M.M. Islam1
1Bangladesh Meteorological Department
Abstract:
The December 13, 2009 earthquake and its aftershocks were generated near the Chittagong folded belt. This active earthquake source structure is located near the subduction zone of the India-Myanmar plates boundary. The generation of earthquakes larger than 5 indicates that the region is tectonically active and as such thrust faults are capable of generating future large earthquakes. Chittagong and Chittagong hill tracts districts are located on the folded sedimentary rocks of tertiary age. The focal mechanism analysis bears information on the seismic fault and tectonics of the earthquake source region. The tectonic movement along Point Chittagong is 5.5 cm/y with direction NNE. Using the data set from the event area saome areas have b = 0.71 and some b = 0.61. This b-value may indicate the situation of crustal deformation of the area. Low b-values of the event area suggest that the ground has large potential for future large earthquake. The subduction structure of Bangladesh, Myanmar continues to Andaman Islands area and to Sumatra. So the background of historical earthquake and recent low to medium magnitude earthquakes in this area indicate that the possibility of damaging earthquakes cannot be ruled out.
