Earthquake related deformation cycle: perspectives from 2004 Sumatra and 2010 Chile mega-earthquakes

Abstract

An earthquake cycle consists of pre-seismic, inter-seismic, co-seismic and post-seismic phases of deformation. Studying these processes using geodetic observations facilitates estimating earthquake recurrence time interval. The advances made in space-borne technologies e.g. Global Positioning System (GPS) and Interferometric Synthetic Aperture Radar (InSAR) have made most profound impact on these measurements and understanding of the processes in earthquake cycle. In the past two decades, high resolution observations before, during and after large earthquakes reaffirmed the basic concept of earthquake cycle. The mega earthquakes: Mw 9.3 Sumatra earthquake on December 26, 2004 and the recent Mw 8.8 Chile earthquake on February 27, 2010 and many other such large earthquakes, prompted lithosphere-scale studies in which spaceborne geodetic data are acquired and used to infer the mechanical properties of faults and the rheology of the lower crust and lithospheric mantle. As these parameters essentially control the temporal and spatial distribution of surface strain at all scales, evaluating their characteristics is one of the present day challenges in continental dynamics. This paper focuses on geodetic, geologic and historic studies, as well as laboratory investigations of the earthquake related deformation cycle.