The Botany of Iceland - 01.12.1914, Side 101

PHYSICAL GEOGRAPHY
285
sequence. As the rainfall, however, is often accompanied by storms,
the weather is frequently very unpleasant for man and beast. It is
especially in South Iceland that complaints are heard of the storms of
sleetduring autumn, wlien everything becomes saturated with moisture
and rain penetrates into the houses through every chink and crevice.
The humidity is more considerable in South than in North Iceland,
which is shown for instance by the fact that houses with turf walls
must be rebuilt more often in the southern districts. A cold, damp,
whitish fog, accompanied by sleet, is very characteristic of the
northern headlands, especially when the Greenland ice drifts back-
wards and forwards along the coast; then fog may shroud the coast
for weeks and extend far into the valleys. The fog persists for a
long time also in other places along the coast, especially in East
Iceland. The amount of cloud also is generally great, especially in
North Iceland.1
The amount of rainfall varies greatly in the diíferent parts of
Iceland, and in most places it is generally greatest during autumn
and winter; on Grímsey, however, it is greatest during summer and
autumn. The precipitation is greatest along the south and south-
east coasts: in the Vestmannaeyjar 1320 mm., and at Berufjord
1166 mm. The greatest amount ol'annual rainfall in the Vestmanna-
eyjar was 1587 mm., and at Berufjord 1737 mm. Along the west
coast the rainfall is much less, and still less in North Iceland, being
at Stykkisholm 656 mm., but on Grímsey only 345 mm. At Stykkis-
holm there are, however, on an average 207 rainy days, but on
Papey only 135, consequently, a much greater amount of rain falls
there at a time. At Berufjord the greatest amount of rainl’all within
24 hours was 10972 mm. (July); at Stykkisholm 51.9 mm. (January);
and on Grímsey 34.3 mm. (November). Heavy showers and sudden
torrents of rain do enormous damage to the soil-layer on the moun-
tain-sides, which are usually woodless and unprotected, and occasion
numerous rock-slips which have often proved very disastrous to
property and human life. The frequency of fogs differs greatlj' at
different parts of the coast, but it is inost frequent along the southern
part of the east coast where the warm and cold ocean currents
meet. At Beruljord there are on an average 171 foggy days annually;
here fogs are frequent at all the periods of the year, but thejr occur
most frequently during summer. On Papey (in the neighbourhood
1 Amount of cloud (0—10): Vestmannaeyjar 6.2; Stykkisholm 6.7; Berufjord
; and Grímsey 8.3.
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