Thursday, 21 June 2018

Volcanos

Roundup of Global Volcanic Activity – New Activity for the week of13 June – 19 June 2018

Fernandina | Ecuador : IG reported that a seismic swarm at Fernandina began at 0837 on 16 June. Nine earthquakes stronger than M 2.5 were detected with the largest event, a M 4.1, located NE of the island at a depth of 4 km. An eruption that began between 1100 and 1115 was confirmed by guides on a passing boat passing, and by thermal anomalies identified in satellite images. The eruption occurred from a radial fissure on the NNE flank, producing gas plumes with low ash content that rose 2-3 km and drifted more than 250 km WNW. Lava flows reached the sea within a few hours. After two days of intense eruptive activity, tremor levels decreased significantly, thermal anomalies decreased (though continued to remain intense), and a significant drop in sulfur dioxide emissions was recorded.

Fuego | Guatemala : During 13-19 June INSIVUMEH and CONRED reported that strong lahars at Fuego were often hot, steaming, and had a sulfur odor, and were generated from heavy rains and the recent accumulation of pyroclastic-flow deposits from the 3 June events. Lahars descended the Cenizas (SSW), Las Lajas (SE), Mineral, Santa Teresa (W), El Gobernador, and Taniluyá (SW) drainages. They were 20-45 m wide, as deep as 3 m, and often carried blocks up to 3 m in diameter, tree trunks, and branches. On 14 June lahars disrupted communication in the communities of Morelia (9 km SW), Panimaché I and II (8 km SW), Santa Sofia (12 km SW), El Porvenir (8 km ENE), Yucales, and Sangré de Cristo (8 km WSW), all of Yepocapa (8 km N), and Chimaltenango (21 km NNE), requiring assistance from the Army. Water levels in the Pantaleón River began to rapidly rise in the afternoon of 17 June.

During 16-19 June as many as seven explosions per hour produced ash plumes that rose as high as 1.2 km above the crater and drifted as far as 15 km W, SW, and S. Some explosions were heard in areas within a 10-km radius. Avalanches of material descended the Santa Teresa, Las Lajas, and Cenizas drainages during 17-18 June, producing ash plumes, and ashfall in Panimache, Morelia, Sangre de Cristo, and finca Palo Verde. According to CONRED, as of 19 June, the number of people confirmed to have died due to the 3 June pyroclastic flows remained at 110, and 197 more were missing. In addition, 12,823 people had been evacuated.

Great Sitkin | Andreanof Islands (USA) : AVO reported that satellite images captured after the short-lived steam explosion at Great Sitkin on 10 June indicated minor changes in the summit crater, characterized by possible new fumaroles in the N part of the main crater and slightly more vigorous steaming at pre-existing fumaroles. Seismicity declined to background levels during 15-16 June.

Ibu | Halmahera (Indonesia) :PVMBG reported that during 14-19 June white-to-gray plumes rose 200-600 m above Ibu’s crater rim. 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.

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