Anatomy of an Expedition
On a journey to the most remote continent on Earth and across its roughest ocean, I anticipated the experience of a lifetime—one that has included more than 30 years of research at sea. I was not disappointed.
In the late winter of 1998, we carried out an expedition through one of our planet’s most inhospitable regions—working our way from Antarctica some 2,500 miles across the southern ocean to New Zealand, aboard the icebreaker Nathaniel B. Palmer. This is an account of our adventures.
The big picture and the tiny target
Our expedition’s broad focus was the inner workings of the great ocean that surrounds Antarctica. More particularly, we sought to learn how the ocean absorbs carbon from the atmosphere, transfers it to the depths, and buries it in the seafloor.
The central protagonists of this so-called “biogeochemical pump” are microorganisms at the sea surface, which take carbon dioxide from the atmosphere and convert it via photosynthesis into the organic carbon of their cells. When the microorganisms subsequently die, or are consumed and excreted, some portion of that carbon sinks to the seafloor, where it is buried.
As we confront the threat of global warming, understanding the pump is important because it could extract huge amounts of excess heat-trapping carbon dioxide from our atmosphere. A key clue lies in the tiny interface where seawater meets seafloor—where critical chemical reactions determine how much carbon dissolves back into the water and how much remains in the sediments. I focus on that piece of the puzzle.
A one-ton WHIMP
All seagoing expeditions require extensive planning and preparations that often begin years in advance. In a way, we started preparing for this trip in the 1980s when we first began to develop an instrument that could precisely extract water samples from upper layers of seafloor sediments—at intervals as fine as one millimeter.
Frankly, it’s hard to design a precision instrument that works under the unusual and rigorous conditions in the ocean and at the seafloor. Materials behave differently under 7,000 pounds per square inch of pressure. Often, the smaller the samples you want, the bigger and more complex the instrument you need to get them.
The tool we ultimately built is a one-ton, 11-foot-tall tripod device that lands on seafloor muds and inserts probes into the sediments. Much like a syringe, it extracts water samples at various depths, ranging from less than an inch to two feet. We called it the Woods Hole Interstitial Marine Probe, or WHIMP.
Nantucket road test
Summer 1997—We anticipated little opportunity to troubleshoot and modify the WHIMP in an environment where snow, ice, and 20-foot seas would be constant companions on deck. Since no local test vessel existed that was big enough to put the WHIMP through some paces, we organized a five-day cruise aboard R/V Oceanus off Nantucket.
Testing equipment is critical. Things may work like a charm on deck, and then you can get the dickens beat out of you on the sea-floor. As it turned out, we found two design flaws that would have been terminal in the Antarctic.
Turning a whale into a tricycle
Fall 1997—We spent the months following the Oceanus cruise making essential modifications to the WHIMP and assembling and packing five tons of equipment. This is a major undertaking under normal circumstances, but shipping to Antarctica hardly rates as normal.
Our equipment had to be trucked in containers to California, where cargo was consolidated and loaded by the Navy onto Greenwave, a supply ship that makes annual voyages to Antarctica. Because interior storage is extremely limited in Antarctica, we were instructed to put equipment that could not be frozen in boxes painted black.
The WHIMP created some challenges. In many respects, it is akin to a whale—robust and extremely functional in water, but a fish out of water on land. The WHIMP was too tall to fit into a standard container. WHOI machinist Charlie Peters, who (before his death in September 1997) was instrumental in building the WHIMP, found the solution by tipping it onto its side and supporting it on three wheels. This, in essence, created a one-ton, 7.5-foot-tall tricycle that we could maneuver in and out of shipping containers without using forklifts, whose rough movements jeopardized the WHIMP’s precision components.
In November we were ecstatic to see our 18-wheeler pull away from the WHOI loading dock with our equipment. Seeing it halfway around the world in February seemed quite soon enough.
Past the point of no return
February 11 to 16, 1998—A 24-hour trip took us from the northern winter to late summer in New Zealand. The flowering plants of Christchurch provided pleasant contrast to the Cape Cod winter we left behind—as well as what awaited us in the Antarctic “summer” (a misnomer if ever there was one). Over three days, we received the required Antarctic indoctrination and safety lectures and were issued Extreme Cold Weather (ECW) gear.
