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Seismic risk at the rift‐transform junction in North Iceland
Author(s) -
Jouanne F.,
Villemin T.,
Ferber V.,
Maveyraud C.,
Ammann J.,
Henriot O.,
Got J.L.
Publication year - 1999
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/1999gl005408
Subject(s) - geology , rift , seismology , ridge , rift zone , fault (geology) , transform fault , echelon formation , plate tectonics , fracture zone , tectonics , triple junction , paleontology , geophysics
The current tectonics of north Iceland are characterised by max M 6–7 earthquakes in the transform zone between the northern rift zone and the Kobleinsey Ridge. The last rifting period (1975–1984) was associated with an opening of up to 9 m along the Krafla fissure swarm. This period was followed by the disappearance of microseismicity along the eastern part of Husavik‐Flatey Fault, the main structure of the transform zone. A GPS network was occupied in 1995 and again in 1997 to study present‐day deformation on both sides of the on‐land part of HFF and around its junction with the northern rift zone. The main deformational features observed are: (1) in Tjörnes, the HFF is locked above the ductile/brittle boundary below which ductile creep is occurring, and (2) aseismic opening along the Theystareykir and Krafla fissure swarms and along a N 120°E superficial fault that marks the southern boundary of Tjörnes.