Volcanos

Roundup of Global Volcanic Activity – Ongoing Activity for the week of 17 October - 23 October 2018

Aira | Kyushu (Japan) : JMA reported that occasional, very small events occurred at Minamidake crater (at Aira Caldera’s Sakurajima volcano) during 12-19 October. Sulfur dioxide emissions were slightly less than 400 tons per day on 17 October. The Alert Level remained at 3 (on a 5-level scale).

Dukono | Halmahera (Indonesia) : Based on satellite data, wind model data, and notices from PVMBG, the Darwin VAAC reported that during 18-23 October ash plumes from Dukono rose to altitudes of 1.5-2.1 km (5,000-7,000 ft) a.s.l. and drifted E and NE.

Ebeko | Paramushir Island (Russia) : Volcanologists in Severo-Kurilsk (Paramushir Island), about 7 km E of Ebeko, observed explosions during 12-19 October that sent ash plumes to 4.5 km (14,800 ft) a.s.l. Ash plumes drifted in multiple directions, and caused ashfall in Severo-Kurilsk during 14-16 October. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Etna | Sicily (Italy) : INGV reported that during 15-21 October activity at Etna was characterized by gas emissions at the summit craters, with periodic Strombolian activity from vents in Bocca Nuova, Northeast Crater (NEC), Southeast Crater (SEC), and New Southeast Crater (NSEC). Strombolian activity at the N vent in the W part of Bocca Nuova’s (BN-1) crater floor ejected incandescent material higher that the crater rim. Spattering from the southernmost vent was also visible. Gas emissions increased at Voragine Crater from a vent that formed on 7 August 2016 on the E rim of the crater, and the crater continued to gradually widen and deepen. NEC activity was characterized by gas emissions and explosive activity of variable frequency and intensity. Fumarolic plumes rose from the rim and crater walls of NSEC and SEC. The E vent in NSEC produced Strombolian explosions and ash emissions which rapidly dispersed.

Fuego | Guatemala : INSIVUMEH and CONRED reported that on 20 October hot lahars descended Fuego’s Las Lajas (SE) and Mineral drainages, carrying blocks up to 2 m in diameter along with branches and tree trunks. The lahars were 20-30 m wide and 2 m deep. During 20-23 October there were 8-15 weak explosions recorded per hour, producing gray ash plumes that rose 750-850 m above the crater rim and drifted 12 km W and SW. Ashfall was reported in areas downwind, including Morelia (9 km SW), Santa Sofia (12 km SW), Sangre de Cristo (8 km WSW), Finca Palo Verde, Panimaché (8 km SW), and San Pedro Yepocapa (8 km NW). Lava fountains rose 100-200 m high. Avalanches of blocks descended the El Jute (SE), Ceniza (SSW), and Las Lajas (SE) drainages, with material reaching vegetated areas.

Ibu | Halmahera (Indonesia) : PVMBG reported that at 1223 on 19 October an event at Ibu generated an ash plume that rose 400 m above the crater rim and drifted E. Another event at 1809 on 22 October generated an ash plume that rose 400 m above the crater rim and drifted N. On both days seismic signals indicated explosions and rock avalanches. The Alert Level remained at 2 (on a scale of 1-4), and the public was warned to stay at least 2 km away from the active crater, and 3.5 km away on the N side.

Kadovar | Papua New Guinea : According to the Darwin VAAC, ash plumes from Kadovar were visible in satellite images on 21 October drifting NE at an altitude of 2.4 km (8,000 ft) a.s.l.

Krakatau | Indonesia : Based on satellite data, the Darwin VAAC reported that during 17-19 October ash plumes from Anak Krakatau rose to altitudes of 1.5-2.4 km (5,000-8,000 ft) a.s.l. and drifted in multiple directions. The Alert Level remained at 2 (on a scale of 1-4); residents and visitors were warned not to approach the volcano within 2 km of the crater.

Merapi | Central Java (Indonesia) : PVMBG reported that during 12-18 October the lava dome in Merapi’s summit crater grew at a rate of 6,200 cubic meters per day, faster than the previous week. By 18 October the volume of the dome, based on photos from the SE sector, was an estimated 201,000 cubic meters. White emissions of variable density rose a maximum of 100 m above the summit. The Alert Level remained at 2 (on a scale of 1-4), and residents were warned to remain outside of the 3-km exclusion zone.

Piton de la Fournaise | Reunion Island (France) : OVPF reported that the eruption at Piton de la Fournaise continued during 17-23 October. Strong gas emissions rose from the main vent as well as from areas along the lava tube. Periodic field surveys indicated active lava flows, several tens of meters long, at the base of the cone, and possibly active lava in the main vent.

Sabancaya | Peru : Observatorio Vulcanológico del Sur del IGP (OVS-IGP) and Observatorio Vulcanológico del INGEMMET (OVI) reported that explosions at Sabancaya averaged 23 per day during 15-21 October. Hybrid earthquakes were infrequent and of low magnitude. Gas-and-ash plumes rose as high as 3 km above the crater rim and drifted 40 km W, NE, and SE. The MIROVA system detected five thermal anomalies, and on 19 October the sulfur dioxide gas flux was high at 2,200 tons per day. The report noted that the public should not approach the crater within a 12-km radius.

Santa Maria | Guatemala : INSIVUMEH reported that during 20-23 October explosions at Santa María's Santiaguito lava-dome complex generated ash plumes that rose 500-700 m and drifted SW and W. Avalanches of material descended the W and E flanks of the lava dome.

Sheveluch | Central Kamchatka (Russia) : KVERT reported that a weak thermal anomaly over Sheveluch was identified in satellite data during 14-15 October; weather clouds prevented views on the other days during 12-19 October. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Turrialba | Costa Rica : OVSICORI-UNA reported frequent Strombolian events at Turrialba since 5 October. Periodic gas-and-ash emissions rose 200-500 m above the crater rim and drifted E, NW, and SW during 17-23 October.

Veniaminof | United States : AVO reported that the eruption at Veniaminof continued during 10-16 October, as evidenced by elevated surface temperatures from lava fountains and flows visible in satellite and webcam data, and low-level continuous tremor. Satellite data indicated that the W part of the S-flank flow field was active. A persistent steam plume, visible in webcam views, also contained sulfur dioxide and possible ash. The plume was particularly robust on 18 October, drifting 30 km NE; plumes drifted NE on 19 October and S the next morning. The Aviation colour Code remained at Orange and the Volcano Alert Level remained at Watch.