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: