Antarctica and Some of Its Problems Author(s): T. W. Edgeworth David Source: The Geographical Journal, Vol. 43, No. 6 (Jun., 1914), pp. 605-627 Published by: geographicalj Stable URL: http://www.jstor.org/stable/1779145 Accessed: 03-06-2016 21:59 UTC Your use of the JSTOR archive indicates your acceptance of the Terms & Conditions of Use, available at http://about.jstor.org/terms JSTOR is a not-for-profit service that helps scholars, researchers, and students discover, use, and build upon a wide range of content in a trusted digital archive. We use information technology and tools to increase productivity and facilitate new forms of scholarship. For more information about JSTOR, please contact [email protected]. The Royal Geographical Society (with the Institute of British Geographers), Wiley are collaborating with JSTOR to digitize, preserve and extend access to The Geographical Journal This content downloaded from 132.77.150.148 on Fri, 03 Jun 2016 21:59:03 UTC All use subject to http://about.jstor.org/terms The Geographical Journal. No. 6. JUN1, 1914. Vol. XLIII. ANTARCTICA AND SOME OF ITS PROBLEMS.* By Prof. T. W. EDGEWORTH DAVID, O.M.G., F.R.S. I. Physiogbaphy. Area and Relief?The area of Antarctica has been estimated by Dr. W. S. Bruce at over five million square miles. Its mean altitude is perhaps the greatest of any of the continents. This has been roughly calculated at about 6000 feet, including in this altitude its icy eovering. If this were removed, the mean altitude would be much reduced, by perhaps from 1000 to 2000 feet. Coast-line.?With omission of minor indentations, and with inclusion of the seaward boundary of thick, fast ice on the coast-line, this measures no less than about 14,000 miles in length. Of this only about 4000 miles have been even approximately explored, and only about 2500 miles in very moderate detail. With the exception of the 2500 miles charted, mostly in rough detail, very little is known about the actual boundary between land and sea ice for no less a distance than about 11,500 miles. The difficulty of defining this unknown boundary by oceanographic survey alone, unsupported by inland sledging parties, arises from the fact that old pack ice, ancient fast bay ice, " schollen-eis " (formed of fleets of grounded bergs with the intervening spaces levelled up with drift snow), coastal ice of the nature of piedmont ice aground or afloat, together with large glacier tongues, fend off ships so far from the true rock coast, that the latter, unless it is formed of high bare rock, is invisible from a'ship. Also over large areas of the coast-line there is a more or less gradual ascent from the coastal shelf ice to the inland ice without any bare rock whatever showrng at the surface, to indicate where the ice leaves the sea and is * Royal Geographical Society, January 15, 1914. No. Yt?Jum, 1914.] v 2 rj This content downloaded from 132.77.150.148 on Fri, 03 Jun 2016 21:59:03 UTC All use subject to http://about.jstor.org/terms 606 ANTARCTICA AND SOME OF ITS PROBLEMS. resting on land. Moreover, it is very easy to mistake, in the distance, grounded bergs for table-shaped mountains. As an instance of the distance to which glaciers from inland spread seawards from the coast-line before they break off and form bergs, it may be mentioned that Wild, of Mawson's Australasian Antarctic Ex? pedition, found that in Queen Mary Land the Watson glacier projects for considerably over 120 miles into the sea. The Ross barrier extends at a maximum about 400 miles seawards of the true rock coast at its apex. Such portions of the Antarctic coast as are moderately well known may be divided (1) into more or less high rock coasts, of the nature partly of riickland, partly of rias coasts, with, in the case of East Graham Land, some foreland coast; (2) coasts with occasional nunataks rising above the general level of the inland ice, which may be termed nunatak coast; and (3) an ice coast. The last mentioned might be subdivided according to the nature of the ice, forming it into (a) land barrier ice, where the ice forms a sea cliff resting on a rock foundation; and (b) shelf ice, where the ice projects some distance from the shore seawards. The latter ice might be further subdivided, according to its mode of origin, into (i.) old bay ice, where it represents sea ice thickened by many years' growth; and (ii.) piedmont ice, either aground or afloat, formed through land ice advancing seawards for a greater or less distance beyond the true coast-line. Of these three principal types of coast about 2500 miles are rock coast, about 1000 miles are known to be nunatak coast, but undoubtedly this type of coast will be found later to be far vaster in extent than the above-known distance.