Roundup of Global Volcanic Activity – Ongoing Activity for the week of 5 April – 11 April 2017
Bagana | Bougainville (Papua New Guinea) : Based on analyses of satellite imagery and wind model data, the Darwin VAAC reported that during 6-9 April ash plumes from Bagana rose to an altitude of 2.1 km (7,000 ft) a.s.l. and drifted NE, E, S, and W.
Bezymianny | Central Kamchatka (Russia) : KVERT reported that during 1-6 April lava continued to advance down the NW flank of Bezymianny’s lava dome. A thermal anomaly was identified in satellite images daily. The Aviation Colour Code remained at Orange.
Bogoslof | Fox Islands (USA) : On 5 April AVO reported that the Aviation Colour Code for Bogoslof was lowered to Yellow and the Volcano Alert Level was lowered to Advisory based on the absence of detected activity at the volcano for the past three weeks; the last large explosion occurred on 8 March. No significant volcanic activity was detected in seismic, infrasound, or satellite data during 6-11 April.
Chirinkotan | Kuril Islands (Russia) : Based on Tokyo VAAC data, SVERT reported that on 7 April an ash plume from Chirinkotan rose to an altitude of 5 km (16,400 ft) a.s.l. and drifted NE. The Aviation Colour Code remained at Yellow (on a four-Colour scale).
Cleveland | Chuginadak Island (USA) : AVO reported that no significant volcanic activity at Cleveland was detected in seismic, infrasound, or satellite data since an explosion occurred on 24 March. The Aviation Colour Code was lowered to Yellow and the Volcano Alert Level was lowered to Advisory on 5 April.
Colima | Mexico : On 7 April the Centro Universitario de Estudios e Investigaciones de Vulcanologia – Universidad de Colima reported that during the previous week the seismic data revealed 38 high-frequency events, 23 long-period events, 2.4 hours of tremor, 18 landslides, and two low-intensity explosions. The sulfur dioxide flux was as high as 640 tons/day.
Dukono | Halmahera (Indonesia) : Based on analyses of satellite imagery, wind model data, and notices from PVMBG, the Darwin VAAC reported that during 5-11 April ash plumes from Dukono rose to altitudes of 1.8-2.1 km (6,000-7,000 ft) a.s.l. and drifted NE, SE, and S.
Ebeko | Paramushir Island (Russia) : KVERT reported that during 4-6 April several explosions at Ebeko were observed by residents of Severo-Kurilsk (Paramushir Island) about 7 km E. Ash plumes rose as high as 4 km (13,100 ft) a.s.l. Minor amounts of ash fell in Severo-Kurilsk on 6 April. The Aviation Colour Code remained at Orange (the second highest level on a four-Colour scale).
Etna | Sicily (Italy) : INGV reported that the eruptive episode that began on 15 March from a vent in the saddle between Etna’s Southeast Crater (SEC) – New Southeast Crater (NSEC) cone complex was characterized by Strombolian activity and ash emissions. Lava had traveled down into the Valle del Bove from the W rim; by the afternoon of 18 March almost continuous collapses of parts of the lava flow produced several avalanches of incandescent material which reached the base of the wall. Explosive activity had greatly declined earlier that morning. The collapsing stopped by early the next evening, 19 March, and the lava reached the base of the valley. That lava flow stopped advancing on 20 March though a few lava flows closer to the vent remained active the next few days. On 21 March a new lava flow expanded SSW, but then stopped in the last days of March at an elevation of 2,300 m. A few more lava flows had followed a similar path in early April and then also stopped at the same elevation. Around 28 March a new pit crater had formed on the S part of the pyroclastic cone which had formed around the SEC-NSEC saddle vent. Strong glow form the pit crater was observed at night.
Fuego | Guatemala : INSIVUMEH reported that during 6-11 April explosions at Fuego generated ash plumes that rose as high as 850 m above the crater rim and drifted as far as11 km W, SW, and S. Ashfall was reported in areas downwind including Panimaché I and II (8 km SW), Morelia (9 km SW), and Santa Sofía (12 km SW). Rumbling from the explosions was sometimes heard. During 10-11 April incandescent material was ejected 100-150 m above the crater, generating minor avalanches in the area of the cone.
