[SEM19-P08] Nation-wide spatial distribution of the ultra-long period magnetic transfer functions in the China Mainland
Keywords:geomagnetic depth sounding, horizontal transfer function, china mainland, ultra long period, mantle electrical conductivity structure
In this study, in order to elucidate the mantle electrical conductivity structure down to the transition zone beneath whole China mainland, we investigated the geomagnetic records obtained by the National Geomagnetic Center of China. We analyzed hourly geomagnetic data from 42 stations with absolute measurements for nearly 8 years (2008/01/01-2016/12/31). After we calculated the angle between azimuth of the geomagnetic pole and that of the geographic pole at respective stations with the aid of the IGRF models, we obtained the geomagnetic data rotated to the geomagnetic dipole field coordinates. The vertical component to the horizontal components transfer functions (GDS transfer functions) and inter station horizontal field transfer functions of periods up to 100days were estimated with the aid of the remote reference method with a robust estimation scheme. In the presentation, we will show the characteristics of the spatial distribution of both the GDS and the horizontal transfer functions. We will also show results from the OCCAM 1-D inversion with minimum and smooth structure constraints by using the GDS transfer functions.