* The remainder of the coast, whose proportion to types (1) and (2) is as yet unknown, cannot exceed about 10,500 miles in total length. This third type of coast, whose boundary varies with the winds, ocean currents, tides, seasonal and secular variations in temperature, snowfall, etc, is the most characteristic feature of the Antarctic coast. It is, of course, a false coast in relation to the true outline of the land, and in the case of the Ross barrier, the Weddell barrier, and the Great ice-flelds of New South Greenland is some hundreds of miles in advance of the true coast. It is quite worthy of some distinctive name such as the Cryoihis^ or if the meaning of the term " shelf " can be extended to include old pack ice, old bay ice, " schollen-eis," piedmonts aground or afloat, glacier tongues, etc, it may be termed the ice shelf coast, or, as it is hardly a true coast at all, simply ice shelf. In the Ross sea region the rock coast, for the 1400 miles already known, is of Atlantic type.J It is a tectonic coast bounded by stupendous fractures all along the western shores of Ross sea, with several subordinate cross fractures. * Dr. Mawson's surveys, with those of Captain J. K. Davis of Mawson's ship Aurora, will have probably added 1300 miles to the known Antarctic coast. t Kpv6s, ice, and dls, a shore or beach. % Prof. Gregory has proposed to class it as of ?eeondary Pacific type. This content downloaded from 132.77.150.148 on Fri, 03 Jun 2016 21:59:03 UTC All use subject to http://about.jstor.org/terms ANTAECTICA AND SOME OF ITS PEOBLEMS. 607 Within 10 miles back from the coast the land in places rises to elevations of no less than 8000 feet, but usually there is a coastal platform, formed of rock and sub-glacial debris, from 10 to 20 miles wide, and joining, at SKETCH MAP SHOWING PROBABLE PETROGRAPHIO ZONE OF ANDES AND THE POSSIBLE FRAOTURE VIRGATION OF THE ANDEAN ZONE TO JOIN THE ANTARCTIC HORST. 180 tAniipades I? MJaucqiMrw, I mawson's 15 , -^ Adelie ^ng/Georgeyi/and A, i^L. J^OatesLahd South Magnebif ^ /feioxLand ?le \0 Area Jueen Maryliaiid WILO 1913^ \ iserT^lhelmll ?,/ \ O r Carmen * " / Landl <% ? 0 ^-- fl2(J SOUTli FOIjE / .o C /ce streams /^ ?? 0 feeding barrierpf &? Weddell seaX^o ^FILCHNER ^ / / "^. iiod SOiarcdtljaiid ^ .Mle^biderl^JL^ :South ^V Shetlandl? South OrknejI- .'Sandwieh .,. GrouP\ FalMandl^' **? South Georgia 4sO "~ Scale 1:60.000.000 orlIneli = 947 StatMles &00 O 50O 1O00 > i ? i ??I I-=^?r^=J WlQr. 1, 2 TJ 2 This content downloaded from 132.77.150.148 on Fri, 03 Jun 2016 21:59:03 UTC All use subject to http://about.jstor.org/terms 608 ANTARCTICA AND SOME OF ITS PROBLEMS. that distance inland, the steep face of the block-faulted range of the Antarctic Horst. In places, as at Cape Adare, Cape Washington, etc, this Atlantic coast is bounded by clifis of marine erosion, several hundreds of feet high. In West Antarctica, in the area from Charcot Land through Graham Land to Terre Louis Philippe, the coast with its tuffaceous Jurassic strata at Hope bay, somewhat overfolded towards the east, its granodiorites and andesite-producing volcanoes, such as Deception Island, etc, its archi- pelago of the South Shetlands, and its foreland of marine Cretaceous, and partly marine, partly freshwater strata at Snow Hill, Seymour, and James Ross islands, with extensive sheets of basaltic lava and tufi, recalls the geological structure of Patagonia, and of the Chonos and Madre de Dios archipelagoes. We hardly know sufficient yet of the rock coast from Hope bay to King Oscar II. Land and Foyn Land, and its relation to New South Greenland, to be able to classify it definitely. In regard to New South Greenland, discovered by Johnson in 1822, and seen by Morrell in 1823, there is still some doubt whether it exists. But it must be remembered that Ross, that most accurate of navigators, reported an appearance of land in this direction further to the north, and that the soundings taken by Lieut. Filchner in the Deutschland show a distinct shallowing of the ocean floor in the direction of Morell Land ; and R. C. Mossman has pointed out that the direction of the winds on the western side of Weddell sea is very suggestive of the existence of land in New South Greenland. Morrell, when he sighted the land to the south, at a considerable distance, was in lat. 68? 52' S., long. 48? 11' W. Filchner's sledge journey over the sea ice in this direction was, perhaps, not far enough to crucially test MorrelPs statement, as at the end of the journey Filchner was still at least 60 or 70 miles to the east of where Morrell stated that he sighted land.