Observations: Iceberg from 1,500 ft (credit SM)

When members of our NASA science party complain about the internet or hot water going down at our hotel in Punta Arenas, it is easy for me to say that this is much better than dying of frost bite, malnutrition and exhaustion

Editor’s note: one year ago, the author thrilled us with an account of his scientific mission to scope out Antarctica’s shrinking ice from the air. Back in his flying laboratory once again, Seelye Martin filed this report in the midst of another trip to the South Pole, exactly one hundred years since Robert Scott’s began his famous mission to that same territory.

My trip to the South Pole began on Friday, October 15th, when I flew from Seattle to Los Angeles, took a shuttle to Palmdale, then a cab to the NASA Dryden Aircraft Operations Facility (DAOF). This is a giant hanger in the Mojave Desert that contains the NASA DC-8 we’d be calling our home for the next few weeks. At midnight, Sunday, we departed Palmdale on the plane for an 11-hour flight to Santiago, Chile. We spent Monday night in Santiago, then on Tuesday, flew on to Punta Arenas to begin Antarctic operations. We are to return to Palmdale on November 23.

November 2010 is the centennial of the departure in November 1910 of the British ship Terra Nova, carrying the twenty-four men led by Captain Robert Scott, from New Zealand to McMurdo Sound in the Ross Sea. Two excellent books on this expedition are Scott’s journals, published as Scott’s Last Journey, and a book by a junior member of the party, Apsley Cherry-Garrard (1886-1959), The Worst Journal in the World, published in 1922, and available as a free e-Book via the web. (Apsley was a shy man who loved penguins. So much so that at age 50, when he proposed to his 20-year-old wife to be, Angela Turner, he wordlessly handed her a small quartz stone. This stone exchange is part of the penguin courtship ritual, the stones being used in the construction of their nests.) The science leader of the expedition was the remarkable Edward Wilson, a doctor, artist, and scientist; an exhibit of his paintings is currently at the Scott Polar Research Institute in Cambridge, England.

Mascot The flying laboratory (photo credit Seeyle Martin)

The Scott expedition is most famous for the story of its failed polar party. It is not my goal to recap the tribulations suffered by the Scott polar party, although when members of our NASA science party complain about the internet or hot water going down at our hotel in Punta Arenas, it is easy for me to say that this is much better than dying of frost bite, malnutrition and exhaustion.

Cherry-Garrard came south with Scott at age 24; he participated in a winter journey to a penguin colony led by Wilson, and was part of the rescue/discovery party that found Scott’s tent. The tent contained the bodies of Scott, Bowers and Wilson; Cherry-Garrard’s party collapsed the tent, built a snow cairn over it, and marked the site with a cross made from a pair of skis. Following Scott’s instructions, they removed only papers and letters from the tent, including one to the King Haakon of Norway that Amundsen left for Scott at the pole. The tent remains on the Shelf, now buried deep in snow and ice. Cherry-Garrard observes that “by the time Scott comes home - for he is coming home: the Barrier is moving…, the hardships that wasted his life will be only a horror of the past”.

At the current rate of ice shelf advancement and calving, the ice surrounding Scott’s tent will take another century to reach the shelf edge, where it will probably calve off as an iceberg. If the iceberg is large enough, ocean currents and winds will carry it north to exit the Ross Sea at Cape Adare. A recent study in which I participated shows that at the Cape, large icebergs tend to run aground and fracture. We found that at least one of these groundings generated a seismic signal that was observed at South Pole, 1,100 nautical miles away. If in the next century, this occurs for Scott’s iceberg, he may have one last interaction with the pole before his iceberg leaves the continent to melt in the Southern Ocean.

Cherry-Garrard survived the Scott expedition, returned to Britain, served for two years in France during World War I, then wrote his book. In his last chapter, titled “Never Again”, Cherry-Garrard critiques the expedition, where he felt its members had inadequate equipment and were overworked. One of his conclusions was that Antarctic research requires “[s]pecially built ships and enough of them; specially engineered tractors and aeroplanes; specially trained men and plenty of them will all be needed if the work is to be done in any sort of humane and civilized fashion…”

On the job A researcher puts in time (photo credit Seeyle Martin)

Forty-four years elapsed before another person set foot at the pole. In October 1956 and as part of Operation Deep Freeze, Admiral George Dufek and six crewmembers landed at the pole in a small ski-equipped plane, the Que Sera Sera. In 1958, as part of International Geophysical Year, the United States set up the first base at the pole, Amundsen-Scott Station.

