Jökull - 01.12.1969, Qupperneq 75

Fig. 2. The ice coverage east of Greenland. Distance from lines N, M and S in nautical miles.
Fig. 3. The ice amount east of Greenland in excess of the 6 years mean for the month.
which is 80 miles a month or 5.7 cm/sec. We
can, therefore, assume that so rnucli of the
southwestwards drilt of the ice in winter is
due to winds on the average. fn some months
the NE wincl is twice as strong as the mean
wind, and presumably the ice drift increases
correspondingly. Preceding the arrival of the
ice in 1968 the average speed of the NE wind
components for the months January to March
was 18 knots in region N, 17 knots in region
M and 11 knots in region S.
The wind component perpendicular to the
ice edge is much weaker and more irregular
as shown in Fig. 4, especially in region M.
The maximum SE wind occurs in spring, and
the rapid recess of the ice at this time of the
year must partly be due to this maximum. fn
region S the wind direction is frorn the SE
all year around with maxima in tlie spring
ancl fall. This inwards component is, at least
in part, responsible in keeping the ice belt to
the Greenland coast. It happens only when
this component fails that the drift spreads out.
And the danger of spreading out of the ice
JÖKULL 19. ÁR 71