Jökull - 01.12.1972, Síða 5

it is very likely that lack of records is the
reason, rather than lack of ice. It should also
be noted in this connection, although it may
not be significant, that no year with little ice
is recorded until after 1801, not even in the
17th and 18th centuries. It should also be
emphasized, that judging from the number of
severe ice years, the 13th century seems not to
have been much less severe than later centuries,
such as the 17th or 18th (or the first two third
of the 20th).
The annal writers recorded occurrences of
sea ice together with other events, but in the
later part of the 19th century, collection of ice
reports as a scientific activity independent of
other historical writings was begun. Þorvaldur
Thoroddsen was the pioneer here, as in several
other fields of natural history, and his activi-
ties in this respect are recorded in some of his
books. At about the same time the Danish
Meteorological Institute began to collect re-
ports from Greenland and the surrounding seas,
including the Denmark Strait and the shipping
routes around Iceland. Near the end of the
19th century this activity of the Meteorological
Institute became international. It was extended
over the whole of the Arctic Ocean, and was
carried on, partly at least, under the auspices
of the International Geographical Institute.
Naturally, these reports covered only a small
area at the time, since they were mainly bas-
ed on observations from coasts and shipping
routes. Several Icelandic ships participated in
this programme. Many observations of the East
Greenland ice were obtained from seal hunting
vessels, especially during the first three to four
decades of the present century. Ice charts were
constructed from all of these observations, and
published later on, at first for the months
March—August, but later for April—September.
The Icelandic Meteorological Office began
collections of ice reports from the seas around
Iceland as soon as it was established, and it
also issued ice reports when required.
1901- . . I • • • -10- • • • i • • • -20' • • . i • • • -30- • • • i • • • -40- • • • I • • • -50- • • • I • • ■ -60- •••!••• -70' • • • l • • • -80- • • • I • • • -90- •••!••• -2000
Fig. 1. Sea ice near Iceland in the 20th century. The upper part shows the period when ice
was observed. The lower part shows an “ice index”, i.e. the product of number of weeks with
ice per year, and the number of coastal areas near which it was observed. Insert map shows the
limits of the areas. Redrawn and extended from Koch (1945). The outlined ice periods in the
upper part are late additions, not includecl in the index.
1. mynd. Hafis viö ísland á þessari öld. Efri hluti sýnir, hvenœr is sást. Neöri hluti sýnir
hafískvarða, sem er margfeldi af fjölda isvikna á ári og fjölda strandsvœða, þar sem is sást.
fnnskotsmynd sýnir skiptingu i strandsvœöi. Endurteiknað og framlengt frá Koch (1945). Hvítar
súlur i efri hluta eru nýlegar viöbætur og ekki teknar með í kvarðanum i neðri hluta.
JÖKULL 22. ÁR 3