Volcanos

Global Volcanic Activity - Ongoing Activity for the week of 17 April - 23 April 2019

Agung | Bali (Indonesia) : PVMBG reported two explosive eruptions at Agung on 21 April. The first was recorded at 0321 and produced a dense gray ash plume that rose 2 km above the crater rim and drifted W and S. Ashfall was reported in areas downwind including Besakih (7 km SW), Rendang (12 km NW), Klungkung (~40 km S), Gianyar (20 km WSW), Bangli (17 km WNW), Tabanan (51 km WSW), and the International Gusti Ngurah Rai (IGNR) airport (60 km SW) in Denpasar. The second event was recorded at 1856 and generated a dense ash plume that rose 3 km and drifted S. Minor ashfall was reported in Besakih, Rendang, Sebudi (6 km SW), and Selat (12 km SSW). The eruptions were accompanied by a boom heard at both the Rendang and Batulompeh observation posts. Ejected incandescent material from the two events fell on the flanks in all directions within a radius of 4 km. The Alert Level remained at 3 (on a scale of 1-4) with the exclusion zone set at a 4-km radius.

Aira | Kyushu (Japan) : JMA reported that the sulfur dioxide emission rate at Minamidake crater (at Aira Caldera’s Sakurajima volcano) was somewhat high on 16 April at 1,600 tons/day. An explosion on 17 April generated a plume that rose 2 km above the crater rim and ejected material as far as 900 m. During 19-22 April plumes from two events rose as high as 1.4 km. The Alert Level remained at 3 (on a 5-level scale).

Ambrym | Vanuatu : On 24 April the Vanuatu Meteorology and Geo-Hazards Department (VMGD) reported ongoing seismic activity at Ambrym and steam emissions. The lava lakes in Benbow and Marum craters had ceased to be active on 16 December 2018, one day after a fissure eruption began in the ESE part of the summit caldera near the Lewlembwi crater, and continued to be inactive. 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-km radius from Marum Crater. An additional Danger Zone was defined as a 1-km radius around the December 2018 fissures.

Dukono | Halmahera (Indonesia) : Based on satellite and wind model data, the Darwin VAAC reported that during 17-23 April ash plumes from Dukono rose as high as 2.1 km (7,000 ft) a.s.l. and drifted in multiple directions. The Alert Level remained at 2 (on a scale of 1-4), and visitors were warned to remain outside of the 2-km exclusion zone.

Ebeko | Paramushir Island (Russia) : Volcanologists in Severo-Kurilsk (Paramushir Island), about 7 km E of Ebeko, observed explosions during 12-15 April that sent ash plumes up to 3.2 km (10,500 ft) a.s.l. A thermal anomaly was identified in satellite images on 13 April. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Fuego | Guatemala : INSIVUMEH reported that on 18 April steaming hot lahars descended Fuego’s Ceniza (SSW) and Taniluyá (SW) drainages, carrying variously-sized material including blocks up to 2 m in diameter. The lahars were 1 m deep, 15 m wide, and had a sulfur odor. During 20-23 April there were 17-22 explosions per hour, generating ash plumes that rose almost as high as 1.1 km and drifted 15-20 km S, SW, and W. Shock waves vibrated local structures. Incandescent material was ejected 300-450 m high and caused avalanches of material that occasionally traveled long distances down Seca, Taniluyá, Ceniza, Trinidad, Las Lajas, and Honda ravines. A lava flow, 600 m long, advanced in the Seca drainage. Ashfall was reported in reported in Yepocapa (8 km N), Morelia (9 km SW), Santa Sofia (12 km SW), Sangre de Cristo (8 km WSW), and Panimache (8 km SW).

Ibu | Halmahera (Indonesia) : The Darwin VAAC reported that on 18 April an ash plume from Ibu was identified in satellite images drifting E at an altitude of 2.1 km (7,000 ft) a.s.l. 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.

Karymsky | Eastern Kamchatka (Russia) : KVERT reported that a weak thermal anomaly over Karymsky was visible in satellite images during 13-14 April. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Krakatau | Indonesia : PVMBG reported that there were four eruptive events during 15-22 April and multiple events on 23 April recorded by Anak Krakatau’s seismic network, though no emissions were visible. The Alert Level remained at 2 (on a scale of 1-4), and residents were warned to remain outside of the 2-km radius hazard zone from the crater.

Merapi | Central Java (Indonesia) : PVMBG reported that during 15-21 April the lava dome at Merapi continued to grow slowly, with any extruded material channeled into the SE-flank Gendol River drainage. White emissions rose 70 m. Block-and-ash flows traveled as far as 1.5 km in the Gendol drainage on 21 April. 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.

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

Sheveluch | Central Kamchatka (Russia) : KVERT reported that a thermal anomaly over Sheveluch’s lava dome was identified daily in satellite images during 12-18 April. Ash plumes were visible on 13 and 15 April drifting 83 km SE. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Stromboli | Aeolian Islands (Italy) : INGV reported that during 15-21 April activity at Stromboli was characterized by ongoing Strombolian activity and degassing from multiple vents within the crater terrace, though activity intensified on 19 April. Explosions originated at a rate of 3-16 per hour mainly from two vents (N1 and N2) in Area N (north crater area, NCA) and at least four vents (including C, S1, and S2) in Area C-S (South Central crater area). Explosions from the N1 vent ejected lapilli and bombs mixed with ash no more than 150 m high. Low-intensity explosions at the N2 vent ejected tephra to heights under 80 m. Vent C produced gas emissions. Incandescent material from S1 jetted as high as 150 m above the crater. Explosions from two vents at S2 ejected tephra more than 150 m high.