HERS: Heterogeneities and its Effect of Rotational Seismology

The project aims to understand the behavior of heterogeneities in the Earth medium and identify its effect in the simulation of rotational ground motions.  Conventionally, the earth medium is modeled as a layered half space where each layer is assigned a different material property to cater for material variation along the depth of the Earth. However, there are instances where due to the presence of heterogeneities, there is a sudden change observed in the material property. Though local variations in the material property do not affect the translations, the spatial gradients, rotations and strain are affected by these variations. In this project we plan to understand the effect of these local heterogeneities on the rotations and develop a numerical model incorporating heterogeneities for a region of the European Union. The developed model will be validated against the recorded rotations available for past earthquakes. Once validated, the developed model can be used to predict peak ground rotation contour maps for an earthquake in the European Union.