Volcanos

Roundup of Global Volcanic Activity – Ongoing Activity for the week of 13 September-19 September 2017

Aira | Kyushu (Japan) : JMA reported that during 4-11 September there were 52 events detected at Showa Crater (at Aira Caldera’s Sakurajima volcano), seven of which were explosive and ejected material as far as 500 m. Ash plumes rose as high as 2.4 km above the crater rim. Crater incandescence was observed most nights. The Alert Level remained at 3 (on a 5-level scale).

Bezymianny | Central Kamchatka (Russia) : KVERT reported that during 8-15 September a lava flow continued to move down the W flank of Bezymianny’s dome, and incandescence from the dome was visible at night. A thermal anomaly was identified in satellite images during 8-9 and 12-13 September. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Bogoslof | Fox Islands (USA) : AVO reported that during 13-19 September nothing significant was observed in partly to mostly cloudy satellite images of Bogoslof, and no activity was detected in seismic or infrasound data. Weakly elevated surface temperatures were identified in satellite images during 13-14 and 16-17 September, indicating ongoing unrest. On 17 September discoloured ocean water was visible in satellite data, possibly representing outflow from the crater. The Aviation colour Code remained at Orange and the Volcano Alert Level remained at Watch.

Cleveland | Chuginadak Island (USA) : AVO reported that during 13-19 September nothing significant was observed in often cloudy satellite images and web camera views of Cleveland; elevated surface temperatures were identified in satellite images during 13-15 September and minor steaming was noted during 17-19 September. Nothing noteworthy was detected in seismic or infrasound data. The Aviation colour Code remained at Orange and the Volcano Alert Level remained at Watch.

Dukono | Halmahera (Indonesia) : Based on analyses of satellite imagery, wind model data, and notices from PVMBG, the Darwin VAAC reported that during 13-16 and 18 September ash plumes from Dukono rose to altitudes of 1.8-2.1 km (6,000-7,000 ft) a.s.l. and drifted SW, W, and NW.

Ebeko | Paramushir Island (Russia) : Based on observations by volcanologists in Severo-Kurilsk (Paramushir Island), about 7 km E of Ebeko, explosions during 13-14 September generated ash plumes that rose 2.2 km (7,200 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 notifications, CONRED reported that Fuego’s ninth effusive eruption phase in 2017 began on 13 September. Explosions generated ash plumes that rose 1.2 km above the crater and drifted 15 km W and SW, causing ashfall in communities downwind including San Pedro Yepocapa (8 km N), El Porvenir (8 km ENE), and Sangre de Cristo (8 km WSW). Pyroclastic flows descended the Seca (Santa Teresa) ravine on the W flank. The eruptive phase ended about 35 hours later. INSIVUMEH noted that on 14 September, explosions generated ash plumes that rose 750 m and drifted 10 km W and SW. Shock waves from some explosions vibrated nearby structures. A lava flow was active in the Santa Teresa ravine. Explosions on 15 September produced ash plumes that rose as high as 750 m and drifted 5 km NW and SW. The lava flow was 300 m long. During 17-18 September ash plumes from explosions rose almost 1 km and drifted W and SW. Incandescent material was ejected 250 m above the crater rim, and caused avalanches of material around the crater area. Ashfall was reported in areas including Panimaché I and II (8 km SW), Morelia (9 km SW), and El Porvenir.

Karymsky | Eastern Kamchatka (Russia) : Based on satellite data, KVERT reported that ash explosions at Karymsky occurred at 0420 on 20 September, producing an ash cloud that drifted 95-100 km NNE. The Aviation colour Code was raised to Orange (the second highest level on a four-colour scale).

Kilauea | Hawaiian Islands (USA) : During 13-19 September 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 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. Surface lava flows were active above and on the pali, and on the coastal plain. On 13 September geologists noted that several prominent cracks running parallel to the coastline had widened in the past two weeks, underscoring the potential for bench collapse into the sea.

Klyuchevskoy | Central Kamchatka (Russia) : KVERT reported that on 8 September a weak thermal anomaly at Klyuchevskoy was identified in satellite images. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Popocatepetl | Mexico : Each day during 12-19 September CENAPRED reported 141-299 steam and gas emissions from Popocatépetl. Cloud cover often prevented observations, though gas-and-steam plumes were visible daily. During 12-13 September there were 22 explosions detected, four of which generated emissions with minor amounts of ash and ejected incandescent tephra. An explosion was detected at 1820 on 14 September. On 19 September a plume with low ash content rose 1 km. CENAPRED stated that there was no significant increase in activity at Popocatépetl related to the M 7.1 earthquake, centered beneath Puebla (45 km E), that occurred at 1314. The Alert Level remained at Yellow, Phase Two.

Reventador | Ecuador : On 15 September, in a special report, IG summarized recent activity at Reventador noting lava flows during 24 June-1 July and 23-24 August, periods of frequent small explosions in August, and periods of explosions that were less frequent but moderate-to-large in size during July and September. Data indicated no changes in the internal and external activity of the volcano, suggesting that the eruption will continue with alternation of effusive and explosive activity in the next days to weeks.

Sabancaya | Peru : Observatorio Vulcanológico del Sur del IGP (OVS-IGP) and Observatorio Vulcanológico del INGEMMET (OVI) reported that explosive activity at Sabancaya continued to decline; there was an average of 29 explosions recorded per day during 11-17 September. The earthquakes were dominated by long-period events and signals indicating emissions, with fewer numbers of hybrid events. Gas-and-ash plumes rose 2.5 km above the crater rim and drifted no more than 30 km E and SE. The MIROVA system detected one thermal anomaly. The report warned the public not to approach the crater within a 12-km radius.

Sheveluch | Central Kamchatka (Russia) : KVERT reported that a thermal anomaly over Sheveluch was identified daily in satellite images during 8-15 September. Several explosive events during 8-13 September generated ash plumes that rose 9-10 km (29,500-32,800 ft) a.s.l. and drifted about 400 km NW, E, and SE. The Aviation colour Code remained at Orange.

Sinabung | Indonesia : Based on observations by PVMBG, webcam and satellite images, and model data, the Darwin VAAC reported that during 13-16 and 18 September ash plumes from Sinabung rose 3-7.5 km (12,000-18,000 ft) a.s.l. and sometimes drifted ESE, SE, SW.

Turrialba | Costa Rica : OVSICORI-UNA reported that events at Turrialba at 1555 on 13 September and 0600 on 14 September generated plumes that rose 300 m above the crater rim and drifted NW and W. Another event at 0703 on 18 September produced a plume that rose 400 m.

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Volcanos

Roundup of Global Volcanic Activity – New Activity for the week of 13 September-19 September 2017

Agung | Bali (Indonesia) : Increased seismicity at Agung, as well as the severity of past eruptions, prompted PVMBG to raise the Alert Level to 2 (on a scale of 1-4). The report noted that volcanic earthquakes (VA) began to be recorded on 10 August and shallow volcanic earthquakes (VB) began to be recorded on 24 August. Local tectonic earthquakes were also recorded and began to increase consistently on 26 August. PVMBG warned the public to stay at least 3 km away from the crater. On 13 September a climber observed a sulfatara plume rising from the bottom of the crater as high as 50 m above the crater rim. During 14-18 September four earthquakes centered around Agung were felt. On 18 September PVMBG reported that the number of VA and VB events continued to increase; the Alert Level was increased to 3. The exclusion zone was increased to 6 km, with an additional expansion to 7.5 km in the N, SE, and SSW directions. Elevations above 950 m were also restricted.