Our flight was one of the last scheduled into Antarctica before the nine-month “winter over” started. Since we would have no chance to dress on the cargo plane, we were required to wear our full ECW gear—in case of an unintentional landing in Antarctica and to provide some warmth in the unheated aircraft. Human and regular cargo are treated similarly, and we would be packed in with the boxes.
We were bused to our waiting C-130 plane, but it was being worked on by mechanics. So we spread out on the tarmac, fully dressed for sub-zero Antarctica in bright orange survival suits and white snowpack boots. It was 80°, and the airfield provided little shade. Two hours later, we had shed our ECW gear and the mechanics had given up on our plane. But the Kiwis stepped into the breach, issued us earplugs, and put us aboard a New Zealand Air Force C-130.
We were packed onto strap benches with our fellow travelers for an eight-hour flight that seemed much longer. The planes cannot carry enough fuel for a roundtrip and often turn back this late in the season in the face of storms. But fortune smiled. A snowstorm had indeed developed during our flight to McMurdo Station, the US Antarctic research base—but not until after we reached “the point of no return.” We had no choice but to fly on, which spared us a repeat of the whole muster process.
Welcome to the Hotel California
February 16 to 24—Landing on McMurdo’s ice runway in a heavy snow squall was a fitting introduction to summer in Antarctica. It snowed frequently during our stay. McMurdo reminded me of pictures of early 20th-century mining camps in Alaska: rows of quonset huts and cargo containers not very neatly placed, and heavy equipment everywhere—some operable, some derelict. Snowdrifts piled against or over anything standing out for more than a few days, driven by nearly incessant strong winds. All road surfaces were made of snowpack.
We were assigned to the “Hotel California,” a standard McMurdo dormitory. I bunked with three pleasant youngsters some 40 years my junior. They excitedly awaited their flight out before the imminent onset of winter and were completely averse to sleep. It had been almost four decades since my last dorm stint. The strong smell of stale beer in the dorm lounge stirred ancient memories of fraternity houses.
At this time of year, the sun worked its way around the horizon, providing light throughout the day. On bright days the Antarctic is an awesome landscape of stark yet beautiful contrasts. Brilliant white dominates, but is broken by the black of the volcanic rock that surrounds much of McMurdo. What little color there is comes from the light blue sky and reflections of sky in a few slivers of open water in the ice. All horizons, near and far, are mountainous. The air is so dry and clear that distances are very deceptive. The Antarctic explorer Robert Scott once set off with dog sleds to cross the Ross Ice Shelf to the Royal Society Range, which he believed was less than 30 miles away. It is about twice that far.
This difficult environment appeals to only the most dedicated and resourceful. The last plane out of Antarctica before winter left during our stay, and we mingled with the “winter-overs” who would remain at McMurdo for nine months, including four in darkness. Most were young, with an unmistakable air of pioneers living on the edge. McMurdo is definitely the edge of civilization, far from help, in time and distance. Everyone we dealt with was determined to meet our needs. Rarely did things go as planned, but with a large measure of ingenuity they always got done.
The best-laid plans
The WHIMP awaited us at a quonset building called McMurdo Playhouse—the only place with heat and a door high enough for the WHIMP to fit through. But finding the rest of our equipment proved challenging.
In California, the Navy had repacked all gear bound for Antarctica. Our boxes ended up liberally distributed throughout five 40-foot cargo containers, which were spread over a square mile of snowdrifts and mostly buried.
We used a frontloader to dig a road through five feet of snow and cleared a space to offload boxes. This offloading space tended to refill with snow at surprising speed. Boxes typically weighed 250 to 350 pounds, but we had to haul them by hand because forklifts could not make it through the snow.
We also discovered that our carefully prepared black boxes (“Do Not Freeze”) were interspersed throughout the unheated vans. We grabbed as many black boxes as possible to store in the warm Playhouse and moved the remaining equipment directly to the dock to await our icebreaker. There we found about 20 boxes offloaded from Greenwave two weeks earlier and left to be covered by drifts.
