A new active volcano in the Tyrrhenian Sea?

E Rubino E Rubino,B Di Sabatino B Di Sabatino,A De Santis A De Santis,P Favali P Favali,G DAnna G DAnna,M Sedita M Sedita

doi:10.4401/ag-3127

Abstract

A strong earthquake occurred in 2002 offshore from the northern coast of Sicily in the Southern Tyrrhenian Sea (Italy), and was followed by a series of hundreds of aftershocks. Communications through the fibre-optic cable between Palermo and Rome were interrupted a few hours after the occurrence of the main shock. After the required technical checks, the failure point was found a few kilometres away from the seismic sequence area. A few days later, a specialised cable ship reached the failure area. One side of the cable was completely burnt, while about three kilometres of cable was found locked. Tests on slices of cable showed that the temperature at which the cable was heated went well above 700oC. We can speculate that the earthquakes triggered off the emission of a submarine lava flow that buried, trapped and burnt the fibre-optic cable. The revising of the bathymetric survey made before the cables deployment allowed for the identification of a seamount in the vicinity of the rupture. This structure could represent the lava flows source volcano.

Highlights

This paper deals with some very interesting observations on a possible seafloor eruption in the Southern Tyrrhenian Sea
The time difference (3:34 h) between the main seismic event and the line interruption makes it unlikely that trapping, pulling and breaking of the underwater cable could be due to fractures, faults, collapses directly linked to the seismic events
A 5.9 earthquake occurred off-shore WSW Alicudi, and 3 h later the communications along the main fibre-optic cable connecting Palermo to Rome were interrupted

Summary

Introduction

This paper deals with some very interesting observations on a possible seafloor eruption in the Southern Tyrrhenian Sea. We tried to demonstrate, by laboratory experiments, that the occurrence of a strong off-shore earthquake (September 2002) triggered off a significant lava flow. By laboratory experiments, that the occurrence of a strong off-shore earthquake (September 2002) triggered off a significant lava flow This flow trapped the Rome-Palermo submarine communication cable, burning it and interrupting communications in the process. In May of that year the off-shore earthquake was preceded by the strong high-energy «strombolian» activity of Stromboli It was followed by an unusually explosive Etna eruption with associated earthquakes starting in October, and by a remarkable degassing episode at Panarea in November. It is hard to tell whether there are physical links between all the aspects of this sequence of events; this lies beyond the aim of our paper

Tectonic outline

Seismicity

Communications cable failure

Laboratory test results

Discussion

Conclusions