Volcanos

Roundup of Global Volcanic Activity – Ongoing Activity for the week of 2 August – 8 August 2017

Bagana | Bougainville (Papua New Guinea) : Based on analyses of satellite imagery and model data, the Darwin VAAC reported that during 5-8 August ash plumes from Bagana drifted in multiple directions at an altitude of 2.1 km (7,000 ft) a.s.l.

Bezymianny | Central Kamchatka (Russia) : KVERT reported that during 28 July-4 August a daily thermal anomaly was identified over Bezymianny in satellite images. A lava flow continued to flow down the W flank of the dome. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Bogoslof | Fox Islands (USA) : AVO reported that during 2-6 August no activity at Bogoslof was observed in mostly cloudy satellite images, and no activity was detected in seismic, infrasound, or lightning data. An explosive eruption began at 1000 on 7 August, following more than an hour of increased seismicity. A pilot reported that an ash cloud rose to an altitude of 9.8 km (32,000 ft) a.s.l., prompting AVO to raise the Aviation colour Code (ACC) to Red and the Volcano Alert Level (VAL) to Warning. The eruption lasted about three hours, and was longer lived than most of the events in the eruptive sequence that started in December 2016. At 1341 AVO noted that the ash plume had formed a continuous cloud which stayed attached to the volcano and drifted S. The ACC was lowered to Orange and the VAL was lowered to Watch on 8 August. Satellite images acquired on 8 August showed a significant expansion of the island towards the N with thick tephra deposits around the vent area forming a new crater lake.

Cleveland | Chuginadak Island (USA) : On 7 August AVO stated that recent data suggested that the extrusion of lava at the bottom of Cleveland’s summit crater may have slowed or paused during the previous week, though unrest continued. Elevated surface temperatures in the summit crater were identified in satellite data and vigorous steaming was recorded by the webcam during 7-8 August. The Aviation colour Code remained at Orange and the Volcano Alert Level remained at Watch.

Copahue | Central Chile-Argentina border : According to ONEMI, OVDAS-SERNAGEOMIN reported that during 16-31 July surficial activity at Copahue had decreased. The webcam recorded constant gas emissions with sporadic ash rising no more than 280 m from El Agrio crater. Crater incandescence was visible during favorable weather conditions. The Alert Level remained at Yellow (second highest level on a four-colour scale); SERNAGEOMIN recommended no entry into a restricted area within 1 km of the crater. ONEMI maintained an Alert Level Yellow (the middle level on a three-colour scale) for the municipality of Alto Biobío.

Dukono | Halmahera (Indonesia) : Based on analyses of satellite imagery, wind model data, and notices from PVMBG, the Darwin VAAC reported that during 2-5 and 7-8 August ash plumes from Dukono rose to altitudes of 1.8-2.1 km (6,000-7,000 ft) a.s.l. and drifted in multiple directions as far as 140 km.

Ebeko | Paramushir Island (Russia) : KVERT reported that satellite images of Ebeko showed a weak thermal anomaly over the volcano on 31 July. Volcanologists working at Kambalny (90 km NE) on 1 August observed explosions generating ash plumes that rose as high as 1.6 km (5,200 ft) a.s.l. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Fuego | Guatemala : Based on INSIVUMEH special bulletins, CONRED reported increased activity at Fuego on 4 August, characterized by explosions ejecting incandescent material as high as 300 m above the crater rim and lava traveling 600 m down the Ceniza (SSW) ravine. Explosions generated ash plumes that rose almost 1 km and drifted 12 km W and SW. INSIVUMEH reported that multiple explosions during 5-6 August generated ash plumes that rose as high as 850 m above the crater and drifted 10 km W. Some explosions generated shock waves that rattled nearby structures. Incandescent material was ejected 100 m above the crater rim, and caused avalanches of material that traveled down the Ceniza, Taniluyá (SW), Santa Teresa (W), Las Lajas (SE), Honda (E), and Trinidad (S) drainages. Ash fell in areas downwind, including Sangre de Cristo (8 km WSW) and Yepocapa (8 km WNW). A lava flow was active 600 m down the Ceniza drainage. Explosive activity increased on 7 August. Ash plumes rose as high as 750 m and drifted 10 km W and SW. Ballistics were ejected more than 150 m above the crater and fell 200 m away. Shock waves continued to vibrate houses in nearby communities. During 7-8 August two lava fountains rose 150 m high, heralding the seventh effusive episode at Fuego in 2017. The fountains fed lava flows, 1.5 km and 700 m long, in the Ceniza and the Santa Teresa ravines, respectively. Explosions (occurring at a rate of 6-8 per hour) produced ash plumes that drifted 20 km W, causing ashfall in Panimache (8 km SW), Morelia (9 km SW), Santa Sofía (12 km SW), El Porvenir (8 km ENE), and Yepocapa.