Dieng Volcanic Complex | Central Java (Indonesia) : PVMBG reported that during 8 July-14 September measurements indicated an increase in water temperature at Sileri Crater lake (Dieng Volcanic Complex) from 90.7 to 93.5 degrees Celsius. Soil temperatures also increased, from 58.6 to 69.4 degrees Celsius. At Timbang Crater temperatures in the lake increased from 57.3 to 62.7, and in the soil they decreased from 18.6 to 17.2. The report noted that conditions at Timbang Crater were normal. Temperature increases at Sileri, along with tremor detected during 13-14 September, prompted PVMBG to raise the Alert Level to 2 (on a scale of 1-4). PVMBG warned the public to stay at least 1 km away from the crater rim, and for residents living within that radius to evacuate.

Zhupanovsky | Eastern Kamchatka (Russia) : Based on visual observations, KVERT reported that on 17 September explosions at Zhupanovsky generated gas-and-steam plumes with small amounts of ash that rose to altitudes of 6-7 km (19,700-23,000 ft) a.s.l. and drifted 20 km SW. The Aviation colour Code was raised from Green to Orange, the second highest level on a 4-colour scale. About 30 minutes later satellite images showed ash plumes drifting 10 km E. Later that day gas-and-steam plumes rose 4 km (13,100 ft) a.s.l. The Aviation colour Code was lowered to Yellow, and then on 20 September it was lowered to Green.

Volcanos

Roundup of Global Volcanic Activity – Ongoing Activity for the week of 6 September-12 September 2017

Aira | Kyushu (Japan) : JMA reported that 30 explosive events at Showa Crater (at Aira Caldera’s Sakurajima volcano) during 4-11 September ejected material as far as 800 m. Ash plumes rose as high as 2.2 km above the crater rim. Crater incandescence was observed most nights. The Alert Level remained at 3 (on a 5-level scale).

Bagana | Bougainville (Papua New Guinea) : Based on analyses of satellite imagery and model data, the Darwin VAAC reported that during 11-12 September an ash plume from Bagana rose to an altitude of 2.1 km (7,000 ft) a.s.l. and drifted NW.

Bezymianny | Central Kamchatka (Russia) : KVERT reported that during 1-8 September a thermal anomaly over Bezymianny was identified daily in satellite images. A lava flow continued to flow down the W flank of the dome; incandescence from the dome was visible at night. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Bogoslof | Fox Islands (USA) : AVO reported that during 6-12 September nothing significant was observed in mostly cloudy satellite images of Bogoslof, and no activity was detected in seismic or infrasound data. The 8 September report noted that the crater lake had been bisected by a narrow isthmus of land. Elevated surface temperatures were identified in one satellite image during 10-11 September. The Aviation colour Code remained at Orange and the Volcano Alert Level remained at Watch.

Cleveland | Chuginadak Island (USA) : AVO reported that during 6-12 September nothing significant was observed in often cloudy satellite images and web camera views of Cleveland; minor steaming was noted during 10-11 September. In addition, nothing noteworthy was detected in seismic or infrasound data. The Aviation colour Code remained at Orange and the Volcano Alert Level remained at Watch.

Dukono | Halmahera (Indonesia) : Based on analyses of satellite imagery, wind model data, and notices from PVMBG, the Darwin VAAC reported that during 6-10 and 12 September ash plumes from Dukono rose to an altitude of 2.1 km (7,000 ft) a.s.l. and drifted SW, W, and NW.

Ebeko | Paramushir Island (Russia) : Based on observations by volcanologists in Severo-Kurilsk (Paramushir Island), about 7 km E of Ebeko, explosions on 2 September generated ash plumes that rose 4 km (13,100 ft) a.s.l. Explosions during 3 and 6-7 September produced ash plumes that rose 2.1 km (6,900 ft) a.s.l. Minor amounts of ash fell in Severo-Kurilsk during 2-3 and 6-7 September. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Kilauea | Hawaiian Islands (USA) : During 6-12 September HVO reported that the lava lake continued to rise, fall, and spatter in Kilauea’s Overlook crater, though a deflationary trend the second half of the week caused the lake level to mostly drop. Several rockfalls and collapses of the inner crater wall veneer were noted during 7-10 September; frequent rockfalls were not uncommon during periods of lake level lowering. Webcams recorded incandescence from long-active sources within Pu’u ‘O’o Crater 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. Surface lava flows were active above and on the pali, and on the coastal plain. HVO noted that cracks running parallel to the coastline underscored the potential for bench collapse into the sea.

