Page:Quarterly Journal of the Geological Society of London, vol. 33.djvu/184

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AHUND HELLAND ON THE FJOKDS, LAKES,

determine the thickness of this mass of Inland Ice. At Ilartdlek the surface of the ice, some thousand metres from the end of the glaciers, has an elevation of 251 metres. The ice itself prevents us from seeing how much the bed of the valley beneath the glacier has risen ; but if there is not a basin below, this can hardly be less than 50 metres above the sea; hence the thickness of the Inland Ice near its border cannot exceed 250 metres, and is probably not more or is even less than 200 metres ; but since its surface rises as we pro- ceed inland, its thickness may possibly increase in that direction.

As the interior of Greenland has been so little visited, not much is known of the limits of this vast ice-field, those on the west, nearest to the inhabited outer land, are best known. Here the accounts of the old Norwegians, the Esquimaux, and modern travellers agree that the Inland Ice is everywhere found in going eastwards ; so we may take it as settled that its western border extends continuously from the northern colonies to the district of Julianehaab. It is evident that the Inland Ice will also be found by ascending the fjords westward from the east coast, because of the abundance of icebergs in this neighbourhood. Captain Graah * states that these are innumerable near the coast at all times. Kaiser Franz- Joseph's Fjord in 73° NT. lat., discovered by the second German Polar Expedition, is an ice fjord giving rise to bergs above 200 feet high ; these can only be produced by a great inland ice-field. From such observations, then, we may assume that the Inland Ice feeding the glaciers on the west coast is continuous with that from which the bergs on the east coast are derived.

The existence of this ice-sheet is, indeed, an assumption, as no one yet has travelled across Greenland; but it is in accordance with the few observations that have been made ; and the existence of an ice-free district in Inner Greenland would require that its physical features should be very peculiar and exceptional f.

The amount of precipitation in North Greenland seems to indicate indirectly the great extent of the Inland Ice ; for where the glaciers are largest, it is not considerable ; at the colony of Jakobshavn the rainfall from July 1873 to July 1874 was 219*7 mm., from July 1874 to July 1875, 183*7 mm. In the district of Umanak, where there are a number of great ice-fjords, the rainfall seems to be no greater; yet here the glaciers are very large, one may say, the largest known ; so that we can only account for them by supposing that they are supplied from a very extensive upland district on which there is a considerable snowfall, and thus that there can be little land in the interior free from ice. Be this as it may, there is no doubt that the ice-sheet extends into Greenland beyond the range of vision.

As the interior of the country is unknown, so is the configuration of the ground beneath the ice ; still it may be possible to obtain from analogy an idea of this. Even in the writings of some of the most modern Arctic travellers we find the idea expressed that all Green-


 * Undersogelses Reise til Ostkysten af Gronland.

t See Dr. Rink's ' Om Gh*onlands Inclre.' Fra Videnskabens Verclen, 2den Rsekk. No. 9.