Source estimation technique of vertical deformation without assuming the model shape

Abstract

In this paper, I suggest an inversion technique to estimate the source structure of a vertical deformation without assuming the model shape. This method estimates a source structure that explains the vertical deformations observed at the surface by minimizing the area having an arbitrary target value established; it is capable of clearly showing the source structure. I applied this technique to the vertical deformation observed in the Jigokudani valley (Midagahara volcano, central Japan), and found that the estimated source depth was compatible with the upper depth of the cap rock structure obtained by the AMT(Audio-frequency Magneto Telluric) survey and with the source depth estimated from past crustal movements.