Popular Science Monthly/Volume 60/January 1902/Antarctic Exploration
| ANTARCTIC EXPLORATION. |
By PROFESSOR J. W. GREGORY, F.R.S.,
UNIVERSITY, MELBOURNE.
I. The Search for the 'Terra Australis.'
THE search for the supposed great southern continent roused interest in the South Polar area, even earlier than the commercial need for the Northeast or Northwest Passage directed the attention of the European nations to the Arctic seas. Long before Hudson had started the northern whale fishery, or Barents had discovered Spitzbergen, or Willoughby had set out on that 'new and strange navigation' which, according to Milton, was intended to save England from the commercial ruin threatened by foreign competition, Arabian, Dutch and Spanish sailors had searched for a continent in the great southern sea.
Belief in the existence of this 'Terra Australis' dates from the time of the earliest classical geographies. They regarded it as a corollary of the spherical shape of the earth; for it was thought that terrestrial equilibrium could only be maintained by two land masses acting as counterpoises to the land of the old world. The existence of America was therefore predicted as the necessary western antipodes, and a great southern continent was assumed as the southern antipodes. The land that Ptolemy represented as connecting Africa and southeastern Asia and closing the Indian Ocean as a Mediterranean Sea, was regarded as part of the northern shore of this southern continent. Faith in this 'Terra Australis' has survived in spite of the repeated failures to prove its existence; for more than two and twenty centuries the supposed limits of this land have receded as geographical research advanced southward. One of the geographical results of the Indian expedition of Alexander the Great was the separation of Ceylon from the southern continent. Ptolemy's land connection between southern Africa and eastern Asia was pushed backward by the Arabian sailors who reached Australia. Confirmation of the theory was however claimed by the discovery of Terra del Fuego and Australia; but the passage of Drake's Straits and Tasman's voyage along the southern coast of Australia showed that both areas were bounded southward by the sea. Then it was asserted that New Zealand was part of the southern continent, and de Bougainville was sent in 1763 to discover colonizable parts of it, so that France might replace her lost American possessions by new settlements in the south. The French expedition, however, was disappointed
—C—C— Cook. —W—W— Weddell. —B—B— Biscoe. —Wl—Wl— Wilkes. —R—R— Ross in the Ross Sea. —Sx—Sx— Southern Cross. —Bl—Bl— Belgica.
at finding only some insignificant islands, and Cook's first voyage showed that New Zealand was an independent archipelago.
In spite of the great shrinkage of the supposed southern continent caused by the expeditions of Cook and de Bougainville, there was still left an unknown area round the south pole large enough to hold a big land mass. Various new arguments were used to prove that such land must exist. De Quiros in the New Hebrides felt earthquakes traveling from the south; as it was believed that earthquakes could only originate on land, they were taken to prove the existence of a southern land.
Cook was accordingly sent on his second voyage, with orders to circumnavigate the south polar area in as high a latitude as possible. He was to search first for the land reported by Bouvet, and find if it were an island or part of a continent. If the latter he was to "explore it as much as possible, to make such notations thereon and observations as may be useful to navigation or commerce or tend to the formation of natural knowledge. He was also directed to observe the genius, temper and disposition of the inhabitants, if any, and endeavor by all proper means to cultivate their friendship and alliance, making presents and inviting them to traffic."
Cook's voyage was brilliantly successful, and still ranks as the greatest of Antarctic achievements. He circumnavigated the south polar region, and reached latitudes which in some parts of his circuit have not yet been passed. Cook's magnificent results were all the more remarkable because of his distaste of the work. He described the sea as 'so pestered with ice' and the lands as having 'an inexpressibly horrid aspect, and though he saw the beauty of the icebergs he regarded them with a 'mind filled with horror.' While so many coasts were uncharted and so many seas were unsurveyed Cook thought it a preposterous waste of time to hunt for a land, which, even if it existed, would be absolutely useless to his or to several succeeding generations. At times Cook was so impressed by the worthless nature of the Antarctic lands, that he believed they would be severely let alone when men heard his report of them and that they are uninhabited, uninhabitable and tradeless. If any one go further south than I have been, said Cook, 'I shall not envy him the honor of the discovery, but I will be bold to say that the world will not be benefited by it.'
