Greinar (Vísindafélag Íslendinga) - 01.01.1935, Qupperneq 78

76
the subterranean equilibrium caused by its sinking and
rising is therefore less than that caused when larger
areas of land like Scandinavia sink or rise.
In Öskjuhlíð, which is a hill just south of Reykjavík,
I have measured the height of the highest limit of the
old coast-line as 43 metres above the present sea-level,
but atHafnarfjörður thesamecoast-line is decidedly lower.
In the hill by Hvaleyri, which is south-west of Hafnarf jörð-
ur, I measured the height of the old coast-line as 32 metres,
or 11 metres lower than in Öskjuhlíð. The distance bet-
ween these two places is 8.5 kilometres, so that the dif-
ference in height amounts to 1.3 metres per kilometre.
It is not possible to trace this old coast-line further to
the SSW because here all the land is covered with more
recent volcanic products, mostly lava. But if we extend
the line to the NNE we come to the places in Borgar-
fjörður investigated by G. G. Bárðarson. With the same
tilt of the coast-line it ought to be at 77 metres above
sea-level on the northern side of Akrafjall, but at 83
metres in Miðfellsmúli. Bárðarson could not see a clearly
marked coast-line in Akrafjall, but mentions that the
sea reached higher than 60—70 metres there, and in
Miðfellsmúli there is a coast-line at least 60—70 metres
up. This old coast-line seems therefore to rise towards
to the NNE, though its tilting is not quite so great per
kilometre further north as it is between Reykjavík and
Hafnarfjörður.
The weight of the glaciers during the Akureyri-stage
must have exerted the greatest pressure in the high-
lands about the centre of Iceland, and we should there-
fore expect a greater sinking of the land at Akrafjall
than at Reykjavík and Hafnarfjörður, but most likely
this can only explain the present tilt of the old coast-
line to some extent, especially if there was also at that
time a local glacier on the Reykjanes range almost at
right angles with the line of the coast. But after this
coast-Iine was formed a great deal of lava and volcanic
ashes were spread over Reykjanes and without doubt