Volcanos

Global Volcanic Activity - Ongoing Activity for the week of 27 February - 5 March 2019

Aira | Kyushu (Japan) : JMA reported that incandescence from Minamidake crater (at Aira Caldera’s Sakurajima volcano) was occasionally visible during 25 February-4 March. There were four events and seven explosive events. Plumes rose as high as 2.3 km, and material as ejected as far as 1.1 km from the crater. The Alert Level remained at 3 (on a 5-level scale).

Dukono | Halmahera (Indonesia) : Based on satellite and wind model data, ground observations, and notices from PVMBG, the Darwin VAAC reported that during 27 February-5 March ash plumes from Dukono rose to altitudes of 2.1-2.4 km (7,000-8,000 ft) a.s.l. and drifted in multiple directions. On 28 February two plumes rising from the crater were visible; a northern plume was identified in satellite images and a southern plume rising to less than 1.5 km (5,000 ft) a.s.l. was reported by a ground observer. 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.

Ibu | Halmahera (Indonesia) : The Darwin VAAC reported that on 28 February an ash plume from Ibu was identified in satellite images drifting N 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.

Karangetang | Siau Island (Indonesia) : PVMBG reported that during 25 February-5 March a low rate of lava effusion continued at Karangetang’s Kawah Dua (North Crater). White plumes rose as high as 500 m above the summit crater rims. The Darwin VAAC reported that on 27 February a pilot observed an ash plume rising to an altitude of 1.8 km (6,000 ft) a.s.l. and drifting SE. The Alert Level remained at 3 (on a scale of 1-4), and residents were warned to remain outside of the 2.5-km exclusion zone around the N and S craters, and additionally within 3 km WNW and 4 km NW.

Manam | Papua New Guinea : The Darwin VAAC reported that on 1 and 5 March ash plumes from Manam were identified in satellite images rising to an altitude of 3 km (10,000 ft) a.s.l. and drifting SE, ESE, and E.

Merapi | Central Java (Indonesia) : PVMBG reported that during 22 February-5 March the volume of the lava dome in Merapi’s summit crater had not changed since the last measurement of 466,000 cubic meters estimated on 21 February. There were no apparent morphological changes; most of the extruded lava fell into the upper parts of the Gendol River drainage on the SE flank. Block-and-ash flows traveled 600-1,100 m down the Gendol drainage on 25 and 27 February, and on 2 March as many as 10 traveled as far as 2 km. Incandescent avalanches were visible at night. 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.

Nevados de Chillan | Chile : ONEMI and SERNAGEOMIN reported that an explosive event at Nevados de Chillán’s Nicanor Crater was recorded at 2323 on 1 March and was associated with a long-period earthquake signal. The explosion ejected high-temperature incandescent material deposited in areas around the crater, and likely destroyed part of the lava dome. The Alert Level remained at Orange, the second highest level on a four-colour scale, and residents were reminded not to approach the crater within 3 km. ONEMI maintained an Alert Level Yellow (the middle level on a three-colour scale) for the communities of Pinto, Coihueco, and San Fabián.

Santa Maria | Guatemala : INSIVUMEH reported that during 1-5 March as many as four explosions per hour at Santa María's Santiaguito lava-dome complex generated white plumes with ash that rose 500-700 m above the domes and drifted SE and SW. Avalanches of material descended the E and SE flanks of the lava dome. An explosion at 2155 on 4 March was heard in areas as far away as 10 km W, SW, S, and SE. The event ejected incandescent material 100 m high, produced ashfall around the volcano, and generated avalanches that traveled down the E and SE dome flanks reaching the base.

Sheveluch | Central Kamchatka (Russia) : KVERT reported that a thermal anomaly over Sheveluch’s lava dome was identified daily in satellite images during 22 February-1 March. Strong gas-and-steam emissions contained variable amounts of ash on 21, 25, and 27 February, and rose 4-5 km (13,100-16,400 ft) a.s.l. and drifted 100 km SW and E. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Suwanosejima | Ryukyu Islands (Japan) : JMA reported that crater incandescence at Suwanosejima’s Ontake Crater was visible at night during 22 February-1 March. Small events were occasionally recorded, generating plumes that rose as high as 900 m above the crater rim. The Alert Level remained at 2 (on a 5-level scale).

Turrialba | Costa Rica : OVSICORI-UNA reported that an event at Turrialba at 1050 on 28 February generated a plume that rose 500 m above the crater rim and drifted SW. Some additional ash pulses were recorded that day. An event at 0444 on 1 March produced a plume that rose 200 m and drifted NE. A period of continuous emissions rising 200-300 m was recorded during 2-4 March; the plumes contained minor amounts of ash at least during 2-3 March.