Improved Source Imaging of the Kleifarvatn Earthquake, Iceland, through a Combined Use of Ascending and Descending Insar Data

We re-investigated the surface deformation of the Kleifarvatn earthquake on Reykjanes Peninsula, an event that was dynamically triggered by a moderatesize magnitude 6.5 earthquake 80 km away on 17 June 2000. Two ERS-2 interferograms from descending and ascending tracks were formed and used in combination with campaign GPS measurements to invert for the source parameters of rectangular faults for the Kleifarvatn and the adjacent and smaller Núpshlíðarháls earthquakes assuming uniform slip. With our more complete data set that includes the ascending ERS-2 data, we demonstrate an efficient suppression of model parameter trade-offs between fault dip and fault slip. We consider the correlated noise of InSAR by propagating the full data covariance to a weighting matrix, which balances the complete data set consistently. Our best model agrees not only with the regional faulting system, it is also supported by locations of recently relocated aftershocks.