A Variable Slip Fault Model For the 1908 Messina Straits (Italy) Earthquake, By Inversion of Levelling Data

Abstract

A variable slip fault model is presented for the 1908 December 28 Messina (Italy) earthquake. It has been obtained by inversion of levelling data, using a gradient method. Fault location and mechanism are consistent with an approximately N‐S orientation and normal faulting on a low‐angle plane dipping 39°, with about 45° of strike‐slip component. The main difference from a homogeneous slip model is represented by a higher slip area (up to 3 m), located close to the city of Reggio Calabria. It is interpretable as a major asperity, which is related to the main fracture episode. This is in agreement with some macroseismic evidence and the same structure could be responsible for the nearby recent seismic activity. The area which effectively slipped is all confined within the Messina straits. This result differs from the homogeneous slip model recently proposed by Capuano et al. (1988). Copyright © 1991, Wiley Blackwell. All rights reserved