shrimp, and even some shells of muscles and tubeworms. As of this writing, Jason has collected one sample of the rocks and is on the move after calibrating its cameras.  

I will send an update when Jason reaches its first vent site target.  

Stay tuned!  

The view from the ROV van

Fun Jason facts:  
* Jason has nine cameras, including two high-definition video cameras.  
* It weights between 8,000 and 9,300 pounds and is the size of a Mini Cooper.  
* Jason is tethered to a second vehicle, Medea, which hangs 47 meters above it. This allows tension on the cable from the surface to be placed on Medea so Jason can maneuver on its tether more easily and unaffected by motion of the ship.  
* Both vehicles descend at a rate of 30 meters per minute.  
* It takes 6 people to operate Jason. They work in a control station called the "ROV van," a converted cargo container that can be moved from ship to ship as needed  
* The team controls Jason from the ROV van, making adjustments according to data and video displayed on several monitors.  
* The pilot controls Jason's arms through a joystick replica of the vehicle's actual arms.  
* There are two rules when in the ROV van: Do not bring anything in to eat that requires a plate (there's very little space), or anything that smells bad (it's a small, enclosed room). 

Read more about Jason and Medea in the link at the top of the page.

January 6: To Sea!

Atlantis the morning of departure.
(photo by Chris German, WHOI)

We are all extremely excited that Atlantis finally left Port Everglades near Ft. Lauderdale, Florida, at 8:00 a.m. on January 6. The ship will take roughly two and one half days to reach its first station over the Mid-Cayman Rise just south of Cuba.

Before embarking, the science team was very busy preparing Atlantis for departure. Everyone was to be on board by January 4 so we could ensure a full day on the 5^th to unpack, unload equipment, and secure everything on board. It was also the time to give loved ones a good-bye phone call, as communication is now very limited from the ship.

The science team in their "gumby suits."

The morning of the 6^th was slightly hectic as the LAST shipment of equipment arrived at 7:30 a.m.—just 30 minutes before departure! Luckily everything went off without a hitch.  So far it has been mostly clear skies and calm waters and we’re off to a great start.

After departing. the science team had safety training, which involved putting immersion suits—better known as "gumby suits"—and afterwards deploying a rescue boat as part of a practice drill.

Heading west

After heading south past the Florida Keys, we turned west, into the sunset to skirt Cuba, and right now we have nothing but smooth sailing.

January 5: T’was the night before sailing . . . and everyone was stirring

Sunset from Atlantis, above.
Moonrise, below.

This will be a short first post, as we are getting ready to sail. Last night we all enjoyed our last hours on land. Most of science team was exhausted from running around all day making last-minute trips to Home Depot. Despite the whirlwind of activity, it was hard not to pause and admire Atlantis catching the last rays of the sun with a nearly full moon over head. Some of us were even able to find time to enjoy one last drink before returning to the ship, as there is a strict no-alcohol policy on board. 

Who is on board

There are roughly 50 people on board Atlantis for the OASES cruise and about half are on the science team. The other half are members of Atlantis staff, comprised of officers, engineers, deckhands, and the galley crew, as well as the team trained to operate Jason our remotely operated vehicle (ROV) that will be exploring the sea vents. Everyone aboard Atlantis plays a vital role in the smooth functioning of the ship and the success of the expedition.

It is truly a symbiotic relationship.

Searching for Life on the Seafloor 
Mid-Cayman Spreading Center could harbor unknown organisms
by Jill McDermott
Jill is a student in the MIT/WHOI Joint Program in Oceanography and a member of the OASES 2012 expedition. This article appears in the most recent issue of Oceanus Magazine, published by WHOI.


Smaller than a fingernail, like bits of downy red feathers, baby tubeworms cling to a vertical wall towering alongside the submersible Alvin 2,500 meters beneath the sea in 2006. Repaved with fresh rock during an eruption at the East Pacific Rise, the walls mark the edge of the caldera of a deep-sea volcano. We three—pilot Pat Hickey, biologist Timothy Shank, and I—are the first human observers of these new colonizers, which are still so young they don’t yet have tubes to protect them from hungry crabs.

Fresh rock on the seafloor is typically a glassy, iridescent black color, but these rocks are coated with a thick layer of white microbes. The key to all this new life is the warm, shimmering, chemical-rich water bathing them. Pressing my face to the 4.5-inch-round window, I have just encountered my first black smoker hydrothermal vent, where hot fluids, laden with chemicals and minerals, spew like smoke from chimney-like rock formations. We have sampled fluids from the vent, collected rocks and animals around it, and seen how the gills of baby tubeworms flutter in the current. Continue reading