Klyuchevskoy | Central Kamchatka (Russia) : KVERT reported that on 7 September explosions at Klyuchevskoy recorded by a webcam generated ash plumes that rose as high as 6 km (19,700 ft) a.s.l. and drifted about 50 km NE. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Poas | Costa Rica : OVSICORI-UNA reported that an event at Poás at 0820 on 13 September generated plume that rose 300 m above the crater rim.

Sabancaya | Peru : Observatorio Vulcanológico del Sur del IGP (OVS-IGP) and Observatorio Vulcanológico del INGEMMET (OVI) reported that explosive activity at Sabancaya was slightly lower compared to the previous week; there was an average of 38 explosions recorded per day during 4-10 September. The earthquakes were dominated by long-period signals, with fewer numbers of hybrid events and emission signals. Gas-and-ash plumes rose 3.5 km above the crater rim and drifted no more than 40 km SE. The MIROVA system detected five thermal anomalies. The report warned the public not to approach the crater within a 12-km radius.

Sangay | Ecuador : Based on information from the Guayaquil MWO, the Washington VAAC reported that on 6 September an emission from Sangay rose 7.3 km (24,000 ft) a.s.l.

Sheveluch | Central Kamchatka (Russia) : KVERT reported that a thermal anomaly over Sheveluch was identified daily in satellite images during 2-3 and 6-7 September. Two explosive events on 7 September generated ash plumes that rose 8-10 km (26,200-32,800 ft) a.s.l. and drifted NE, SE, and S. The Aviation colour Code remained at Orange.

Sinabung | Indonesia : Based on observations by PVMBG, webcam and satellite images, and model data, the Darwin VAAC reported that during 6-8 and 12 September ash plumes from Sinabung rose 3-5.5 km (10,000-18,000 ft) a.s.l. and drifted W, NW, and E.

Suwanosejima | Ryukyu Islands (Japan) : Based on JMA notices and satellite-image analyses, the Tokyo VAAC reported explosions on 6 September generated plums that rose 1.5-1.8 km (5,000-6,000 ft) a.s.l. and drifted E.

Turrialba | Costa Rica : OVSICORI-UNA reported that an event at Turrialba at 0730 on 11 September generated a plume that rose 500 m above the crater rim and drifted N. Another event at 0820 on 13 September passively produced an ash plume that rose 100 m and drifted NW.

Volcanos

Roundup of Global Volcanic Activity – New Activity for the week of 6 September-12 September 2017

Aoba | Vanuatu : On 30 August the Vanuatu Geohazards Observatory (VGO) stated that conditions at Aoba had been changing, increasing the potential for eruptive activity. On 6 September a VGO report noted that activity continued to increase; the Alert Level was raised to 3 (on a scale of 0-4) signifying that the volcano is in a minor eruption phase. VGO reminded residents and tourists not to approach the volcano within a 3-km radius, and to stay out of areas subject to trade-wind exposure.

Fernandina | Ecuador : IG reported that activity at Fernandina began on 4 September with the detection of hybrid earthquakes followed by long-period events, and finally the onset of tremor at 1225 which heralded the beginning of the eruption. Lava emerged from a circumferential fissure near the SSW rim of the caldera and flowed down the S and SW flanks (with no evidence of the flows reaching the sea). A gas plume with low ash content rose 4 km above the crater rim and drifted W. Flows continued to be active on 5 September but by the evening the intensity had weakened. An eruptive plume rose about 2.5 km. Activity decreased significantly by 6 September.

