After his awakening from the month of July (https://ingvvulcani.wordpress.com/2018/07/24/letna-da-segni-di-risveglio-attivita-stromboliana-in-area-sommitale/) and the gradual intensification of the eruptive activity at the summit craters (https://ingvvulcani.wordpress.com/2018/08/23/aumenta-di-intensita-lattivita-eruttiva-sommitale-delletna/), Etna started a new episode of Strombolian activity and emission of lava flows in the night between 23 and 24 August 2018 (Fig. 1).
In the late afternoon of August 23, a sudden increase in the amplitude of the volcanic tremor (Fig. 2) announced the beginning of a weak explosive activity from the so-called "mouth of the saddle", which is located exactly halfway between the old cone of the Southeast Crater and that of the New Southeast Crater.
This activity quickly became almost continuous, with incandescent lava bombs being dropped up to about 100-150m above the crater. Around 20.30 (local time), a small lava flow was observed which was emitted from another mouth of the New Southeast Crater, the one located on the high eastern flank of its cone; the lava emission was accompanied by sporadic and weak explosions from the same vent. This flow slowly lengthened in the direction of the Valle del Bove (eastern side), slowing down after having covered a few hundred metres. Shortly afterwards, lava overflow also began from the "mouth of the saddle" and poured onto the northern flank of the cone of the New Southeast Crater, reaching its base in the late evening (Fig. 3).
In the following hours, the activity continued without significant changes. At dawn on August 24, the amplitude of the volcanic tremor began to decrease slightly and the Strombolian activity was less intense. However, in the morning, a new, small lava overflow was also observed towards the upper southern slope of the cone of the New Southeast Crater, which reached a length of a few tens of metres. After 9.20, a continuous ash emission also began (Fig. 4) which fed a plume several hundred meters high above the crater.
At 11.00 today, 24 August, the eruptive phenomenon is still in full evolution.
The phenomenon is constantly monitored by the Etna Observatory of the National Institute of Geophysics and Volcanology (INGV).