Robin Bell

Holding out for those last few lines of data

Published January 18th, 2009 in Uncategorized. 2 Comments

The original flight plans for the project have been configured and reconfigured since we started our planning. The scientists hoped to squeeze every opportunity out of the field season. After spending several years planning the project, to leave any of the survey area unexamined was unthinkable. However even before we started, the logistics crews had shortened the project. Concerns with the narrow weather window, the altitude issues, the fuel needs, and camp logistics all pushed against the original 35 days in the field to shrink it to a 25 days, a 30% loss.

In all, fifty flights were planned from AGAP S camp, and every one had valuable data that we would need to put together the images and information we sought. 50 flights would mean 2 flights a day for 25 straight days of survey work. Our late arrival at camp left us 20 days, and weather delays and equipment issues have shortened that further, but a determined science team can work through these setbacks. When we were able, we flew 4 flights a day. The day crew would fly out for one round, return to refuel and go back out again. When they returned to eat and sleep the second crew repeated the process.

The British team from AGAP N finished their flights, and leaving a team to close their camp they came to help with the remaining flight lines. But the weather turned poor and several days passed without any planes in the air. We finally sent the British team on to McMurdo and worried about whether we should be leaving too. But there was an unfinished bit of business that kept us holding out. The remaining flight lines connected to the Recovery Lakes, 4 lakes on the Northwest edge of the study area, that feed into the 800 km long Recovery Ice Stream. We had located these subglacial lakes in 2007 at what appeared to be the head of the ice stream, an ice stream that moves about 35 billion tons of ice into the Southern Ocean each year. When the ice stream moves over these lakes it accelerates. Gathering data on these lakes may offer clues to the ice sheet plumbing, and explain the connection between subglacial lakes and ice sheet movement.

We waited. Finally we were able to send out a flight, and as we celebrated our success at having sent the plane to capture the data, the plane returned! Problems in the fuel lines. One more lost attempt. Finally five days after we were to have packed out of the camp we celebrated success! The weather cleared, the plane flew, the data was captured!

Peering at those hidden mountains and lakes

Published January 10th, 2009 in Earth and Science. 2 Comments

At last we are able to mount flights out of AGAP S. With the flat white topography all around us it is hard to visualize a mountain range anywhere near us. Our flight from S. Pole located some minor 100 foot peaks close to camp, but these are not the range we are looking for. Our plan involves surveying beneath the ice to the north with the airborne radar. The data on the flights between South Pole and the camp let us know the systems work well over the thick cold ice. Although we have tested the system, first in Greenland this past summer, and then at McMurdo once in Antarctica, there was a concern that it might not work at this colder environment.

The radar system that makes the data profiles transmits energy from four antennae on the right wing of the aircraft and records the returning echos from the ice on the four antennae on the left wing. While radar systems are widely used in environmental engineering for studying the upper 1-10 meters of the earth surface, radar can be used to map through 4-5 kilometers of ice. The electrical conductivity of ice makes radar a perfect tool. The first echo actually travels straight though the air from one side of the aircraft to another. The second echo is from the surface of the ice sheet. We can use this system to map crevasses, mega dunes and floating ice over lakes, although our laser system will be more accurate. Within the ice sheet there are changes in electrical conductivity as a result of the changing makeup of the ice – sometimes the result of volcanic dust landing on Antarctica. These chemical changes show up as many layers within the ice sheet, layers reminiscent of a fancy layer cake. The final echo is from the bottom of the ice sheet. Rocks will return a signal, but water at the bottom of the ice sheet will return a really strong signal. The strong reflectivity of water makes lakes easy to spot.

A large lake has emerged under three km of ice, and the mountains are beginning to emerge forming a map of what is underneath the extensive ice sheet. Our survey area is twice as big as the state of California. A large area to cover but despite the setbacks we are finally capturing the images we had hoped for!

Data, data, data - how we dream of data

Published January 3rd, 2009 in Climate & Weather and Earth. 2 Comments

Moving from McMurdo to South Pole to AGAP S Camp is something that on paper was designed to take a week…four days at South Pole to adjust to the change in altitude, and another three at AGAP S. However, plans on paper and realities in Antarctica have proven to be two different things. Small issues continued to cause a slowing in progress - issues with camp readiness, team member illness, flight crew medical clearances, and the ever present issue of weather. As the days marched by it was difficult to sit quietly acclimatizing while our partnering AGAP N crew was actively flying flight lines and collecting data.

