Náttúrufræðingurinn - 1970, Page 132

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NÁTTÚRUFRÆÐINGURINN
Malmberg, Svend-Aage. 1968: Beinar straummælingar á hafi úti. Straummæl-
ingar í Faxaflóa 12.—13. 8. 1966. Náttúrufr. 37: 1—2. Reykjavík.
Thorarinsson (Þórarinsson), Sigurður. 1966: Flvaðan mun vera sá stóri steinn?
Náttúrufr. 36: 1—2. Reykjavík.
Vilmundarson, Þórhallur. 1969: Heimildir um hafís á síðari öldum. Hafísinn.
Almenna bókafélagið, Reykjavík.
S U M M A R Y
Drift ice off NW Iceland in late April 1969
hy
Svend-Aage Malmberg,
Marine Research Institute, Reykjavik.
The extension of drift ice was somewhat unusual off NW Iceland in late
April 1969 (Fig. 1), primarily due to unfavourable ice conditions in Nortli
Icelandic and East Greenland waters and also due to strong northeasterly
winds. Tlie southernmost drift ice was observed in the coastal water off Látra-
bjarg on April 25. The hydrographic conditions in this area — with sea tem-
peratures as low as 1° C (Figs. 2—3) — were no barrier to the ice drift once
it had crossed the warm Irminger Current branch at the shelf break.
Records of drift ice reaching south past Látrabjarg and into Breidafjördur
have been infrequent (1685, 1787; see Sigurður Þórarinsson, 1966). However,
the present author believes that drift ice would have passed Látrabjarg and
entered Breidafjördur in late April 1969, if winds and currents had been
“favourable”. According to direct current measurement off Látrabjarg on May
1—2, the current at that time was of tidal character only (Fig. 4). Therefore it
seems that winds have been the decisive factor in the ice drift away from the
coastal area westwards into the Irminger Current system.