Ten Months of Monitoring the Stromboli Volcano with Ground-Based INSAR

On 30 December 2002, 10 million m¿3 of volcanic material collapsed from the NE slope pf the Stromboli volcana (Sciara del Fuoco) and caused a tsunami. From 20 February 2003 to 31 December 2003 a ground-based SAR interferometer, InGrIDLiSA, has been installed on the flank of the Sciara. Through this innovative radar system it has been possible to identify the unstable areas (Sciara del Fuoco and upper part of flank of NE crater) and to assess their evolution. The system is capable of producing a radar image of the observed area every 12 minutes, with a pixel resolution of about 2 m ${\times}$ 2 m and a millimetric accuracy. By comparing two radar images with the interferometric technique it is possible to obtain a map of deformation field. Through the different types of interferometric analysis it has been possible to follow the temporal evolution of the mass movement and to differentiate four processes: 1) lava flows which move at a high speed rate usually channelled into morphological depressions and sometimes diverting over the slope; 2) gravitational slow viscous flow of cooling lava masses accumulated on the Sciara; 3) gravitational sliding of volcanoclastic materials on the Sciara along a deep-seated slip surface, related to the landslide of December 2002; 4) incipient detachment of a rockslide of about 1 million m$¿3$, deriving by a translational slide on the flank of the crater. By the acquisition of radar data it has been possible to detect that the upper part of the flank of NE crater suffered a rapid acceleration on 5 April 2003, when a violent explosion occurred. For this reason the velocity of this planar slide increased one order of magnitude, returning to the normal values after two months. The landslide in the Sciara shows the wide fluctuations of the rate of displacement between 0.6 and 10 mm/h, with accelerating phases coincident with episodes of intense effusive activity. From July 2003 the velocity in the Sciara decreased progressively, stabilizing around the value of 0.4 mm/h.

ANTONELLO Giuseppe;  CASAGLI Nicola;  FARINA Paolo;  GUERRI Letizia;  LEVA Davide;  NICO Giovanni;  TARCHI Dario; 

2008-09-17

EGU - European Geosciences Union

JRC45217

1607-7962,   

https://publications.jrc.ec.europa.eu/repository/handle/JRC45217,