A submarine peat at Petvik in western Lofoten has been pollen-analysed and 14C-dated. The Petvik data, and some additional data from Ramså in northern Vesterålen, indicate that the sea level at the 7-8 m Main shoreline isobase sank below present mean sea level around 9900 B.P. and at least below -2. 85 m during the time of maximal regression (9000-8000 B.P. ). The 'Tapes' transgression passed the present mean sea leve) at c. 7600 B.P. (interpolated). The climate during the early Holocene sea level regression was at least as warm as present in the whole area, although birch woodlands became established c. 800 years later in western Lofoten than in northern Vesterålen.
The early Holocene climate and sea-level changes in Lofoten and Vesterålen, North Norway