Volcanos

Global Volcanic Activity - Ongoing Activity for the week of 28 August - 3 September 2019

Aira | Kyushu (Japan) : JMA reported that during 26 August-2 September very small eruptive events were detected at Minamidake crater (at Aira Caldera’s Sakurajima volcano), though none of them were explosive. Crater incandescence was visible in webcams at night during 1-2 September. The Alert Level remained at 3 (on a 5-level scale).

Asosan | Kyushu (Japan) : JMA and the Tokyo VAAC reported that an eruptive event at Asosan was recorded at 1929 on 29 August; a plume rose 200 m above the crater rim and drifted N. During 30 August-3 September ash plumes rose as high as 250 m and drifted E, NE, N, and NW. The Alert Level remained at 2 (on a scale of 1-5).

Dukono | Halmahera (Indonesia) : Based on satellite and wind model data, and information from PVMBG, the Darwin VAAC reported that during 28 August-3 September 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. The Alert Level remained at 2 (on a scale of 1-4), and the public was warned to remain outside of the 2-km exclusion zone.

Ebeko | Paramushir Island (Russia) : KVERT reported that a thermal anomaly over Ebeko was identified in satellite images on 23 August. Volcanologists in Severo-Kurilsk (Paramushir Island), about 7 km E, observed explosions during 27-28 August that sent ash plumes up to 3 km (10,000 ft) a.s.l. and drifted E. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Fuego | Guatemala : INSIVUMEH reported that there were multiple explosions per hour recorded at Fuego during 28 August-3 September, generating ash plumes that rose as high as 1.1 km above the crater rim and drifted 10-20 km W and SW. Explosions sometimes produced shock waves that rattled houses in nearby communities. Incandescent material was ejected 200-300 m high and caused avalanches of material that occasionally traveled long distances (reaching vegetated areas) down Seca (W), Taniluyá (SW), Ceniza (SSW), Trinidad (S), El Jute (SE), Las Lajas (SE), and Honda ravines. Ashfall was reported in several areas downwind including Santa Sofía (12 km SW), Morelia (9 km SW), Panimaché I and II (8 km SW), Sangre de Cristo (8 km WSW), Finca Palo Verde, San Pedro Yepocapa (8 km NW), and El Porvenir (8 km ENE).

Ibu | Halmahera (Indonesia) : PVMBG reported that at 1847 on 31 August an ash plume from Ibu rose at least 800 m above the summit and drifted N. Seismicity was characterized by an explosion signal and earthquakes indicating 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.

Karangetang | Siau Island (Indonesia) : PVMBG reported that during 26 August-1 September lava continued to effuse from Karangetang’s Main Crater (S) and Dua Crater (N), traveling as far as 1.5 km SW down the Nanitu and Pangi drainages, 1.4 km down a drainage W of Pangi, and 1.8 km down the Sense drainage. Sometimes dense white plumes rose to 200 m above the summit. The Alert Level remained at 2 (on a scale of 1-4).

Karymsky | Eastern Kamchatka (Russia) : KVERT reported that a thermal anomaly over Karymsky was visible in satellite images during 23-24 August along with ash plumes drifting 51 km SE. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Kerinci | Indonesia : The Darwin VAAC reported that on 2 September a possible minor ash plume from Kerinci rose to an altitude of 4.9 km (16,000 ft) a.s.l. and drifted WSW, based on satellite images and weather models.

Klyuchevskoy | Central Kamchatka (Russia) : KVERT reported that a weak thermal anomaly over Klyuchevskoy was sometimes visible in satellite images and that gas-and-steam emissions continued, though ash was last emitted on 2 July. The Aviation colour Code was lowered to Yellow (the second highest lowest on a four-colour scale) on 30 August.

Merapi | Central Java (Indonesia) : PVMBG reported that during 26 August-1 September the lava-dome volume at Merapi did not change and was an estimated 461,000 cubic meters, based on analyses of drone images on 8 August. Extruded lava fell into the upper parts of the SE flank, generating block-and-ash flows that traveled down the Gendol drainage; one flow traveled 2 km on 27 August. Diffuse white plumes rose as high as 80 m above the summit. The Alert Level remained at 2 (on a scale of 1-4), and residents were warned to stay outside of the 3-km exclusion zone.

Nevados de Chillan | Chile : ONEMI and SERNAGEOMIN issued special reports noting as many as three explosions per day at Nevados de Chillán’s Nicanor Crater during 28 August-1 September, with each explosion associated with long-period earthquakes. The webcam recorded gas emissions that turned gray with explosions rising 160-550 m above the crater during the daytime, and explosions ejecting incandescent material onto the NNE flank at night. Plumes drifted SE, NE, and NNW. The Alert Level remained at Orange, the second highest level on a four-colour scale. ONEMI maintained an Alert Level Yellow (the middle level on a three-colour scale) for the communities of Pinto, Coihueco, and San Fabián, and stated that the public should stay at least 3 km away from the crater on the SW flank and 5 km away on the ENE flank.

