Jökull - 01.12.1969, Page 155

TABLE 1
Years classified according to sea ice ancl grass production
in the period from settlement to 1780
Century Years of sea ice Annual Grass Production (years of sea ice)
Poor Medium Good
12th and before 2-3 6
13 3-4 4 1
14 6 6 (3) 2
15 1 2 1
16 8 3 (1) 7
17 27 29 (14) 14 (8?) 20 (5)
18 23 37 (15) 31 (2?) 32 (4)
the connection between sea ice and the growth
of grass. It is sufficient to quote one example,
i.e., an entry in the law officer’s records for
the year 1374: “Winter and spring severest in
living memory, grass did not grow at all in
the north. Sea ice was present until 24th
August." There must be some exaggeration
here, when the recorder considers sea ice to
have prevented the growth of all grass in
North Iceland that year but the correlation
between growth and ice is quite clear. If we
try to collate all information found in the
annals ancl other sources about the growth of
grass for this period and to compare it with
the information on ice years, it is apparent
that the details are scanty and hardly suitable
for making a true estimate of the frequency
of ice years in individual centuries. Neverthe-
less the records give some information about
the correlation between ice years and the
growth of grass. These entries in the annals
are compared in Table 1, where a clear cor-
relation between ice years and a shortage of
grass may be noticed. For instance, little sea
ice is to be found near the coasts during good
grass years.
For the second period it is convenient to use
tlie details of ice in the years 1780—1900 com-
piled by Thoroddsen for a comparison with
the information about the growth of grass.
The estimation of grass growth is obviously
very unsystematic in this period, and is prob-
Fig. 7. Years of varying grass growth, graded in ten classes (10 = best growth) and grouped
according to duration of sea ice at the coast of Iceland (in days).
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