Going with the Floe?
An analysis of luck versus skill in the epic polar expeditions of Fridtjof Nansen and Sir Ernest Shackleton
Stephanie Pfirman, Bruno Tremblay and Charles Fowler
ne hundred years ago, the he- British Imperial Trans-Antarctic Expedi- ice pack and, in Shackleton’s case, the roic age of polar exploration tion of 1914–1917 was to transit to Ant- wind and ocean currents of the open Owas well underway. Expedi- arctica in the Endurance and then land a sea. These are natural forces, outside tions set off one after another to explore, party on the continent who would cross the control of the expedition leaders. map and make national claims. Fridtjof over the ice cap from the Atlantic to the Were Nansen and Shackleton lucky that Nansen and Sir Ernest Shackleton were Pacific by way of the South Pole. But the the ice and ocean delivered them and two of the most famous polar explorers two journeys wound up having much their crews to locations from which they in their time, and their stories still reso- in common. Both ships were frozen into could return? Or were their fates prede- nate today. At first glance the two men the sea ice and meandered at the whim termined by the normal range of natu- and their most famous expeditions were of the pack, both expeditions spanned ral conditions? We cannot reconstruct literally poles apart: Nansen, from the three years, both leaders left their crews the exact wind and ocean patterns that not-yet-independent country of Norway, at some point, and all crew members existed 100 years ago to answer these traveled during 1893–1896 to the Arctic, who sailed with them survived—a high- questions, but using newly available da- attempting a long-planned sea approach ly unusual outcome in that era. tabases, we can look at the patterns of to the North Pole aboard his specially The crucial point that we will explore sea ice drift, winds and ocean currents designed ship, the Fram. The goal of here is the dependence of both expedi- during recent decades to see what is Shackleton’s hastily cobbled together tions on their drift trajectory in the sea normal and what is not.
Nansen and the Fram
“On this same drift-ice, and by this the capital of Greenland. Driftwood same route, it must be no less pos- from Siberia was often deposited along sible to transport an expedition.” the east and west coasts of Greenland. Nansen, Farthest North (1897). Furthermore, the mineral composition of sediments on East Greenland sea ice ansen’s scheme was audacious: were consistent with a Siberian source, he actually planned from the and the assemblage of diatoms sampled Nbeginning to freeze from drifting ice was his ship into the Arctic ice similar to that previ- pack north of Siberia and ously sampled near the then let the migrating ice Bering Strait. transport his party to the Clearly, a major North Pole. He got the stream of sea ice flowed
idea after learning about Mary Evans Picture Library/Alamy consistently from Sibe- various materials that were ria across the Arctic to- carried by sea ice from Si- wards Greenland. Along beria to the coast of Green- its way, this route must land. The most compelling pass by the North Pole, Getty Images piece of evidence was an leading Nansen to state: Inuit (Eskimo) throwing stick ornamented with I believe that if we Chinese glass beads from pay attention to the Figure 1. Hand-colored lantern slide of the Bering Strait that was actually existent Fridtjof Nansen in his cabin on the Fram. At found along the west Greenland coast forces of nature, and seek to work left, a serialization of Nansen’s recounting near Gothaab, now known as Nuuk, with and not against them, we of his expedition.
484 American Scientist, Volume 97 Getty Images Getty
Figure 2. The epic era of polar exploration around the turn of the last century featured two stangely similar episodes: In 1893 Fridtjof Nansen intentionally allowed his ship to become frozen into the drifting polar ice pack to ride the ice over the top of the Earth; two decades later the ship of Sir William Shackleton, decidedly not by intention, became frozen into the moving ice pack of the Weddell Sea of Antarctica. Their adventures featured years of drift, heroism, and ultimately survival. To what degrees were the heroic feats of Nansen and Shackleton, now leg- end, due to luck? Would normal variations in current, weather, and ice motion have assisted or doomed them? Satellite data of ice movements in recent years offers answers. Above, a hand-colored lantern slide of Nansen’s ship the Fram, perched high on arctic ice after its specially designed hull was squeezed out of the forming ice pack.
