Long-term earthquake forecasting model for northeast India and surrounding region: seismicity-based model

An earthquake forecasting model has been proposed for northeast India and surrounding region in a specified time span by exploiting the temporal and the spatial variations in the Gutenberg and Richter parameters ( a and b ). The study region has been divided into grid with a grid interval of 0.1° in latitude and longitude and 14 zones for the seismic activity density and the seismicity parameters estimation, respectively, while the time span of the used earthquake catalog has been divided into time grids with a fixed time interval of 5 years. The seismic activity rate at a grid point has been estimated from seismic activity density at the grid point and seismic activity in zone comprising the grid. The normalized multivariate Gaussian mixture model is considered to estimate the seismic activity density, while seismicity parameters have been estimated using the Gutenberg and Richter relation and the method of maximum likelihood estimation. The seismic activity rates at each grid point in all time grids have been fitted to an autoregressive model of order three, and the inferred coefficients of the model has been used to forecast seismic activity rate in next time grid, e.g., in time grid from 2011 to 2015 including.