Nevados de Chillan | Chile : According to Oficina Nacional de Emergencia-Ministerio del Interior (ONEMI), Servicio Nacional de Geología and Minería (SERNAGEOMIN) Observatorio Volcanológico de Los Andes del Sur (OVDAS) reported that during 16-31 August phreato-magmatic explosions at Nevados de Chillán’s Volcán Arrau dome complex had decreased. The Alert Level remained at Yellow, the middle level on a three-colour scale, and the public was reminded not to approach the craters within a 3-km radius.

Villarrica | Chile : In a summary of August activity at Villarrica, Proyecto Observación Villarrica Internet (POVI) reported that the crater was only partially visible on nine days. On 2 September a small incandescent vent at the bottom of the crater was visible. An explosion at 0924 on 30 August ejected gas and ash that drifted E due to strong winds; observers noted ash and lapilli deposits on the snow during a field visit later that day.

Volcanos

Roundup of Global Volcanic Activity – Ongoing Activity for the week of 30 August – 5 September 2017

Aira | Kyushu (Japan) : JMA reported that six explosive events at Showa Crater (at Aira Caldera’s Sakurajima volcano) during 28 August-4 September ejected material as far as 800 m. Ash plumes rose as high as 2.2 km above the crater rim. Crater incandescence was observed at night. The Alert Level remained at 3 (on a 5-level scale).

Bagana | Bougainville (Papua New Guinea) : Based on analyses of satellite imagery and model data, the Darwin VAAC reported that on 31 August ash plumes from Bagana rose to an altitude of 2.1 km (7,000 ft) a.s.l. and drifted N, W, and SW.

Bezymianny | Central Kamchatka (Russia) : KVERT reported that during 28-30 August a thermal anomaly over Bezymianny was identified in satellite images. A lava flow continued to flow down the W flank of the dome; incandescence from the dome was visible at night. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Bogoslof | Fox Islands (USA) : AVO reported that an explosive event at Bogoslof began at 0405 on 30 August and continued intermittently until 0555; the event produced a low-level ash plume that rose to around 6.1 km (20,000 ft) a.s.l. and drifted SSE. Later that day seismic and infrasound data showed quiet conditions, and a low-level plume (likely steam) drifted almost 65 km SSE. Satellite, infrasound, and seismic data showed nothing notable during 31 August-5 September. The Aviation colour Code remained at Orange and the Volcano Alert Level remained at Watch.

Cleveland | Chuginadak Island (USA) : AVO reported that elevated surface temperatures at Cleveland were identified in satellite data during 29-30 August and 4-5 September; cloudy weather sometimes prevented satellite and webcam observations. Small vapor plumes from the summit was observed in webcam images during 30-31 August. Nothing noteworthy was detected in seismic or infrasound data. The Aviation colour Code remained at Orange and the Volcano Alert Level remained at Watch.

Dukono | Halmahera (Indonesia) : Based on analyses of satellite imagery, wind model data, and notices from PVMBG, the Darwin VAAC reported that during 30 August-1 September and 3-5 September ash plumes from Dukono rose to altitudes of 1.5-2.4 km (5,000-8,000 ft) a.s.l. and drifted SW, W, and NW.

Ebeko | Paramushir Island (Russia) : Based on observations by volcanologists in Severo-Kurilsk (Paramushir Island), about 7 km E of Ebeko, explosions during 28-29 August generated ash plumes that rose as high as 2.2 km (7,200 ft) a.s.l. Minor amounts of ash fell in Severo-Kurilsk on 28 April. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Karymsky | Eastern Kamchatka (Russia) : KVERT noted gas-and-steam emissions at Karymsky since 12 August. The Aviation colour Code was lowered to Yellow (the second lowest level on a four-colour scale) on 30 August.