shall thus find the safest and easi- it take to perform this journey? If A lucky find of the remnants of a est method of reaching the Pole. the drift took ten years, it would be tragedy gave Nansen the last piece of While safe and perhaps easy in hard to find a crew willing to hitch information he needed to propose us- relative terms, how long would such a slow ride to the North Pole. ing the ice drift as the foundation of his
Stephanie Pfirman, Hirschorn Professor and chair of the Environmental Science Department at Barnard College, Columbia University, uses the IceTracker in her re- search on sea ice origin and fate, and also in her undergraduate First Year Seminar “Exploring the Poles.” Pfirman recieved her PhD from the Massachusetts Institute of Technology-Woods Hole Oceanographic Institution joint program in Oceanography and Oceanographic Engineering. velese feum et ut nostrud tio consequat. Usto doluptat veleniam dolore vullaor in hent num velit, sequip exeratue ming eniam, sit ullaortion voleseq uipisci ncilissisl dunt volor senis nos non vent illandrer si ercilit at esto od dio odolessis am, consed magna alit lumsand ionsent verat, consent dignisl el estrud del del ero od ercillaoreet il dunt wis accum adiamet aliquat,
www.americanscientist.org 2009 November–December 485 a number of articles which appear, from sundry indubitable marks to process from the sunken vessel. 8 +VMZ The distance from the New Si-
& /BOTFOTBJMT berian Islands to the 80th degree of 4FQUFNCFS GSPN/PSXBZ latitude on the east coast of Green- 5IF'SBNJTGSP[FOJO land is 1360 miles, and the dis- CZTFBJDF tance from the last-named place to .BSDI Julianehaab is 1540 miles, making /BOTFOBOE together a distance of 2900 miles. +PIBOTFOEFQBSU This distance was traversed by GSPNUIF'SBN the floe in 1100 days, which gives & "QSJM a speed of 2.6 miles per day. The 5IFZSFBDI{/ time which the relics drifted after UIFIJHIFTUMBUJUVEF having reached the 80th degree of BDIJFWFEUPUIBUUJNF +VMZ latitude till they reached Juliane- /PSUI1PMF 5IFZXJOUFSPWFS 8 CFGPSFEFQBSUJOH haab, can be calculated with tol- GPS4QJU[CFSHFO erable precision, as the speed of the above-named current along / m the east coast of Greenland is well known. It may be assumed that it took at least 400 days to accom- m/ plish this distance; there remain, "VHVTU then, about 700 days as the longest 5IF'SBNFNFSHFT time the drifting articles can have GSPNUIFJDF / taken from the New Siberian Is- m land to the 80th degree of latitude.
8 Nansen proceeded to design and m/ build a ship that could withstand the pressures of the ice and outfit it for five Figure 3. Route of Nansen’s Fram: solid black lines indicate sailing; dotted black line indicates years, more than twice as long as he ex- Fram’s drift trajectory in with the sea ice. The yellow line is the sledge and kayak route of Nansen and Johansen. pected to be drifting within the pack. The main point in this vessel is North Polar expedition. He wrote: after she foundered to the north that it be built on such principles of these islands there was found as to enable it to withstand the The Jeanette drifted for two years in frozen into the drift-ice, in the pressure of the ice. The sides must the ice, from Wrangel Island to the neighborhood of Julianehaab, on slope sufficiently to prevent the New Siberian Islands. Three years the southwest coast of Greenland, ice, when it presses together, from getting firm hold of the hull, as was the case with the Jeanette and other vessels. Instead of nipping the ship, the ice must raise it up out of the water. With such a ship and a crew of ten, or at the most twelve, able- bodied and carefully picked by me, with a full equipment for five years, in every respect as good as modern appliances permit of, I am of opinion that the undertaking would be well-secured against risk …When the right time has arrived, then we shall plough our way in amongst the ice as far as we can. While many criticized this plan, call- ing it “sheer madness,” “extremely dan- gerous,” “based on fallacious ideas,” and leading to “barren results” as well
The Mariners’ Museum, Newport News, VA News, Newport Museum, Mariners’ The as to “suffering and death among its Figure 4. Nansen (right) and Jackson meet on Franz Josef land. “Suddenly I thought I heard a members,”, Nansen persevered in fund- shout…I ran up on the hummock and hallooed with all the strength of my lungs.” raising and outfitting his expedition. On
486 American Scientist, Volume 97 July 21, 1893, Nansen left Norway and realized that he could not advance as bear meat. They emerged in the spring made his way along the coast of Siberia rapidly toward the Pole as he planned: of 1896 and continued south through towards the point where the Jeanette the ice itself was moving south and it the archipelago, making their way back had been crushed. Here he maneuvered was heavily ridged. Nansen and Jo- towards home. his ship into the ice, and let it freeze all hansen headed towards the Franz Jo- At this point, one of those coincidenc- around him. “All at once in the after- sef Land archipelago, from where they es occurred that are so improbable and noon, as we were sitting idly chatting, planned to kayak west to Spitzbergen, yet so common in the exploration lit- a deafening noise began, and the whole now better known as Svalbard. They erature. While planning the expedition, ship shook. This was the first ice-pres- made landfall on the Franz Josef Land Nansen had turned down a request by sure. Everyone rushed on deck to look. archipelago August 15, 1895, after an Frederick Jackson, an Englishman, who The Fram behaved beautifully, as I had amazing 700-kilometer sledge and kay- wanted to come along. In response, expected she would. On pushed the ice ak journey from 85oN to 86oN back to Jackson decided to put together his own with steady pressure, but down under 80oN over ridged ice and open water. expedition, using Franz Josef Land as a us it had to go, and we were slowly lift- They were too late to continue the jour- base. According to Roland Huntford, ed up.” This first part of the expedition ney that season so they overwintered in biographer of polar explorers, Jack- went according to plan, in large part a stone and snow hut, living mainly on son had announced his expedition in due to the care and time Nansen took in preparing for the expedition. Compar- ing his expedition with previous ones, Nansen noted The present expedition, however, could not be equipped in so short a time [months], and if the voyage itself took three years, the prepara- tions took no less time, while the scheme was conceived thrice three years earlier.
