4.2 Routes and Aids to Navigation
The foremost factors determining the safety and economic feasibility of maritime shipping are the geographical setting, the ship routing and the natural conditions of the route, including both meteorological and oceanographical aspects. The convenience of a given route is also critically affected by the extent of infrastructure providing navigation aids and the availability of systems to provide timely hydrometeorological information for navigation. In this section, we describe the features of the NSR and how the route was selected, then proceed to describe the kinds of infrastructure and information systems that are required to support NSR navigation.
4.2.1 Features of the NSR and Route Selection
(1) Natural environment and geographical setting
The range of the NSR and the seas through which it passes vary with the purposes of operations and activities there. For the purposes of the present discussion, we adopt the Russian administrative definition found in "The Regulations for Navigation on the Seaways of the Northern Sea Route." According to this definition, the NSR is a passage linking Novaya Zemlya with the Bering Strait, which includes, from west to east, the Kara Sea, Laptev Sea, East Siberian Sea and Chukchi Sea. Depending on the context, it may also be taken to include the Barents Sea, which links these seas with the North Atlantic Ocean.
Obviously the most salient difference between the NSR and other sea lanes is the harshness of its natural environment. Ships traversing the NSR must cross numerous seas in the freezing Arctic environment, facing problems not encountered in other sea lanes. In this extremely cold environment, ice quickly accretes onto ship hulls and fittings, the job performance of crews deteriorates, steel toughness decreases, water and other liquids inside pipes freezes, some cargoes have to be insulated. Besides the direct problem of low temperatures are other issues relating to the high latitudes of the NSR. Passing through the Arctic night, NSR vessels suffer from poor visibility. Proximity to magnetic north renders the use of compasses difficult. Because satellite communication does not provides adequate coverage, sea-to-land communications are often blocked or unreliable. In sum, the extreme cold and high latitudes of the NSR create a uniquely difficult environment for shipping. The biggest problem, however, is the presence of ice. The ice conditions in the NSR are discussed in section (2) below.
Though climatic and hydrological conditions change dramatically in the NSR from sea to sea and from season to season, the route can be broadly divided into an eastern, a central and a western section. Various features distinguish these sections as follows.
* Western (from the Barents Sea to the western Kara Sea)
This section is relatively warm, under the influence of the Gulf Stream. The Barents Sea in particular is almost completely free of ice even in the harshest winter. For this reason, Murmansk is an ice-free port.
* Central (from the eastern Kara Sea through the Laptev Sea to the western East Siberian Sea)
This region is extremely cold, due to the influence of the continental climate, cold water and ice fields of the North Pole, where a huge volume of freshwater inflows from large rivers stimulates the formation of sea ice.
* Eastern (from the eastern East Siberian Sea to the Chukchi Sea)
Sea ice formation is moderate in this region compared to the central region, due to the warming influence of ocean water flowing in from the North Pacific Ocean.
Other central features of NSR navigation concern the geography of the NSR. Many islands obstruct the route from west to east, such as Novaya Zemlya, Severnaya Zemlya, the New Siberian Islands and Wrangel Island.