Volcanos

Global Volcanic Activity – Ongoing Activity for the week of 6 March – 12 March 2019

Agung | Bali (Indonesia) : PVMBG reported that at 0452 on 4 March an event at Agung was recorded for just under three minutes and produced ashfall in Besakih (7 km SW) around 0615. No ash plume was visible although foggy conditions prevented views of the summit. An event that began at 0047 on 9 March lasted for 3 minutes and 50 seconds, and produced an ash plume that drifted E. 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 incandescence from Minamidake crater (at Aira Caldera’s Sakurajima volcano) was occasionally visible during 4-11 March. Occasional small events and three explosions were detected during 8-11 March. Plumes rose as high as 1.9 km. The Alert Level remained at 3 (on a 5-level scale).

Dukono | Halmahera (Indonesia) : Based on satellite images, wind model data, and ground observations, the Darwin VAAC reported that during 5-9 and 11-12 March ash plumes from Dukono rose to altitudes of 1.8-2.4 km (6,000-8,000 ft) a.s.l. and drifted WSW, SW, S, and SE. 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.

Karangetang | Siau Island (Indonesia) : PVMBG reported that during 4-10 March a low rate of lava effusion continued at Karangetang’s Kawah Dua (North Crater) as evident by avalanches in the Malabuhe River drainage on the NW flank. White plumes rose as high as 500 m above the rims of the summit craters during 4-12 March. The Darwin VAAC reported that on 7 March an ash plume rose to an altitude of 2.7 km (9,000 ft) a.s.l. and drifted SW. 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.

Kerinci | Indonesia : PVMBG reported that at 1850 on 7 March a brown ash emission rose 150 m above the rim of Kerinci summit vent and drifted NE. Ash also drifted down the SE and E flanks. Another brown ash emission was observed at 1209 on 8 March rising 700 m and drifting W. Brown ash emissions at 1607 on 10 March and 0919 on 11 March rose 300 m and 500 m, respectively, and drifted NE. Seismicity was dominated by volcanic tremor during 7-11 March.

Manam | Papua New Guinea : The Darwin VAAC reported that during 5-6 March ash plumes from Manam rose to an altitude of 3 km (10,000 ft) a.s.l. and drifted E based on satellite data and ground-based observations. A significant thermal anomaly was also visible in satellite images, and seismicity was elevated.

Merapi | Central Java (Indonesia) : PVMBG reported that during 1-12 March white-and-gray emissions of variable density rose as high as 1 km above Merapi’s summit. The volume of the lava dome was 470,000 cubic meters on 5 March, as estimated from drone photographs, and relatively unchanged from the previous weeks. 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 500-1,900 m down the Gendol drainage on 2, 3, and 7. 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 0845 on 8 March and was associated with a long-period earthquake signal. The explosion ejected and deposited material in areas around the crater, mainly to the N, and produced a plume that rose 2.7 km above the crater rim. 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.

Poas | Costa Rica : OVSICORI-UNA reported that, although weather conditions often prevented visual observations of Poás during 7-8 and 10 March, gas plumes sometimes containing ash were observed rising as high as 500 m above the crater rim and drifting SW. A sulfur odor and ashfall were reported in Naranjo and Grecia (16 km SW).

Sabancaya | Peru : Instituto Geofísico del Perú (IGP) and Instituto Geológico Minero y Metalúrgico (INGEMMET) reported that an average of 15 explosions per day occurred at Sabancaya during 4-10 March. Long-period seismic events were recorded, and hybrid earthquakes were infrequent and of low magnitude. Gas-and-ash plumes rose as high as 2.8 km above the crater rim and drifted 20 km SW, W, and NW. MIROVA detected four thermal anomalies, and on 3 March the sulfur-dioxide gas flux was high at 3,360 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 a thermal anomaly over Sheveluch’s lava dome was identified daily in satellite images during 1-8 March. Strong gas-and-steam emissions containing variable amounts of ash rose to altitudes of 3.5-4 km (11,500-13,100 ft) a.s.l. and drifted about 50 km E on 1 March. On 9 March explosions generated ash plumes that rose 10-11.2 km (32,800-36,700 ft) a.s.l. and drifted 70 km NW and N, prompting KVERT to raise the Aviation colour Code to Red (the highest level on a four-colour scale). Early on 10 March the Aviation colour Code was lowered to Orange. Ash plumes continued to rise from the crater, to an altitude of 8 km (26,200 ft) a.s.l., and drift 375 km N. Later that day gas-and-steam plumes with some ash rose as high as 4.5 km (14,800 ft) a.s.l. and drifted 15 km NE. On 11 March an ash plume rose as high as 4.7 km (15,400 ft) a.s.l. and drifted 70 km SE.

Suwanosejima | Ryukyu Islands (Japan) : JMA reported that crater incandescence at Suwanosejima’s Ontake Crater was visible at night during 1-8 March. Small events were occasionally recorded, generating plumes that rose as high as 600 m above the crater rim. The Alert Level remained at 2 (on a 5-level scale).

Turrialba | Costa Rica : OVSICORI-UNA reported that during 9-12 March plumes of gas sometimes containing small amounts of ash rose as high as 1 km above Turrialba’s crater rim

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