m/ Fram immediately began drifting /035) with the ice. Each time the ship would 10-& loop to the north, Nansen and his crew would celebrate, only to grow despon- dent when the winds would change and the ship would loop back towards the south. On December 31, 1893—dur- ing the first year of drift—Nansen com- mented: 'SBN4USBJU But you fell off at the end, old year; you hardly carried us as far as you ought. Still you might have done worse; you have not been so bad after all. Have not all hopes and calculations been justified, and are we not drifting away just where I 'SBNTBDUVBM wished and hoped we should be? ESJGUEVSBUJPO Only one thing has been amiss—I did not think the drift would have gone in quite so many zigzags. As time went on, Nansen came to realize that, while the ship was drift- ing towards Greenland as planned, it ESJGUEVSBUJPO ZFBST was drifting too far south of the North Pole to reach it. On March 14, 1895 (one and a half years later), Nansen left Otto Sverdrup in charge of the Fram and tried to ski to the Pole himself. He took a companion, Frederik Hjalmer Johan- TUBSUEBUF sen, three sledges drawn by dogs with Figure 5. Using the web application IceTracker, drift trajectories for the years 1979–2006 were provisions for 100 days, two kayaks, a calculated, beginning at the point where the Fram froze in. The black line is Nansen’s actual tent and a double sleeping bag. He got drift path. The computer-generated drift paths are here superimposed on a 3D globe. The as far north as 86o14’ on April 8, 1895. graph below shows the durations of the drift paths in (a) compared with the actual duration He turned back at this point because he of the Fram drift. www.americanscientist.org 2009 November–December 487 that she was not already here, and I NBYJNVNESJGU thought with horror that if the au- MBUJUVEFBDIJFWFE tumn were to pass without news of m her, the coming winter and summer / would be anything but pleasant. / /BOTFOTIJHIFTU 85ºN ESJGUMBUJUVEF Fortunately, exactly one88º week after 8 / / his arrival, on August 20, 1896, Nansen got a telegram from Sverdrup saying that the Fram was out of the ice and that / the crew were all fine. The Fram’s clos- est approach to the North Pole (figure 1) turned out to be 85o56’N—just 18’ south of the northern point of Nansen (86o14’). Another coincidence was that the Fram had emerged from the ice between Greenland and Svalbard, through what is now known as Fram Strait, on exactly the same day that Nansen had arrived in Norway, August 13, 1896. Nansen was hailed as a hero in Nor- way and around the world. However, there were some detractors who focused on Nansen’s leaving the Fram and strik- ing out on his own towards the Pole. Nansen, himself, quoted one of them in his introduction to Farthest North: “… It passes comprehension how Nansen could have thus deviated from the most sacred duty devolv- Figure 6. Figure 6. Red dots indicate the closest approach to the pole (highest latitude ing on the commander of a naval achieved) for each of the drift trajectories plotted in Figure 5, for the start years 1979 to 2006. The blue ring indicates the Fram’s highest latitude of 85.9oN. expedition. The safe return of brave Captain Sverdrup with the Fram does not excuse Nansen.” February, 1893, so Nansen would have farther off came another figure, known about it—and Nansen referred and that was a man. Who was it? Others rose to support Nansen in the in Farthest North to the “contemplated” Was it Jackson, or one of his com- face of this criticism. Jackson expedition in the area. How- panions, or was it perhaps a fel- ever, Jackson would write that Nansen low-countryman? We approached Alternative Nansen Fates was not aware that he would be there. one another quickly. I waved my In the light of this controversy, what At any rate, Nansen could not know hat; he did the same. I heard him would have happened if the Fram had if the expedition actually happened or speak to the dog, and I listened. It taken longer to drift out of the Arctic where Jackson would set up camp in was English, and as I drew nearer pack ice? It was wonderful that she ar- the maze of islands that make up the I thought I recognized Mr. Jack- rived in Norway only one week after Franz Josef Land archipelago. So he was son, whom I remembered once to Nansen. What if she came out of the just making his way along the coast, have seen. ice one year later? Or even more? Was trying to figure out a way to continue Nansen just lucky that she emerged on to Spitzbergen, when the following Nansen joined Jackson’s relief ship when she did? took place (figure 2): back to Norway, arriving on August Also, how would things have been 13, 1896. When he got there, he found different if the Fram had attained the Suddenly, I thought I heard a out that the Fram had not yet arrived North Pole? Was Nansen unlucky that shout from a human voice, a and he started to grow concerned: the drift was too far south, or is that strange voice, the first for three the usual path that the sea ice takes years. How my heart beat, and But what of the Fram? I had tele- from the location where he started? the blood rushed to my brain, as graphed confidently that I