[S-VC31] Active Volcanism

[SVC31-13] Deformation of an infinite elastic cone due to a point pressure source and gravity change on the surface

*Ryuichi Nishiyama¹ (1.Earthquake Research Institute, The University of Tokyo)

Keywords:volcanic deformation, conical topography, semi-analytical solution, point dilatation source, gravity change

In the context of volcanic deformation, we present a semi-analytical solution describing the deformation of an infinite elastic cone due to a point pressure source buried on the axis (Nishiyama, 2023). The solution is based on the displacement potentials developed by Love and is solved as a boundary value problem using the Mellin transform. The present work can be considered as an extension of Mogi's model (Mogi, 1958) to a conical topography with an arbitrary apex angle (α). The present model can be used to calculate the expected gravity change on the cone surface. For the half-space case (α = 90°), the gravity change on the surface does not depend on the density of the medium (Hagiwara, 1977; Okubo, 1991). For the conical topography case (α < 90°), the density of the medium would affect the surface gravity change.

References
Mogi, K., 1958. Relations between the eruptions of various volcanos and the deformations of the ground surfaces around them, Bull. Earthq. Res. Inst., Univ. Tokyo, 36, 99–134.
Hagiwara, Y., 1977. The Mogi model as a possible cause of the crustal up- lift in the eastern part of Izu Peninsula and related gravity change, Bull. Earthq. Res. Inst., Univ. Tokyo, 52, 301–309.
Okubo, S., 1991. Potential and gravity changes raised by point dislocations. Geophys. J. Int., 105, 573-586.
Nishiyama, R., 2023. Deformation of an infinite elastic cone due to a point pressure source buried on the axis: implications to volcanic deformation, Geophys. J. Int., 232(2), 1129–1139.