Friday 22 February 2019

Volcanos

Global Volcanic Activity - Ongoing Activity for the week of 13 February - 19 February 2019

Agung | Bali (Indonesia) : PVMBG reported that an explosive event at Agung was recorded at 0434 on 14 February, causing ashfall in Bugbug village, 20 km SE. Crater incandescence was recorded at night by webcams in Karangasem City (16 km SE). 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 12-18 February incandescence was visible from Minamidake crater (at Aira Caldera’s Sakurajima volcano), and two events and two explosions were recorded. One of the explosions occurred at 0624 on 14 February, producing a plume that rose 1.5 km above the crater rim and ejecting material 500-700 m from the crater. An explosion on 17 February generated a plume that rose 2.3 km above the crater rim and ejected material 1-1.3 km from the crater. The Alert Level remained at 3 (on a 5-level scale).

Cleveland | Chuginadak Island (USA) : AVO reported that unrest at Cleveland continued during 13-19 February, though no activity was detected in seismic or infrasound data. Elevated surface temperatures were identified in satellite images; weather clouds sometimes prevented views of the volcano. The Aviation colour Code remained at Orange and the Volcano Alert Level remained at Watch.

Dukono | Halmahera (Indonesia) : Based on satellite data, wind model data, and ground-based observations, the Darwin VAAC reported that during 13-19 February ash plumes from Dukono rose to an altitude of 2.1 km (7,000 ft) a.s.l. and drifted S and SW. 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 8-15 February that sent ash plumes to 2.5 km (8,200 ft) a.s.l. Ash fell in Severo-Kurilsk on 11 February. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Etna | Sicily (Italy) : On 19 February INGV summarized Etna’s fissure eruption that occurred high on the SE flank during 24-27 December 2018, noting that 3-4 million cubic meters of lava erupted and covered an area of 1 square kilometer. After the event seismicity gradually decreased. The last significant event was a ML 4.1 recorded on 8 January 2019; afterwards seismicity was characterized as frequent events with modest magnitudes. Since the beginning of January ash emissions intermittently rose mainly from Northeast Crater (NEC) and more sporadically from Bocca Nuova. News sources noted that the Catania Airport (Aeroporto di Catania – Sicilia) was closed during 26-27 January. Preliminary assessments of some of the ash deposits showed they contained no juvenile material. During 11-17 February ash emissions of variable intensity rose from NEC and were notable on 14 and 18 February. Volcanic tremor amplitude did not significantly vary compared to the previous week, having average values overall. The Catania Airport announced the partial closure of airspace and flight delays during 17-18 February due to ash emissions.

Kadovar | Papua New Guinea : Based on satellite data and wind model data, the Darwin VAAC reported that on 16 February ash plumes from Kadovar rose to an altitude of 1.8 km (6,000 ft) a.s.l. and drifted ESE.

Kerinci | Indonesia : PVMBG reported that at 1309 on 13 February an observer noted a brownish-white ash plume rising 400 m above Kerinci’s crater rim and drifting NE. The Alert Level remained at 2 (on a scale of 1-4).

Krakatau | Indonesia : PVMBG reported that a brief explosive event at Anak Krakatau was recorded at 0026 on 14 February, though weather conditions prevented clear views of the event. During 15-17 February diffuse white plumes rose 50 m above the summit. At 1402 on 18 February another short-lived event produced an ash plume that rose about 500 m above the summit and drifted S and SW. The Alert Level remained at 3 (on a scale of 1-4), and residents were warned to remain outside of the 5-km radius hazard zone from the crater.

Manam | Papua New Guinea : Based on analyses of satellite imagery and model data, the Darwin VAAC reported that on 15 February an ash plume from Manam rose to an altitude of 4.9 km (16,000 ft) a.s.l. and drifted E.

Merapi | Central Java (Indonesia) : PVMBG reported that during 8-17 February the volume of the lava dome in Merapi’s summit crater was about the same as the previous week, and there were no apparent morphological changes. Most of the extruded lava did not add to the dome volume but instead fell into the upper parts of the Gendol River drainage and the SE flank. Incandescent avalanches traveling down the SE flank were visible at night. At 0858 on 11 February a pyroclastic flow traveled 400 m down the Gendol drainage. 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 during 5-12 February growth of the lava dome in Nevados de Chillán’s Nicanor Crater was very slow (10.8 cubic meters per hour). White water vapor emissions, occasionally grayish from included tephra, rose as high as 1.7 km and drifted SE and NE. Crater incandescence was recorded by a webcam each day. At 0109 on 15 February an explosive event partially destroyed the lava dome and ejected incandescent material onto areas near the crater. 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.

Popocatepetl | Mexico : CENAPRED reported that each day during 13-19 February there were 20-140 steam-and-gas emissions from Popocatépetl, some of which contained ash. Seismicity began to increase at 2100 on 14 February coincident with the onset of Strombolian activity. Incandescent material was ejected 1.5 km onto the flanks, and gas-and-ash plumes rose as high as 2 km above the carter rim and drifted SW. The phase lasted for about seven hours. Explosions were recorded at 1528, 1602, 1824, and 1935 on 14 February and at 0409 on 15 February. Ashfall was reported in areas downwind including Tetela del Volcán (20 km SW), Zacualpan (31 km SW), Jonacatepec (43 km SW), Cuautla (43 km SW), Ocuituco (24 km SW), Yecapixtla (31 km SW), and in Tochimilco (16 km SSE).

During 0044-0606 on 16 February Strombolian activity ejected incandescent material that fell back into the crater. Gas-and-ash plumes rose 1 km and drifted SE. A period of harmonic tremor began at 1600, accompanied by emissions of water vapor and gas that rose 1.5 km. By 1830 ejected incandescent fragments were visible and fell onto flanks 400 m from the crater. Plumes rose 2 km and drifted NNE. Seismicity decreased by 2100 and material was no longer being ejected above the crater rim, though crater incandescence remained visible. There were at least 14 explosions detected on 17 February; the more significant events were recorded at 0438, 0457, 0719, 0821, and 0956, generating plumes that rose 2 km and drifted NNE. Minor ashfall was reported in areas downwind including Tlaxco (85 km NE) and Xalostoc, Nativitas (40 km NE), Hueyotlipan (57 km NNE), Amaxac de Guerrero (60 km NE), Tepetitla de Lardizábal (37 km NE), Texoloc, and Tlaxcala (51 km NE). An explosion at 0704 on 18 February produced a plume that rose 2 km and drifted NNE. An explosion was detected at 0613 on 19 February. On 20 February CENAPRED noted growth of lava dome #82. The Alert Level remained at Yellow, Phase Two (middle level on a three-colour scale).

Sheveluch | Central Kamchatka (Russia) : KVERT reported that during 8-15 February Sheveluch’s lava dome continued to grow, extruding blocks on the N side, and producing hot avalanches and fumarolic plumes. A thermal anomaly was identified in satellite images daily. Video and satellite data recorded gas-and-steam plumes with variable ash content rising to 4 km (13,100 ft) a.s.l. and drifting in multiple directions. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Turrialba | Costa Rica : OVSICORI-UNA reported that during 13-15 February a period of almost continuous gas emissions with minor ash content rose 200-300 m above the rim of Turrialba’s active vent. The plumes drifted NW, W, and SW. An event at 1330 on 15 February produced a plume that rose 1 km and drifted W. During the morning of 18 February a plume with low ash content rose from the vent. An event at 1310 generated a plume that rose 500 m and drifted W.

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