The North Pole - Robert E. Peary (e book reader pdf .txt) 📗

Owing to the comparatively short distance between Cape Bryant and Cape Morris Jesup, it is probable that at the latter point the crest of the wave transmitted from the southwest will appear to arrive much earlier than will the crest of the wave passing between Spitzbergen Islands and Greenland. In this way the small size of the semidaily tide at Cape Morris Jesup, as well as its time of occurrence, can be partially explained.

A no-tide point doubtless exists in Lincoln Sea, off Peary Land.

The semidiurnal tidal forces vanish at the Pole and are very small over the entire Arctic Ocean. As a consequence the semidiurnal portion of the tide wave in these regions is almost wholly derived from the tides in the Atlantic Ocean. The diurnal forces attain a maximum at the Pole and produce sensible tides in the deeper waters of the Arctic Ocean. Such tides are essentially equilibrium tides for this nearly enclosed body of water. The diurnal portion of the Baffin Bay tide produces the diurnal portion of the tide in Smith Sound, Kane Basin, and Kennedy Channel. In passing from Fort Conger to the Arctic Ocean one could reasonably expect to find a great change in the time of occurrence of the diurnal tide in going a comparatively short distance; in other words the change in the tidal hour for the diurnal wave would probably be considerable where the Baffin Bay tide joins the arctic tide.

Peary's observations show that such is the case. They show that the diurnal tide at Cape Bryant, Cape Sheridan, Point Aldrich, and Cape Morris Jesup follows that at Fort Conger by respective intervals of 3½, 5, 6, and 8 hours. They also show that in going northward from Fort Conger to Point Aldrich the ratio of the two principal diurnal constituents approximates more and more nearly to the theoretical ratio; that is, to the ratio between the two corresponding tidal forces. This is what one would expect to find in passing from a region possessing diurnal tides derived from the irregular tides of Baffin Bay to a region where the equilibrium diurnal tides of the Arctic become important.

The range and time of occurrence of the diurnal tide at Point Aldrich do not differ greatly from their equilibrium values based upon the assumption of a deep polar basin extending from Grant Land and the Arctic Archipelago to the marginal waters off the portion of the coast of Siberia lying east of the New Siberian Islands. But De Long's party observed tides at Bennett Island in 1881. From these observations it is seen that the diurnal tide has a much smaller range than would be permissible under the hypothesis of deep water in the portion of the Arctic Basin just referred to. The diurnal tides at Pitlekaj, Point Barrow, and Flaxman Island are, as noted below, also too small to permit of this hypothesis. The smallness of the diurnal tide in the cases cited can probably be explained on no other assumption than that of obstructing land masses extending over a considerable portion of the unknown region of the Arctic Ocean.

No further attempt will be made here to prove the necessity for a tract of land, an archipelago, or an area of very shallow water situated between the present Arctic Archipelago and Siberia. A brief discussion of this question, together with a tidal map of the Arctic Regions, will be found in a paper about to be issued by the Coast and Geodetic Survey and which has been already referred to. A few pertinent facts may, however, be mentioned.

(1) At Point Barrow, Alaska, the flood stream comes from the west and not from the north, as the hypothesis of an extensive, deep polar basin implies.

(2) The semidaily range of tide at Bennett Island is 2.5 feet, while it is only 0.4 foot at Point Barrow and 0.5 foot at Flaxman Island, Alaska. This indicates that obstructing land masses lie between the deep basin or channel traversed by the Fram and the northern coast of Alaska.

(3) The observed tidal hours and ranges of tide show that the semidaily tide is not propagated from the Greenland Sea to the Alaskan coast directly across a deep and uninterrupted polar basin.

(4) The observed ranges of the diurnal tides at Teplitz Bay, Franz Josef Land; at Pitlekaj, northeastern Siberia; and at Point Barrow and Flaxman Island have less than one-half of their theoretical equilibrium values based upon the assumption of an uninterrupted and deep polar basin.

In addition to these facts are the following items which have a bearing upon the shape and size of this unknown land:

The westerly drifting of the Jeannette.

The westerly drifting north of Alaska observed by Mikkelsen and Leffingwell.

The existence of Crocker Land.

The shoaling indicated by a sounding of 310 fathoms taken in Lat. 85° 23´ N.

The eastward progression of the tide wave along the northern coast of Grant Land as shown by observations at Point Aldrich, Cape Sheridan, and Cape Bryant.

The great age of the ice found in Beaufort Sea.

Items of some importance in this connection, but which cannot be regarded as established facts are:

The probable westerly courses taken by casks set adrift off Point Barrow and off Cape Bathurst, the one recovered on the northeastern coast of Iceland, the other on the northern coast of Norway;

The question suggested by Harrison whether or not enough ice escapes from the Arctic to account for the quantity which must be formed there if one were to adopt the assumption of an unobstructed polar basin.

Taking various facts into consideration, it would seem that an obstruction (land, islands, or shoals) containing nearly half a million square statute miles probably exists. That one corner lies north of Bennett Island; another, north of Point Barrow; another, near Banks Land and Prince Patrick Island; and another, at or near Crocker Land.

Meteorology.—Regular hourly observations of the thermometer and barometer were carried on day and night by the tide observers.

A brief résumé of the results obtained is given below, together with a few taken from the Report of the Proceedings of the U. S. Expedition to Lady Franklin Bay by Lieutenant (now General) A. W. Greely.