ANTARCTICA

the antarctic regions may be generally defined as that portion of the globe which lies within the 6oth parallel of south latitude, and for purposes of reference it is now customary to divide it into four quadrants of go° which, reckoning eastwards from the meridian of greenwich, are named the enderby, victoria, ross and weddell quadrants. a less precise division into sectors referred to the contiguous continents is perhaps more useful to the general reader; and the african, australian and american sectors denote the portion of the regions to the south of those continents respectively. the 60th parallel passes through no land whatever, but it does in fact roughly coincide with the northern limit of a belt of floating ice which surrounds the regions and forms an efficient barrier to a ship’s progress except in the late summer and autumn. it therefore includes nothing which does not share in the general characteristics of these polar regions, though it does exclude the south georgia and south sandwich groups of islands in the southern atlantic which are definitely antarctic in character. contrust between northern and southern regions.—in con- sidering this parallel as a boundary we are at once impressed with a marked contrast between the amenities of the northern and southern polar regions. within the area poleward of 60° north latitude live more than 1,000,000 human inhabitants and countless land animals. some of the largest and most valuable timber forests are north of 60°, and not a few industries connected with lumber, mining and fishing flourish. in the similar area in the southern hemisphere, there is not a single permanent human inhabitant, nor a single land animal larger than an insect. there are no trees and very few plants of any kind at all. the sole industry which can be said to exist in the antarctic regions is that of whaling, which is now carried on during a few months in each year in the american and australian sectors. the reasons for this contrast naturally depends largely upon temperature. the explorations of the 2zoth century have shown us that the south polar region, again in complete contrast to the north, is largely occupied by a continent of more than 5,000,000 sq. m. in extent, that is to say, equivalent in size to australia and europe ww ithout russia. the south pole is placed centrally in this con- tinent, which, though far from being symmetrical, may for gen- eral purposes be considered as bounded by the voth parallel, characteristics of antarctica —the most noticeable feature about the continent is its unique isolation. it is possible to trav- erse all the other continents without crossing more than about 60 m. of shallow sea, but to reach the antarctic continent one must voyage over at least 600 m. of practically oceanic depths and that across the roughest seas and fiercest winds in the world. between 55° and 65° south latitude there is no land to interfere with the west to east circulation of sea and air, and that zone is therefore the home of the permanent west winds, the westerly drift and the wandering albatross, all of which encircle the ant- arctic continent ceaselessly. there are, in short, none of the inter- changes of warm and cold air and w ater between temperate and polar regions which in the northern hemisphere lead to such curious anomalies as an almost ice free spitsbergen in 79° n. and an almost icebound labrador coast 20° farther south. in this fact, therefore, we have an almost complete explana- animals—antarctica tion of the strange contrasts in climate, and consequently in habitability, between the opposite polar regions, and the re- mainder of the explanation is forthcoming when we consider the relicf of this vast deserted continent. the south pole itself is situated on a plateau nearly 10,000 ft. in height, and there is every reason to suspect that the greater part of the continent is continuous plateau. allowing for the incomplete nature of the data we can with some fairness compute the average height of the continent as of the order of 6,000 ft., which is just twice as high as asia, the next in order of magnitude. when we add to this conception of a high and isolated conti- nent the fact that, of its 5,000,000 sq. m. probably less than 100 sq. m. is free from a permanent covering of ice we can well un- derstand that here there is no attraction for man or beast or plant. we have further to conceive of a climate in which, south of 70°, it never rains and rarely thaws, except in the neighbour- hood of exposed rocks, where in fact any land animal would have to lead the life led by the two or three minute insects so far dis- covered, consisting of an active life of some few days in the height of summer followed by some 360 days of hibernation, frozen solidly in the rock pool or clump of moss which is its home. the continent is thus in the grip of an ice age, more rigorous than that which has left its marks upon europe and north america, and naturally the study of such a region resolves itself largely into a study of its manifold ice forms. of these the least known and the most impressive is the ice- cap, whose lateral dimensions are those of the continent itself and which supplies the myriad glaciers which everywhere fringe the coast, sometimes in ice-worn valleys, but more often as a con- tinuous glacier-front running down into the sea for hundreds of miles along the coasts. the thickness of the inland ice is probably not so great as its extent would suggest. no direct measure- ments have been made, but from an examination of the outlet glaciers it appears unlikely that the sheet is ever more than 2,000 ft. thick except in basins, and in general is much thinner, a con- clusion which is confirmed by the fact that many hundreds of miles inland from the coast the ice sheet appears to follow closely