Geodetic measurements and horizontal crustal movements in the rift zone of NE-Iceland

Abstract

Based on the special geodetic network set up by Niemczyk and Emschermann in 1938 in order to determine horizontal movements of the Earth's crust in the fissure area of the neo-volcanic zone of NE-Iceland, a number of repeated measurements were carried out from 1965 to 1977. In this article, modern geodetic measuring techniques and the (constantly improving) positional accuracy achieved are described; this is followed by an evaluation showing significant crustal movements in the riftzone. In the period of 1965 to 1971, movements in the total area of approximately 110 km from east to west were restricted to compressions, whereas afterwards, and in particular since 1975, expansions of up to 2 m/km have occurred in the central rift area. At present, this expansion is largely compensated by compression in the peripheral areas of up to 0.05 m/km, so that between 1971 and 1977 a total east-west expansion of the neovolcanic zone of only about 0.4 m has resulted over a distance of about 90 km.

          ARK: https://n2t.net/ark:/88439/y096107

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