Reply to comment by Y. Fialko on “Deformation of compliant fault zones induced by nearby earthquakes: Theoretical investigations in two dimensions”

[1] Fault zone structure and properties may contain important information about past earthquake rupture and subsequent healing processes. Damaged fault zones are observed geologically in the field [e.g., Chester and Chester, 1998; Ben-Zion and Sammis, 2003]. Seismic studies have revealed the existence of low-velocity fault zones around active faults [e.g., Li et al., 1998; Ben-Zion et al., 2003]. Compliant fault zones are inferred from InSAR observations of the displacement field of recent earthquakes [e.g., Fialko et al., 2002; Fialko, 2004]. However, the width and depth extent of fault zones are still under debate in the community. [2] Duan et al. [2011] conduct detailed theoretical investigations of the response of compliant fault zones to nearby earthquakes using spontaneous rupture models with offfault elastoplastic rheology in a 2-D plane-strain framework, built upon an earlier study by Duan [2010]. They call for a reexamination of existing observations, based on possible constraints on the in situ stress state by the inelastic response of compliant fault zones revealed by their theoretical studies, and possible deficiencies in previous studies in deducing the structure and properties of compliant fault zones. Fialko [2011] (hereafter referred to as Fialko11) provides a comment to Duan et al. [2011] and refutes the call. Although primarily defending the previous studies [Fialko et al., 2002; Fialko, 2004] which considered only the elastic response of compliant fault zones to static stress changes, Fialko11 also downplays significance of the possible inelastic response of compliant fault zones to dynamic stress changes. I will first discuss significance of both the previous studies on elastic response to static stress changes and the recent studies on inelastic response to nearby ruptures. Then I will reply in some details to the comments made by Fialko11.