All through Cook's journal we feel his irritation at having been sent on a mission which he regarded as a waste of his time and powers. He was comforted by the thought that he had, however, finally shown that there is no room for the Terra Australis of classical and mediaeval cartographers. Nevertheless he was convinced that there was a nucleus of land in the middle of the ice-pestered sea, for he accepted the view that thick ice is not formed on the open sea. This view was based on the argument advanced by de Brosses in 1756, that as sea ice is sweet it must be formed on land, until in 1776 Nairsie explained that ice formed by the freezing of the sea water is fresh because the salt is extruded as brine. Cook, however, was no doubt quite correct in the view that the great fiat-topped Antarctic bergs could not be formed by the direct freezing of the open sea, but must have been formed on land.
Hence in spite of the comparatively narrow limits within which Cook's work had restricted the possible existence of Antarctic land, the search for it was still continued. Islands were found south of the Atlantic; but it was not till 1840 that any extensive land area was discovered south of the Pacific and Indian Oceans. Then almost simultaneously a French expedition under Dumont d'Urville, and the American expedition under Wilkes discovered the long coast line or chain of islands known as Wilkes Land.
Wilkes' work was not only important because he traced this coast line at intervals for 60 degrees of longitude; but the geological collections made by his expedition showed that the land is formed of granites, massive sandstones and other rocks of continental types.
Two years later the extension of Wilkes Land to the east and the south was proved by the famous expedition of Sir James Clark Ross, which circumnavigated the Antarctic area and passed all previous records by reaching the latitude of 78°. On his own lines Ross's work was magnificent. His magnetic survey has not been equalled in the Antarctic; his southern record was not passed until 1900; his discovery of Victoria Land and Mounts Erebus and Terror were geographical results of high importance. But Ross's range of interest was narrow; he did not land on the main land he discovered, and would not let his doctor, McCormick; he advanced erroneous theories of oceanic circulation, assigned wrong temperatures to the sea water, owing to misunderstanding his thermometers; he told us practically nothing of the geology of the Antarctic lands, for the few pebbles he brought back were neglected until they were recently unearthed and described by Mr. Prior.
After the voyage of Ross there was a long interval before-serious work in the Antarctic was renewed. Sealers and whalers made minor geographical discoveries, and the voyage of the 'Challenger' in 1874 showed that the Antarctic sea is full of scientific interest. But it was not until 1885 and 1886 that the papers of Professor G. Neumayer, now of Hamburg, and formerly director of the Flagstaff Observatory at Melbourne, and of Sir John Murray roused fresh interest in Antarctic research. Since then the voyages of some Dundee and Norwegian sealers, of the 'Antarctic' and 'Southern Cross' in Victoria Land and the Ross Sea, and of the 'Belgica' to the south of the Atlantic have made important additions to our Antarctic knowledge.
II. The Four Antarctic Expeditions.
Now, in the year 1901, four expeditions are starting for the Antarctic: an English expedition under Commander R. F. Scott, E. N., in the 'Discovery,' with Mr. G. E. Murray, F.R.S., as head of the civilian scientific staff; a German expedition under Professor E. von Drygalski in the 'Gauss'; a Swedish expedition under Dr. Otto Nordenskjöld in the 'Antarctic' and a Scotch expedition under Mr. W. S. Bruce.
The four expeditions will work as far as possible on a common plan, but in different areas. The 'Discovery' will start from New Zealand and go thence into the Ross Sea, which will be its central field of work. The German expedition will go south from Kerguelen to the western end of Wilkes Land, geographically the least known part of the Antarctic; its route will depend on the geography of the area, but the idea is to work southwestward toward the Weddell Sea, south of the Atlantic. The Swedish and Scotch expeditions both go to the South Atlantic.
The work of these expeditions will depend primarily on the geographical character of their fields of operation. The Antarctic area includes three main geographical divisions, (1) Wilkes and Victoria Lands; (2) the division south of the Pacific from Ross's Sea to Alexander Land; (3) the Graham Land with its associated archipelagoes and the Weddell Sea that separates it from the western end of Wilkes Land.
