Jökull - 01.12.1982, Page 117

Earthquake Fractures in the Districts Land and
Rangárvellir in the South Iceland Seismic Zone
PÁLL EINARSSON and JÓN EIRÍKSSON
Science Institute, University of Iceland,
Dunhagi 3, 107 Reykjavík, Iceland
ABSTRACT
Large earthquakes have been accompanied by extensive
surface fracturing throughout the South Iceland Seismic
Zone, one of the major fracture zones of the Mid-AÚantic
plate boundary. Fracture systems in the eastemmost part of
the zone, in the districts Land and Rangárvellir, have been
mapped. The fractures generally strike NE and form en
echelon arrays which trend N-S. They are interpretedas the
surface expression of underlying righl-lateral strike-slip
faults. Thefaults are arranged side by side within the E-W
Fig. 1. Map of the seismic zones of Southwest Iceland showing fissure swarms associated with crustal
spreading, the seismic zone on Reykjanes peninsula, and destruction zones ofmajor earthquakes in South
Iceland since 1700 (from P. Einarsson et al. 1981).
Mynd 1. Yfirlitskort af Suðvesturlandi. Sýndir eru sprungusveimar á Reykjanesskaga og í vestara gosbeltinu, einnig
skjálftabeltið á Reykjanesskaga og tjónasvœði hetstu jarðskjálfta á Suðurlandsundirlendi síðan 1700. Myndin er tekin úr
grein Páls Einarssonar o.fi. 1981).
JÖKULL 32. ÁR 113