Shan....I am getting beyond my area of expertise but ...yes, there should be a lot of frictional heat released during the earthquake....but at a depth of many km. It can take 1000s (100s of thousands?) of years for that heat to make it to the surface. Since there have been earthquakes here for millions of years, you would expect there to be a higher heat flow than would be the case without earthquakes, and indeed, you have volcanos in Sumatra. This is all complicated by subduction bringing down cool crust and water-filled sediment....but the water lowers the melting point of some of the rocks, which is related to the existence of the volcanos.

I think your predictions would be better if you learned more about how faults behaved during earthquakes and also plate tectonics...you would not be predicting a M9 to be near 2 to 3 deg North...you would be predicting it south of the equator. Or, you would be predicting a smaller quake in your 2 to 3 deg N area...less than M8.

Chris