As the first essential to the scientific investigation of a country is some acquaintance with its general topography, the primary factor in determining the work of the expeditions is the grade of our geographical knowledge of their fields of operations.
Geographical knowledge of the Antarctic is at present on two grades; in some areas the pioneer exploration has been done as far as concerns work at sea; of other areas we know nothing. Our knowledge is of the first grade in respect to only two or three areas; they are Graham Land with its associated islands and the coast of Victoria Land with the adjacent Ross Sea; perhaps we should also include in this category the northern shore of Wilkes Land, though it is known only at intervals and one of its most important areas, the angle between it and Victoria Land, is quite unknown. The rest of the Antarctic regions is on the second grade; the shores of the Weddell Sea have never been sighted; the western termination of Wilkes Land is quite hypothetical; speculations as to the area to the south of the Pacific are dependent on general considerations and the interpretation of a couple of distant and imperfectly recorded views.
Accordingly the plan of operations of each expedition should be dependent on the extent of our geographical knowledge of its field of operations. The English expedition has the advantage of a well-known entry into its central area, in which the most fruitful work will be scientific observations taken with the highest degree of accuracy and in the fullest detail. For pioneer geographical work it will be dependent on sledge expeditions inland, and at sea on how far it can push eastward from the Ross Sea into the southern Pacific.
The German expedition on the other hand goes into the region of which our ignorance is most complete. Its first work will therefore be pioneer geographical exploration, on the basis of which its expert scientific staff can found the observations that will be made concurrently. The expedition starts from the French island of Kerguelen where a base station and observatory have been established. Thence the 'Gauss' will sail due southward toward the supposed western end of Wilkes Land, and enter the ice near Enderby Land. Thenceforth its progress will depend on the character of that region. The general idea is to work slowly southwestward into the Weddell Sea, sending out sledge expeditions to explore any lands that may be seen. The proposed route of the ship has the drawback that it may be contrary to the prevalent drift of the ice and currents. Accordingly the expedition has been equipped on the expectation of a long, slow battle with the ice. The 'Gauss' has been designed for strength, not speed, and has been fitted up so as to make the minimum possible demands on its coal consumption for steaming, scientific work and domestic use. The number of the staff has been kept lower than on the English expedition so that the food supply may be larger and last longer. To make up for the smallness of the crew, 70 dogs have been provided for sledge expeditions. Further various tempting fields of scientific work are to be left unentered as impracticable with the available cargo capacity of the ship.
The Swedish and Scotch expeditions both go to an area where the opportunity for work largely depends on the particular ice conditions of the season. If the ice be open and the Weddell Sea fairly clear, they may reach high latitudes and discover the southern boundary of the South Atlantic basin. As so much depends on the chances of the weather, the plan in both cases is to establish stations on shore as far south as possible, and for the ships to leave the ice at the end of the summer and undertake oceanographic research outside the ice pack during the winter.
III. The Problems of the Antarctic.
The frequency of enquiries as to the practical value of Antarctic research shows that popular interest in the subject still values results from what it chooses to call their 'usefulness.' Information as to the meteorology and magnetic phenomena of the Antarctic regions may prove of value in navigation and weather prediction. Unexpected stores of economic products may be found on land or at sea. Nevertheless it must be admitted that the hope of practical rewards is a less powerful incentive to Antarctic exploration than the desire for new facts of theoretical value. The expeditions seek knowledge because it is knowledge rather than because it may be power. The first problem which the collated reports of the four expeditions will be expected to answer is whether the hypothetical 'Terra Australis' has any existence at the present day. Opinions are divided on this question. According to one school the Antarctic lands mostly belong to a great south polar continent; according to another there is no continent but only a number of comparatively small and widely scattered islands. Sir John Murray is the leading champion of the continental hypothesis; he has sketched the probable outline of his 'Antarctica' and represents it as an irregularly triangular area, of a size fully entitling it to rank as a continent.
That the Antarctic lands belong to a continent geologically there can be no doubt; for rocks of a typical continental character have now been collected from most of them, including Victoria Land, Wilkes Land and Graham Land. Specimens are now especially wanted from Dougherty Island and Peter Island in the southern Pacific. Meteorological evidence supports the idea that the Antarctic is still a continent geographically, and that the center of the land is not coincident with the south pole, but is in the eastern part of the area.
