Acocella, Boris Behncke, Marco Neri and Salvatore D'Amico (2003)
Link between major flank slip and 2002-2003 eruption
at Mt. Etna (Italy)
Geophysical Research Letters, volume 30, No.
The 2002-2003 Etna
eruption is studied through earthquake distributions and surface fracturing.
In September 2002, earthquake-induced surface rupture (sinistral offset
~0.48 m) occurred along the E-W striking Pernicana Fault (PF), on the
NE flank. In late October, a flank eruption accompanied further (~0.77
m) surface rupturing, reaching a total sinistral offest of 1.25 m; the
deformation then propagated for 18 km eastwards to the coastline (sinistral
offest 0.03 m) and southwards, along the NW-SE striking Timpe (dextral
offset 0.04 m) and, later, Trecastagni faults (dextral offset 0.035
m). Seismicity (<4 km bsl) on the E flank accompanied surface fracturing:
fault plane solutions indicate an overall ESE-WNW extension direction,
consistent with ESE slip of the E flank also revealed by ground fractures.
A three-stage model of flank slip is propsed: inception (September earthquake),
climax (accelerated slip and eruption) and propagation (E and S migration
of the deformation).
volcano seismology, surface fracturing, flank slip, eruption, Etna.