NATURE 



549 



THURSDAY, OCTOBER 6, 1904. 



THE NORTH POLAR SEAS. 

 The Norwegian North Polar Expedition, 1893-1896. 

 Scientific Results. Edited by Fridtjof Nansen. 

 Vol. iv. Published by the Fridtjof Nansen Fund 

 for the Advancement of Science. Pp. 232 ; 32 

 plates. (London : Longmans, Green and Co., 

 1904.) Price 21s. net. 



THE present volume, in continuation of those pre- 

 viously published,' contains three articles, 

 which may be noticed in sequence, although the con- 

 tribution by Dr. Nansen constitutes the principal 

 portion of the work. 



In article xi. H. H. Gran deals viiith " Dia- 

 tomacese from the Ice-floes and Plankton of the 

 Arctic Ocean." It is pointed out that the plankton 

 samples collected on previous expeditions to the 

 Polar seas contained a considerable quantity of 

 algce, especially diatoms ; whereas the samples 

 brought home by Nansen indicate that the deep 

 Polar Sea is deficient both in species and specimens. 

 When found in quantity, they were principally oceanic 

 diatoms; but the author remarks that it is difficult 

 to understand how all the crustaceans (Calantis 

 finmarchichus, &c.) that swarm in the upper portions 

 of the Polar Sea can find means of sustaining life. 

 The samples of diatoms taken upon the drift-ice, 

 partly upon the ice-floes and at their edge, partly 

 from channels in the ice, are of greater botanical 

 interest. Most of them must have lived and multi- 

 plied on the ice; others, including a few fresh-water 

 forms, were probably transported casually on to the 

 ice. At present little is known concerning the dis- 

 tribution of ice-diatoms, but the samples examined 

 indicate that those of North Siberia and East Green- 

 land are directly connected with one another ; and 

 the study of these organisms appears likely to prove 

 of value in determining the drift of the ice. 



In article xii. Johan Kiaer describes " The Lower 

 Silurian at Khabarova." Fossiliferous calcareous 

 slates were discovered by Nansen in 1893 on the 

 south side of Yugor Strait, near Khabarova, south- 

 west of the Yalmal peninsula. The fossils, though 

 badly preserved, could be identified as belonging to 

 the brachiopods Leptaena sericea, Orthis and Stropho- 

 mena ; and to the trilobites Asaphus, Megalaspis, 

 and Remopleurides. They indicate the zone of 

 Asaphus platyurus, which belongs to the middle part 

 of the Ordovician. 



In article xiii. Nansen contributes an elaborate 

 essay on " The Bathymetrical Features of the North 

 Polar Seas, with a Discussion of the Continental 

 Shelves and Previous Oscillations of the Shore-line." 

 This work, illustrated by 29 maps and profiles, em- 

 bodies the more important observations and conclu- 

 sions of the great explorer; and it will be of con- 

 siderable interest to geologists, as well as to 

 geographers, as some aspects of the subject have 

 been vigorously discussed by Prof. Hull, Dr. J. W. 

 Spencer, Mr. Hudleston, and Sir Archibald Geikie. 



^ Notices of previous volumeA appeared in Nature for June 14, 1900, 

 p. 146; June 13, 1901, p. 151 : and December 4, 1902, p. 97. 



NO. 1823, VOL. 70] 



As pointed out by the author, the general idea 

 prevailing before the expedition was that the North 

 Polar ocean, between Siberia and North America, 

 was a shallow sea, with a comparatively rapid de- 

 position of sediments carried into it by the Siberian 

 and American rivers, or brought from the coasts by 

 drifting ice. The expedition has shown that the sea 

 occupies a basin with depths approaching 4000 

 metres, and that at present there is no rapid deposi- 

 tion in it of sediments. Even the dust carried by the 

 winds, or otherwise derived from the atmosphere by 

 precipitation, settles on the floating ice, giving it a 

 dirty brown appearance, and is transported to 

 more southern latitudes, where the ice melts. 

 Proof has likewise been obtained that Franz Josef 

 Land is a group of comparatively small islands, and 

 that probably no extensive land-masses exist to the 

 north of the New Siberian Islands. The deep basin 

 appears to be separated from the Norwegian sea by 

 a shallow suboceanic ridge extending from Spits- 

 bergen to Greenland. 



As the Fram was heavily laden, Nansen had not 

 encumbered her with the equipment necessary for 

 sounding in very deep water. In the course of his 

 drift across the North Polar basin he soon dis- 

 covered that his arrangements for sounding were 

 insufficient, and new line had to be made from one of 

 the ship's thick steel-wire cables. Eventually, after 

 much arduous labour, a fairly good sounding line, 

 4450 metres long, was constructed. According to the 

 soundings thus made, and to those known from 

 other expeditions, a chart has been prepared to show 

 the bathymetrical conditions of the northern seas, 

 but much naturally remains to be done to delineate 

 in detail their submarine contours. The most strik- 

 ing feature in this region is the broad and shallow 

 continental shelf extending northwards from the 

 Eurasian continent, and on which are situated Bear 

 Island, Spitsbergen, Franz Josef Archipelago, and 

 Novaya Zemlya. Continued as it is along the American 

 borders, it forms the most extensive submarine shelf. 

 Davis Strait, with the deep Baffin Bay, and the 

 Norwegian sea with the deep depression of the 

 North Polar basin, form, with their many branches 

 {e.g. the Barents Sea), enormous fjords penetrat- 

 ing this platform. Soundings show that its depths 

 are, on the whole, very uniform. 



The Siberian continental shelf is regarded as a sub- 

 merged tract that was originally sculptured with 

 furrows which were the continuations of the sounds, 

 fjords, and valleys of the borderland. These depres- 

 sions may have been filled up by ground moraines 

 during the Glacial epoch, and also by the deposi- 

 tion of glacial sediments outside the margin of the 

 Siberian ice-sheet, as well as by comparatively recent 

 silting up by deposits from the rivers and shores. 

 Floating ice also assisted in the process. 



.'\fter describing the American Arctic continental 

 shelf, the author discusses the features of the 

 Barents, Murman, and Kara seas, in which he 

 infers evidence of sculpturing by subaerial agents, 

 fluviatile and glacial. It is interesting to read 

 (p. 28) that " the possibility exists that there has 



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