Regional and local vertical crustal movements in northern Iceland, 1965–1980

Abstract

Since 1965, repeated gravity and height measurements have been carried out in northern Iceland across the exposed part of the constructive plate boundary in order to detect vertical crustal movements. Regional movements have been observed across the neovolcanic zone between the western and eastern Tertiary basalt zones. The center of activity is situated below the Krafla caldera, and since 1975 a rift process is affecting the 100‐km‐long and 5‐km‐wide fissure zone associated with this central volcano. Local vertical movements have been investigated by reobserving transverse profiles approximately 10 km south and 15 km north of Krafla. The recent rifting process is characterized by regional uplift and gravity decrease on the flanks and local subsidence and gravity increase in the central fissure zone. The results of repeated levelings and gravity measurements are used to produce common and continuous models of vertical crustal movements.