The McMurdo staff was as helpful and cooperative as one could wish—even though some of them nervously kept an eye on nearby cargo planes. They didn’t want to miss the last flight out of Antarctica and have to winter over.
Nathaniel B. Palmer arrived a day early and we put our gear aboard, often in a blinding snow.
In the ice
February 25 to March 6—In a heavy snow, fittingly, we departed McMurdo and broke through rapidly forming ice toward the center of the Ross Sea. Palmer’s mess deck at the bow is not far above the waterline, and the sound of breaking through ice was absolutely deafening and precluded any mealtime conversation.
Through new ice, two to three feet thick, we picked our way at six to eight knots, but slowed when it reached five feet thick. The entire ship rumbled as three-foot blocks of ice tumbled along the sides of the ship and often stacked up at the bow wedge.
The early sea ice cover seemed to bode ill for our primary task in the Ross Sea: retrieving three moorings set the year before. But Captain Joe Borowski deftly opened the ice over the mooring locations, then moved updrift to fend off the ice as the moorings surfaced and were recovered. He only became edgy when we scientists futzed around with the release signals. Once he had the ice open, he wanted the moorings up. Had they come up under the ice they would almost certainly be lost, but our recovery record was perfect.
Along with the early ice came unusually cold temperatures. During our 10 days in the ice it remained at 5°F. Despite our best-laid plans, this was too cold for WHIMP. We had used antifreeze to prepare the WHIMP’s hydraulics to work in cold temperatures, but our seafloor water samples would freeze as soon as they hit the air and corrupt any chemistry we wanted to examine. Further, as water turned to ice, it would expand and damage our apparatus. The WHIMP remained in a well-heated helicopter hangar during our entire stay in the ice.
We took the opportunity to observe our spectacular surroundings. Sea ice stretched from horizon to horizon, broken by huge tabular icebergs released from Antarctica’s ice shelves. At times we counted as many as 80 bergs surrounding us. Emperor penguins, the most anthropomorphic wildlife I have ever seen, appeared regularly. They seemed little concerned with what to them must have been a gigantic and strangely colored (orange in a sea of white) object. They watched our approach, at first waddling and then tobogganing away on their bellies, always in single file.
Across the southern ocean
March 6 to April 2—Once out of the ice, the air temperature rose to a balmy 32°F, well-suited to WHIMP’s tolerance range. The seas rose along with the temperature, and we experienced the southern ocean’s just reputation as a very rough body of water. Over 26 days we took samples and measurements at eight locations. We recovered moorings at five of them and did seafloor coring, water sampling, and WHIMP deployments at all eight.
Anti-cyclonic low pressure cells, many hundreds of miles in diameter, barreled across our path nearly every 36 hours. Winds from these storms typically topped 50 knots. On several occasions winds exceeded hurricane force. Back home, everyone runs from storms like these. In the southern ocean, there was no place to hide from them.
A good day was one during which the winds did not reach 40 knots. For the most part, we could work in winds up to about 45 knots, but only with a good deal of angst. I found it particularly unappealing to look up at wave tops. Sustained winds above 45 knots led us to secure the decks and ride out the blow.
The ship’s performance under these trying conditions was nothing short of remarkable. We held station to within 50 meters using the Global Positioning Satellite system in winds of 40 knots. We launched a variety of large equipment, and the mooring crew recovered five moorings averaging 4,000 meters in length and containing five sediment traps and other instrumentation, without mishap. The variety and complexity of operations successfully carried out under extreme conditions is a testament to the skill and care of both the ship’s personnel and the scientific parties. Indeed, had someone told me that we would need to work routinely with winds of 35 to 40 knots, I almost certainly would not have undertaken this trip.
As it turned out, the weather did not prevent us from achieving any scientific objectives. Given the difficulty of getting to and operating in this part of the world, we were grateful to come away with as much information as we did. It was a very good cruise.
As for the open ocean, its raw power was impressive. The sky was gray and so was the water, unless it was whipped to a white froth by the latest storm. It was a long and trying experience. With the recovery of the last mooring at 53°S, it was most definitely a relief to head for balmy autumn in Christchurch.
Marine Chemistry & Geochemistry Dept.