Modeling of Bouguer Gravity Anomaly and Tsunami Warning due to Makran Subduction Zone (Case Study: Beris Region)

The present tectonic activity and seismicity of Makran subduction zone is affected northward movement of Neo-Tethys oceanic plate under Eurasia plate. According to scientific and historical observations, Makran fault has high seismicity and is completely capable to create tsunami hazard on Iranian southeastern coasts and Pakistanian western coasts. Topography, Free-Air and Bouguer gravity anomalies show critical changes on this region, which related to the changes in the earth deep structures. Western Makran experiences more negative Free-Air gravity values rather than eastern parts, this indicates that dip of subducting plate in the western Makran is more than eastern part. Many of earthquakes which magnitudes are 6 and above happened in the regions Free-Air gravity change abruptly positive to negative values, these regions might predict big earthquakes. Bouguer gravity values change 150 mGal in the oceanic crust of Oman sea to the -90 mGal in the Eurasian continental region. Moho depth is about 14 km beneath Oman sea and increases up to 32 km under Eurasian continent. Subducting plate dip is around 5.70. Studying and numerical simulation of run up due to tsunami, by consideration of earthquakes, is very important. In this research, the run up of tsunami on Makran fault in Sistan and Baluchestan province coastlines (Beris region) by using numerical methods has been studied. The results were tested by earthquakes magnitude of 8,8.5 (Pakistan, 1945) and 9 (Japan, 2010).Therefore the maximum flood of model was up to 0.5m (for earthquake magnitude of 8), 3.4m (for earthquake magnitude of 8.5) and 14m (for earthquake magnitude of 9). The maximum flood width would be 1.4Km and arrival time of the first tsunami waves would be 22 minute. These results could be possible to determine high risk region to optimize development planning.