© 2019 Published under licence by IOP Publishing Ltd.Based on world stress map, the in-situ stress along the Great Sumatran Fault (GSF) is assumed to be strike-slip, and the maximum principal stress is oriented N14°E. However, this estimation neglects the local impact of fault branching and material heterogeneity which might have a significant impact on the stress heterogeneity. Despite its importance, very few studies have been performed on this issue in GSF. We intend to analyze variations of the in-situ stress in GSF from the geological data and seismicity pattern. This was performed on a catalogue data set of 707 earthquakes with magnitude (Mw) >3.5 between January 1, 1970 and April 1, 2017. The preliminary results of this study highlight the stress rotation of around 30° clockwise in the central part of GSF. Geological observation also shows faults branching and bifurcation which are interpreted as the product of the stress changes. Furthermore, the seismicity analysis quantifies this issue by showing a sharp different of b-values for subduction and GSF zones, i.e. 1.0 and 0.7, respectively. Therefore, it can be concluded that the stress heterogeneity in the central part of GSF affects both the seismicity occurrence and magnitude.

Fault branching,Geological data,Insitu stress,Material heterogeneity,Maximum principal stress,Seismicity pattern,Stress changes,Stress rotation

https://doi.org/10.1088/1742-6596/1204/1/012091