Unveiling the deep plumbing system of a volcano by a reflection matrix analysis of seismic noise

TL;DR

This paper introduces a novel seismic noise analysis method using reflection matrix techniques to image the complex internal structure of a volcano at high resolution, aiding in better understanding and monitoring of volcanic activity.

Contribution

It presents a new approach to image volcano interiors by leveraging seismic noise and reflection matrix analysis, achieving unprecedented resolution in volcanic imaging.

Findings

Revealed detailed magmatic and hydrothermal plumbing system

Achieved half-wavelength resolution imaging

Provided new insights for volcano monitoring

Abstract

In geophysics, volcanoes are particularly difficult to image because of the multi-scale heterogeneities of fluids and rocks that compose them and their complex non-linear dynamics. By exploiting seismic noise recorded by a sparse array of geophones, we are able to reveal the magmatic and hydrothermal plumbing system of La Soufri\`ere volcano in Guadeloupe. Spatio-temporal cross-correlation of seismic noise actually provides the impulse responses between virtual geophones located inside the volcano. The resulting reflection matrix can be exploited to numerically perform an auto-focus of seismic waves on any reflector of the underground. An unprecedented view on the volcano's inner structure is obtained at a half-wavelength resolution. This innovative observable provides fundamental information for the conceptual modeling and high-resolution monitoring of volcanoes.