American Geophysical Union Become an AGU Member
Subscribe to AGU Journals		 AGU Home AGU Publications

Read Full Article (file size: 2259212 bytes)    Cited by

JOURNAL OF GEOPHYSICAL RESEARCH, VOL. 108, NO. B5, 2247, doi:10.1029/2001JB000657, 2003

Coupled magma chamber inflation and sector collapse slip observed with synthetic aperture radar interferometry on Mt. Etna volcano

P. Lundgren

Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California, USA


P. Berardino

Istituto per il Rilevamento Elettromagnetico dell'Ambiente (IREA-CNR), Naples, Italy


M. Coltelli

Istituto Nazionale di Geofisica e Vulcanologia, Catania, Italy


G. Fornaro

Istituto per il Rilevamento Elettromagnetico dell'Ambiente (IREA-CNR), Naples, Italy


R. Lanari

Istituto per il Rilevamento Elettromagnetico dell'Ambiente (IREA-CNR), Naples, Italy


G. Puglisi

Istituto Nazionale di Geofisica e Vulcanologia, Catania, Italy


E. Sansosti

Istituto per il Rilevamento Elettromagnetico dell'Ambiente (IREA-CNR), Naples, Italy


M. Tesauro

Istituto per il Rilevamento Elettromagnetico dell'Ambiente (IREA-CNR), Naples, Italy


Abstract

Volcanoes deform dynamically due to changes in both their magmatic system and instability of their edifice. Mt. Etna features vigorous and almost continuous eruptive activity from its summit craters and periodic flank eruptions. Even though its shape is that of a large stratovolcano, its structure features two rift systems and a flank collapse structure similar to Hawaiian shield volcanoes. We analyze European remote sensing (ERS) satellite differential interferometric synthetic aperture radar (InSAR) data (1993–1996) for Mt. Etna spanning its quiescence from 1993 through the initiation of renewed eruptive activity in late 1995. We use synthetic aperture radar (SAR) data from both ascending and descending ERS satellite tracks. Comparison of independent interferograms covering the first 2 years of the inflationary period shows a pattern consistent with inflation of the volcano. Calculation of the tropospheric path delay based on meteorological data does not change this interpretation. Interferograms from late summer 1995–1996 show no significant deformation. Joint inversion of interferograms from ascending and descending satellite tracks require both inflation from a spheroidal magmatic source located beneath the summit at 5 km below sea level, and displacement of the east flank of Etna along a basal decollement. Both sources of deformation were contemporaneous within the resolution of our data and suggest that inflation of the central magma chamber acted to trigger slip of Etna's eastern flank. These results demonstrate that flank instability and recharge of a volcano's magma system must both be considered toward understanding how volcanoes work and in their hazard evaluation.

Received 1 June 2001; accepted 30 October 2002; published 14 May 2003.

Index Terms: 8434 Volcanology: Magma migration; 8419 Volcanology: Eruption monitoring (7280); 8414 Volcanology: Eruption mechanisms; 1244 Geodesy and Gravity: Standards and absolute measurements.

Read Full Article (file size: 2259212 bytes)    Cited by

Citation: Lundgren, P., P. Berardino, M. Coltelli, G. Fornaro, R. Lanari, G. Puglisi, E. Sansosti, and M. Tesauro (2003), Coupled magma chamber inflation and sector collapse slip observed with synthetic aperture radar interferometry on Mt. Etna volcano, J. Geophys. Res., 108(B5), 2247, doi:10.1029/2001JB000657.