Kilauea | Hawaiian Islands (USA) : During 5-11 April HVO reported that the lava lake continued to rise, fall, and spatter in Kilauea’s Overlook crater. Webcams recorded incandescence from long-active sources within Pu’u ‘O’o Crater, from a vent high on the NE flank of the cone, and from a small lava pond in a pit on the W side of the crater. The 61G lava flow, originating from a vent on Pu’u ‘O’o Crater’s E flank, continued to enter the ocean at Kamokuna from the end of the lava tube, about 20 m above the water. A growing lava delta was an estimated 25 m out from the base of the sea cliff by 10 April. Surface lava flows were active above the pali and on the coastal plain.
Klyuchevskoy | Central Kamchatka (Russia) : KVERT reported that during 1-4 April explosions at Klyuchevskoy generated ash plumes that rose to altitudes of 5-6 km (16,400-19,700 ft) a.s.l. Satellite images showed a thermal anomaly over the volcano during 1-2 and 4 April, and ash plumes that drifted 400 km in multiple directions. No explosions were recorded after 4 April; the Aviation Colour Code was lowered to Yellow on 10 April.
Nevado del Ruiz | Colombia : Servicio Geológico Colombiano’s (SGC) Observatorio Vulcanológico y Sismológico de Manizales reported that during 4-11 April seismicity at Nevado del Ruiz continued to indicate unrest. Signals indicating fracturing rock slightly increased in both size and number as compared to the previous week. During 10-11 April a period of short-duration and very low energy drumbeat signals were recorded, indicating rising magma. Water vapor and gas continued to be emitted. Gas, steam, and ash plumes rose 1.5 km above the crater rim on 10 April and drifted NW. Thermal anomalies were identified on 4, 6, and 7 April. The Alert Level remained at III (Yellow; the second lowest level on a four-Colour scale).
Nevados de Chillan | Chile : The Buenos Aires VAAC reported that on 6 and 8 April a webcam recorded ash emissions rising from Nevados de Chillán and dissipating quickly. On 6 April the emissions rose as high as 4 km (13,000 ft) a.s.l. Minor ash emissions were observed on 10 April.
Pacaya | Guatemala : INSIVUMEH reported that incandescence from Pacaya’s Mackenney cone was visible at night and at dawn during 6-11 April. Weak explosions accompanied by rumbling was sometimes noted.
Sabancaya | Peru : Observatorio Vulcanológico del Sur del IGP (OVS-IGP) and Observatorio Vulcanológico del INGEMMET (OVI) reported that during 3-9 April seismicity at Sabancaya declined compared to the previous week, with an average of 27 explosions recorded per day. Ash plumes rose as high as 3.2 km above the crater rim (on 8 April) and drifted more than 40 km NW and NE. Ashfall was reported in Pinchollo (20 km N), Maca, and Chivay. The Buenos Aires VAAC reported that diffuse ash plumes drifted 100 km E on 9 April. Intermittent ash emissions during 10-11 April rose as high as 7 km (23,000 ft) a.s.l. and drifted SE. The Alert Level remained at Orange (the second highest level on a four-Colour scale).
Sheveluch | Central Kamchatka (Russia) : KVERT reported that during 1-6 April lava-dome extrusion onto Sheveluch’s N flank was accompanied by strong fumarolic activity, dome incandescence, ash explosions, and hot avalanches. Satellite images showed a daily thermal anomaly over the dome, and ash plumes that drifted 20 km SE on 3 April. The Aviation Colour Code remained at Orange (the second highest level on a four-Colour scale).
Sinabung | Indonesia : Based on PVMBG observations and wind data, the Darwin VAAC reported that during 7 and 9-11 April ash plumes from Sinabung rose to altitudes of 3.4-8.2 km (11,000-27,000 ft) a.s.l. and drifted E, SE, and WNW.