Volcanos

Roundup of Global Volcanic Activity – Ongoing Activity for the week of 31 January - 6 February 2018

Aira | Kyushu (Japan) : JMA reported that very small events occurred at Minamidake crater (at Aira Caldera’s Sakurajima volcano) on 1 and 3 February. Crater incandescence from the summit crater was visible during 2-3 February. The Alert Level remained at 3 (on a 5-level scale).

Cleveland | Chuginadak Island (USA) : AVO reported that unrest at Cleveland continued during 31 January-6 February, though nothing significant was detected in seismic or infrasound data. Moderately elevated surface temperatures were identified in satellite images during 30-31 January; cloudy weather prevented observations the rest of the week. 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 31 January-6 February ash plumes from Dukono rose to an altitude of 2.1 km (7,000 ft) a.s.l. and drifted NE, E, and ESE.

Ebeko | Paramushir Island (Russia) : Based on observations by volcanologists in Severo-Kurilsk (Paramushir Island), about 7 km E of Ebeko, explosions during 26-27 and 29-31 January generated ash plumes that rose as high as 2.5 km (8,200 ft) a.s.l. Ash fell in Severo-Kurilsk on 29 January. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Karymsky | Eastern Kamchatka (Russia) : KVERT reported that an ash plume from Karymsky was identified in satellite images drifting 80 km NE on 27 January. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Kilauea | Hawaiian Islands (USA) : During 31 January-6 February HVO reported that the lava lake continued to rise, fall, and spatter in Kilauea’s Overlook crater. Webcams recorded incandescence from a small lava pond in a pit on the W side of Pu'u 'O'o Crater. Surface lava flows were active above and on the pali, and on the coastal plain.

Nevados de Chillan | Chile : Servicio Nacional de Geología and Minería (SERNAGEOMIN) Observatorio Volcanológico de Los Andes del Sur (OVDAS) reported that growth of the lava dome in Nevados de Chillán’s Nicanor Crater was 2,540 m3/day, determined by photos taken during overflights on 23 and 31 January. The total volume of the lava dome was an estimated 106,700 m3. A small area of deposits from collapses of the dome walls was observed. Temperatures on the surface of the dome were 305 and 480 degrees Celsius, mainly from a crack which generated the explosions. A larger explosion from a possible partial dome collapse was recorded at 1202 on 2 February, generating a gas-and-ash plume that rose about 2.5 km above the crater rim. Shock waves from the explosion were reported in the community of Las Trancas (10 km) and at the Gran Hotel Termas de Chillan (5 km). Explosive activity continued through 6 February. The Alert Level remained at Yellow, the middle level on a three-colour scale, and the public was reminded not to approach the craters within a 4-km radius.

Sabancaya | Peru : Observatorio Vulcanológico del Sur del IGP (OVS-IGP) and Observatorio Vulcanológico del INGEMMET (OVI) reported that explosive activity at Sabancaya decreased compared to the previous week; there was an average of 22 explosions recorded per day during 29 January-4 February. Seismicity was dominated by long-period events, with signals indicating emissions. Gas-and-ash plumes rose 3.5 km above the crater rim and drifted 50 km NW, SW, and S. The MIROVA system detected two thermal anomalies. The sulfur dioxide flux was high, at 3,388 tons per day on 31 January. 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 on 1 February. The Aviation colour Code remained at Orange.

Turrialba | Costa Rica : OVSICORI-UNA reported that an event at Turrialba at 0830 on 5 February generated a plume that rose 200 m above the crater rim and drifted SW. An event at 0730 on 6 February generated an ash plume that rose 1 km and drifted SW. Ashfall was reported in Goicoechea and Heredia.