Seismological evidence of a near-vertical dyke feeding the July 2001 lateral eruption at Mt. Etna volcano (Italy)
Abstract
In this study we report seismological evidence for the onset and emplacement of the final intrusion which fed the July 18- August 10, 2001 lateral eruption at Mt. Etna volcano. The shallow intrusion and the opening of the fracture system on July 13-18 were accompanied by one of the most relevant swarms recorded in the last 20 years. The overall number of earthquakes (M>1), recorded from the beginning of the swarm until the end of the eruption (August 10), was 2694 with maximum magnitude 3.9. However, the majority of the events (2645) occurred in the first 123 hours. On the basis of the earthquake locations and fault plane solution analysis, we constrained the kinematic process acting during the swarm. Seismic evidence collected are also supported by other geophysical and volcanological observations as well as surface surveys. In particular, the hypocentral pattern and the inferred orientation of the compressive axis of the most reliable focal mechanisms show that both seismicity and ground deformations are caused by the same stress source. We suggest that the emplacement of a near-vertical dyke, oriented about N-S a few kilometres south of the summit region, is the origin of the local stress source inferred .
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2001
- Bibcode:
- 2001AGUFM.S21C0591P
- Keywords:
-
- 7280 Volcano seismology (8419)