برآورد ضخامت لايه ي الاستيك پوسته در مناطق مختلف ايران با استفاده از تيوري ايزوستازي و آناليز طيفي

Estimation of Elastic Thickness of Lithosphere with Spectral Analysis and Isostasy in Different Regions of Iran

The upper part of the lithosphere is imposed by the lateral movement of the crustʹs plates and, as a result, it is strained and the elastic energy accumulates within it. This process continues for several decades and the layer of rocks which covers the faults will be ruptured finally, hence, the release of its energy causes ruinous earthquakes. The period of the energy accumulation and its amount is depended to elastic thickness of lithosphere; therefore, the estimation of it can be very helpful for the evaluation of the probable future earthquakesʹ magnitude and their focal depth. In this paper, the crust is assumed to be flexed by the loading of topography on it and the elastic thickness of lithosphere is estimated by Fourier spectral analysis of the free air gravity anomaly and topography in different regions in Iran. In order to generate the free air gravity anomaly and topography in a regular 30ʹx30ʹ grid, the EIGEN-GL04C and ET0P05, which are satellite based models, are used, respectively. Finally, it could be proved that the crust is not bent in some areas like Alborz zone which other investigation confirm this conclusion.