At last we were cleared to move on to our ultimate destination, AGAP S, eleven days behind our planned departure. The camp, at 11,482 ft., is nestled on the Western side of Dome Argus. We had seen early images as supplies were dropped and a tent or two erected, so to actually see the full camp set up and ready to house about 40 staff and scientists was exciting. The camp personnel includes the flight crew, engineers, scientists and graduate students, the seismic team, and camp staff. In order to try and capture as much data as possible, flight lines were flown as people were moved from South Pole to AGAP S camp. While it felt great to finally be collecting data, the flight area from South Pole to camp is fairly flat, and not our primary target. Christmas Eve we had one team of pilots and one scientist cleared to begin to fly. Finally we would get our chance to look beneath the East Antarctic Ice Sheet and find the hidden Gamburtsev Mountains.

At last moving into position

Published December 27th, 2008 in Earth and Science. 0 Comments

We had been waiting for clearance to move the team from McMurdo to South Pole, which at 9,300 ft. of elevation is the first step in acclimatizing for work in the high altitude AGAP S camp, our ultimate destination. McMurdo Station is located at sea level so acclimatizing the group will be done in two steps. We will be working about 796 miles west of McMurdo on Dome A, the highest point of the East Antarctic Ice Sheet, rising more than 13,000 feet above sea level. Our AGAP S camp will be nestled on the South side of the Dome at a slightly lower elevation of 11,482 feet.

We had been prepared for the issues with altitude. It poses a problem for our equipment, which will operate at 40 percent efficiency, but it poses a more serious problem for people. The high altitude class we took at McMurdo sobered us with stories of the last high altitude East Antarctica science program which resulted in seven medical evacuations from the camp, one with serious acute cerebral edema. The issue is that atmospheric pressure decreases with altitude and so the air is thinner at high altitudes, as there are fewer oxygen molecules in the air. People’s bodies have to adjust to compensate for this reduction in oxygen in the air.

Because of being in a Polar region the problems with altitude are magnified. At the poles the effect of the spinning earth and the cold temperatures means that the surface of the Earth is about 13 miles closer to the center of the Earth than near the equator in Singapore. These rotational forces act on the ocean and the atmosphere causing them to bulge. The net result is there is more atmosphere at the equator than at the poles. With this decrease in pressure at the poles the altitude issues are accentuated. For example, the AGAP S camp (11,482 ft.) is at a similar elevation to a Colorado ski resort, a challenging, but not extreme altitude. However, when combined with the polar low the average pressure is closer to 14,800 feet – more like the highest peaks in the Rockies, a very difficult working environment.

The acclimatization schedule has been complicated by two factors. First, the limited number of beds at South Pole means that for any new person, or group of person, to move to the station someone else must move out. There are teams of scientists who normally work out of South Pole and so there are a limited number of mobile spaces that can be taken advantage of. This short field season there is our AGAP S geophysical team, our AGAP S seismic team, our AGAP N team, our overland fuel traverse team, and the Norwegian/US traverse team, all converging on the pole and hoping for accommodations.

Secondly there has been an issue with inadequate power being available at South Pole to accommodate some of the new quarters that have been constructed, and the project equipment needs. Because of the cold temperatures in East Antarctica it is essential to keep the airplanes and instruments plugged in when not flying. This adds to the already stretched electrical demands on the station. The camp cook is preparing meals for 16 people on two Coleman camping stoves but it seems the tents are filling with carbon monoxide.

At last it seems they have worked this all out and we are cleared to move on to South Pole, as our AGAP N team moves on to their final destination for serious data collection.

Science in Antarctica - still about overcoming obstacles

Published December 15th, 2008 in Earth and Science. 1 Comment

McMurdo Station, Antarctica

Our planning has lasted for over two years…equipment was designed & built, engineers employed, planes were located, testing was completed, alliances were forged and meetings arranged in multiple countries. All this planning and organizing was key to making this project a reality, and yet science in Antarctica is still all about overcoming obstacles. The continent is vast and travel is still difficult, with the most normal means of moving people and supplies being air travel. But planes are restricted by visibility and calm winds, and these are not predictable.

Having the right amount of fuel in the right location for the planes has been a logistical challenge. Last year we had hoped that the Chinese overland traverse would be able to move some of the fuel the Germans had provided, from their position on the continent perimeter up to the AGAP camp. Unfortunately this became impossible. Fortunately some of the fuel could be relocated using air-drops (see photo), but there was still fuel to be moved to the other camp. The U.S. support team agreed to an overland traverse from McMurdo Station on the perimeter of the continent, up to the South Pole. This traverse can not run a straight trajectory due to the terrain, and crevasses loomed in front of the vehicles causing the crews to set off explosives to smooth the way. The going has been slow.

