Coulomb stress changes in the South Iceland Seismic Zone due to two large earthquakes in June 2000 -: art. no. 1205

[1] The South Iceland Seismic Zone experienced the largest earthquakes for 88 years in June 2000, with a M-S = 6.6 event on June 17, followed by another M-S = 6.6 earthquake on June 21. These events occurred on two parallel N-S striking, right-lateral strike slip faults, separated by about 17 km. We calculate the static Coulomb stress change for the June 17 and 21 earthquakes using a distributed slip model derived from joint inversion of InSAR and GPS data. We find that the static stress change caused by the June 17 event is about 0.1 MPa at the location of the June 21 hypocenter, promoting failure on the second fault. Locations of aftershocks agree well with areas of increased Coulomb failure stress. Our calculations indicate that positive stress changes due to the two earthquakes make the area west of the June 21 rupture the most likely site of the next large earthquake in South Iceland.