expected To address these questions, we used I ran up on the hummock, and her home this year; but why had an application called IceTracker to as- hallooed with all the strength of she not already arrived? I began sess the drift trajectory each year from my lungs. Behind that one human more and more to think over this, 1979 to 2006. IceTracker, a project that voice in the midst of the icy des- and the more I calculated all chanc- originated at the Colorado Center for ert… Soon I heard another shout, es and possibilities, the more firmly Astrodynamics Research, University of and saw, too, from an ice-ridge, a was I convinced that she ought to Colorado at Boulder, is a web-based dark form moving along the hum- be out of the ice by this time if noth- tool that allows users to reconstruct the mocks farther in. It was a dog; but ing had gone amiss. It was strange drifting of sea ice in the Arctic and Ant-
488 American Scientist, Volume 97 arctic, based on thirty years of satellite the ship emerged from the pack). Only If Nansen had been able to maneuver and buoy data. Starting at any time and two years had drift durations less than 3 the Fram slightly more to the east before location where there is sea ice, IceTrack- years (2.5 years in 1987 and 2.6 in 2006). freezing her in, the average sea ice drift er pinpoints the daily changes in the There were four start years with drifts would have taken her even closer to location of the drifing ice. (More infor- longer than five years (1979, 1980, 1981 the Pole. The 2006 Tara expedition did mation on ice motion data can be found and then again in 1998). Nansen had freeze in to the east (79o53’N, 143oE) and at http://tinyurl.com/icemotion. The provisioned the ship for five years and reached a more northerly latitude than IceTracker tool is located at http://ti- could supplement the ship’s stores by did the Fram: 88o32’N (160 kilometers nyurl.com/icetracker.). hunting and fishing, so the crew would from the geographic North Pole). But For our drift start point we used the probably have survived even these ex- the most remarkable aspect of the Tara location and date that the Fram was tended voyages. expedition was its extremely short drift frozen into the ice (September 22, 1893 The average maximum latitude of duration, only 461 days—1.3 years!—to at 78o42’N and 133o35’48”E). We must the simulated trajectories was 88o6’N reach 80oN in Fram Strait. This faster acknowledge that Nansen had to make (standard deviation of 1.1o) which is 240 drift rate was likely due to decreased his way along the Siberian coast to get kilometers closer than the 85o56’ that the resistance of the sea ice to wind forcing to this point, and that some years the Fram attained in 1895. In fact, every year caused by less extensive sea ice condi- sea ice conditions would have been since 1979, the Fram would have been tions, and the presence of younger, thin- too difficult to make that trip possible. just about as close (86o1’N in 1985) or ner ice than that which Nansen encoun- Thus, he might have made different closer to the Pole than it was during the tered. choices about where to freeze in the 1893–1896 drift (figure 6). Roger Colony If Nansen had initiated his expedi- ship, depending on the sea ice condi- in an unpublished analysis (1988) found tion during conditions like those that tions he encountered along the shelf.. a similar result using computer model- occurred in 1979 through 1983 or 1998, Our analysis indicates that, using ing: the Fram would have passed closer he may have realized that the drift was Nansen’s start location and ending the to the Pole for nine out of ten possible going too slowly, putting the future drift at 40 percent ice concentration or drifting paths. Our analysis indicates of the expedition in jeopardy, and he when the ship would have emerged that in 1988, 1989, 1993, 1994, 1999, and might have decided that it was not safe through Fram Strait at 80oN, the aver- 2004 the Fram’s drift would have taken it to leave the crew of the Fram. If, howev- age drift duration of the Fram from 1979 north of 89oN. The best year for Nansen er, he had left the ship and made it back through 2006 would be 3.7 years with would have been 1989: the ship would safely to Norway, he definitely would a standard deviation of 0.8 years (fig- have gotten to 89o58’N (89.96o) and still have faced difficult circumstances as ure 5). Fram’s actual drift rate was 2.9 would have emerged within 3.3 years he waited month after month and then years (9/22/1893 to 8/13/1896, the date (figures 3 and 4). year after year for the Fram to return
Shackleton and the Endurance
