Title: The continent we live on
Identifier: continentweliveo00sandrich (find matches)
Year: 1961 (1960s)
Authors: Sanderson, Ivan Terence, 1911-1973
Subjects: Physical geography; Natural history
Publisher: New York : Random House
Contributing Library: New College of California
Digitizing Sponsor: Internet Archive

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This polar bear with tzvin cubs on a rotting will swim back to shore or to the ice front. berg may drifted for hundreds of tnilc tumbled ice, the whole world seems to be floodlighted with ten million colored arcs for twenty-four hours a day. never quite the same but never going away, and all often cast upon a backdrop of dark rocks and sculptured ice. THE POLAR ICE RAFT Even the Arctic ice raft itself is not. despite its somewhat deplor- able appearance at first, a complete waste. It is a great cap of sea ice. very slightly curved to fit the earth, varying in thickness from a few feet to—as the submarines which have now traveled under it have shown—some four hundred feet, and compounded of frozen sea surface and snow that has fallen upon the surface of the ice and compacted. It is a thousand miles wide measured from the top of the Atlantic via the Pole to the Pacific, but only six hundred miles wide measured at right angles to that line. The extra mass lies on the Pacific side, north of Siberia and Alaska. It is not homogeneous, for there is ice of various origins and ages in its composition, and it contains some vast rafts of what are called palaeocrystic ice. These behave like huge float- ing islands and are very ancient; they may even be relics of an ice raft formed before this great sea unfroze the last time—this it may have done, according to some climatologists. in immedi- ately prehistoric times. Some of these ice islands are today used as permanent bases and landing fields for aircraft. Held in the thinner, newer ice. they drift slowly round the pole. The polar ice raft as a whole is not. however, permanent. It is continuously being added to on top and melting away below; and it is aug- mented all around its edge by sea-formed pack ice. It has holes in it that open and close hither and yon. and its various parts move reciprocally about among themselves so that ships caught in it may wander in all directions, their courses leaving extraor- dinary patterns on a chart. As a whole, it revolves slowly rela- tive to the adjoining land, due to being unable to quite keep up with the spin of the earth, so that its edge moves from east to west as looked at from the south. The polar pack ice lies right against the upper edge of this continent. One would have thought, therefore, that these shores would also be profoundly icebound and snow-covered. Very surprisingly, this is not the case; the Cape Maurice Jesup area at the northern tip of Greenland is not glaciated at all. Even in winter comparatively little snow falls there and this usually melts off quite fast. In summer it is an almost lush land with a 13

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