GEOGRAPHICAL SKETCH OF JAPAN 5 



to tlie west, it extends over a large area of water, estimated at about 

 1,043,820, sq. km. It is quite open with a few islands in the midst 

 and is very deep in its northern half, where the depths of most 

 places on the line drawn between the mouth of the Eiver Tumen and 

 the Tsugaru Strait exceed 3,000 metres, and reach a maximum depth 

 of 3,712 metres. 



The southern half of the sea is less deep, having the so-called. 

 Yamato Bank in the centre, which is joined by a submarine ridge 

 with the coast of Honshu. The northern end of this sea is connected 

 by the Gulf of Tartary and the Strait of Mamiya with the Sea of 

 Okhotsk. This passage is very narrow and shallow. It is only eight 

 kilometres wide, and is totally frozen when winters come. Then the 

 island of Sakhalin is solidly tied to the continent with ice. The 

 mails are carried on sledges across the strait, and similarly tie freez- 

 ing of the strait admits of the free migration of land animals between 

 the continent and the island. The Sea of Okhotsk, which is enclosed 

 by the island chain of Chishima and the Kamchatka Peninsula to the 

 east, is likewise an open depression with a remarkable depth of over 

 3,000 metres. The deepest sounding, obtained to the north of Nemuro, 

 is 3,374 metres. 



In contrast to the seas just mentioned, the China Sea is merely 

 a stretch of shallow water on a great continental shelf, along the edge 

 of which runs the Eyukyu arc. Special attention may be asked for 

 the existence of a trench along the inside of the said arc, with an 

 average depth exceeding 2,000 metres and a maximum depth of 2,681 

 metres. The China Sea is connected with the Sea of Japan by Korea 

 Strait, which is divided into two passages by the island of Tsushima 

 lying in the channel. 



The southeastern coast of the archipelago is washed by the warm 

 Japan current. This stream is commonly called the Kuroshiwo, or 

 "Black current," on account of its remarkable dark blue tint. Tsushima 

 current, a branch of it, enters the Sea of Japan and affords moisture 

 and warmth to the northwestern coast of Honshu. It is indeed an 

 astonishing fact that an enormous amount of snow falls, at least one 

 metre on the coastal plain and sometimes more than three metres on the 

 slopes of those mountains which form barriers against the moisture-carrying 

 northwest monsoon of winter. The northeastern coast of the archipelago 

 is washed by the cold Chishima current or Oyashiwo, which is pale 

 green in contrast to the dark color of the former. In the sea near 



