Jökull - 01.12.1969, Page 107

The Effect of Glacier Changes in Iceland Resulting from
Increase in the Frequency of Drift Ice Years
S. THORARINSSON,
SCIENCE INSTITUTE, DIVISION OF GEOSCIENCES, UNIVERSITY OF ICELAND, REYKJAVIK, ICELAND
S U M M A R Y
There is undoubtedly a close correlation be-
tween the occurrence of drift ice at the coasts
of Iceland and the air temperature in the
country.
The changes in tlre occurrence of drift ice
— as well as the temperature changes — are
ultimately the result of climatic changes which
affect great parts of the globe.
Changes in the atmospheric circulation have
a much greater climatic effect in Iceland than
in continental areas, as they also influence the
ocean currents and the drift ice, whicft in tlieir
turn have an additionaf effect on the cfimatic
changes.
Previous investigations have shown that the
temperature is the most influential climatic
factor affecting the budget of Iceland’s glaciers.
Consequently an increase in the frecjuency of
drift ice years in Iceland will almost certainly
result in thickening and aclvance of the glaciers
in the country.
The main consequences of a general advance
of the glaciers in Iceland are the following:
1) The glacier fronts will become steeper and
more broken up than now and thus rnore
difficult to cross by motor vehicles.
2) “Zungenbecken” lakes will diminish or
disappear.
3) Most of tlte ice-dammed lakes in the
country will increase in size and so will
glacier bursts from tliem. The glacier bursts
from Grimsvötn will probably increase in
size too.
4) The daily discharge variations of the gla-
cier rivers will increase.
5) The courses of the glacier rivers will be-
come less stable than they are now.
6) A change to a generally positive budget
of the glaciers will result in decrease in
the discharge of the glacier rivers in Ice-
land and reduce considerably the develop-
able hydropower in the country.
JÖKULL 19. ÁR 1 03