Shallow Rupture of the 2011 Tarlay Earthquake (Mw 6.8), Eastern Myanmar

Abstract

We use L‐band Advanced Land Observation Satellite PALSAR data to infer the distribution of subsurface fault slip during the Tarlay earthquake (M_w 6.8) in eastern Myanmar. We find the total length of surface rupture is approximately 30 km, with nearly 2 m maximum surface offset along the westernmost section of the Nam Ma fault (the Tarlay segment). Finite‐fault inversions constrained by Interferometric Synthetic Aperture Radar (InSAR) and pixel‐tracking data suggest that fault slip is concentrated within the upper 10 km of the crust. Maximum slip exceeds 4 m at a depth between 3 and 5 km. Comparison between field measurements and near‐fault deformation obtained from the InSAR range‐offset result suggests about 10%–80% of displacement occurred within a 1 km wide zone off the main surface fault trace. This off‐fault deformation may explain the shallow slip deficit that we observed during this earthquake. We estimate a recurrence interval for Tarlay‐like events to be 1600–6500 yrs at this section of the Nam Ma fault. A detailed paleoseismological study is essential to clarify the slip behavior and the earthquake recurrence interval of the Nam Ma fault.