Etna update, 20 April 2013
A new episode of lava fountaining (paroxysm) has taken place on the afternoon of 20 April 2013 at Etna's New Southeast Crater (NSEC), the 12th event of this type within two months. Explosive activity had resumed on 19 April, less than 24 hours after the end of the previous paroxysm. During the night of 19-20 April, the explosive activity switched to quiet, non-explosive emission of lava from the eruptive fissure at the southeastern base of the NSEC cone, which had opened a the end of the 12 April paroxysm but remained inactive during the subsequent paroxysm on 18 Apeil. During the day of 20 April, effusive activity continued, but explosive phenomena were virtually absent until about 15:00 GMT (=local time -2), when violent explosions started, which rapidly passed into a lava fountain accompanied by the formation of an eruption column. The lava fountains reached heights of 800-1000 m above the crater, whereas the cloud of pyroclastic material expanded toward east-southeast, leading to heavy falls of ash and lapilli over the areas of Zafferana Etnea, Milo, Santa Venerina and further downslope, in the area of Giarre. A well-fed lava flow expanded down the western slope of the Valle del Bove, locally interacting with residual patches of snow, which resulted in the formation of lahars and ground-hugging steam and ash clouds, a phenomenon seen several times during previous paroxysms during the winter season on Etna. Lava fountaining continued for about one hour, and then passed into sporadic explosions and ash emission between 16:15 and 16:25. The episode was essentially over by 16:40, although the lava flow is still showing movement and possibly is still being fed from its source vent (19:00 GMT on 20 April 2013).