East Siberian Sea runoff into the East Siberian Sea is relatively small at about 250 km/year that makes only 10% of the total runoff in all the Arctic seas of Russia. The largest contribution is from the Kolyma River at 132 km, followed by the Indigirka River at 59 km. Most runoff (90%) occurs in summer; it is concentrated near the coast, owing to the weak river currents, and therefore does not significantly affect the sea hydrology. The water exchange between the neighboring seas is as follows. The annual outflow to the Laptev Sea, Chukchi Sea and Arctic Ocean is 3,240, 6,600 and
East Siberian Sea southwest to northeast, covered in a mixture of silt, sand and stones and lacking significant depressions and elevations. About 70% of the sea is shallower than 50 m, with predominant depths of 20–25 m. North-east to the mouth of the Kolyma and Indigirka rivers, there are deep trenches on the seabed, which are attributed to the ancient river valleys, now submerged by the sea. The region of small depths in the western part forms the Novosibirsk shoal. The greatest depths of about 150 m are found in the north-eastern part of the sea. The climate is polar and is influenced