But fuel has not been our only challenge. Weather and paperwork have also held us hostage. Now we face a new obstacle - there is a clean air sector between South Pole and our camp, that is as big as the state of New Jersey! Just what is a clean air sector? Antarctica is protected by International Treaty. The first environmental treaty, this sets aside many areas for protection. The aim of the clean air sector is to preserve the unique climatic record of the cleanest place on earth. Here far away from the influence of human activities the snow captures air samples. Any activity that might contribute contaminants to the air samples is restricted. Established in 2007, and shaped like a pizza wedge, the South Pole Clean Sector starts at the pole and widens as you move away. 2007 was well into our planning, which would explain why no one caught this.

Our flight plans called for flying through this area at a height of 500m above the ice. This will not be allowed due to concern for the aircraft engines emissions. The 2000m allowable height is out of range of both our radar and our laser. We can either appeal through diplomats to fly the area, or we can fly around the perimeter, adding many hours to our already long flying day. We chose to move forward on both.

Walking in Scott’s Memories

Published December 11th, 2008 in Earth and Uncategorized. 3 Comments

I had read about the one way British expedition of Robert Scott and his team, but reading about it and coming face to face with it are two very different things. We had the opportunity to venture to Cape Evans where Scott’s hut remains almost 100 years after his departure. I was unprepared for the effect of staring straight into the wooden framed shelter. Here was where the Expedition’s meteorological measurements had been recorded those many years ago. This shelter with the wind rattled planks was much like the image I show in my many talks of the first International Polar Year (1881-1884), with scientists huddled in the doorways collecting data in shelters much like this. I am walking into the history of Antarctic scientific data collection. In some areas we have learned little about this vast continent since then, and in others we have made tremendous advances.

Entering the shelter my breath was taken away. The light streamed in through the East facing windows illuminating the inside where time had stopped moving. The table looked exactly as it does in the photos of the expeditions feasts. Nothing has changed since the hut was abandoned after the loss of life on the return from the Pole. It is much like looking at a photograph. Food stock such as penguin eggs and slabs of blubber, line the entry ready for the team members. Bottles of ketchup and mustard line the shelf as if waiting for the next meal. Shoes, socks and hats rest on the bunk as if they were waiting for the return of their owner. A bicycle hangs on the wall, waiting for its rider, the geologist of the expedition. In the stables in the back hay is waiting for the ponies that Scott chose to bring. A choice that slowed his progress, and perhaps led to the failure of his journey. The pony snowshoes he invented were hanging on the walls.

I stand for awhile and let the history be absorbed. I wonder what Scott was thinking when he last walked from this doorway. Perhaps his thoughts, like mine, were brimming with enthusiasm for an upcoming expedition.

Antarctic Update: Held hostage by weather

Published December 10th, 2008 in Climate & Weather. 2 Comments

McMurdo Station, Antarctica.

For several weeks our AGAP project team has been battling the delays of Antarctic spring weather. Our carefully orchestrated logistics have been pulling apart piece by piece as we watch and wait. Our project requires several stop overs on our way to the AGAP camps; stop overs designed to allow us to complete instrument testing, and to acclimatize to the changes in pressure as we climb higher and higher onto Dome A.

We have become accustomed to checking the weather screen in the science lab on multiple occasions each day. The weather screen is the main indicator of what we will be up against each day. Spring weather in Antarctica can be an ongoing rhythm of comma shaped cyclonic systems racing around the continent in a clockwise fashion, and regularly slamming into the continent as blizzards. These systems are the result of the continent’s cold air as it runs off and intersects the relatively warm ocean. If only we could accelerate the season to the polar summer where high pressure systems set up over the center of the ice sheet and force the southern ocean cyclones offshore.

Weather has delayed flight after flight for our project, throwing our carefully planned, and endlessly debated, timeline out the window. The bright red British twin otter plane arrived 23 days late in McMurdo after being caught by weather first in Patagonia, South America and then in Rothera, on the Antarctic peninsula. The crew has worked round the clock to get the plane outfitted and ready to collect data. But the plane will be no use unless we can get the camp put in. The Aussies are currently holed up in Prydz Bay, unable to fly out to start on the camp called AGAP North, which will house the British plane and crew. Maybe soon.

The U.S. twin otter plane has been outfitted and testing has been underway on the new radar system. Our camp, AGAP S, is also behind schedule, but our next stop is South Pole and that is ready and waiting for us. We will continue to plan and re-plan our logistics and hope that we can still accommodate all the science we planned to accomplish.

Good news just in! The Aussies are heading out to AGAP N to start putting in the camp.

About

Robin Bell is a geophysicist and research scientist at Lamont-Doherty Earth Observatory of Columbia University. She has coordinated seven major aero-geophysical expeditions to Antarctica studying subglacial lakes, ice sheets and the mechanisms of ice sheet movement and collapse, and currently the Gamburtsev Mountains, a large alp sized subglacial mountain range in East Antarctica. .

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