Surface deformations from moderate-sized earthquakes in Mongolia observed by InSAR

Abstract

We investigate surface deformations associated with two moderate-sized shallow earthquakes that occurred in the southeastern and northwestern stable regions of Mongolia using an analysis of ENVISAT/ASAR and ALOS/PALSAR data, respectively. Differential interferograms generated by a standard two-pass interferometric analysing technique depicted an uplift of up to ~1 cm for the M ^sub w^ 5.2 Hatanbulag composite earthquake (20 July, 2005, moderate-size foreshock in three hours) and a subsidence of up to ~10 cm for the M ^sub w^ 5.1 Büsiin Gol earthquake (19 January, 2008) in the radar line-of-sight directions, respectively. We inverted the observed deformations for the source parameters of the two earthquakes using elastic dislocation modeling. Our preferred model has geodetic moments of ~3.83 × 10^sup 17^ (M ^sub w^ 5.6) and 5.56×10^sup 16^ N m (M ^sub w^ 5.1) for the Hatanbulag and Büsiin Gol earthquakes, respectively.