Page:Quarterly Journal of the Geological Society of London, vol. 26.djvu/929

 equivalent of the bergs) are detached, as the attraction of gravity overcomes the cohesiveness of the ice. These have been seen and described by Dr. Kane on many parts of the Arctic coast. I noticed them in the shape of "miniature glaciers between the cliffs" (Trans. Bot. Soc. ix. 13) at Sakkak, lat. 70° 0' 28" N., and on the Waygatz shore of Disco Island. In this latter locality they were the overflow of the inland ice of the island. They are also seen in the little local glaciers, where the bed they move in is shallow, and the seaward or outward end high, as near Omenak, where, however, I did not see them, but depend for my information on intelligent Danish officers resident in that section. In Alpine regions away from the coast, the glacier, as it pushes its way down into warmer regions, either advances or retreats according to the heat of the summer ; but in either case it gives off no great masses of ice from its inferior extremity. The same is true of the Arctic glacier when it protrudes into some mossy valley without reaching the sea ; but when it reaches the sea another force comes into operation. We have seen (1) the inland ice-field emptied by (2) the glacier ; we now see the glacier relieving itself by means of (3) the iceberg or " ice mountain," as the word means.

3. The Iceberg. — When the glacier reaches the sea (fig. 1, e) it grooves its way along the bottom under the water for a considerable distance ; indeed it might do so for a long way did not the buoyant action of the sea stop it. For instance, in one locality in South Greenland, in about 62° 32' N. lat., between Fredrikshaab and Fiskernaesset, or a little north of the Eskimo fishing-station of Avigait, and south of another village called Tekkisok, is a remarkable instance of this. Here the " Iisblink," or the " ice glance," of the Danes (i. e. the projecting glacier — though English seamen use the word iceblink in a totally different sense, meaning thereby the " loom " of ice at a distance), projects bodily out to sea for more than a mile. The bottom appears to be so shallow that the sea has no effect in raising it up ; and the breadth of the glacier itself is so considerable as to form a stout breakwater to the force of the waves. It was long supposed that the iceberg broke off from the glacier by the mere force of gravity ; this is not so. It is forced off from the parent glacier by the buoyant action of the sea from beneath. The ice groans and creaks ; then there is a crashing, then a roar like the discharge of a park of artillery ; and with a monstrous regurgitation of waves, felt far from the scene of disturbance, the iceberg is launched into life. The breeze which blows out from the land, generally for several hours every day, seems, according to my observation, to have the effect of blowing the bergs out to sea ; and then they may be seen sailing majestically along in long lines out of the ice-fjords. Often, however, isolated bergs or groups of bergs will float away south or north. Bergs from the ice-streams of Baffin's Bay will be found in the southern reaches of Davis Straits, while others, bearing debris which could only have been accumulated in South Greenland, will be found frozen in the floes of Melville Bay, or Lancaster Sound. It is a common mistake,

VOL. XXVI. — PART I. 3d