Continuous dynamic response along a pre-existing structural discontinuity induced by the 2001 eruption at Mt. Etna
© The Society of Geomagnetism and Earth, Planetary and Space Sciences (SGEPSS); The Seismological Society of Japan; The Volcanological Society of Japan; The Geodetic Society of Japan; The Japanese Society for Planetary Sciences. 2004
Received: 5 September 2003
Accepted: 23 March 2004
Published: 24 June 2014
The intrusive process of the 2001 Mt. Etna eruption was accompanied by marked ground deformation and relevant seismic activity recorded between 12 and 17 of July (INGV-CT, 2001). At the same time, extensometer data evidenced the re-activation of a dry surface failure zone on the high south-eastern sector of Mt. Etna; this fracture system, formed in 1989, has been related to the propagation of a shallow blade-like dike along a NNESSW discontinuity (Bonaccorso and Davis, 1993; Bianco et al., 1998). The NNW-SSE discontinuity represents a complex low cohesion structure in which deformation may concentrate. Displacement measurements recorded on the surface fracture and the constraints obtained from seismicity show that the intrusion phase of the 2001 eruption has forced the NNE-SSW structure to move continuously with prevalent left-lateral displacement from a depth of 2–2.5 km b. s. l. to the surface with a compositive slip of about 3–5 centimeters.