Kilauea | Hawaiian Islands (USA) : During 30 August-5 September 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. Surface lava flows were active above the pali and on the coastal plain. Slumping of seaward portions of the delta continued, and cracks running parallel to the coastline continued to widen. HVO warned of the potential for larger-scale delta collapses.

Klyuchevskoy | Central Kamchatka (Russia) : Based on satellite data, KVERT reported that ash plumes from explosions at Klyuchevskoy rose 6 km (19,700 ft) a.s.l. and drifted 550 km in multiple directions during 24-25 and 30 August. On 6 September KVERT noted that activity had decreased and that there was snow on the flanks; ash emissions were last observed on 30 August. The Aviation colour Code was lowered to Yellow (the second lowest level on a four-colour scale).

Langila | New Britain (Papua New Guinea) : Based on analyses of satellite imagery and model data, the Darwin VAAC reported that during 1-2 September ash plumes from Langila rose 1.8 km (6,000 ft) a.s.l. and drifted N and NW.

Manam | Papua New Guinea : Based on analyses of satellite imagery and model data, the Darwin VAAC reported that on 2 September an ash plume from Manam rose 2.1 km (7,000 ft) a.s.l. and drifted NNW.

Nishinoshima | Japan : The Japan Coast Guard reported that visual observations of Nishinoshima from an aircraft during the afternoon of 11 August suggested that the eruption was continuing; a high temperature area at the ocean entry on the W flank and a steam plume indicated flowing lava. Lava in the central crater could not be confirmed; a small fumarolic emission rose from the crater’s edge. Observations on the afternoon of 24 August suggested no lava flowing into the ocean.

Sabancaya | Peru : Observatorio Vulcanológico del Sur del IGP (OVS-IGP) and Observatorio Vulcanológico del INGEMMET (OVI) reported that explosive activity at Sabancaya was similar to the previous week; there was an average of 44 explosions recorded per day during 28 August-3 September. The earthquakes were dominated by long-period signals, with fewer numbers of hybrid events and signals indicating emissions. Gas-and-ash plumes rose 3.2 km above the crater rim and drifted no more than 40 km SE and S. The MIROVA system detected five thermal anomalies. The report warned the public not to approach the crater within a 12-km radius.

Sheveluch | Central Kamchatka (Russia) : KVERT reported that a thermal anomaly over Sheveluch was identified daily in satellite images during 25 August-1 September. The Aviation colour Code remained at Orange.

Sinabung | Indonesia : Based on observations by PVMBG and the Jakarta MWO, satellite images, and wind data, the Darwin VAAC reported that during 31 August-1 September ash plumes from Sinabung rose 3.3-4 km (11,000-13,000 ft) a.s.l. and drifted WSW, NW, and ENE.

Suwanosejima | Ryukyu Islands (Japan) : Based on JMA notices and satellite-image analyses, the Tokyo VAAC reported explosions during 30 August-2 September.

Turrialba | Costa Rica : OVSICORI-UNA reported that an event at Turrialba at 0820 on 5 September generated a plume that rose 400 m above the crater rim and drifted NW. Another event at 1550 that same day produced a plume that rose 500 m and drifted SW.

Ulawun | New Britain (Papua New Guinea) : Based on analyses of satellite imagery and model data, the Darwin VAAC reported that during 31 August-1 September and 5 September ash plumes from Ulawun rose to an altitude of 2.7 km (9,000 ft) a.s.l. and drifted SW, W, NW, and N.

Volcanos

Roundup of Global Volcanic Activity – New Activity for the week of 30 August – 5 September 2017

Ambrym | Vanuatu : On 30 August the Vanuatu Geohazards Observatory (VGO) reported that “drastic changes” at Ambrym prompted an increase in the Alert Level from 2 to 3 (on a scale of 0-5). Areas deemed hazardous were near and around the active vents (Benbow, Maben-Mbwelesu, Niri-Mbwelesu and Mbwelesu), and in downwind areas prone to ashfall. According to a news article, a representative of VGO indicated that the Alert Level change was based on increased seismicity detected since the beginning of August but which became more notable on 25 August. Since monitoring of the volcano started around 20 years ago, the Alert Level had never been elevated past 2.

