Present kinematics of the Tjornes Fracture Zone, North Iceland, from campaign and continuous GPS measurements

Abstract

The Tjrnes Fracture Zone (TFZ), North Iceland, is a 120 km transform offset of the Mid-Atlantic-Ridge that accommodates 18 mm yr -1 plate motion on two parallel transform structures and connects the offshore Kolbeinsey Ridge in the north to the on-shore Northern Volcanic Zone (NVZ) in the south. This transform zone is offshore except for a part of the right-lateral strike-slip Hsavk-Flatey fault (HFF) system that lies close to the coastal town of Hsavk, inducing a significant seismic risk to its inhabitants. In our previous work we constrained the locking depth and slip-rate of the HFF using 4 yr of continuous GPS measurements and found that the accumulated slip-deficit on the fault is equivalent to a M w 6.8 0.1 earthquake, assuming a complete stress release in the last major earthquakes in 1872 and a steady accumulation since then.