A Detailed Study of b and D Value Distribution and Variation in Indo-Burma Subduction Zone (IBSZ)

We study the frequency-magnitude relationship and the fractal dimension for earthquakes in the Indo- Burman plate boundary system. The Gutenberg-Richter b value gives an estimate of the frequency of earthquake in a region and the fractal dimension (D value) relates to the seismic moment of the earthquakes. The b and D value of earthquakes are related to each other using Aki's famous formula of ?. In our analysis we use earthquakes of magnitude (mb) > 0, recorded between 1967 and 2017, from the online catalogue of the International Seismological Centre. Our analysis is done as a two-step process: (a) linear regression to the distribution of frequency of earthquakes within given ranges of moment magnitude using the Gutenberg-Richter relationship using the process of bootstrapping, and (b) estimation of fractal (box-counting method) dimension D of earthquake hypocenters calculated from sliding windows having large number of events. We looked into the spatial, temporal and depth wise variation of b and D values and the corresponding correlation between the two values in the Indo Burma Subduction Zone(IBSZ). The tectonic evolution of the IBSZ being an effect of the oblique convergence between the Indian and Asian plates, makes this region important for this study. This study will lead to an overall understanding of the seismicity of the region and the general trend followed over a long temporal, spatial and depth wise expanse. This study also introduces a new algorithm that is being used to identify the Magnitude of Completeness in b value determinations and automatically excludes the plateau regions while applying linear regression to the distribution of frequency of earthquakes.