Presenter: Jau-yu Lee
Date: 2017/03/16
Abstract
The plate boundary region between the India and Sunda plates in the northwestern Sunda Arc consists of the Indo-Burmese wedge (IBW), the Myanmar Central Basin, and the Sagaing fault. Plate models and geological structures in the region suggest that subduction in the IBW occurred in the past, but whether it is still active and how the plate motion between the India and Sunda plates is partitioned between motion in the IBW and Sagaing fault is still unknown. Here present GPS measurements of crustal deformation and available long-term rates of motion across the Sagaing fault suggest that ~20 ± 3 mm/yr ,the relative plate motion between the India and Sunda plates is ~36 mm/yr. Use GPS and seismic data to construct a fault model suggest that the steeply dipping Churachandpur-Mao fault(CMF) in the IBW accommodates the remaining motion of ~18 ± 2 mm/yr between the India and Sunda plates. We also use a 3D fault deformeter to detect the motion of CMF. Results show that the motion of CMF is aseismic. The aseismic behavior of the CMF suggest that the earthquake hazard in the IBW due to great and major interplate earthquakes is very low.
Reference
Gahalaut, V. K. et al. Aseismic plate boundary in the Indo-Burmese wedge, northwest Sunda Arc. Geology 41, 235238 (2013).
Kumar, A., M. Sanoujam, L. Sunil, and T. Dolendro, 2011, Active deformations at the Churachandpur Mao fault (CMF) in Indo Burma Ranges: Multidisciplinary evidences: International Journal of Geosciences, 2, no. 4, 597–609, http://dx.doi.org/10.4236/ijg.2011.24062.