I have often marveled at the thin ble ice conditions that existed that year line that divides success from fail- “… the worst they had ever been in ure and the sudden turn that leads the memory of the Norwegian whaling from apparently certain disaster skippers operating in the area.” Some to comparative safety. Shackleton, even advised him not to pursue the ex- South (1919) pedition that year. He spent a month in South Georgia hoping the conditions nlike Nansen, Shackleton did would get better and learning from not want to be caught in the the whalers about the local environ- Robert Harding Picture Library Ltd/Alamy Uice—far from it. ment. Then he decided to He planned for a shore see for himself, depart- party to be dropped from ing from South Georgia his ship, the Endurance, on December 5, 1914, to at Vahsel Bay where make his way south into Filchner had attempted a Trinity Mirror/Mirrorpix/Alamy the ice. Endurance worked landing in 1912. Shackle- through openings in the ton would then attempt floes until eventually to cross the continent, Shackleton was just over meeting up with the Ross 100 kilometers away Sea party which was lay- from his coastal goal of Figure 7. Portrait of Sir William Shackleton, ing depots from the other Vahsel Bay. based on a famous black and white portrait side to assist his crossing. At this point, Shack- by Sir Wally Herbert. At left, the Daily Mirror But when he arrived at leton’s luck turned. A of December 30, 1913 announces that Shack- South Georgia, his last port of call, the storm came up with winds from the leton will lead an English expedition from whaling captains told him of the terri- northeast, pushing the pack ice togeth- sea to sea across the Antarctic continent. www.americanscientist.org 2009 November–December 489 On October 27, 1915, ten months after freezing in, the Endurance was crushed, 8 %FDFNCFS leaving 28 men with three lifeboats 8 &YQFEJUJPOEFQBSUT camping on the ice. Shackleton: “We GSPN4PVUI(FPSHJB are alive and well, and we have stores and equipment for the task that lies be- 8 fore us. The task is to reach land with $"1&)03/ 4 all the members of the expedition. It is "QSJM hard to write what I feel.” Fortunately, 4IBDLMFUPOBOE "QSJM their drift continued to the north, final- TNBMMDSFXTFUPVU .FOBOEMJGFCPBUT GPS4PVUI(FPSHJB ly dumping the men in their lifeboats 4 JOGSFFXBUFS JOUIFNFUFS into the ocean on April 9, 1916, at the LFUDI$BJSE marginal ice zone near the tip of the 0DUPCFS Antarctic Peninsula. $SFXBCBOEPOT 4 EFTUSPZFE From here, Shackleton, with the &OEVSBODF guidance of his navigator, Worsley, set sail for Elephant Island, the nearest at- tainable land mass. They made landfall 4 with all crew still alive after a hard, six- day, 150 kilometer journey in freezing +BOVBSZ &OEVSBODFGSFF[FTJO conditions among an ice-riddled sea, with high waves and difficult landings. Figure 8. Route of Shackleton’s Endurance expedition. The solid black line shows sailing of Now on land, they were still not the Endurance. The dotted black line represents drifting on the sea ice, first in the Endurance safe. The shore of Elephant Island was and then on the ice after the crushed Endurance was abandoned. The orange line traces the exposed to strong winds and storms boat journey in the Caird. and was so out of the way that no one would look for them there. Shackleton er against the shore and dumping snow it was drifting with the ice to the north, requested that the carpenter ready their into the water around the ship. By Janu- Shackleton made the best of the situa- biggest boat, the Caird, a 22.5-foot (8 me- ary 19, 1915, the Endurance was stuck in tion, with fun and games on board. He ter) ketch, so that he could go for help. the ice at 76o34’S, 31o30’W. Later efforts knew from his conversations with the (It was not possible to make all three of to maneuver out of the pack were not whalers on South Georgia that “great their boats seaworthy.) Together with successful. The ship was “frozen,” as quantities of ice sweep along the coast Worsley and four others, Shackleton set crewmember Thomas Orde-Lees put from the east under the influence of the sail on April 24, 1916 for South Georgia, it, “like an almond in the middle of prevailing current, and fill up the bight 1300 kilometers away to the east. While a chocolate bar.” As conditions were of the Weddell Sea as they move north Cape Horn of South America was closer fairly comfortable on the ship, and as in a great semicircle.” in distance, only 900 kilometers to the north, the strong Antarctic Circumpolar Current running from west to east made it impossible to reach. According to Worsley, by the first evening of the boat journey they still had not decided where to go:
Again and again we discussed the best point to make for, Shackle- ton emphasizing once more that he wanted to get to the north as quickly as possible, even though the route might be lengthened, so as to avoid all danger of ice and to relieve us from the almost over- whelming cold. “What do you think about Cape Horn?” he asked, adding, “it’s the nearest.” “Yes, I replied, “but we can never reach it. The westerly gales would blow us away. With luck,
Underwood & Underwood/Corbis & Underwood though, we might fetch the Falk- Figure 9. Endurance became immobilized in the thickening ice of the Weddell Sea January 19, 1915. land Island.” Gale winds compressed the ice against the land and the ship until finally Endurance was shattered “I am afraid that, although it by the pressure in late October. When the icepack relented in late November, the ship sank. is the longest run,” he remarked,
490 American Scientist, Volume 97 “we shall have to make for South Georgia as you originally sug- gested. The gales will drive us to leeward.”
