Modeling deformation and gravity changes from arbitrary positioned point inflation source beneath conical terrain
Ryuichi Nishiyama1, Mizuki Kohama2, Takahito Kazama2
Affiliations: 1Earthquake Research Institute, The University of Tokyo, Japan; 2Graduate School of Science, Kyoto University, Japan
Presentation type: Poster
Presentation time: Friday 16:30 - 18:00, Room Poster Hall
Poster Board Number: 27
Programme No: 2.3.13
Abstract
Geodetic observations and modeling play a vital role in understanding magma dynamics, crustal stress distribution, and predicting potential volcanic hazards. Accurate modeling of surface displacements and gravity changes induced by magmatic sources provides invaluable insights into subsurface structures and dynamics. Historically, a wide range of models has been developed to describe volcanic deformation. Among these, the Mogi model, which assumes a point spherical inflation source in an elastic half-space, has been extensively employed due to its simplicity and explanatory power. In this work, we extend the Mogi model to an infinite conical topography, where a point inflation/deflation source is embedded at an arbitrary position inside the elastic cone. We have successfully derived a semi-analytical solution to the three-dimensional elastostatic problem using Mellin and Fourier transformations. The accuracy of our solution is verified by comparisons with finite-element methods across several scenarios. A prominent characteristic of our cone model is that the surface displacements and gravity changes expected near the summit are enhanced compared to the Mogi source with the same volume change and depth. The proposed method serves as a useful first-order approximation for addressing topographic effects on the deformation field. The flexibility in source positioning enabled by our model allows for diverse applications, including source parameter inversion from geodetic data. References: https://doi.org/10.1093/gji/ggac379 https://doi.org/10.1093/gji/ggae146