Roundup of Global Volcanic Activity – Ongoing Activity for the Week 26 August 2020 – 1 September 2020
Aira | Kyushu (Japan) : JMA reported that very small eruptive events at Minamidake Crater (at Aira Caldera’s Sakurajima volcano) were recorded during 17-28 August; the volcano was quiet during 29-31 August. The Alert Level remained at 3 (on a 5-level scale).
Asosan | Kyushu (Japan) : JMA reported that no eruptions at Asosan had been observed since 16 June; only white plumes rose as high as 1 km above the crater afterwards. Sulfur dioxide emissions had been low since mid-June, and volcanic-tremor amplitude decreased to low levels on 18 July. During a field inspection on 17 August, observers noted no water in the crater and a whitish area at the center of the crater floor. On 18 August the Alert Level was lowered to 1 (on a scale of 1-5).
Dukono | Halmahera (Indonesia) : Based on satellite and wind model data, the Darwin VAAC reported that during 19 August-1 September ash plumes from Dukono rose 2.1-2.7 km (7,000-9,000 ft) a.s.l. and drifted in multiple directions. 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 14-17 and 21-28 August that sent ash plumes up to 4 km (13,100 ft) a.s.l. and drifted NE, E, S, and NW. Ashfall was reported in Severo-Kurilsk on 22 August. A thermal anomaly over the volcano was identified in satellite images during 16 and 24-25 August. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).
Fuego | Guatemala : INSIVUMEH reported that there were 3-16 explosions per hour at Fuego recorded during 26 August-1 September, generating ash plumes as high as 1.1 km above the crater rim that generally drifted 10-20 km NW, W, and SW. Shock waves rattled buildings within a 20-km radius. Incandescent material was ejected 100-300 m high, causing avalanches of blocks in the Ceniza (SSW), Seca (W), Trinidad (S), Taniluyá (SW), Las Lajas, and Honda drainages; avalanches sometimes reached vegetated areas. Ashfall was reported in several areas downwind including Morelia (9 km SW), Panimaché I and II (8 km SW), Finca Palo Verde, Santa Sofía (12 km SW), San Pedro Yepocapa (8 km NW), and Sangre de Cristo (8 km WSW). During 26-27 August a lava flow traveled 150 m down the Ceniza drainage and lengthened to 400 m on 28 August; the front of the lava flow generated block avalanches. By 30 August the continuously active flow was 500 m long. During 31 August-1 September the first 200 m of the lava flow was active and continued to produce block avalanches.
Ibu | Halmahera (Indonesia) : PVMBG reported that during 18-29 August white and gray ash plumes rose 200-800 m above Ibu’s summit and drifted in multiple directions; weather conditions prevented observations on 27 August. The Darwin VAAC noted a thermal anomaly over the volcano on 23 August. Emissions were brown and white on 30 August. 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.
Irazu | Costa Rica : OVSICORI-UNA reported that Irazú’s seismic network recorded land movement 1.2 km SW of the SW crater rim in a high area used for radio and television antennas. Landslides in the area had been observed since 2014, but activity accelerated in the previous months. The number of events indicating landslides began to exponentially increase particularly after 20 August. The rate of movement had increased to 20 m/year horizontally and about 25 m/year vertically by 24 August; movement of more than 20 cm was recorded during 23-24 August. A large block collapsed to the NW, into the Rio Sucio drainage, during the morning of 26 August.
Kadovar | Papua New Guinea : Based on satellite data, the Darwin VAAC reported that on 26 August an ash plume from Kadovar rose to an altitude of 2.1 km (7,000 ft) a.s.l., drifted WNW, and quickly dissipated.
Karymsky | Eastern Kamchatka (Russia) : KVERT reported that a thermal anomaly over Karymsky was identified in satellite images on 18 and 21 August; weather clouds prevented views of the volcano on the other days during 14-28 August. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).
Kerinci | Indonesia : PVMBG reported that during 19-22 August brown emissions from Kerinci rose as high as 600 m above the summit and drifted W. Pilots reported that during 20-21 August ash plumes rose to 4-4.6 km (13,000-15,000 ft) a.s.l., or 150-770 m above the summit, and drifted NE and SW. The Alert Level remained at 2 (on a scale of 1-4), and the public was warned to remain outside of the 3-km exclusion zone.
Nishinoshima | Japan : Japan Coast Guard reported that during an overflight of Nishinoshima on 19 August scientists observed a white plume comprised of volcanic gases rising 3 km from the crater. No lava effusion was visible, though the inner crater was hot. The entire island was covered with ash.
Pacaya | Guatemala : INSIVUMEH reported that during 26 August-1 September Strombolian explosions at Pacaya’s Mackenney Crater ejected material as high as 150 m above the crater rim. By 30 August lava flows advanced 300 and 650 m on the NE and N flanks, respectively. A continually active 300-m-long lava flow originated from a vent on the NW flank. By 31 August no fumes rose from the NE lava flow, suggesting it was no longer advancing. Two lava flows, 50 and 350 m long, advanced N on 1 September.
Popocatepetl | Mexico : CENAPRED reported that each day during 25 August-1 September there were 96-331 steam-and-gas emissions from Popocatépetl, some of which contained minor amounts of ash. The Alert Level remained at Yellow, Phase Two (middle level on a three-colour scale).
Rincon de la Vieja | Costa Rica : OVSICORI-UNA reported continuing phreatic activity at Rincón de la Vieja during 19 August-1 September. Phreatic explosions were recorded almost daily, sometimes multiple times a day, though weather conditions often prevented visual confirmation of emissions. Plumes were seen rising 0.5-1 km above the crater rim on 19, 24, 28, and 31 August.
Sabancaya | Peru : Instituto Geofísico del Perú (IGP) reported a daily average of 29 explosions at Sabancaya during 24-30 August. Gas-and-ash plumes rose as high as 3.5 km above the summit and drifted E, SE, and S, SW, and NW. Four 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. On 29 August Instituto Geológico Minero y Metalúrgico (INGEMMET) reported increased activity during 28-29 August and noted higher seismic levels and inflation over the previous few weeks. 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.
Santa Maria | Guatemala : INSIVUMEH reported that during 26 August-1 September explosions at Santa María’s Santiaguito lava-dome complex generated ash plumes that rose as high as 1 km above the crater and drifted as far as 1 km W and SW. Block avalanches descended multiple flanks of Caliente cone; some reached the base of the cone and were sometimes accompanied by small pyroclastic flows. The lava dome was incandescent most nights, sometimes for prolonged periods of time.
Sheveluch | Central Kamchatka (Russia) : KVERT reported that a thermal anomaly over Sheveluch was identified almost daily in satellite images during 14-28 August; weather cloud cover prevented views on 15 and 27 August. A plume of resuspended ash drifted 75 km ESE on 24 August. 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 14-24 August. Occasional eruptive events and about 12 explosions were recorded during 18-24 August. One of the explosions, detected at 0452 on 21 August, ejected blocks as far as 600 m from the crater. An explosion at 1449 that same day generated a grayish white ash plume that rose more than 2 km above the crater rim. Ashfall was noted in Toshima village (4 km SSW) on 21 August. The Alert Level remained at 2 (on a 5-level scale).
Turrialba | Costa Rica : On 21 August OVSICORI-UNA reported that fracturing of SW wall of Turrialba’s active crater, along with an area of incandescence within the fracture zone, had been observed during the previous month. An eruption was recorded at 1253 on 22 August, though a plume was not visible due to weather conditions. At 2301 on 24 August a plume rose 1 km above the crater rim.