Volcanos

Roundup of Global Volcanic Activity – Ongoing Activity for the week of 27 September - 3 October 2017

Aira | Kyushu (Japan) : JMA reported that at 0055 on 29 September an explosive event at Showa Crater (at Aira Caldera’s Sakurajima volcano) produced a plume that rose 2.8 km above the crater rim, and ejected material as far as 1,300 m. Two of eight events were explosive during 30 September-2 October; plumes rose 2.8 km and material was ejected 1,300 m away. The Alert Level remained at 3 (on a 5-level scale).

Bezymianny | Central Kamchatka (Russia) : KVERT reported that during 22-29 September lava continued to flow down the W flank of Bezymianny's dome, and incandescence from the dome was visible at night. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Bogoslof | Fox Islands (USA) : On 27 September AVO reported that the last explosion at Bogoslof was detected on 30 August, and no new volcanic activity was observed in satellite, seismic, or infrasound data since then. The Aviation colour Code was lowered to Yellow and the Volcano Alert Level was lowered to Advisory.

Cleveland | Chuginadak Island (USA) : AVO reported that two small explosions at Cleveland were detected at 0516 and 0558 on 28 September in infrasound and seismic data. Elevated surface temperatures were identified in satellite data, and a weak plume rising from the summit crater was recorded by the webcam. Satellite data indicated that lava effusion in the summit crater began on 30 September, and by 1 October the new lava dome had grown to about 4,200 square meters. The Aviation colour Code remained at Orange and the Volcano Alert Level remained at Watch.

Dieng Volcanic Complex | Central Java (Indonesia) : PVMBG reported that since 20 September tremor and water temperature at Sileri Crater lake (Dieng Volcanic Complex) both declined. The Alert Level was lowered to 1 (on a scale of 1-4) on 2 October. PVMBG warned the public to stay at least 100 m away from the crater rim.

Dukono | Halmahera (Indonesia) : Based on analyses of satellite imagery, wind model data, and notices from PVMBG, the Darwin VAAC reported that during 27 September-3 October ash plumes from Dukono rose to an altitude of 2.1 km (7,000 ft) a.s.l. and drifted in multiple directions.

Ebeko | Paramushir Island (Russia) : Based on observations by volcanologists in Severo-Kurilsk (Paramushir Island), about 7 km E of Ebeko, explosions on 24 September generated ash plumes that rose 2 km (6,600 ft) a.s.l. Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Karymsky | Eastern Kamchatka (Russia) : KVERT reported that a weak thermal anomaly over Karymsky was identified in satellite images during 23-25 September. An ash cloud drifted about 54 km E on 23 September. The Aviation colour Code was raised to Orange (the second highest level on a four-colour scale).

Kilauea | Hawaiian Islands (USA) : During 27 September-3 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, although during 1-3 October the plume at the entry waxed and waned. Surface lava flows were active above and on the pali, and on the coastal plain.

Popocatepetl | Mexico : Each day during 26 September-3 October CENAPRED reported 21-61 emissions from Popocatépetl and 2-6 volcano-tectonic earthquakes. Cloud cover often prevented visual observations. Periods of harmonic tremor and as many as 10 explosions per day were detected during 26-30 September. Beginning at 0315 on 27 September an episode of Strombolian activity that lasted for six hours and sixteen minutes ejected incandescent tephra as far as 1 km onto the flanks. Ash plumes rose 1.5 km above the crater rim and drifted W. Ash fell in the towns of Ecatzingo and Atlautla in Estado de México, and in Atlatlahuacán, Ocuituco, Oaxtepec, Jiutepec, and Yautepec in Estado de Morelos. An explosion at 2257 on 30 September ejected incandescent tephra no more than 800 m onto the flanks, and produced an ash plume that rose 2 km. An explosion was detected at 1417 on 3 October. The Alert Level remained at Yellow, Phase Two. CENAPRED stated that there was no significant increase in activity at Popocatépetl related to the M 7.1 earthquake, centered beneath Puebla (45 km E), that occurred at 1314 on 19 September.

Rincon de la Vieja | Costa Rica : OVSICORI-UNA reported that at 0858 on 29 September a small phreatic explosion at Rincón de la Vieja produced a plume that rose 1 km above the crater rim; material also flowed down the S flank. On 3 October events at 0848 and 1445 generated plumes that rose 700 m and 1,500 m, respectively.

Sabancaya | Peru : Observatorio Vulcanológico del Sur del IGP (OVS-IGP) and Observatorio Vulcanológico del INGEMMET (OVI) reported that explosive activity at Sabancaya increased; there was an average of 45 explosions recorded per day during 25 September-1 October. The earthquakes were dominated by long-period events, with fewer numbers of signals indicating emissions and hybrid events. Gas-and-ash plumes rose 3.5 km above the crater rim and drifted no more than 40 km E and NE. The MIROVA system detected seven thermal anomalies. The report warned the public not to approach the crater within a 12-km radius.

Sheveluch | Central Kamchatka (Russia) : KVERT reported that a thermal anomaly over Sheveluch was identified daily in satellite images during 22-29 September. The Aviation colour Code remained at Orange.

Sinabung | Indonesia : Based on observations by PVMBG, webcam and satellite images, and model data, the Darwin VAAC reported that during 27-29 September and 1-2 October ash plumes from Sinabung rose 3.7-5.5 km (12,000-18,000 ft) a.s.l. and drifted in multiple directions.

Suwanosejima | Ryukyu Islands (Japan) : Based on JMA notices and satellite-image analyses, the Tokyo VAAC reported an explosion on 29 September which generated a plume that rose 2.4 km (8,000 ft) a.s.l. and drifted E.

Turrialba | Costa Rica : OVSICORI-UNA reported that daily events at Turrialba during 27 September-1 October and on 3 October generated plumes that rose as high as 1 km above the crater rim and drifted NW, W, SW, and S. On 30 September explosions ejected hot material out of West Crater and minor ashfall was reported in Coronado (San José). Ash fell in Santa Cruz (7 km SE), Las Verbenas, Santa Teresita, Calle Vargas, Guayabito, and La Isabel on 3 October.