Karymsky | Eastern Kamchatka (Russia) : KVERT reported that satellite images showed a weak thermal anomaly over Karymsky on 1 and 3 August, and ash plumes drifting about 30 km ESE on 3 August. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Kilauea | Hawaiian Islands (USA) : During 2-8 August 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. The 61G lava flow, originating from a vent on Pu’u ‘O’o Crater’s E flank, continued to enter the ocean at Kamokuna. Slumping of seaward portions of the delta continued, and cracks running parallel to the coastline continued to widen. HVO noted that as recently as 28 July a small slice of the delta fell into the ocean, and warned that there was potential for larger-scale delta collapses.

Klyuchevskoy | Central Kamchatka (Russia) : KVERT reported that ash plumes from Klyuchevskoy were identified in satellite images drifting 65 km SW on 2 August and 250 km ESE on 3 August. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Langila | New Britain (Papua New Guinea) | 5.525°S, 148.42°E | Elevation 1330 m

Based on analyses of satellite imagery and wind model data, the Darwin VAAC reported that on 7 August ash plumes from Langila rose 2.1 km (7,000 ft) a.s.l. and drifted 55 km NW.

Manam | Papua New Guinea : Based on analyses of satellite imagery and model data, the Darwin VAAC reported that during 5-6 and 8 August minor ash emissions from Manam rose to altitudes of 1.8-2.1 km (6,000-7,000 ft) a.s.l. and drifted NW and W.

Poas | Costa Rica : On 3 August OVSICORI-UNA reported that plumes of magmatic gases, water vapor, and aerosols continued to rise from Poás’s vent A (Boca Roja), and plumes of water vapor and abundant yellow particles of native sulfur were emitted from vent B (Boca Azufrada). Plumes rose as high as 1 km above the vents and drifted SSW. Incandescence from the bottom of the crater was recorded at night by the webcams. Recent measurements indicated that sulfur dioxide was emitted at a rate of 1,000-1,500 tons per day, which were values similar to those measured in the first months of 2017, before the phreato-magmatic eruptions of April and May. Gas plumes continued to rise from the vents and drift SW and NW at least through 8 August.

Sabancaya | Peru : Observatorio Vulcanológico del Sur del IGP (OVS-IGP) and Observatorio Vulcanológico del INGEMMET (OVI) reported that explosive activity at Sabancaya increased compared to the previous week; there was an average of 65 small explosions recorded per day during 31 July-6 August. The earthquakes were dominated by long-period signals; the number of hybrid and tremor events had decreased. Gas-and-ash plumes rose 4 km above the crater rim and drifted no more than 30 km N and SE. Sulfur dioxide flux was as high as 2,254 tons per day, recorded on 2 August. The MIROVA system detected nine thermal anomalies. The report reminded the public not to approach the crater within a 12-km radius.

Sheveluch | Central Kamchatka (Russia) : KVERT reported that a thermal anomaly was identified daily during 28 July-4 August in satellite images over Sheveluch. Strong explosions on 4 August generated ash plumes that rose 6.5 km (21,300 ft) a.s.l. and drifted ESE. The Aviation colour Code remained at Orange.

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