Effects of topography on the interpretation of the deformation field of prominent volcanoes - Application to Etna

Geophysical Research Letters
By:  and 

Links

Abstract

We have investigated the effects of topography on the surface-deformation field of volcanoes. Our study provides limits to the use of classical half-space models. Considering axisymmetrical volcanoes, we show that interpreting ground-surface displacements with half-space models can lead to erroneous estimations of the shape of the deformation source. When the average slope of the flanks of a volcano exceeds 20°, tilting in the summit area is reversed to that expected for a flat surface. Thus, neglecting topography may lead to misinterpreting an inflation of the source as a deflation. Comparisons of Mogi's model with a three-dimensional model shows that ignoring topography may lead to an overestimate of the source-volume change by as much as 50% for a slope of 30°. This comparison also shows that the depths calculated by using Mogi's solution for prominent volcanoes should be considered as depths from the summit of the edifices. Finally, we illustrate these topographic effects by analyzing the deformation field measured by radar interferometry at Mount Etna during its 1991–1993 eruption. A three-dimensional modeling calculation shows that the flattening of the deflation field near the volcano's summit is probably a topographic effect.

Publication type Article
Publication Subtype Journal Article
Title Effects of topography on the interpretation of the deformation field of prominent volcanoes - Application to Etna
Series title Geophysical Research Letters
DOI 10.1029/98GL51512
Volume 25
Issue 10
Year Published 1998
Language English
Publisher American Geophysical Union
Description 4 p.
First page 1979
Last page 1982
Google Analytic Metrics Metrics page
Additional publication details