Friday, 15 February 2019

Volcanos

Global Volcanic Activity - Ongoing Activity for the week of 6 February - 12 February 2019

Agung | Bali (Indonesia) : PVMBG reported that a 97-second-long explosive event at Agung began at 0012 on 8 February. A plume was not visible, though webcams recorded crater incandescence. 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 visible during 4-12 February. At 1919 on 7 February an event generated a plume that rose 1.3 km above the crater rim and ejected material 1.3-1.7 km from the crater. During 8-12 February there were four events, three of which were explosive. Plumes rose as high as 1.9 km, and boulders were ejected as far as 900 m from the crater. The Alert Level remained at 3 (on a 5-level scale).

Copahue | Central Chile-Argentina border : On 6 February OVDAS-SERNAGEOMIN lowered the Alert Level for Copahue to Green, the lowest level on a four-colour scale, noting the return of the crater lake and infrequent surficial activity. In addition, data from the geodetic monitoring network showed only slight deformation during the previous three months. ONEMI lowered the Alert Level to Green (the lowest level on a three-colour scale) for the municipality of Alto Biobío.

Dukono | Halmahera (Indonesia) : Based on satellite data, wind model data, and notices from PVMBG, the Darwin VAAC reported that during 9-10 and 12 February ash plumes from Dukono rose to an altitude of 2.4 km (8,000 ft) a.s.l. and drifted 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 2-8 February that sent ash plumes to 2.3 km (7,500 ft) a.s.l. Ash fell in Severo-Kurilsk on 4 February. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Etna | Sicily (Italy) : INGV reported that during 6-10 February webcams at Etna recorded gas emissions from New Southeast Crater (NSEC) and Voragine Crater, and occasional ash clouds from Northeast Crater (NEC); inclement weather prevented observations during 4-5 February. From the beginning of the afternoon on 6 February discrete ash emissions rose from NEC. The ash emissions were continuous from about 2215 on 7 February to 1015 on 8 February, producing relatively diffuse ash plumes that drifted S and then SE. Ash fell in Nicolosi (14 km S) and Pedara (15 km SSE). A diffuse ash plume drifted SW on 9 February.

Ibu | Halmahera (Indonesia) : PVMBG reported that during 5-12 February dense white-to-gray plumes from Ibu rose 200-800 m above the summit and drifted E, S, and W. Foggy conditions occasionally prevented visual observations. 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.

Kadovar | Papua New Guinea : According to Brad Scott of GeoNet, the Royal New Zealand Air Force released photos of a plume rising from Kadovar at 1640 on 10 February.

Merapi | Central Java (Indonesia) : PVMBG reported that during 1-11 February the volume of the lava dome in Merapi’s summit crater was about the same as the previous week’s estimate of 461,000 cubic meters, and there were no apparent morphological changes. Most of the extruded lava fell into the upper parts of the Gendol River drainage and the SE flank. On 7 February a pyroclastic flow traveled 2 km 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 (0.003-0.004 cubic meters per second). White water vapor emissions, occasionally grayish from included tephra, rose as high as 1 km and drifted in multiple directions. Crater incandescence was recorded by a webcam each day. 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.

Pacaya | Guatemala : INSIVUMEH reported that during 7-12 February Strombolian explosions at Pacaya’s Mackenney Crater ejected material as high as 25 m above the crater rim. Multiple lava flows traveled 10-250 m down the NW flank, advancing towards Cerro Chino, and on the E flank. Minor avalanches of material from lava-flow fronts descended the flanks.

Rincon de la Vieja | Costa Rica : OVSICORI-UNA reported possible events at Rincón de la Vieja at 1906 and 1950 on 5 February and at 0120 on 6 February. An event at 0000 on 6 February was also recorded; the report noted that poor weather conditions prevented visual observations of the crater.

Sabancaya | Peru : Observatorio Vulcanológico del Sur del IGP (OVS-IGP) and Observatorio Vulcanológico del INGEMMET (OVI) reported that an average of 26 explosions per day occurred at Sabancaya during 4-10 February. Long-period seismic events were recorded, and hybrid earthquakes were infrequent and of low magnitude. Although weather conditions sometimes prevented visual observations, gas-and-ash plumes were seen rising as high as 3 km above the crater rim and drifted 30 km S and SW. MIROVA detected one thermal anomaly. The report noted that the public should not approach the crater within a 12-km radius.

Santa Maria | Guatemala : INSIVUMEH reported that during 7-12 February explosions at Santa María's Santiaguito lava-dome complex generated ash plumes that rose 500-700 m and drifted E and SW, causing ashfall on the flanks. Avalanches of material descended the NE, E, and SE flanks of the lava dome.

Sheveluch | Central Kamchatka (Russia) : KVERT reported that during 2-8 February Sheveluch’s lava dome continued 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 some ash content rising to 4-5 km (13,100-16,400 ft) a.s.l. and drifted 105 km E and W. 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 during 1-8 February. Were 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 a period of sporadic ash emissions from Turrialba began at 0540 on 8 February and lasted more than one hour. The activity produced ash plumes that rose no more than 200 m above the vent rim. A very small ash emission was visible on 11 February.

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