Fernandina | Ecuador : IG reported that increased seismicity at Fernandina was detected at around 0955 on 4 September. Based on accounts from Galapagos Park personnel and photos of the volcano, an eruption started at around 1225. The Washington VAAC reported that lava was detected in satellite images beginning at 1230; a steam-and-gas plume rose 2.4 km (8,000 ft) a.s.l. and drifted almost 60 km W. At around 1428 IG noted that an eruptive plume was identified in satellite images rising 4 km above the crater and drifting NW. The VAAC reported that on 5 September a plume likely composed of sulfur dioxide and water vapor, and possibly some ash, rose to 2.4 km (8,000 ft) a.s.l. and drifted SW. There are no residents on Fernandina.

Nevados de Chillan | Chile : Based on webcam views, Volcanes de Chile reported that an eruption at Nevados de Chillán occurred around 0925 on 30 August.

Sangay | Ecuador : Based on satellite and model data, and information from the Guayaquil MWO, the Washington VAAC reported that ash plumes from Sangay rose to altitudes of 6.1-8.5 km (20,000-28,000 ft) a.s.l. The plumes drifted NW on 2 September.

Volcanos

Roundup of Global Volcanic Activity – Ongoing Activity for the week of 23 August – 29 August 2017

Aira | Kyushu (Japan) : JMA reported that 17 explosive events at Showa Crater (at Aira Caldera’s Sakurajima volcano) during 21-28 August ejected material as far as 800 m. Ash plumes rose as high as 1.4 km above the crater rim. The Alert Level remained at 3 (on a 5-level scale).

Bagana | Bougainville (Papua New Guinea) : Based on analyses of satellite imagery and model data, the Darwin VAAC reported that during 24-28 August ash plumes from Bagana rose to altitudes of 2.1-2.4 km (7,000-8,000 ft) a.s.l. and drifted WNW, W, and SW.

Bezymianny | Central Kamchatka (Russia) : KVERT reported that during 18-25 August a daily thermal anomaly over Bezymianny was identified in satellite images. A lava flow continued to flow down the W flank of the dome; incandescence from the dome was visible at night. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Bogoslof | Fox Islands (USA) : AVO reported that a satellite image of Bogoslof acquired at 0628 on 24 August showed elevated surface temperatures and a small plume that was most likely steam drifting 17 km S. During 24-25 August a robust steam plume drifting 70 km SE and elevated surface temperatures were identified in satellite data. A four-minute-long explosion that began at 1629 on 26 August generated an eruption cloud that rose 8.2 km (27,000 ft) a.s.l. and drifted SE. The event was also observed in seismic and infrasound data, and one lightning stroke was detected. Three short-duration eruptive events occurred during 27-28 August. The first, a two-minute-long explosion at 1508 on 27 August, produced a volcanic cloud that rose 7.9 km (26,000 ft) a.s.l. and drifted SE. The second event started at 0323 on 28 August and lasted 25 minutes. The resulting small cloud drifted ESE and quickly dissipated. The third event was detected at 1117 on 28 August and generated a small volcanic cloud that rose 7.6-9.1 (25,000-30,000 ft) a.s.l. Slightly elevated surface temperatures were observed in a few satellite images during 28-29 August. The Aviation colour Code remained at Orange and the Volcano Alert Level remained at Watch.

Cleveland | Chuginadak Island (USA) : AVO reported that elevated surface temperatures at Cleveland were identified in satellite data during 25-28 August. Small vapor plumes from the summit were observed in webcam images during 28-29 August. The Aviation colour Code remained at Orange and the Volcano Alert Level remained at Watch.

