Geoscience Reference
In-Depth Information
up, there will be compression zones elsewhere in the ice cover. In large lakes the
unpredictability of sudden displacements in the ice cover endanger ice
shermen.
Sometimes in good
fishermen are driven out by the ice and
need to be rescued by hydrofoils or helicopters. E.g., on February 9th, 2009, in all
150
fishing days a large number of
fishermen experienced this event together in Lake Erie, 3 North America.
When the ice breakage becomes more regular, the ice cover appears as broken ice as
usually called in the research of lake ice and river ice. It is a granular medium, where the
'
300
-
floes contain the stress generating mech-
anisms, and variations in smaller scale properties become less important. When the scale
of interest is much more than the size of
grains
'
are ice
floes. Interactions between ice
oes, continuum models are employed. This is the
regime of drift ice (Leppäranta 2011), to be treated in Sect. 5.5 .
5.3
Bearing Capacity of Ice
One of the fundamental problems in the research of
floating ice is the bearing capacity (see
overview by Goldstein et al. 2014). Ice cover has been used for travel and transportation
as long as cold regions have been inhabited. In his map and booklet of northern Europe,
Olaus Magnus Gothus (1539) described ice crossing by skiing, skating (metal and bone
blades) and riding, and also showed
fishing from ice-covered lakes. A dramatic case in the
1200s was a battle between Novgorod and Livonian Knights on the ice of Lake Peipsi,
located at the border between the present Estonia and Russia. According to historical
sources, the ice broke under the Livonian troops and the battle was then done. 4 The
world
rst
time the track was laid on the ice cover of the Volga River near the town Kazan. The
successful experience contributed to the creation of similar crossings in other regions, in
particular, on the Volga River near Saratov (1895) and Lake Baikal (1904).
Substantial progress on the use of
'
s
first railway ice crossings were built in the late 19th century in Russia. For the
floating ice cover for support and transportation of
heavy loads has been made in North America in the 1970s and 1980s in connection with
the development of mineral deposits in Northern Quebec, the Canadian Arctic and
Northern Alaska (Masterson 2009; Mesher 2008). The longest winter ice road is 568 km
long connecting Tibbitt Lake and Contwoyto Lake and crossing 65 smaller lakes in the
Canadian Arctic (Mesher 2008). This road was operated annually from 1979 to 1998 and
it provided transportation of cargo to the mines and minerals extracted in the opposite
direction. In this road the
first attempt was made to use a mobile radar to monitor the
thickness of ice. In recent years, interests in ice crossings, roads and islands to support
3 This case was reported in many Canadian and U.S. news sites on February 10, 2009; the number
of fishermen varied in different sources.
4 The scale of this event is not clear but it is thought to have a true basis. This battle on ice is a scene
in the film Alexander Nevsky by Sergey Eisenstein (1938), one of the most famous scenes in the
film history.
 
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