Shallow Seismicity Forecast for the India-Eurasia Collision Zone Based on Geodetic Strain Rates

Geodetic strain rates from increasing Global Positioning System data provide a promising approach for seismicity forecast. With the strain rate field presented in Zheng et al. (2017, ) derived from the most complete and up-to-date Global Positioning System data set in the India-Eurasia collision zone, we forecast the shallow seismicity of this region, and infer that about 11 Mw7.5, 36 Mw7.0, 109 Mw6.5, and 326 Mw6.0 earthquakes may occur here every 100years. We indicate that shallow seismicity forecast may be able to help us distinguish between block and continuum models, and block model cannot well describe the kinematics of the Tibetan Plateau, Tien Shan, West Mongolia, North China, and Myanmar. We suggest that the regions with high forecasted earthquake rates but lack of historical earthquakes are undergoing high seismic risk, such as the west-central Himalaya (overdue for Mw7.5 earthquakes, possibly Mw8.0) and the central Altyn Tagh fault (overdue for Mw7.0 and Mw7.5 earthquakes). Plain Language Summary Seismicity has brought enormous losses of life and property to human, especially to the India-Eurasia collision zone. The society is eager for a good seismicity forecast to help reduce the losses from earthquakes. Geodetic strain rates from increasing Global Positioning System data provide a promising approach for the seismicity forecast. In this study, we forecast the shallow seismicity of the India-Eurasia collision zone in different magnitude ranges based on the most complete and up-to-date Global Positioning System data set for this region. The forecast results show that the India-Eurasia collision zone may suffer from about 11 Mw7.5, 36 Mw7.0, 109 Mw6.5, and 326 Mw6.0 shallow earthquakes every 100years. We associate shallow seismicity forecast with the long-term debate between block and continuum models for the crustal deformation in the India-Eurasia collision zone, and suggest that the forecast results may help clarify the debate. Also, we indicate that the combination of the forecast results and the historical seismic catalog can be used to identify seismic gaps, such as the west-central Himalaya that is overdue for Mw7.5 earthquakes (possibly Mw8.0) and the central Altyn Tagh fault that is overdue for Mw7.0 and Mw7.5 earthquakes.