GEOPHYSICAL SURVEYS FOR THE IDENTIFICATION OF CAVES: THE CASE STUDY OF “MICIO CONTI LAVA TUBE” - SAN GREGORIO DI CATANIA (SICILY)

Lava tubes are the result of cooling of the outer portion of the lava flow due to contact with the atmosphere, while the inner portion that remains at a high temperature allows the lava to continue flowing. As a result, a crust is gradually formed on the upper surface of the lava flow and this crust eventual-ly welds to the channel levees (Fig. 2). A lava tube is built when the crust is sufficiently thick to endure the resi-stance of the surrounding flow and to support itself under its weight. The height of the lava within the flow caves depends on the topographical proper-ties of the area over which the lava flow is moving and the variations in the la-va flow emitted. Applied geophysical surveys (noise records, Masw, seismic tomography and electrical resistivity tomography) were carried out within the “Complesso Immacolatelle e Micio Conti” Natural Reserve, in the municipality of San Gre-gorio di Catania (eastern flank of Mt. Etna), where are located nine natural ca-ves (lava tube) (Fig.1), aims to test the attitude of different applied geophysi-cal methods in identifying the presence of lava caves in the subsoil. The investigated cave, known as “Micio Conti Lava Tube” (Fig. 1b,c), ex-tends over a lenght of about 130 meters with NW-SE orientation and is cha-racterized by the presence of two entrance (blue triangles in Fig. 1a).