Friday, 2 October 2020

Volcanos

Roundup of Global Volcanic Activity – Ongoing Activity for the Week 23 September 2020 – 29 September 2020

Aira | Kyushu (Japan) : JMA reported that very small eruptive events at Minamidake Crater (at Aira Caldera’s Sakurajima volcano) were occasionally recorded during 14-21 September. Crater incandescence was visible at night. The daily sulfur dioxide emission rate was high at 2,000 tons per day on 25 September. The Alert Level remained at 3 (on a 5-level scale).

Copahue | Central Chile-Argentina border : SERNAGEOMIN reported continuing activity at Copahue during 1-15 September. Webcams recorded gas-and-ash plumes rising as high as 1.1 km, sometimes associated with nighttime crater incandescence. The plumes drifted 6-15 km SW and SE. Sulfur dioxide emissions were high, averaging 1,499 tonnes per day (ranging from 1,148 to 1,850 tonnes per day), with a high value of 3,435 on 12 September. Two thermal anomalies were identified in satellite images. The Alert Level was remained at Yellow (the second lowest level on a four-colour scale). ONEMI maintained the Yellow Alert (the middle level on a three-colour scale) for residents of the Alto Biobío municipality and access to an area within 1 km of El Agrio Crater was restricted to the public.

Dukono | Halmahera (Indonesia) : Based on satellite and wind model data, the Darwin VAAC reported that during 23-28 September ash plumes from Dukono rose 2.1 km (7,000 ft) a.s.l. and drifted W and WNW. The Alert Level remained at 2 (on a scale of 1-4), and the public was 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 20-23 September that sent ash plumes up to 3.5 km (11,500 ft) a.s.l. and drifted SE, E, and NE. A thermal anomaly over the volcano was visible in satellite data on 21 and 22 September. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Ibu | Halmahera (Indonesia) : PVMBG reported that at 0554 on 26 September a white-to-gray ash plume from Ibu rose 600 m and drifted S. At 0641 on 27 September and at 0554 on 28 September ash plumes rose 500 m and drifted N. 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.

Laguna del Maule | Central Chile-Argentina border : SERNAGEOMIN reported that during 1-15 September inflation continued to be detected at the Laguna del Maule Volcanic Complex, although at a lower rate of 0.7 cm per month which is below the 2 cm per month average for this year. Seismicity in the S sector was low in both number and magnitude of events. The Alert Level remained at Yellow, the second lowest colour on a four-colour scale, as activity remained above baselines. ONEMI recommended restricted access within a radius of 2 km from the emission center.

Langila | New Britain (Papua New Guinea) : Based on analyses of satellite imagery and wind-model data, the Darwin VAAC reported that on 23 September an ash plume from Langila rose to an altitude of 2.7 km (9,000 ft) a.s.l. and drifted NW.

Nevados de Chillan | Chile : SERNAGEOMIN reported that activity at Nevados de Chillán’s Nicanor Crater was ongoing during 1-15 September. Explosions at the lava dome in the crater produced plumes that rose less than 1.5 km. Ashfall was mainly distributed within 300 m E and NE. Deposits from larger explosions were visible to the ESE. Incandescence at the E part of the crater was visible. The lava flow on the NNE flank (L5) was 500 m long and was advancing at a rate of 1.7 meters per hour by 15 September. The W levee of the flow channel ruptured, causing the channel to widen and the toe of the flow to thicken. The Alert Level remained at Yellow, the second lowest level on a four-colour scale, and residents were reminded not to approach the crater within 3 km. ONEMI stated that Alert Level Yellow (the middle level on a three-colour scale) remained in place for the communities of Pinto and Coihueco, noting that the public should stay at least 3 km away from the crater on the W and SW flank and 5 km away on the NE flank.

Sabancaya | Peru : Instituto Geofísico del Perú (IGP) reported a daily average of 36 explosions at Sabancaya during 21-27 September. Gas-and-ash plumes rose as high as 2.5 km above the summit and drifted NE, E, SE, SW, and NW. Eleven thermal anomalies over the crater were identified in satellite data. Minor inflation was detected in areas N of Hualca Hualca (4 km N) and on the SE flank. Ashfall was reported in Lluta (30 km SW) and Huanca (75 km SSE) on 24 September. The Alert Level remained at Orange (the second highest level on a four-colour scale) and the public were warned to stay outside of a 12-km radius.

Sheveluch | Central Kamchatka (Russia) : KVERT reported that a thermal anomaly over Sheveluch was identified in satellite images during 18-25 September. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Suwanosejima | Ryukyu Islands (Japan) : JMA reported nighttime incandescence at Suwanosejima’s Ontake Crater during 18-25 September. An explosion at 0923 on 25 September generated a gray-white ash plume that rose 600 m above the crater rim and disappeared into weather clouds. Ashfall was reported in Toshima village, 4 km SSW. The Alert Level remained at 2 (on a 5-level scale).

Villarrica | Chile : SERNAGEOMIN reported that activity at Villarrica was characterized by an active lava lake, minor explosions, and gas emissions during 1-15 September. Webcam images showed whitish gas emissions rising no higher than 500 m above the crater rim during the day, with occasional nighttime crater incandescence and ejected material seen at night. Satellite images showed tephra deposits around the crater extending from the rim up to 36 m on the E and SE flanks on both 5 and 7 September. Two thermal anomalies were visible in satellite images on 14 September. At 1350 on 25 September the seismic network recorded a long-period earthquake associated with a moderate explosion. The explosion generated an ash plume that rose 800 m above the vent and drifted ENE, and ejected blocks onto the flanks. Another long-period event and explosion were recorded at 1829 later that day that generated another ash plume, though weather clouds obscured views. The Alert Level remained at Yellow, the second lowest level on a four-colour scale. ONEMI maintained an Alert Level Yellow (the middle level on a three-colour scale) for the municipalities of Villarrica, Pucón (16 km N), Curarrehue, and the commune of Panguipulli, and the exclusion zone for the public of 500 m around the crater.



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