Roundup of Global Volcanic Activity – New Activity for the week of 5 July – 11 July 2017
Bogoslof | Fox Islands (USA) : On 5 July AVO reported that no further activity was detected at Bogoslof after the explosions the day before; the Aviation colour Code (ACC) was lowered to Orange and the Volcano Alert Level (VAL) was lowered to Watch. A nine-minute-long eruption pulse was detected in seismic data starting at 1015 on 8 July was followed by a shorter pulse that began at 1029 and then a decline in seismicity. An ash plume identified in satellite images rose 9.1 km (30,000 ft) a.s.l. and drifted N. AVO raised the ACC to Red and the VAL to Warning, but lowered them back down to Orange and Watch, respectively, the next day. An eruption began at 2347 on 9 July, lasted five minutes, and was followed 15 minutes later by another explosion that lasted seven minutes. A small ash cloud visible in satellite images drifting SE may have risen as high as 6.1 km (20,000 ft) a.s.l. Explosions ended at 0235 on 10 July. The ACC was raised to Red and the VAL was raised to Warning but lowered back down one level early on 10 July. An eruption began at 1000 on 10 July and lasted eight minutes. Infrasound data indicated ash emissions but ash was not confirmed in satellite data. A 15-minute-long event began at 1706 on 10 July; no volcanic plume was identified in satellite data, and no volcanic lightning nor infrasound was detected. Seismicity declined after the episode.
Fuego | Guatemala : INSIVUMEH reported that 4-7 explosions per hour at Fuego during 6-7 July generated ash plumes that rose as high as 950 m above the crater and drifted 6-10 km SW and W. Incandescent material was ejected 100-200 m above the crater rim, and caused avalanches of material that traveled down the Ceniza (SSW), Taniluyá (SW), Santa Teresa (SW), and Trinidad (S) drainages. Later on 7 July the rate of explosions increased to 7-10 per hour. During 7-9 July ash plumes rose as high as 1.1 km and drifted 15 km W, causing ashfall in Santa Sofía (12 km SW), Morelia (9 km SW), Panimaché I and II (8 km SW), El Porvenir (8 km ENE), Sangre de Cristo (8 km WSW), and possibly San Pedro Yepocapa (8 km N). A lava flow traveled 1.5 km down the Las Lajas (SE) drainage. On 11 July INSIVUMEH declared that the 6th eruption of the year with lava effusion was in progress. Explosions generated ash plumes that rose as high as 1.3 km above the crater and drifted 35 km W, and shock waves rattled nearby structures. Ash fell in areas including Morelia, Panimache, Santa Sofía, El Porvenir, and Sangre de Cristo. Two lava flows were fed by lava fountains 150-250 m high; one lava flow traveled 2.3 km down the Las Lajas drainage and another traveled 1.7 km down the Santa Teresa (SW) drainage. Later that day INSIVUMEH reported that the 31-hour-long eruption had ended. A few weak-to-moderate explosions continued, generating ash plumes that rose 850 m and drifted 6 km W.
Rincon de la Vieja | Costa Rica : OVSICORI-UNA reported that at 0849 on 5 July a small phreatic eruption at Rincón de la Vieja ejected material that fell within the crater.
Sheveluch | Central Kamchatka (Russia) : KVERT reported that a thermal anomaly was identified daily in satellite images over Sheveluch during 1-7 July. Explosions on 2 July generated ash plumes that rose 10-11 km (32,800-36,100 ft) a.s.l.; one plume drifted 1,050 km SW and another drifted 350 km NE. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).