The available evidence appears to be decidedly in favor of Sir John Murray's theory, though the question cannot be definitely settled until the range of the land has been mapped. This task may be facilitated by the guidance as to the probable trend and position of the coasts, that is given by the principles of geomorphology.
If the current theory of the structural unity of the Pacific ocean be correct, then that ocean must be bounded on the south by a coast of the 'Pacific type.' With one exception in Central America the whole of the known coasts of the Pacific belong to what Suess has called the 'Pacific type.' The main character of this form of coast is that the trend is determined by mountain ranges running parallel to the shore. In the South Pacific this type is well exemplified by New Zealand on one side and by the Andes of South America on the other. In southern Patagonia the Andes are turned from their meridional course and run eastward across Terra del Fuego. The tectonic line of the Andes is then apparently bent suddenly southward and reappears in Graham Land. It is probably continued round the southern Pacific, meeting the known end of the New Zealand line near Mounts Erebus and Terror.
The theory of the structural unity of the Pacific is sufficiently established to render it probable that Cook was close to land when he turned back from his furthest south in the South Pacific (71°S. 123°E.), that the 'ice-barriers' of Ross and Bellingshausen are both the fronts of glaciers flowing from highlands to the south; that there is a land connection of the Pacific coast type running from Ross's ice barriers northeastward to Graham Land; and that Victoria Land is connected to Wilkes Land by a broad bight.
There are no such data for predictions as to the distribution of land and water in the German and Scotch areas of work. For Wilkes Land and the lands that may extend thence westward towards Graham Land are no doubt plateau countries bounded to the north by coasts of the 'Atlantic type'; and the trend of such coasts is not determined by simple continuous tectonic lines. That Wilkes Land and Geikie Land repeat the structure of southern Australia is rendered probable by the geological collections of all the expeditions from Wilkes to the 'Southern Cross.' The westward extension of this land line has probably the same structure, and it is accordingly impossible to predict how far the Weddell cuts into the Antarctic lands.
The principles of geomorphology not only suggest the external shape of 'Antarctica' but also its internal relief. It is probable that it is not a dome of land increasing in height slowly from the coasts to a central point near the South Pole; it is more likely to consist of a lofty mountain range running near the Pacific shore and of a broad plateau sloping downward from this mountain axis across the pole to Weddell Sea on the one side and the bight between Wilkes Land and Enderby Land on the other.
The remaining problems of the Antarctic are of less general and more technical interest. The magnetic survey, the need for which led to the British Government's contribution of £45,000 to the cost of the 'Discovery,' is generally regarded as the most important item in the scientific program. The principal point to be determined by the British expedition is the variation in the magnetic elements since the surveys of Ross and of Clerk and Moore. The deep fauna of the Antarctic seas was proved by the 'Challenger' and the 'Belgica' to be rich in new forms of life; and according to Murray the Antarctic and Arctic faunas have many elements in common. More material is needed for the proper analysis of the resemblances between the two faunas, and the collections may be expected to yield some hitherto undiscovered animals of ancient types.
The exact shape of the earth is another question which cannot be settled without fresh evidence from the Antarctic. For this purpose two at least of the expeditions have been provided with pendulum outfits; by noting the exact length of time occupied by the swing of a pendulum the distance of the place of observation from the earth's center can be determined. It is held that the south polar region projects further from the plane of the equator than does the north polar region; according to one estimate the south pole is slightly more than one hundredth further from the earth's center than the north pole.
The work of the expeditions includes researches in the physics of glacier ice, a subject in which Professor von Drygalski is an expert, on the distribution and spectroscopic phenomena of the Aurora; on the composition and movements of the atmosphere, and the currents of the Antarctic Seas.
If the explorers only have the success which they deserve their arduous and devoted labors will contribute materially toward the progress of many branches of science. In fact, as Sir John Murray assures us, 'the results of a successful Antarctic expedition would mark a great advance in the philosophy—apart from the mere facts—of terrestrial science.'