Sezione di Catania - Osservatorio Etneo reported that Strombolian activity continued at Etna's Voragine Crater after the 5-6 March paroxysm at the New Southeast Crater (NSEC), but was rarely detected by 14 March. Sometime during the afternoon of 15 March, numerous explosion signals were detected, and the volcanic tremor amplitude increased through the evening. After nightfall, incandescence from the NSEC was visible, and nearby residents (on the SE flank) heard loud bangs coming from the crater. This activity continued during the night and through the following morning. At daybreak on 16 March, numerous gas rings formed by the more powerful explosions were recorded by the monitoring cameras and photographed by observers in the field.

During the early afternoon of 16 March, activity started to intensify more rapidly, and frequent jets of incandescent lava were launched up to150 m above the crater rim. At about 1800 lava started to flow through the deep breach in the SE rim of NSEC. Approximately 15 minutes later, explosions became progressively more energetic, ejecting incandescent bombs onto the outer flanks of the cone; contemporaneously, the quantity of pyroclastic material (ash and lapilli) in the eruptive plume increased. Ash plumes drifted SE.

Between 1830 and 1845, the eruptive activity changed from Strombolian explosions to lava fountaining, with the highest jets rising 600-800 m above the crater rim. The eruption column rose about 2 km above the summit of Etna before it was blown SE by the strong winds. Around 1900, several lightning flashes within the eruptive cloud were observed. Large, incandescent bombs and scoriae were deposited on the entire cone of the NSEC and the adjacent areas to the S and SE. Observations made after the end of the paroxysm revealed that a lava flow was emitted from the area of the saddle between the SEC cones. During the phase of most intense lava fountaining, numerous volcanic bombs fell onto the pyroclastic cones formed during the 2002-2003 eruption, up to 2 km from the NSEC. In this phase, the lava fountains were also spectacularly visible from the town of Randazzo, on the NNE flank, about 15 km from the NSEC.

Heavy tephra fall, mostly in the form of scoriaceous lapilli, affected the SE flank; on the W headwall of the Valle del Bove this material was still incandescent. Further downslope, in the towns of Zafferana Etnea, Santa Venerina, and a number of villages to the N of Acireale, the tephra fallout formed a continuous deposit of scoriaceous lapilli, which in the N portion of Zafferana Etnea locally was up to 10 cm thick. Many clasts in this area had diameters from 5 to 8 cm, and more rarely up to 10 cm. Numerous car windshields, skylights, and roof tiles were broken. Even on the Ionian coast, the deposit consisted largely of lapilli, with only a minor fraction of ash.

The activity started to decrease around 1904, and at 1910 the activity evolved into violent explosions that ejected broad fans of large, incandescent bombs, accompanied by loud bangs and detonations. These explosions ceased at 1920, but at 1927 two particularly powerful explosions ejected large incandescent rock fragments towards the SW at least 1.5 km from the crater. A few weaker Strombolian explosions occurred shortly after 1930. At 0449 on 17 March, a series of explosions started at Voragine, which continued for about 5 minutes, generating strong thermal anomalies that were recorded by the thermal surveillance camera, and probably produced small ash puffs. During the next few hours, weak glow coming from Voragine was recorded by a monitoring camera. There were also small collapses and slides of still hot material from unstable portions on the NSEC cone, which generated minor quantities of ash.

Source: Sezione di Catania - Osservatorio Etneo (INGV)

INSIVUMEH reported that during 13-18 March explosions from Fuego produced ash plumes that rose as high as 4.5 km above the crater, and drifted SW, W, NW, and NE, as far as 12 km. Explosions sometimes ejected incandescent material, generated rumbling noises, and produced shock waves. During 13-14 March ash fell in Panimache I and II (8 km SW) and shock waves vibrated structures. Ash again fell in the Panimache villages as well as in Morelia (9 km SW) during 14-15 March. Avalanches traveled SSW down the Ceniza drainage during 16-19 March.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)

Based on analyses of satellite imagery and wind data, the Darwin VAAC reported that on [15 March] an ash plume from Karkar rose to an altitude of 8.5 km (28,000 ft) a.s.l. and drifted 75 km N and 130 km E.

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

INSIVUMEH reported that during 13-14 and 16-18 March weak gas-and-ash plumes rose from Pacaya and drifted N, NW, and S. A diffuse white plume rose less than 500 m and drifted E on 19 March.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)

IG reported that the seismic network at Reventador recorded multiple explosions during 12-17 March. Observers reported falling and rolling incandescent material on the S flank on 12 March. Explosions produced ash plumes that rose more than 1 km and drifted SW. The next day ash plumes rose as high as 3 km. On 15 and 17 March explosions were detected by the seismic network; cloud cover prevented visual observations. On 16 March an ash plume rose 1 km and drifted W.

Source: Instituto Geofísico-Escuela Politécnica Nacional (IG-EPN)

INGEMMET reported that during 24 February-6 March fumarolic emissions from Sabancaya rose 400-1,000 m above the crater. On 27 February scientists who visited the volcano noted no ash deposits, and observed that the fumarolic emissions were comprised mostly of water vapor, carbon dioxide, and sulfur dioxide. During 28 February-5 March there were 400-500 earthquakes per day recorded, mostly volcano-tectonic events. The temperature of La Calera hot spring was unchanged from the previous year. The Alert Level remained at Yellow.

Source: Instituto Geológico Minero y Metalúrgico (INGEMMET)

CVGHM reported that phreatic eruptions from Tangkubanparahu's Ratu Crater occurred on 28 February and during 4-6 March, and generated ash plumes that rose up to 100 m above the crater. Sulfur dioxide emissions increased to a high level on 24 February and then decreased through 3 March. Sulfur dioxide emissions again increased during 5-9 March; CVGHM speculated that the increase was due to an enlargement of the eruptive vent, which had grown to a diameter of 20 m. Gas emissions decreased abruptly on 10 March and emission sounds stopped.

Seismicity had significantly increased on 22 February, marked by a growing number of daily events. A significant decrease was detected on 9 March. Deflation was detected from 24 February through early March, but was then stable during 7-14 March. On 18 March the Alert Level was lowered to 1 (on a scale of 1-4).

Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)

IG reported that during 13-17 March seismicity at Tungurahua was high. On 13 March ash plumes rose 1-3 km above the crater, and generated ashfall in Choglontús (SW) and Puela (8 km SW). The next day nearly continuous emissions of gas and ash rose 500 m. Explosions produced ash plumes that rose 3 km; ash fell between the Mapayacu (SW) and Rea drainages, and in Choglontús, Cahuají (8 km SW), and El Manzano (8 km SW). Blocks rolled 500 m down the flanks. On 15 March ash plumes drifted SE and W. An explosion generated an ash plume that rose 4 km and drifted E. A pyroclastic flow occurred near the crater. Explosions on 16 March generated ash plumes; ashfall was reported in Puela, Pillate (8 km W), and Ambato (31 km NW). On 17 March explosions again produced ash plumes that rose 4 km. Lava fountains rose 200-300 m above the crater and incandescent material fell on the flanks. A pyroclastic flow descended the upper parts of the Mandur (NW) drainage. Ashfall was reported in El Manzano, Palictagua and Choglontús.

Source: Instituto Geofísico-Escuela Politécnica Nacional (IG-EPN)