Over 16 days, with only a few navi- gational sightings, Worsley steered and sailed the ship towards South Georgia, an island 170 kilometers long. After a harrowing open-sea journey transiting a region with some of the worst wave conditions in the world, they caught sight of land. Just then a terrible storm rose up with hurricane force winds that almost dashed their boat against the rocky shore. They finally made landfall on South Georgia the next day, May 10, 1916, an almost unbelievable feat of navigation and endurance. Having accomplished the amazing, they now faced another dilemma: the whaling village was on the other side of the island and their boat was too bat- tered to sail more than 150 kilometers around. Shackleton decided that their only chance was to walk across the is- land, a straight line distance of 50 kilome- ters. They knew that the trek would be more grueling than that because running down the center of the island was a spine of mountains, some over 2000 meters high. The carpenter took two-inch brass screws from the Caird and put them into the soles of their shoes, eight in each foot, 4IBDLMFUPOTBDUVBM ESJGUEVSBUJPO to give them a better grip on the ice. They didn’t take a tent or sleeping bags, just food for three days—they had to go as fast as possible, without sleeping, or they would never make it. No one had ever crossed the island this way before, but ESJGUEVSBUJPO ZFBST they did, in just 36 hours. On his fourth attempt, Shackleton fi- nally got through the sea ice and rescued his men from Elephant Island on Au- gust 30, 1916. He then proceeded to help rescue the Ross Sea party, returning the TUBSUEBUF remainder of the Imperial Transantarc- tic Expedition back to New Zealand on Figure 10. Starting from the point at which Endurance became entrapped, drift trajectories February 9, 1917. were generated by IceTracker for the years 1981–1998. All of the recent trajectories (red) are well to the east of the drift path of Endurance and crew (black). The durations for Alternative Shackleton Fates the calculated trajectories are in general considerably longer than that of the Endurance What were the alternative fates for expedition’s 1.3 years. Shackleton and his crew? What if the sea ice drift had not taken them to El- did for Nansen, and the other looking tion of winds and ocean currents. The ephant Island but had instead taken at the ocean segment of the boat jour- drag coefficient between the water and them eastward, out into the Antarctic ney using a high-resolution coupled boat was set based on an estimated Circumpolar Current and far from any ice-ocean model forced with observed draft and surface area of the ship, but landfall? Further, what if Shackleton’s winds and other atmospheric fields the results proved to be not sensitive to boat journey had not been successful from the National Centers for Environ- the exact value of this drag coefficient. in locating South Georgia? mental Prediction–National Center for The effect of the winds on the ship drift Here we approach these questions Atmospheric Research. In this model, was parameterized in such a way as to in two different ways, one using the the Shackleton boat journey was simu- obtain a total drift distance of 1300 ki- IceTracker for the sea ice drift, as we lated as a passive drifter under the ac- lometers in the 16 days that Shackleton www.americanscientist.org 2009 November–December 491 elephant ru o
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8 4 8 4 8 8
Figure 11. Ocean models simulate the drift of a tracer from the point at which Shackleton departed for Elephant Island. The simulations reflect conditions for a start day of April 24 during the years 1979 to 1999. The paths at left are driven by ocean currents only. The analysis at right includes ocean currents plus winds.
