Ice road
Ice roads are traffic routes that lead across frozen lakes, rivers or oceans.
In countries where the climatic conditions permit, such as Sweden , Finland , Estonia , Canada , the United States or Russia , ice roads are set up in winter if the weather conditions are suitable. These can lead over icy waters and thus replace ferry routes . For example, the Finnish road administration regularly sets up a seven-kilometer-long official ice road across Lake Pielinen in winter , which more than halves the distance between Lieksa and Koli .
In the past, an ice road was even set up through the Kvarken (strait 80 km wide and islands) over the Gulf of Bothnia between Finland and Sweden in cold winters , for example during the winter war of 1939/40 and most recently in 1966 and 1970. Since then, an icebreaker has been a fairway in the Bothnian region Keeping the bay free is no longer possible.
In Estonia, up to 7 ice roads will be opened for use in winter. The longest ice road in Estonia connects the Baltic island of Hiiumaa with the mainland and is around 25 km long.
A well-known historical ice road was the so-called “ Road of Life ”, through which Leningrad was supplied via Lake Ladoga during the siege in World War II . Ice roads can also lead to remote locations where no paved roads lead. This applies, for example, to Tuktoyaktuk in the Canadian Northwest Territories , which was only accessible by plane in the summer until 2017 because of the swampy tundra floors.
The longest ice road is the Tibbitt to Contwoyto Winter Road , which connects Tibbitt Lake near the Canadian city of Yellowknife via several gold and diamond mines with the Jericho Diamond Mine 400 km to the north . It has a total length of 568 km, of which 73 km are overland. Their main purpose is to handle heavy haulage to supply the mines. It is open only two months a year and the only road connecting the territory of Nunavut with the rest of the American road network.
Ice roads established by the authorities are public roads, on which special traffic regulations almost always apply. For safety reasons, there is a maximum weight for the passing vehicles. A maximum speed also applies, since if this is exceeded, the wave movements under the ice triggered by the vehicles can lead to dangerous cracks in the ice.
A formula for calculating the load-bearing capacity can be found in the article ice .
Climate change
The rise in temperature in February and March 2019 by up to 20 ° compared to the long-term monthly average in Canada is seen in connection with climate change and causes a decrease in the thickness of ice on ice roads and therefore shortens the time in which these can be used by vehicles.
Web links
Individual evidence
- ↑ Car collapsed in Estonia on the frozen Baltic Sea - three dead orf.at, 7 (6?) February 2018, accessed on 7 February 2018.
- ↑ Heat wave brings Alaska's polar north new records orf.at, March 30, 2019, accessed March 30, 2019.