[M-IS09] Interdisciplinary studies on pre-earthquake processes

[MIS09-05] Seismogenic structure revealed by multi-scale electromagnetic methods

*Qinghua Huang¹ (1.Peking University)

キーワード：Seismogenic structure, electromagnetic methods, earthquakes, multi-scale

Seismogenic structure plays a fundamental role in understanding the potential risk zones of strong earthquakes. Besides the crust-scale structure, the near surface structure and the upper-middle mantle structure also contribute to the seismogenic process. Therefore, multi-scale imaging methods are required for the study on seismogenic structure. Electromagnetic method is one of the main approaches for imaging the interior structure of the earth. Due to its sensitivity to fluid, electromagnetic method has been widely adopted in the study on seismogenic structure and earthquake physics. In this study, we propose a multi-scale imaging approach by combining series of electromagnetic methods. We demonstrate that the broadband magnetotelluric (MT) array data are sensitive to the crust-scale electrical structure, and the traditional geomagnetic depth sounding (GDS) method with the long period source in magnetosphere can reveal the middle mantle structure. To fill in the imaging gap between the traditional MT and GDS methods, we have made use of the geomagnetic diurnal source in ionosphere and developed the alternative/joint inversion method of the electrical structure in the upper-middle mantle. For the near surface structure, we have developed a novel approach of high-resolution imaging by using seismoelectric signals and airborne electromagnetic data, respectively. Our study shows the potential applications for imaging the multi-scale seismogenic structure.