required to cross the passage. In the If the men were in lifeboats when the that collect along the Peninsula also model no attempt was made to repro- ice melted out at this southerly location, pose a greater crushing hazard than duce sailing upwind or crosswind; the they would face difficulties, as they at- does the thinner, younger ice along ship just sails downwind while also tempted “…to row north-west to where the edge. being affected by the eastward ocean we might find land…” (Shackleton). In exploring the fate of the ocean drift. The resulting trajectories indicate This conlusion is reinforced by the most journey between Elephant and South how much active sailing was required surprising aspect of the simulated tra- Georgia Islands, we ask the question, 80 on the part of the crew. jecties: Not one of them headed toward how important was Worsley’s naviga- o o o The IceTracker’s re-creationS of drifts, Elephant Island at –61 10’S, –55 14’ W. tion? What would happen if the boat were each started where Shackleton All of the terminations were farther to just drifted away from Elephant Island, froze into the ice and were terminated at the east than Shackleton’s expedition. like a corked bottle or a piece of drift- either 70 0% sea ice concentration, or when Eastward drift was Shackleton’s wood? Where would it end up? Would the concentrationo was at 40% for more nightmare: “The land lay to the west, it have come close to South Georgia? than one Smonth, whichever came first. so had we drifted to the east we should There is a hint in Worsley’s book about Like the projections for the Nansen ex- have been taken right away to the cen- the expedition that this might be the pedition, in the years since 1981, the ice tre of the entrance to the Weddell Sea, case. He describes their camping place 60 drift duration would generally have and our chances of finally reaching on South Georgia as an area where o been longer than the 1.3 years that land would have been considerably driftwood converged—note how simi- S Shackleton actually experienced: the av- lessoned.” The reason why success- lar the description is to Nansen’s analy- erage is 1.8 years (standard deviation 0.6 ful landfall would be difficult is that sis of the constancy of the Arctic sea ice years), with a maximum in 1989 of 3.0 the lifeboats had to be overloaded to drift that brought the Siberian throwing 50 years (figure 9). Drifting for such a long accommodate the men and necessary stick, driftwood, sediments and biologi- o time on the ice would increase the stores, and they would have had to cal materials as well as remnants of the S crew’s dependence on success in hunt- beat upwind, as well as upcurrent, shipwrecked Jeannette to the coast of ing and fishing and would also take a against the strong eastward flowing Greenland: psychological toll. The four years with Antarctic Circumpolar Current—an 4 shorter drift durations (averaging 1 year impossible task. Close to the boat was a great pile in 1983, 1985, 1992 and 1997) are inter- But the easterly drifts also have an- of driftwood, about half an acre in 0 o S esting because they reached low ice con- other implication: again, they could extent—a graveyard of wreckage centrations at about the position that the mean that the Endurance might not from ships. In places it was piled Endurance was crushed (she was crushed have been crushed. If the ship had eight feet high or more, and there at 69°5’S and the average termination drifted north along the marginal ice were ships’ masts and timbers, latitude for these four years was 69o42’S). zone, and not in the interior of the a great mainyard, bits of figure- This means that she might have been pack, the compression forces driven by heads, teak stanchions with brass released with so little damage that she wind pushing ice against the Antarc- caps, cabin doors, binnacle stands, could have sailed back to port, as Sver- tic Peninsula would likely have been broken oars, and harness casks. drup did with the Fram in the Arctic. smaller. The thicker multiyear ice floes These had been swept from be-
492 American Scientist, Volume 97 fore the westerly gales a thousand average of 1.8 years. The fact that his edu/ScienceForum/ASF15/1517.html miles from Cape Horn, or farther, trajectory was so close to the Antarctic Farley, R. 2005. “By endurance we conquer”: until the wild Southern Ocean had, Peninsula is particularly interesting: all Ernest Shackleton and performances of white male hegemony. International Journal by some strange freak of its eddies, drifts since 1981 were farther to the east. of Cultural Studies 8:231–254. thrown them up here to rot. If the Endurance had actually drifted Fowler, C., J. Maslanik, T. Haran, T. Scambos, along the eastern border of the pack J. Key, and W. Emery. 2000; updated 2007. This passage seems to indicate a ice, it might not have been crushed, and AVHRR Polar Pathfinder Twice-daily 5 km steady delivery from the Antarctic they might have been able to sail it back EASE-Grid Composites V003. Boulder, Col- Fram orado USA: National Snow and Ice Data Circumpolar Current to this location, to port, as Sverdrup did with the . Center. Digital media which collected floatsam from a wide Shackleton’s journey from Elephant Fuchs, A. 2000. “Dear Friends of the Pawprint.” swath of the ocean. Indeed, the ocean Island to South Georgia in the lifeboat URL: http://www.wolfskin.de/eng/text/ model shows that the ocean current was quite extraordinary in the face the professi/aktionen/shack/c2–40.html alone would carry Shackleton to the vi- variable winds in the region. While the Gascard, J.