Volcanos

Roundup of Global Volcanic Activity – Ongoing Activity for the week of 19 September - 25 September 2018

Aira | Kyushu (Japan) : JMA reported that there were eight events and an additional five explosions at Minamidake crater (at Aira Caldera’s Sakurajima volcano) during 18-25 September, with ash plumes rising as high as 2.1 km above the crater rim and material ejected as far as 1.1 km. Crater incandescence was occasionally visible at night. The Alert Level remained at 3 (on a 5-level scale).

Ambae | Vanuatu : On 21 September the Vanuatu Meteorology and Geo-hazards Department reported that during September activity at Ambae’s Lake Voui was characterized only by steam emissions; the eruption had ceased. The Alert Level was lowered to 2 (on a scale of 0-5).

Dukono | Halmahera (Indonesia) : Based on satellite data, wind model data, and notices from PVMBG, the Darwin VAAC reported that during 19-25 September ash plumes from Dukono rose to an altitude of 1.8 km (6,000 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 14-21 September that sent ash plumes to 4.2 km (13,800 ft) a.s.l. A thermal anomaly over the volcano was occasionally visible in satellite data, and an ash plume was identified drifting about 80 km E on 14 September. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Fuego | Guatemala : INSIVUMEH reported that during 20-21 and 24-25 September explosions at Fuego generated ash plumes that rose almost as high as 1 km above the crater and drifted 12 km W and SW. Incandescent material was ejected 150 m above the crater rim, and caused avalanches of material within the crater area. Ashfall was reported in areas downwind including Sangre de Cristo (8 km WSW), Finca Palo Verde, Panimaché (8 km SW), and San Pedro Yepocapa (8 km NW). On 25 September hot, steaming lahars descended the El Jute (SE) and Las Lajas (SE) drainages, carrying blocks up to 2 m in diameter, and branches and tree trunks.

Karymsky | Eastern Kamchatka (Russia) : KVERT reported that a thermal anomaly over Karymsky was identified in satellite images on 19 September; the volcano was obscured by weather clouds the rest of the days during 14-21 September. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Kilauea | Hawaiian Islands (USA) : HVO reported no incandescence from a collapse pit in the central part of Kilauea’s Fissure 8 cone during 19-25 September, though a small amount of fuming was visible during the day. Seismicity and ground deformation remain low at the summit, and small aftershocks from the M 6.9 earthquake in early May were located along faults on the south flank. The combined rate of sulfur dioxide emission from the summit and the LERZ (less than 1,000 tonnes/day) were lower than any time since late 2007. The Volcano Alert Level remained at Watch and the Aviation colour Code remained at Orange.

Krakatau | Indonesia : Based on satellite data, wind model data, and notices from PVMBG, the Darwin VAAC reported that during 18-24 September ash plumes from Anak Krakatau rose to altitudes of 0.9-3.7 km (3,000-12,000 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.

Manam | Papua New Guinea : Based on analyses of satellite imagery and model data, the Darwin VAAC reported that at 2050 on 23 September a short-lived eruption at Manam produced an ash plume that rose 8.5 km (28,000 ft) a.s.l. and drifted NW.

Merapi | Central Java (Indonesia) : PVMBG reported that during 17-23 September the new lava dome in Merapi’s summit crater continued to slowly grow. By 22 September the volume of the lava dome was an estimated 113,000 cubic meters, and the growth rate was 3,000 cubic meters per day. White emissions of variable density rose 100 m above the summit. The Alert Level remained at 2 (on a scale of 1-4), and resident were warned to remain outside of the 3-km exclusion zone.

Pacaya | Guatemala : INSIVUMEH reported that during 17-18, 20-21, and 24-25 September Strombolian explosions at Pacaya’s Mackenney Crater ejected material as high as 25 m above the crater rim. As many as four lava flows originating from Mackenney Crater traveled 50-250 m NW.

Sabancaya | Peru : Observatorio Vulcanológico del Sur del IGP (OVS-IGP) and Observatorio Vulcanológico del INGEMMET (OVI) reported that explosions at Sabancaya averaged 16 per day during 17-23 September. Hybrid earthquakes were infrequent and of low magnitude. Gas-and-ash plumes rose as high as 3.5 km above the crater rim and drifted 40 km N, NE, and SE. The MIROVA system detected eight thermal anomalies, and on 17 September the sulfur dioxide gas flux was high at 1,600 tons/day. The report noted that the public should not approach the crater within a 12-km radius.

Sangay | Ecuador : Based on satellite images and wind model data, the Washington VAAC reported that during 19-20 September ash emissions from Sangay rose to 5.8-6.1 km (19,000-20,000 ft) a.s.l., drifted WNW and W, and became diffuse after 37 km.

Santa Maria | Guatemala : INSIVUMEH reported that heavy rain at Santa María on 20 September produced hot lahars in the San Isidro-Tambor River (S), a tributary of Salamá River. The lahars were 25 m wide, 2 m deep, had a sulfur odor, and carried branches, tree trunks, and blocks up to 2 m in diameter. Lahars also descended the Nimá I (S) drainage. On 21 September explosions generated ash plumes that rose 800 m above the crater rim and drifted W and SW; minor amounts of ash fell locally. Lahars descended the Nimá I, Salamá, and San Isidro drainages. During 24-25 September explosions produced ash plumes that rose 500-700 m and drifted SW. Avalanches of material traveled down the SE and NE flanks.

Semeru | Eastern Java (Indonesia) : Based on analysis of satellite images, the Darwin VAAC reported that on 19 September a possible ash-and-steam plume from Semeru rose to an altitude of 4 km (13,000 ft) a.s.l. and drifted SSW.

Sheveluch | Central Kamchatka (Russia) : KVERT reported that a thermal anomaly over Sheveluch was identified in satellite data during 14, 16-17, and 19-20 September. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).