During their sledging trips, the Scott exploration parties burned about 6,000 calories per day. In honor of the centennial, the British company, Huntley and Palmer, has used the original recipe to duplicate their sledging biscuits, and although these are not yet for sale to the public, samples have been distributed to various polar groups. The problem with the biscuits is that they are designed to maximize the number of calories per biscuit, so they are heavy in saturated fats and lard, perhaps too much so to be sold to a calorie-conscious public. Scott’s party man-hauled their sledges 12 miles per day; we fly 4,000 miles per day sitting in dilapidated first class seats. Scott’s problem was starvation; ours is getting enough exercise and avoiding overeating. The evening before our South Pole flight, we had a presentation from the Dryden flight surgeon on deep-vein thrombosis, which are blood clots that form in the legs from sitting too long, and which can migrate to the lungs and heart, and as the surgeon repeatedly said, result in, ah, death.

The purpose of our flights on the DC-8 is to measure the changing properties of the Antarctic glaciers and sea ice. On a typical day, we carry 24 people, including flight crew, scientists, graduate students and post-docs. The plane is equipped with profiling lasers, ice penetrating radars, a gravimeter, precision navigation, and for personal use, a microwave oven, hot water tap and a coffee maker. Although from the outside, the plane looks like a commercial airliner, inside, most of the seats have been removed, while the remaining forty-four are scattered in pairs around the plane in front of instrument racks. Large steel trunks containing spare parts fill the empty spaces among the seats. A central aisle remains open. In the back of the aircraft, there is a pile of duffle bags filled with survival gear with warm clothing and boots for 40 people, and enough high-density ration bars to provide food for 50 people for 10 days.

Each morning at 6:30 am, we leave the hotel for the airport. By 7 am, our three-person meteorology team that includes me, is sorting out the weather and deciding where we can fly. At 7:30, we go to the airport weather office to confirm our plans, and to take advantage of their numerical models for the peninsula and adjacent coast. We bring a translator with us to supplement our meager Spanish. If the weather looks good, at 8 am, we have a crew brief run by the pilot, where we go through the flight plan, safety considerations and confirm the manifest. We board the plane before the doors close at 8:30, takeoff at 9 am. Most of our flights last for 11 hours; this breaks into a 3-4 hour transit south, 3 hours of taking data, and a 3-4 hour return, with calibration maneuvers at the end of the flight. We return to the hotel between 9 and 10 pm. While we are sleeping, the night crew checks out the aircraft, performs service where necessary and fills the plane with its 110,000 lbs of fuel. In the morning, when we come into the terminal, they are packing up for the night, and the whole process starts again.

Frontier Reflection of a contrail in a window at South Pole station (photo credit David Pablo Cohn)

Although most of our flights concentrate on the ice sheet margins and the sea ice of the Weddell and Bellingshausen/Amundsen Seas, there was one flight planned for the polar plateau. The proposed flight path took us in an arc around 86 S, then transited over the South Pole. On the arc, we used the high altitude laser system to measure the surface topography. Because the 86 S arc coincides with the latitude where the orbits of the ICESat laser satellite converge, our passage along the arc with our high altitude laser system will sample the surface elevation measured by thousands of ICESat shots. The purpose of the polar transit is to calibrate our onboard GPS with that at the South Pole.

The preparation for the South Pole flight depended strongly on the weather. Our primary forecast tool is the Antarctic Mesoscale Prediction System (AMPS) numerical model, which predicts the weather five days into the future, issuing a new forecast at daily intervals of 0 and 12 UTC. AMPS is tuned for the ice sheet, in that it appears to do well in the interior, but less well at the coast. Our second source of forecasts is the airport meteorologists, who use a different model tuned for the Peninsula and coastal Antarctica. On Thursday November 4, the AMPS model predicted good weather over the region, with clouds present only at the beginning of the arc. But when we went to the Chilean meteorology office on the morning of the polar flight, they predicted heavy clouds over the entire region. So at about 8 am, and after 10 minutes of anguished talk in the hallway outside the office, we decide to believe the AMPS model and fly.

