The following news are based on the Volcano Listserv Newsletter for the week 7.-13. August 2017:
Piton de la Fournaise: eruption continous on low levelReunion Island (France) | 21.244°S, 55.708°E | Summit elev. 2632 m
OVPF reported that the eruption at Piton de la Fournaise that began on 14 July continued through 8 August, though tremor levels and surficial activity slowly declined. Satellite data indicated a minimum flow rate of 1-2 cubic meters per second. Some active lava flows were visible at a distance of 520 m from the cone, though most of the flow activity was confined to lava tubes. There were some breakouts from the lava tube; a substantial breakout on 5 August fed a lava flow that traveled hundreds of meters over several hours. During 7-8 August small amounts of material was ejected from a small vent on the N flank of the eruptive vent.
Source: Observatoire Volcanologique du Piton de la Fournaise (OVPF) http://www.ipgp.fr/fr
Sangay: low-energy ash plumesEcuador | 2.005°S, 78.341°W | Summit elev. 5286 m
In a special report from 3 August, IG reported that a new eruptive phase at Sangay began on 20 July, after 8 months without major surface activity. The recent activity was characterized by low-energy ash plumes rising no more than 3 km above the crater rim, incandescent rocks rolling as far as 1 km down the ESE flank, and a possible lava flow on the same flank. Minor amounts of ash fell in uninhabited areas to the W.
Based on Washington VAAC reports, IG noted two ash plumes on 20 July and one on 2 August that rose 2.3-3 km above the crater and drifted W and NW. Numerous thermal anomalies detected during 2-3 August were aligned on the ESE flank. Based on numerical weather prediction (NWP) models, satellite data, and information from the Guayaquil Meteorological Watch Office (MWO), the Washington VAAC reported that on 6 August an ash plume drifted W
Sources: Instituto Geofísico-Escuela Politécnica Nacional (IG) http://www.igepn.edu.ec/
Washington Volcanic Ash Advisory Center (VAAC) http://www.ssd.noaa.gov/VAAC/messages.html
Sinabung |Indonesia | 3.17°N, 98.392°E | Summit elev. 2460 m
BNPB reported intense activity at Sinabung on 2 August; between 0800 and 1200, pyroclastic flows were generated 17 times and traveled as far as 4.5 km ESE. Ash plumes rose up to 4.2 km above the crater and drifted S, causing ashfall in local areas including Perbaji (4 km SW), Sukatendel, Temberun, Perteguhen (7 km ESE), Kuta Rakyat (5 km NE), Simpang Empat (7 km SE), Tiga Pancur (6 km SSE), Selandi (5 km SSW), Payung (5 km SSW), and Kuta Gugung (5 km N). Significant ashfall was noted in Ndokum Siroga (9 km ESE), Gajah (8 km E), and Naman Teran (5 km NE). BNPB noted that there were 2,038 families (7,214 people) displaced to eight shelters, and an additional 2,863 people living in refugee camps. Based on PVMBG observations, webcam and satellite images, and wind data, the Darwin VAAC reported that during 6-7 August multiple ash plumes rose as high as 5.5 km (18,000 ft) a.s.l. and drifted ENE, E, and SE. The Alert Level remained at 4 (on a scale of 1-4), with an exclusion zone of 7 km from the volcano on the SSE sector, and 6 km in the ESE sector, and 4 km in the NNE sector.
Sources: Badan Nacional Penanggulangan Bencana (BNPB) http://www.bnpb.go.id/;
Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM) http://www.vsi.esdm.go.id/;
Darwin Volcanic Ash Advisory Centre (VAAC) ftp://ftp.bom.gov.au/anon/gen/vaac/
Bogoslof: strong explosive eruption |Fox Islands (USA) | 53.93°N, 168.03°W | Summit elev. 150 m
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 Color 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.
Source: US Geological Survey Alaska Volcano Observatory (AVO) http://www.avo.alaska.edu/
Dukono: small ash-eruptionsHalmahera (Indonesia) | 1.693°N, 127.894°E | Summit elev. 1229 m
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.
Source: Darwin Volcanic Ash Advisory Centre (VAAC) ftp://ftp.bom.gov.au/anon/gen/vaac/
Fuego: increased activityGuatemala | 14.473°N, 90.88°W | Summit elev. 3763 m
Based on INSIVUMEH special bulletins, CONRED reported 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.
Sources: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH) http://www.insivumeh.gob.gt/
Coordinadora Nacional para la Reducción de Desastres (CONRED) http://conred.gob.gt/
Kilauea: lava flow 61g activeHawaiian Islands (USA) | 19.421°N, 155.287°W | Summit elev. 1222 m
During 2-8 August HVO reported that the lava lake continued to rise, fall, and spatter in Kilaueas 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.
Source: US Geological Survey Hawaiian Volcano Observatory (HVO) http://hvo.wr.usgs.gov/
Sabancaya: explosive activity increasedPeru | 15.787°S, 71.857°W | Summit elev. 5960 m
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.
Sources: Instituto Geológico Minero y Metalúrgico (INGEMMET) http://www.ingemmet.gob.pe/
Instituto Geofísico del Perú (IGP) http://www.igp.gob.pe/