Dating recent glacier advances in the Svarfadardalur-Skidadalur area of northern Iceland by means of a new lichen curve

Abstract

A new lichenometric curve is presented for the Svarfadardalur-Skidadalur area of north Iceland developed on the basis of 19 dated surfaces, including abandoned farmsteads or ruins, grave stones, memorial stones, bridges and a mudflow. The growth rate for Rhizocarpon geographicum agg. is found to be 0.44mm a-1, a lower figure than that previously adopted in the area and in southern Iceland. Errors in the construction of earlier lichen growth curves in Iceland are outlined and the new curve used to date moraines of recent age in a number of valleys. Use of 10-year running means on these results show glacier advances at ca A.D. 1810, 1850, 1870-80, 1890-1900, 1920s and 1940s, and comparison with similarly treated sea-ice data shows possible correlations for the late 19th century and possibly the 1920s. -Author