Page:Scott's Last Expedition, Volume 1.djvu/77

1910] encountering worse conditions than any ship has had before—worse, in fact, than I imagined would have been possible on any other meridian of those from which we could have chosen.

'To understand the difficulty of the position you must appreciate what the pack is and how little is known of its movements.

'The pack in this part of the world consists (1) of the ice which has formed over the sea on the fringe of the Antarctic continent during the last winter; (2) of very heavy old ice floes which have broken out of bays and inlets during the previous summer, but have not had time to get north before the winter set in; (3) of comparatively heavy ice formed over the Ross Sea early in the last winter; and (4) of comparatively thin ice which has formed over parts of the Ross Sea in middle or towards the end of the last winter.

'Undoubtedly throughout the winter all ice-sheets move and twist, tear apart and press up into ridges, and thousands of bergs charge through these sheets, raising hummocks and lines of pressure and mixing things up; then of course where such rents are made in the winter the sea freezes again, forming a newer and thinner sheet.

'With the coming of summer the northern edge of the sheet decays and the heavy ocean swell penetrates it, gradually breaking it into smaller and smaller fragments. Then the whole body moves to the north and the swell of the Ross Sea attacks the southern edge of the pack.