Roundup of Global Volcanic Activity – Ongoing Activity for the week of 25 October – 31 October 2017
Aira | Kyushu (Japan) : JMA reported that sulfur dioxide flux at Aira Caldera’s Sakurajima volcano was high at 1,000 and 1,400 tons per day on 23 and 27 October, respectively. Very small events at Minamidake summit crater were detected during 24-25 and 29-30 October. A thermally anomalous area on the SE flank, near Showa Crater, was identified on 25 October using a thermal camera. The Alert Level remained at 3 (on a 5-level scale).
Bagana | Bougainville (Papua New Guinea) : Based on analyses of satellite imagery and model data, the Darwin VAAC reported that on 27 October an ash plume from Bagana rose to an altitude of 2.1 km (7,000 ft) a.s.l. and drifted E and NE.
Cleveland | Chuginadak Island (USA) : Based on satellite observations, AVO reported that the lava dome in Cleveland’s summit crater continued to grow, and by 23 October it had dimensions of 140 x 110 m. A small, 30-second-long explosion was recorded at 1045 on 28 October in seismic and infrasound data. Weather conditions were overcast with clouds at approximately 4.6 km (15,000 ft) a.s.l.; no volcanic plumes associated with the explosion were identified in satellite images emerging above the cloud level. A small explosion was recorded at 0320 on 30 October, though no ash plume was observed rising above the weather clouds at 2.4 km (8,000 ft) a.s.l. in satellite data. Slightly elevated surface temperatures were detected the next day. The Aviation colour Code remained at Orange and the Volcano Alert Level remained at Watch.
Dukono | Halmahera (Indonesia) : Based on analyses of satellite imagery, wind model data, and notices from PVMBG, the Darwin VAAC reported that during 25-31 October ash plumes from Dukono rose to an altitude of 2.1 km (7,000 ft) a.s.l. and drifted NE, E, and SE.
Ebeko | Paramushir Island (Russia) : Based on observations by volcanologists in Severo-Kurilsk (Paramushir Island), about 7 km E of Ebeko, explosions during 20-27 October generated ash plumes that rose as high as 2 km (6,600 ft) a.s.l. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).
Karymsky | Eastern Kamchatka (Russia) : On 27 October KVERT reported that gas-and-steam activity at Karymsky continued, and that the last ash-bearing explosions occurred on 3 October. The Aviation colour Code was lowered to Green (the lowest level on a four-colour scale).
Kilauea | Hawaiian Islands (USA) : During 25-31 October HVO reported that the lava lake continued to rise, fall, and spatter in Kilauea’s Overlook crater. Webcams recorded incandescence from long-active sources within Pu’u ‘O’o Crater and from a small lava pond in a pit on the W side of the crater. The 61G lava flow, originating from a vent on Pu’u ‘O’o Crater’s E flank, continued to enter the ocean at Kamokuna. Surface lava flows were active above the pali and on the coastal plain.
Sabancaya | Peru : Observatorio Vulcanológico del Sur del IGP (OVS-IGP) and Observatorio Vulcanológico del INGEMMET (OVI) reported that explosive activity at Sabancaya slightly decreased compared to the previous week; there was an average of 43 explosions recorded per day during 23-29 October. Seismicity was dominated by long-period events, with a relatively steady rate of signals indicating emissions and an increasing number of hybrid events. Gas-and-ash plumes rose 3.9 km above the crater rim and drifted 30 km NW, NE, E, and SE. The MIROVA system detected eight thermal anomalies. The sulfur dioxide flux was high, at 2,635 tons per day on 29 October. The report noted that the public should not to approach the crater within a 12-km radius.
Sheveluch | Central Kamchatka (Russia) : KVERT reported that a thermal anomaly over Sheveluch was identified in satellite images during 20-22 and 25 October. The Aviation colour Code remained at Orange.
Sinabung | Indonesia : Based on observations by PVMBG, satellite images, and model data, the Darwin VAAC reported that on 31 October ash plumes from Sinabung rose 4 km (13,000 ft) a.s.l.
Stromboli | Aeolian Islands (Italy) : INGV reported that a strong explosive sequence began at the vents of Stromboli’s southern crater area (Area CS) at 1604 on 23 October. The explosions ejected coarse pyroclastic material onto the Pizzo Sopra la Fossa, and produced a dense ash plume that quickly dissipated to the SE.
Turrialba | Costa Rica : OVSICORI-UNA reported that events at Turrialba at 1030, 1105, and 1445 on 30 October generated ash plumes that rose 200-500 m above the crater rim and drifted NW, W, and SW. Ashfall was reported in the community of Pacayas (about 12 km SSW). OVSICORI-UNA noted that the ash emissions from the event at 1445 rose from the reddish crater.
Ulawun | New Britain (Papua New Guinea) : Based on analyses of satellite imagery, the Darwin VAAC reported that during 26-27 October ash plumes from Ulawun rose to an altitude of 2.4 km (8,000 ft) a.s.l. and drifted 130 km S and SE.
Yasur | Vanuatu : On 31 October the Vanuatu Geohazards Observatory stated that the Alert Level for Yasur remained at 2 (on a scale of 0-4) and that, based on seismic data, explosions continued to be intense. VGO reminded residents and tourists that hazardous areas were near and around the volcanic crater, within a 395-m-radius permanent exclusion zone, and that volcanic ash and gas could reach areas impacted by trade winds.