Roundup of Global Volcanic Activity – New Activity for the week of 20 June – 26 June 2018
Fernandina | Ecuador : On 21 June Parque Nacional Galápagos reported that lava flows at Fernandina were no longer reaching the ocean, though white plumes continued to rise from flows at the coastline.
Great Sitkin | Andreanof Islands (USA) : AVO reported continuing low-level unrest at Great Sitkin during 20-26 June; seismic activity remained at or near background levels. A recently analyzed satellite image acquired on 11 June, one day after short-duration explosive event was recorded, showed a minor ash deposit on the snow extending 2 km from a vent in the summit crater. The Aviation colour Code remained at Yellow and the Volcano Alert Level remained at Advisory.
Ibu | Halmahera (Indonesia) : PVMBG reported that at 0857 on 21 June an event at Ibu generated an ash plume that rose at least 600 m above the crater rim and drifted N. Signals indicating an explosion and rock avalanches were detected in seismic data. During 22-26 June ash plumes rose as high as 850 m and drifted WNW and W. 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.
Kadovar | Papua New Guinea : According to the Darwin VAAC an ash plume from Kadovar identified by a pilot and in satellite images rose to an altitude of 1.8 km (6,000 ft) a.s.l. on 20 June and drifted W.
Krakatau | Indonesia : PVMBG and BNPB reported that an eruption at Anak Krakatau began on 18 June, along with increased seismicity, and reminded residents that the Alert Level remained at 2 (on a scale of 1-4); visitors were warned not to approach the volcano within 1 km of the crater. Foggy conditions hampered visual observations during 19-20 June, but on 21 June gray plumes were observed rising 100-200 m above the summit. An event at 0714 on 25 June produced a dense ash plume that rose about 1 km and drifted N.
Sierra Negra | Isla Isabela (Ecuador) : On 22 June IG reported increased seismic activity at Sierra Negra on the S end of Isabela Island; the largest event, a M 4.2, was recorded at 0624 and felt in El Cura and San Joaquín, NE of the volcano. A M 5.3 earthquake was detected at 0315 on 26 June, occurring at a depth of 5.3 km below Sierra Negra. The event was strongly felt on the upper flanks and in Puerto Villamil (23 km SE). Several aftershocks and subsequent tremor were recorded. An earthquake swarm began at 1117, characterized by events located 3-5 km depth. A M 4.2 earthquake was recorded at 1338, and followed by increasing amplitudes of seismic and infrasound signals. Parque Nacional Galápagos staff heard noises described as bellows coming from Volcán Chico fissure vent, and coupled with the seismicity and infrasound data, suggested the start of an eruption. An IG report posted 20 minutes later described a thermal anomaly identified in satellite images in the N area of the caldera, near Volcán Chico. Park staff observed lava flowing towards the crater’s interior as well as towards the N flank.
Telica | Nicaragua : INETER and SINAPRED reported that an eruption at Telica began at 0708 on 21 June. Explosions produced an ash plume that rose 500 m above the crater and drifted E, S, and SW, and ejected tephra that was deposited within a 1-km-radius of the volcano. Ashfall was reported in areas including La Joya, Las Marías (7 km NNW), Pozo Viejo (10 km NNW), Ojo de Agua, San Lucas (11 km NNW), Las Higueras, Las Grietas (12 km NNW), and Posoltega (16 km WSW).