the form of the underlying ground. the barrier —the general features of the antarctic ice-cap are reproduced on a smaller scale in greenland, but the floating ice sheets which are to some extent derivatives of the ice-cap are met with nowhere else in the world. when ross in 1841 first penetrated the pack ice into the ice-free ross sea he sailed due south until he was brought up in about 77° south by an ice wall from 50 to 200 ft. high, barring his way to the south. he sailed along the greater part of its 400 m. seaward face. he called it the barrier and the name has remained though it is sometimes re- placed by the name shelf-ice. the ross barrier, as it is now called, is the greatest of these floating ice sheets, but is typical of many others to be met with in the antarctic. it is roughly the size of france and consists of a sheet of ice varying from 500 to i,500 ft. in thickness, the outer end being open to the ocean and the inner end held fast to the continent by the glaciers which act as feeders and by being aground close to the actual coast. its surface is smooth, and it forms the easiest approach to the pole itself, since it reaches to within 30 m. of that spot. it is formed by the snow of countless ages collecting, 1t may be, upon an originally thin crust of sea ice, and it moves at a fapid rate, up to 1,500 yd. in a year, asa result of its own tendency to spread. ‘there is reason to suppose that in some places it also in- creases by freezing from below. the tabular icebergs so typical of the southern hemisphere, with their flat tops and stratified appearance are obviously derived from this and similar barriers, and their immense size, up to 30 m. in length of side, is only natural considering the size of the parent masses. each summer, when the break up of the winter sea ice has allowed the full force of the ocean swell to reach the face of the barriers, large frag- ments are broken off, or “ calved,” and these float away to the northward until they reach warmer and stormier waters where they disintegrate into low but massive pieces known as “ growl- ers,” which are the terror of the ship-master sailing those lati- tudes in the winter. anthropology sea ice.—the sea ice itself is comparatively temporary. it begins to form in sheltered bavs as early as the end of jan. and by the beginning of march any ship is liable to be frozen in unless its harbour is a windy one. there are probably large variations from year to year in the area of sea solidly frozen over, since a strong wind, and such are very frequent, will prevent sea ice forming, or will blow out any which is not of considerable thick- ness, but in sheltered bays the ice will continue to increase in thickness until oct. or nov., by which time it will be anything up to seven feet through. this will begin to break up and float northward from the beginning of dec. onwards, but the inner- most bays may not lose their ice until late in feb., or occasionally not at all for two years in succession. the belt of drifting pack ice which rings the continent is made up of the ice from this summer break-up and it is least dense in autumn after the sum- mer heat has caused a great deal of it to melt. the continent.—the continent, thus hidden or protected, is formed for the most part of old rocks amongst which the most prominent are of permo-carboniferous age and bear coal, which is found in the australian sector up to within 300 m. of the pole. in this sector the rocks have been above sea level since palaeozoic times, except where the ross sea area has broken and sunk below it, giving rise to a series of volcanic centres, of which the largest, the ross island group, still has an active volcano, mount erebus, 13,000 ft. high. on the south american side, however, there has been no wholesale sinking of the crust, but the rocks have been folded into mountains similar in origin to the andean chain. the coal which has been found is of doubtful quality, and on account of the small area of bare rock to be seen it is ex- ceedingly improbable that any other minerals of value will ever be discovered. producis of the continent —since there are no land animals or plants the resources of the region are limited to the products of the sea. of these the most striking are the various species of penguins, which inhabit all zones of the region. fortunately for the preservation of such harmless and delightful birds their blubber coated skins do not possess a marketable value. the seals also, not being of the fur bearing kind, are more or less im- mune from human exploitation. there remain the whales, which in large numbers frequent antarctic seas to feed on the minute animals there to be found which in their turn ultimately depend for their food upon diatoms, the typical marine plants of the region, microscopic in size but so countless in number as to colour the sea ice. the rorqual, the humpback and the huge blue whale are now all hunted in these seas by modern methods and the annual value of the products obtained exceeds £2,000,000 sterling. (see wilales.) until the rise of the whaling industry the antarctic can be said to have had no political significance whatever, but since the beginning of the century the territorial waters of the continent, if not the land itself, have acquired a value and, as will be seen from the map, two sectors are now portions of the british empire and are known as the ross dependency, administered by new zea- land, and the falkland islands dependency administered by the govt. of the falkland islands. (see also potar exploration.) bibltiography.—h, r. mill, the siege of the south pole (1905); r. f. scott, the voyage of the discovery (1905); sir e. shackleton, the heart of the antarctic (1909); r. f. scott, scoti’s last expedition (1913); sir d. manson, the itome of the blizzard (1915). (f. d.)