T h e   l a s t   G l a c i a l    E p o c h . The world ocean.    Ice that covered  the planet was formed at the expense of waters of the world ocean. Accordingly, the more extensive and higher glaciers are, the less water remains in the ocean. The glaciers contain water, the level of the ocean is decreased, uncovering   large regions of  dry-land. So, 50 000 years ago, because of growth of glaciers the level of the ocean decresed to 50 ì, and 20 000 years ago - down to 110-130 m. In this period many modern islands made a continent unit. So, the British, Japanese and Novosibirsk islands are inseparable from the continental. The islands of Oceania  became united, sank nowadays, the continent Meganesia, joint an overland bridge with Australia and Eurasia. A wide zone of  dry land, called Beringia, existed on a place of the Beringov Strait.