Jökull - 01.12.1967, Page 3

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JÖKULL
Á R S R I T
JÖKLARAN NSÓKNAFÉLAGS ÍSLANDS
III 17. ÁR REYKJAVÍK 1967
The Thickness of the Ice Cover of Mýrdalsjökull,
Southern Iceland
SIGURJÓN RIST,
HYDROLOGICAL SURVEY, NATIONAL ENERGY AUTHORITY, REYKJAVÍK, ICELAND
ABSTRACT.
The Ihickness of Myrdalsjökull, Southern
Iceland, was measured by seisrnic methods at
several. points during the summer of 1955. The
ice was found to be 200 t.o 370 m thick. The
accumulation of snow during the winter 1954 j
1955 luas founcl to be 4 to 6 metres in most.
places corresponding to precipitation (as xuaterj
of approximately 3000 mm.
INTRODUCTION
The history of Mýrdalsjökull has been closely
linked with the history of the Icelandic nation
because of frequent eruptions in the volcano
Katla situated under the ice cover. The erup-
tions are always accompanied with catastrophic
jökulhlaups (glacial bursts).
Katla has erupted rather regularly since the
time of the earliest settlement (late 9th cen-
tury). Thorarinsson (1959) considers likely that
the volcano has been active for at least the
last 10,000 years. The last four eruptions took
place in the years of 1755, 1823, 1860 and 1918.
In addition to the catastrophic jökulhlaups
initiated by volcanic eruptions, smaller hlaups
are frequent from ice dammed lakes in the
mountains on the edges of the ice cover.
In 1955 the Icelandic Parliament adopted a
resolution on geological and glaciological study
of Mýrdalsjökull with emphasis on all changes
of the ice cover. The research should focus
on problems that might help to predict vol-
canic eruptions ancl jökulhlaups. One part of
the research involved measurements of the
thickness of the ice cover of Mýrdalsjökull.
LAHDSBOKASAFH
275650
ÍSLAtiBS
JÖKULL 17. ÁR 237