Pacaya | Guatemala : INSIVUMEH reported that during 28 August-3 September Strombolian explosions at Pacaya’s Mackenney Crater ejected material as high as 30 m above the crater rim. Lava flows on the N and NNW flanks continued to advance, producing minor avalanches from the flow fronts.

Sabancaya | Peru : Instituto Geofísico del Perú (IGP) reported that an average of 26 low-to-medium intensity explosions per day occurred at Sabancaya during 26 August-1 September. Gas-and-ash plumes rose as high as 2 km above the summit and drifted SE, NW, and SW. There were 11 thermal anomalies identified in satellite data. The Alert Level remained at Orange (the second highest level on a four-colour scale) and the public were warned to stay outside of a 12-km radius.

Sangeang Api | Indonesia : The Darwin VAAC reported that during 28 August-3 September intermittent ash plumes from Sangeang Api were identified in satellite images rising to 3 km (10,000 ft) a.s.l. and drifting N, NW, W, and SW. The Alert Level remained at 2 (on a scale of 1-4).

Santa Maria | Guatemala : INSIVUMEH reported that on most days during 28 August-3 September there were 2-4 explosions per hour detected at Santa María's Santiaguito lava-dome complex. Ash plumes rose 700-900 m above the complex and drifted SW and W. Avalanches of material descended the E, SE, and S flanks, sometimes producing ash plumes that rose along the path of the avalanche. Ash fell in Monte Claro (S) on 31 August.

Semisopochnoi | United States : AVO reported that low-level eruptive activity at Semisopochnoi possibly continued during 28 August-3 September. Seismic activity was relatively minor and characterized by intermittent low-frequency earthquakes. Minor tremor was detected until 30 August. Satellite images were obscured by clouds. The Volcano Alert Level remained at Watch and the Aviation colour Code remained at Orange.

Sheveluch | Central Kamchatka (Russia) : KVERT reported that a thermal anomaly over Sheveluch’s lava dome was identified daily in satellite images during 22-25 August. Ash plumes on 25 August rose to 4.5-5 km (14,800-16,400 ft) a.s.l. and drifted more than 500 km NW. At 1510 on 29 August explosions produced ash plumes that rose to 10 km (32,800 ft) a.s.l. The leading part of the plume drifted W and then curved counterclockwise to the S, then E, and finally drifted 550 km N. Explosions at 1957 on 30 August produced ash plumes that rose to 7-7.5 km (23,000-24,600 ft) a.s.l. and drifted 50 km SSE. Ash plumes drifted SE at an altitude of 5.5 km (18,000 ft) a.s.l. on 3 September. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Shishaldin | Fox Islands (USA) : Low-level lava fountaining and minor explosive activity within Shishaldin’s summit crater was last observed on 17 August and likely continued during 28 August-2 September; continuous tremor was recorded by the seismic network and moderately-elevated surface temperatures were visible in satellite images. The Aviation colour Code remained at Orange and the Volcano Alert Level remained at Watch.

Tangkubanparahu | Western Java (Indonesia) : PVMBG reported that during 26 August-1 September emissions at Tangkubanparahu's Ratu Crater were characterized by puffs of dense black ash plumes rising as high as 20 m above the vent and white vapor plumes containing minor amounts of ash rising as high as 200 m. A larger event recorded at 0930 on 31 August generated a dense black tephra plume that rose 300 m and a white steam plume that rose 600 m. Ashfall was localized around Ratu Crater. The seismic network recorded continuous tremor. The Alert Level remained at 2 (on a scale of 1-4), and the public was warned to stay 1.5 km away from the active crater.

Ubinas | Peru : IGP reported that during 27 August-2 September gas-and-water-vapor plumes from Ubinas rose to heights less than 1 km above the summit, and three thermal anomalies were recorded by the MIROVA system. The number of seismic events was 2,828 (all under M 2.3), with volcano-tectonic (VT) signals being the most numerous. There was a slight increase in the number of long-period, hybrid, and VT events compared to the previous week. Beginning at 2145 on 1 September a period of continuous ash emissions was recorded by the webcam. An explosion at 1358 on 3 September generated an ash plume that rose 1.3 km above the summit and drifted more than 10 km S and SE. Prior to this event, the last explosion as recorded on 22 July. The Alert Level remained at Orange (the second highest level on a four-colour scale) and the public were warned to stay outside of a 15-km radius.