Roundup of Global Volcanic Activity – New Activity for the week of 19 July – 25 July 2017
Piton de la Fournaise | Reunion Island (France) : OVPF reported that seismicity at Piton de la Fournaise increased on 10 July and was followed by a seismic crisis that began around 1250 on 13 July. Events were mainly located below the S edge of Dolomieu Crater, between 500 and 1,000 m a.s.l. Inflation was also detected, concurrent with increased seismicity. An eruption began at 0050 on 14 July in an area 750 m E of the Kala-Pélé peak, 850 m W of Château Fort, and 2.2 km NE of Piton de Bert. During a survey at 0930 scientists observed a fissure about 450 m long with seven lava fountains rising as high as 30 m. The fountain on the downhill end had built up a cone and produced two lava flows. A sulfur dioxide plume drifted E. On 15 July only three fountains were active. The intensity of the eruption fluctuated during 15-17 July, and by 17 July activity was concentrated at one eastern cone. During 18-19 July a few vents within the cone were active, ejecting lava no higher than 20 m above the cone’s rim. By 21 July several lava tubes had formed, and fractures within the tubes produced small lava flows. During an overflight on 22 July scientists noted that the lava flow was over 2.8 km long with a maximum width of 0.6 km; the front of the flow had not advanced in the past seven days. Three main vents were active within the main cone and a fourth was just sporadically active. The eruption continued at least through 25 July.
Planchon-Peteroa | Central Chile-Argentina border : Observatorio Volcanológico de los Andes del Sur (OVDAS) – SERNAGEOMIN reported that the Alert Level for Planchón-Peteroa was raised to Yellow (the middle level on a three-colour scale) on 10 July, noting elevated seismicity (above baseline levels) on 8 July.
Sangay | Ecuador : Based on satellite images and information from the Guayaquil MWO, the Washington VAAC reported that on 20 July an ash plume from Sangay rose to an altitude of 8.2 km (27,000 ft) a.s.l. and drifted W.
Sangeang Api | Indonesia : Based on analyses of satellite imagery, PVMBG observations, and wind data, the Darwin VAAC reported that during 19-20 July ash plumes from Sangeang Api rose to altitudes of 2.4-4.3 km (8,000-14,000 ft) a.s.l. and drifted NW.