[Some elements of this report were excised at the authors' request.] "Since the August flank eruption, no major volcanic event has occurred on Mount Etna, although on 12 September a moderate phreatic explosion resulted in nine casualties near the W vent Bocca Nuova. On 11 January 1980, ashes were emitted from both Bocca Nuova and the Southeast Crater, where activity has preceded all the flank eruptions for the past two years.

"However, ground temperature measurements made on 21 January in the S part of Etna (Sapienza, Monte Silvestri, Monte Calcarazzi) show that the thermal anomaly has been reduced to a very low level (1-2°C, in contrast to 9°C in August 1979). This is the lowest temperature recorded in this zone since temperature measurements were initiated in September 1978.

Geological Summary. Mount Etna, towering above Catania on the island of Sicily, has one of the world's longest documented records of volcanism, dating back to 1500 BCE. Historical lava flows of basaltic composition cover much of the surface of this massive volcano, whose edifice is the highest and most voluminous in Italy. The Mongibello stratovolcano, truncated by several small calderas, was constructed during the late Pleistocene and Holocene over an older shield volcano. The most prominent morphological feature of Etna is the Valle del Bove, a 5 x 10 km caldera open to the east. Two styles of eruptive activity typically occur, sometimes simultaneously. Persistent explosive eruptions, sometimes with minor lava emissions, take place from one or more summit craters. Flank vents, typically with higher effusion rates, are less frequently active and originate from fissures that open progressively downward from near the summit (usually accompanied by Strombolian eruptions at the upper end). Cinder cones are commonly constructed over the vents of lower-flank lava flows. Lava flows extend to the foot of the volcano on all sides and have reached the sea over a broad area on the SE flank.

Information Contacts: C. Archambault and J. Stoschek, CNET, France; J. Tanguy, Univ. de Paris VI; PIRPSEF, CNRS-INAG.