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NORWAY'S LARGEST GLACIER
The Jostedals Glacier, with its total area of 480 km²,
is the largest continental glacier in Europe. The highest point of the glacier
is Høgste Breakulen,
1,957 meters above sea level, and the lowest, Nigard Glacier, 300 meters
above sea level. The highest mountain on the glacier is the Lodalskåpa with its
2083 above sea level. The bulk of the glacier forms a plateau over 1,600
meters high where almost all the precipitation falls in the form of snow,
even in summertime.
The snow is packed into thicker and thicker layers and gradually turns into
ice under the pressure. The thickest part of the glacier is about 600 m. The
Jostedal Glacier has registered annual snowfalls of up to 12-15 meters, and
winters like these combined with clod summers cause the glacier to grow. The
total length of the Jostedals Glacier is about 60 km and covers almost half of
the National park of Jostedals Glacier.
This was the climate in the middle of the 17th century, when the Jostedal
Glacier grew considerably and in many places reduced farms to rubble. In
this century all Norwegian glaciers have retreated considerably, with the
exception of a small advance in the 1920s.
The Jostedals Glacier and the approximate areas of land, 1310
km², are protected as a national park with
the primary aim of preserving this unique area for future generations. Is
contains important land for international scientific research: moraine,
formations, river deltas, vegetation, wildlife and the historical spread of the
glacier are just few examples.
In 1991 was the foundation of the National Park centre of Jostedal Glacier, and
it opened in 1992 by The prime minister Gro Harlem Bruntland.
A glacier can be compared to a sluggish river. The force of gravity pulls the ice down, the ice masses grinding against the substratum, tearing loose large and small stones and producing large masses of gravel and sand at the foot of the glacier. This creates the typical moraine landscape, and from these moraines the glacial streams obtain their typical grey- green colour.
If a
valley is wide and flat the glacier will flow steadily downwards without
fissures of any note being formed in the surface. If, on the other hand, the
valley is narrow and steep the ice will form fissures both lengthwise and
crosswise, as can be seen, for example, in the Nigard Glacier, The steepest
tributaries of the Jostedal Glacier can move at a speed of one metre per day,
but most of them are considerably slower. It is called the milk of the glacier.
Over thousands of years the ice has rubbed the Norwegian landscape and shaped
the long and deep valleys and the beautiful fjords.
From autumn 2002 to 2003 the glacier of Briksdal melted 51 meter. In the same period the glacier of Bødal melted 23 meter, while the glacier of Kjenndal melted 61 meter, tells Professor Atle Nesje, Department of Geology, University of Bergen.
DEVELOPMENT AFTER THE LATEST ICE AGE
Geologic and botanic researches at the Glacier of Jostedal,
Europe's largest continental glacier, has given us new knowledge about how the
size of the glacier has changed the last 10.000 years. The results of these
researches leads us to believe that big parts or all of the Glacier of Jostedal
was melted, in a mild period, for 8000-6000 years ago. Then a
new glacier grew when the climate got worse again. The largest growth of the glacier
was under the "little ice age", in the middle of the 18th century.
Examination of pollen from sumps near by the Glacier of Jostedal, shows that the climate between 9000 and 8000 years ago was about the temperature we have today. The warmest period after the last ice age was for 8000-6000 years ago, and the summer was 2°C warmer than today. There were Elm forests where today's Birch forests grow.
MELTING OF THE GLACIER
The oldest sediments or fossils found on the West coast of
Norway are dating from the latest ice age that started about 70.000 years ago.
Since then the land has been completely or partly covered by ice. The last time
this happened was about 18-20.000 years ago. Researches show that it was at this
period that the mainland ice was at its biggest. Observations of scrapes marks
of ice in the area shows that the ice floated against W- NW.
In Inner Nordfjord there are proved crumbling mountain and mountainous blocks on the top of the mountains above a certain level. The blocks has a sharply defined lower border. Under this border shows fresh scrape marks after the ice. Observations of the mountains around the glacier of Jostedal show that the block level rises from about 1400 meters above sea level to 1600- 1700 meters above sea level. This border can be due to erosion from the glacier, and marks truly the upper border of the mainland glacier, at the peek of the last ice age. In that case most of the mountain tops in inner Westland, peeked up above the ice as Nunataks.
A change in climate for about 15.000-13.000 years ago, made the mainland glacier to melt and the coast of Nordfjord and Sunnmøre became clear of the ice for 12.000 years ago. In a mild period (Allerød) for 11.000 years ago, the glaciers in the fjords melted. A new change in climate in Younger Dryas (11.000-10.000 years ago) made the glaciers grow again quite fast. Side moraines in the inner half of the fjords, tells until where the ice came in that period. The result of the last growth, were great impressionable valleys. Land that were not covered by the main glacier, has tracks after small local glaciers (glaciers that are not connected to the mainland glacier).
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