Because of the lure of the pole, the flight carried more than the usual number of people, about 30. Our path takes us across the British Rothera station, the George VI ice shelf, the spine of the peninsula, the Ronne Ice Shelf, then over the plateau past the Ellsworth Mountains and the Vinson Massif, the highest mountain in Antarctica. At 1330 local, or 4.5 hours after takeoff, we begin the 86 S arc in heavy clouds; at 1400, we are out of the clouds and taking data, so that our forecast was correct. What a relief! For fuel efficiency, we fly at 39,000 ft, where the outside temperature drops to -70 C. At this temperature, the uneven distribution of insulation means that the aircraft interior becomes cold, in particular, the windows and their aluminum frames are too cold to touch. At these temperatures, water froze in the washbasins of the aft toilets. Based on location of hot air ceiling vents, the plane divides into warm and cold zones, where people cluster in the warm zones. South Pole station knows we are coming, we sent the camp manager an email this morning, and will contact them by radio when we are closer.

On the flight, a curious problem occurred with the high altitude laser optical port. The lasers are mounted in what we call the pit, in what used to be the baggage storage compartment under the passenger deck. This is an eerie place; we enter it through hatches in floor of the passenger compartment. The floor of the pit consists of the bare uninsulated aluminum hull, which is too small to stand up in, too cold to sit down, dark and even noisier than the cabin. The laser views the surface through a port of optically flat glass that is protected by a sliding panel, which is opened only in flight. When we prepared to begin measurements, we found that the glass was partially obscured by spots of frost on the outside of the window, which degraded the laser performance. When we landed, a taste test showed that the port was partially covered with a thin layer of jet fuel, which freezes at about -65 C. The source of this fuel was a slight leakage from our tanks, apparently not fixable in the field. Once in flight with the shutter open, droplets of fuel were blown onto the recessed window, where they froze. Whether this degraded the laser performance to the point that the data is unusable will be evaluated in the next few weeks.

Hidden South Pole Station: black rectangle is main building, South Pole at its lower left corner. The clean station is to the lower left; the optical and radio telescopes and the neutrino observatory is to the lower right (image taken by Digital Mapping System camera, courtesy of NASA)

Over the plateau, the large 1-km scale megadunes on the plateau surface yield a gently rolling terrain, with the superimposed small-scale sastrugi oriented parallel to the wind. This is the largest ice mass in the world, and it is stark. There is no sign of life, and the continuous white surface provides little visual stimulation; to quote Scott’s words at the pole, “Great God! This is an awful place…” At 1450, we finish the arc, then turn toward the pole along 90 E longitude. South Pole station is divided into three sectors; the Clean Air Sector which intends for about three hundred of miles upwind, over which we must maintain an altitude of at least 6,000 ft above surface level, not a problem; the Quiet Sector, which contains the seismograph that detected the iceberg grounding at Cape Adare, and the Dark Sector, which contains the radio and optical telescopes as well as the ICECUBE array of neutrino detectors, over which we must switch off all radiating instruments.

As we approach the pole, the feeling on the plane is like the countdown to midnight on New Year’s Eve. At five minutes or about 40 miles out, we enter the Dark Sector and switch off all radiating instruments. People cluster around the navigational display, waiting to take pictures of 90 S. But the pole is not simply the axis of the earth’s rotation; it is also the point where all longitude lines converge to a single point. This causes our navigational software to break down, such that as we approach the pole, the navigation display goes to 89.59 S, then goes to random numbers. We continue north past the pole, exit the Dark Sector, and head across the plateau for home. Our official pole crossing time is 1817:46 UTC, 1517 Punta Arenas time, or 0717 (next day) South Pole time. We were the first persons to visit South Pole since the beginning of the austral winter. Because the Earth’s time zones also converge at the pole, the pilots complain that they had to spend 4 hours in Friday, and they wonder if they will be able to collect extra pay. I asked if while they were in Friday, they remembered to get the weather. Crossing the pole concludes the data gathering part of the experiment; we arrive at Punta Arenas at about 2030 local, or almost five hours later. We use this air time to write reports, do mission planning for tomorrow, and sleep.

Related information:

I thank Peter Wadhams for the gift of a package of Huntley and Palmer sledging biscuits, and for the background information about their recipe. The seismic iceberg paper referred to above is Martin et el. (2010), Kinematic and seismic analysis of giant tabular iceberg breakup at Cape Adare, Antarctica, J. Geophys. Res., 115, B06311, doi:10.1029/2009JB006700. The online supplement to the paper contains two files of the seismic records of the iceberg grounding and breakup that are speeded up by a factor of 100 so that they can be listened to as audio files. Also, I recommend the biography of Cherry-Garrard by Sara Wheeler, titled Cherry, A Life of Apsley Cherry-Garrard, Jonathan Cape, 2001.