Wave Characteristics of the NSR

(from Navigational Book 4151; translated from Russian)

Development of waves in the Arctic seas depends on a) wind speed and direction; b) on the presence, character and distribution of sea ice; and c) on the water depth. Strong winds are relatively rare in July and August and sea areas clear of ice are small which hinders waves development. Waves of maximum magnitude develop in September and October. In November Arctic seas are almost completely ice-covered leading to the development of small waves or no waves at all. The southern part of the Chukchi Sea is the exception where in some years wave height can reach 4 to 5 m in November.

In the Kara Sea in July and August waves frequently come from the NE. Occurrence of waves 3 m high and greater is 3-6% in July and August, and 6-16% in September and October. This is commonly observed in the NW-part of the Kara Sea. In the SW-part of the Kara Sea ice rarely prevents waves development and subsequently wave heights can reach 8 to 9 m. Heavy seas with waves from any direction are here possible.

In the Laptev Sea the heaviest seas develops when there is no sea ice in the central part and near the western shores. As the shipping route passes through shallow waters in the Laptev Sea the wave heights normally do not exceed 2 m. However, in some areas waves can be steep and dangerous for small crafts during strong northerly winds. In the central part of the Leptev Sea during easterly gales the height of waves can reach 4 to 5 m in July and August. In the SE-part of the sea the height of waves does not exceed 4 m even during wind with a speed of 12 to 20 m/sec, due to shallow water. Wave height in the Laptev Sea commonly reaches 6 m in September and October. The maximum wave height does not exceed 4 m on the shipping route in the Laptev Sea in this period, and only near the shores of Poluostrov Taymyr can it can reach 5 m. Occurrence of wave of 3 m and greater is 4-6% in July and August and 6-8% in September and October.

The East Siberian Sea is rather smooth compared to other Arctic seas due to its more extensive ice coverage and shallow waters. In the middle of August in the W-part of the East Siberian Sea the wave heights can reach 4 to 5 m during NW winds with speed up to 20 m/sec. The wave height in this area does not exceed 2.5 m during NE winds. Wave heights can reach 5 m in Septemher. In coastal waters maximum wave heights are 2.5-3 m. However, even waves with heights less than 2.5 m become steeper there. Occurrence of waves of 3 m and greater is 3-5% in August and September; in July and October the sea is usually covered by ice.

In the Chukchi Sea waves are not high in July and August, and only in the SE-part of the sea do maximum wave heights reach 5 m during this time. Wave heights reach 5-7 m in September and October. The highest waves are observed in the central part of the Chukchi Sea and along the shores of Chukotskiy Poluostrov lying to the east of Mys Serdtse-Kamen. Maximum wave heights observed in the Chukehi Sea are 9 m. Wave heights decrease towards the end of November when sea ice cover intensifies. However, wave heights of 4-5 m occur in November in the vicinity of Mys Uelen. Along the coastal shipping route of the Chukchi Sea wave height can reach 6 m during northerly gales.

In the coastal zone of the Chukchi Sea (in the vicinity of Mys Otto Shmidta) an infrequent but dangerous phenomenon called the "ice storm" is observed, i.e. storm in the presence of sea ice. The "ice storm" was observed in the vicinity of Mys Otto Shmidta for example in 1969, 1972, 1980, 1984 and 1985. This phenomenon occurs when there is about 27 mile wide strip of 2-6 point closed ice blocking the coast. Waves consolidate ice up to 10 points and drive it to the shore. Width of ice strips decreases to 3-4 cables. Waves approaching the shore break down and form a surf. Up to 3 m high waves carry ice blocks and throw them down onto the shore damaging piers, wharves and other constructions. Under the same conditions "ice storms" may also occur in other parts of Arctic seas.

State hydrographic department of the Ministry of Transport of Russian Federation, 1996, Wave Characteristics of the NSR, .©