-C., J. Festy, H. Le Goff, M. Weber, cinity of South Georgia most of the time ocean currents would have taken him B. Bruemmer, M. Offermann, M. Doble, P. (Figure 11). But it would take 120 days! in a similar direction if he had just drift- Wadhams, R. Forsberg, S. Hanson, H. Skou- rup, S. Gerland, M. Nicolaus, J.-P. Metaxian, Shackleton had taken enough food to ed, it would have taken far too long for J. Grangeon, J. Haapala, E. Rinne, C. Haas, last six men for only a month. It actually them to survive—3 months. Also, im- G. Heygster, E. Jakobson, T. Palo, J. Wilkin- took them 16 days, but because one of portantly—no one knew the details of son, L. Kaleschke, K. Claffey, B. Elder, and their water containers became contam- the ocean currents at the time. Shackle- J. Bottenheim. 2008. Exploring arctic trans- inated with seawater, even a slightly ton made the decision to go for help be- polar drift during dramatic sea ice retreat. Eos 89:3. longer journey would have threatened cause he had to. They headed for South Greely, H. 1896. Harper’s Weekly, September their survival. Georgia because they knew that it was 19, 1896. Shackleton got to South Georgia fast- both inhabited and downwind. Huntford, R. (1998) Nansen. London: Gerald er than 120 days, because he sailed. Of Subsequent attempts to recreate the Duckworth & Co Ltd. the roughly 80 kilometers of travel that boat journey and the crossing of South Huntford, R. (1986) Shackleton. New York: he averaged per day, about eleven to Georgia have encountered so many Scribner. fourteen kilometers per day came from challenges that the participants gain Nansen, F. (1897) “Farthest North.” Being the ocean current, and for the remaining new respect for Shackleton: the Record of a Voyage of Exploration of 60 plus kilometers per day he depend- the Ship “Fram” 1893-96 and of a Fifteen ‘Unfavorable gale force winds, the Months Sleigh Journey by Dr. Nansen and ed on the winds and sailing. Sailing 80 unbelievably cramped conditions Lieut. Johansen With an appendix by Otto kilometers per day (3 kilometers per on board, the cold, the ever pres- Sverdrup Captain of the Fram. Harper and hour) is well within the normal speed Brothers Publisher, New York.Jackson, ent penetrating dampness, and range of a sailboat. The winds observed F. G. 1899. A Thousand Days in the Arctic. then the violent rocking of the on the boat journey often came from the New York and London: Harper & Broth- boat in the churning sea, put an ers. (http://www.thepoles.com/news. west but shifted direction frequently, as enormous strain on the strength php?id=16309) was also seen in our 1979 through 1999 of the crew’…. The difficulty of Pfirman, S. and W.F. Haxby. 2000. Animation analysis (figure 11). The fact that Wors- these expeditions should not be of Arctic Sea Ice Origin and Age. http:// ley managed to make landfall on South www.geomapapp.org/arctic/ice_movies/ underestimated. The South Aris Georgia in the face of this variability Pfirman, S., W. F. Haxby, R. Colony, I. Rig- team had to abandon their replica in the winds, as well as high seas and or. 2004. Variability in Arctic sea ice drift, boat after force 10 storms rolled storms, using only a compass and a few Geophysical Research Letters 31, L16402, it repeatedly, while Wake expedi- doi:10.1029/2004GL020063. http:// navigational sightings, makes his navi- tion members failed to traverse www.agu.org/journals/gl/gl0416/ gational feat even more admirable. South Georgia and the Memorial 2004GL020063/ expedition couldn’t manage the Shackleton, Sir Ernest. 1919. South: The Story of Conclusions Shackleton’s Last Expedition 1914–1917. Lon- island landing. Both Nansen and Shackleton were don: Heinemann. lucky and unlucky in the natural con- Analyses such as these, including the Shaler, N. S. 1897. Nansen’s heroic journey. The ditions that they encountered during unpublished Nansen’s Luck by Roger Atlantic Monthly 79:475. their expeditions. Most years since 1979, Colony, and Susan Solomon’s deter- Solomon, S. 2001. The Coldest March: Scott’s Fatal Antarctic Expedition. New Haven, CT: Nansen would have gotten much closer mination of the actual environmental Yale University Press. to the North Pole than he did in 1895, so conditions during the Amundsen-Scott Worsley, F. A. 1931. Endurance: An Epic of Polar he was unlucky in that respect. On the race to the South Pole, reported in The Adventure. New York: W.W. Norton & Co. other hand, the Fram emerged from the Coldest March (2001), help set history pack 2.9 years after freezing in, nearly a and profiles of leadership within a sci- year faster than the average time since entific framework, and aid in under- 1979 of 3.7 years, indicating that the ex- standing the role of the environment, pedition was lucky in their drift rate. environmental variability, and environ- For relevant Web links, consult this This is especially true of the years 1979 mental change. issue of American Scientist Online: through 1981, and 1998, when the drift http://www.americanscientist.org/ duration was more than 5 years. References issues/id.81/past.aspx Shackleton was also lucky in the rap- Colony, R. Unpublished, 1988. Nansen’s Luck. id pace of his drift in the pack—at 1.3 Referred to in Alaska Science Forum No- years it was half a year shorter than the vember 22, 2000; http://www.gi.alaska. www.americanscientist.org 2009 November–December 493 494 American Scientist, Volume 97 www.americanscientist.org 2009 November–December 495