Abstract:
Seismic activity of a region is a result of an underlying tectonic movement that could leave traces of ruptures on the surface in a form of faults. These fault lines exhibit irregular geometry that could be described as fractal dimension. This study focuses on fractal analysis using box-counting method for fault lines in the mainland Southeast Asia and calculates the fractal dimension values. The calculation is executed for three different grid spacings dividing the study area. The value of fractal dimension ranges from 0.831 to 1.204 in 1°×1° grid size, from 0.806 to 1.253 in 0.5°×0.5° grid size, and from 0.802 to 1.229 in 0.25°×0.25° grid size. Segments of fault associate with significantly high fractal dimension are observably complex and irregular on the regional scale. Besides equally divided into grids, the fault lines are extracted according to seismic source zones of the study area resulting in the value of fractal dimension ranges from the lowest of 0.906 in Andaman Basin to the highest of 1.194 in Western Thailand. Earthquake record data is also utilized to calculate seismicity parameters of the study area and be correlated to the fractal dimension. However, there is no significant relationship between fractal dimension to any of the seismicity parameters.
