Volcanos

Roundup of Global Volcanic Activity – Ongoing Activity for the week of 14 November - 20 November 2018

Aira | Kyushu (Japan) : JMA reported that an explosion at Minamidake crater (at Aira Caldera’s Sakurajima volcano) was recorded at 0043 on 14 November, producing a large ash cloud that rose over 4 km above the crater rim. Incandescent material was ejected more than 1 km from the crater. The report noted that this was the first occurrence of an ash plume rising above 4 km since 16 July 2018. Two events occurred during 16-19 November with the larger plume rising 1.6 km into the clouds. The Alert Level remained at 3 (on a 5-level scale).

Ambrym | Vanuatu : On 15 November the Vanuatu Meteorology and Geo-hazards Department (VMGD) reported that the lava lakes in Ambrym’s Benbow and Marum craters continued to be active during October and November, and produced substantial and sustained gas-and-steam emissions. The Alert Level remained at 2 (on a scale of 0-5); the report reminded the public to stay outside of the Permanent Danger Zone defined as a 1-km radius from Benbow Crater and a 2.7-km radius from Marum Crater.

Dukono | Halmahera (Indonesia) : Based on satellite data and wind model data, the Darwin VAAC reported that during 14-15 and 19-20 November ash plumes from Dukono rose to altitudes of 1.8-2.1 km (6,000-7,000 ft) a.s.l. and drifted in multiple directions.

Ebeko | Paramushir Island (Russia) : Volcanologists in Severo-Kurilsk (Paramushir Island), about 7 km E of Ebeko, observed explosions during 9-15 November that sent ash plumes to 4.5 km (14,800 ft) a.s.l. Ash plumes drifted E. A weak thermal anomaly was identified in satellite data during 12-13 November. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Kadovar | Papua New Guinea : The Darwin VAAC reported that discrete, low-level events at Kadovar regularly occurred on 14 November based on satellite data. Ash plumes rose to an altitude of 2.4 km (8,000 ft) a.s.l. and drifted E.

Krakatau | Indonesia : PVMBG reported that seven events at Anak Krakatau were recorded between 0840 on 14 November and 0601 on 15 November. Each event lasted for 33-175 seconds, based on the seismic data, and produced ash plumes that rose 0.3-1 km above the crater rim and drifted N, ENE, and E. A 212-second-long event at 0524 on 16 November generated a dense black ash plume that rose 600 m and drifted NE. An event at 0532 lasted 207 seconds and generated an ash plume that rose 300 m and drifted NE. 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.

Kuchinoerabujima | Ryukyu Islands (Japan) : JMA reported that intermittent events at Kuchinoerabujima’s Shindake Crater had been recorded since 21 October, and crater incandescence began to be periodically visible on 6 November. Ash plumes rose as high as 1.2 km above the crater rim during 12-19 November and, according to the Tokyo VAAC, drifted in multiple directions. During fieldwork on 14 and 15 November observers noted no changes to the thermal areas in the crater. The Alert Level remained at 3 (on a scale of 1-5).

Merapi | Central Java (Indonesia) : PVMBG reported that during 9-15 November the lava dome in Merapi’s summit crater grew at a rate of 2,400 cubic meters per day, slower than the previous week. By 14 November the volume of the dome, based on photos from the SE sector, was an estimated 290,000 cubic meters. White emissions of variable density rose a maximum of 200 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.

Sabancaya | Peru : Observatorio Vulcanológico del Sur del IGP (OVS-IGP) and Observatorio Vulcanológico del INGEMMET (OVI) reported that an average of 20 explosions per day occurred at Sabancaya during 12-18 November. Long-period seismic events were recorded, and 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 NW, SW, and S. MIROVA detected seven thermal anomalies, and on 13 November the sulfur-dioxide gas flux was high at 3,000 tons per day. The report noted that the public should not approach the crater within a 12-km radius.

Sheveluch | Central Kamchatka (Russia) : KVERT reported that explosions at Sheveluch on 9 November generated ash plumes that drifted as far as 460 km E. A weak thermal anomaly was identified in satellite images during 9-11 and 15 November. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Turrialba | Costa Rica : OVSICORI-UNA reported that periodic, passive ash emissions at Turrialba continued to be visible in webcam images or during cloudy conditions inferred from the seismic data during 13-19 November.

Veniaminof | United States : AVO reported that the eruption from the cone in Veniaminof’s ice-filled summit caldera, continued at low levels during 14-20 November. Satellite and webcam data showed elevated surface temperatures from minor lava spattering and lava effusion. Relatively continuous low-amplitude tremor was recorded. Steam and diffuse ash plumes were periodically identified in webcam and satellite images; plumes rose as high as 4.9 km (16,000 ft) a.s.l. on 16 November. Recent satellite data showed that the lava flows had traveled as far as 1.2 km from the vent. Fractures in the ice sheet adjacent to the lava flow continued to grow due to meltwater flowing beneath the ice sheet. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale) and the Volcano Alert Level remained at Watch (the second highest level on a four-level scale).

Yasur | Vanuatu : On 15 November the Vanuatu Meteorology and Geo-hazards Department (VMGD) reported that ongoing explosions at Yasur were sometimes strong during October and November, based on visual observations and seismic data. The Alert Level remained at 2 (on a scale of 0-4). VMGD reminded residents and tourists that hazardous areas were near and around the volcanic crater, within a 395-m-radius permanent exclusion zone, and that volcanic ash and gas could reach areas impacted by trade winds.