HYDROGRAPHY. 17 



At a depth of 10 meters a temperature of + 2. 3° 0. is found and at 25 meters only 

 + 0.6°. Near the Commander Islands, with the same surface temperature of + 9° C, 

 + 7.1°, was found at 25 meters and + 4.3° at 50 meters. We have here absolutely 

 the same phenomenon as in the Japan Sea, viz, that the cold water predominates in 

 the lower beds of the western portion of the sea. The identical phenomenon has been 

 observed in the Okhotsk Sea and the Straits of Tartary. 



The bathymetric observations in Bering Sea, at stations Nos. 108, 109, 110, and 

 113, have established another peculiarity of this sea, viz, the presence in the deeper 

 portions of warm water of high salinity. Near the coast of Kamchatka the increase 

 in temperature is shown as follows : At station No. 108, from 0° 0. at 200 meters to 

 + 3.50 0. at 400 meters; at station 109, from + 0.6° C. at 150 meters to + 2.6° C. 

 at 175 meters and + 3.7° C. at 200 meters; at station 110, in longitude 165° 56' E., at 

 a depth of 100 meters a temperature of + 2© C. was found, and at 150 meters and 

 below, + 3.90 C. The details are shown in the accompanying diagram (pi. 90). 



These temperatures prove to us that the bed of warm water of great specific 

 gravity is found nearer the surface at the Commander Islands than along the coast of 

 Kamchatka. A similar phenomenon has also been observed in the Okhotsk Sea. In 

 other words, the cold and less saline water in descending from north to south 

 approaches the coast toward the western side of the sea and forces the warm water of 

 high salinity to a greater depth. 



Plate 90 shows a section of Bering Se^/ from the coasts of Kamchatka to the 

 Commander Islands. The cold water here occupies an intermediate bed between 

 the surface and a depth of 250 meters. As in the Okhotsk Sea, the bed thickens 

 toward the mainland coast and tapers off as it recedes from it. It wiU also be seen that 

 this cold water, with a temperature lower than 0° C, has a specific gravity of 1.0252 to 

 1.0251. Where does this water come from? Makarof concludes that as it can not 

 come from the Pacific Ocean, which has no such temperature, it must descend from 

 the surface. Since the surface water has a specific gravity of only about 1.0250, he 

 suggests that the great salinity of this surface water is due to freezing in winter. As 

 to the route this water follows, he believes that, as indicated by the temperatures 

 observed by the Tuscarora, it advances from the southwest along the coast of Kam- 

 chatka and consequently also along the Kuril Islands. 



The surface temperatures of the western portion of Bering Sea are indicated on 

 plate 89, showing the existence of two cold zones, viz, one near Capes Tchaplin and 

 Tchnkotski, the other between Capes Navarin and St. Thaddeus. Everywhere else 

 the cold water occupies the western part of Bering Sea and the warm water its eastern 

 portion. In the other places the distribution of the temperature is pretty regular; 

 it decreases gradually toward the north. The temperature near Petropaulski is 

 11° C, and near the island of St. Lawrence about 8° C, i. e., the mean temperature 

 of August. 



Fragmentary as is our knowledge of the waters themselves in the western portion 

 of Bering Sea, the bottom of the sea over which they flow is hardly better known. In 

 fact until the U. S. Fish Commission steamer Albatross ran the four lines of deep-sea 

 soundings in 1892, 1895, and 1896, the shape and nature of the bottom were even less 

 known. The Eussian and English men-of-war patroling the seas around the islands 

 have' of late years added a number of soundings at 100 fathoms and under, so that it 

 has been possible on the appended map (pi. 87) to trace the 100-fathom line with some 

 15183, PT 4 2 