Dukono | Halmahera (Indonesia) : Based on analyses of satellite imagery, wind model data, and notices from PVMBG, the Darwin VAAC reported that during 23-28 August ash plumes from Dukono rose to altitudes of 1.8-2.1 km (6,000-7,000 ft) a.s.l. and drifted N, NW, and W.

Ebeko | Paramushir Island (Russia) : Based on observations by volcanologists in Severo-Kurilsk (Paramushir Island), about 7 km E of Ebeko, explosions on 22 August generated ash plumes that rose as high as 2 km (6,600 ft) a.s.l. and drifted SW. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Fuego | Guatemala : INSIVUMEH reported that on 25 August lahars descended the Pantaleón, Cenizas, El Jute, and Las Lajas drainages on Fuego’s W, SSW, and SE flanks. The lahar in the Pantaleón river (fed by the Santa Teresa and El Mineral rivers) was 35 m wide, 2.5-3 m deep, and carried trees and blocks more than 2-3 m in diameter. The Cenizas river lahar was about 25 m wide, 3 m deep, and carried blocks up to 2 m in diameter. The lahars in El Jute and Las Lajas drainages were 20 m wide, 1.5 m deep, and carried tree debris and blocks up to 2 m in diameter. Explosions during 26-29 August generated ash plumes that rose as high as 950 m above the crater and drifted 7-12 km SW, W, and NW. Incandescent material was ejected 100-200 m above the crater rim, and caused avalanches of material around the crater area. Explosions were audible within a 20-km radius, and shock waves vibrated local structures. Ash fell in areas downwind including Panimache I and II, Morelia, Finca Palo verde, Sangre de Cristo, and El Porvenir. On 29 August lahars 10 m wide and 1.5 m deep descended the Santa Teresa and El Mineral drainages, carrying tree debris and blocks up to 2 m in diameter.

Kilauea | Hawaiian Islands (USA) : During 23-29 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. Surface lava flows were active above the pali and on the coastal plain. Slumping of seaward portions of the delta continued, and cracks running parallel to the coastline continued to widen. HVO warned of the potential for larger-scale delta collapses.

Klyuchevskoy | Central Kamchatka (Russia) : KVERT reported that on 19 August explosions at Klyuchevskoy generated ash plumes that rose 6-7 km (19,700-23,000 ft) a.s.l.; the plumes drifted 140 km NW initially, and then 270 km SW and 90 km NE. Ash plumes during 20-25 August drifted as far as 560 km NW, W, and SW. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Piton de la Fournaise | Reunion Island (France) : OVPF reported that the eruption at Piton de la Fournaise that began on 14 July ended at 0300 on 28 August, as indicated by the disappearance of tremor. OVPF noted that seismic events beneath the SE part of the Enclos Fouqué region continued to be recorded, and carbon dioxide levels in the soil remained high.

Poas | Costa Rica : OVSICORI-UNA reported that events at Poás at 0920 and 0930 on 24 August and at 0945 on 29 August generated plumes that rose 500-600 m above the crater rim.

Sabancaya | Peru : Observatorio Vulcanológico del Sur del IGP (OVS-IGP) and Observatorio Vulcanológico del INGEMMET (OVI) reported that explosive activity at Sabancaya was similar to the previous week; there was an average of 46 explosions recorded per day during 21-27 August. The earthquakes were dominated by long-period signals and signals indicating emissions, with fewer numbers of hybrid events recorded. Gas-and-ash plumes rose 3.4 km above the crater rim and drifted no more than 50 km SE and NW. The MIROVA system detected eight thermal anomalies. The report warned the public not to approach the crater within a 12-km radius.

Sheveluch | Central Kamchatka (Russia) : KVERT reported that a thermal anomaly over Sheveluch was identified daily in satellite images during 18-25 August. The Aviation colour Code remained at Orange.

Sinabung | Indonesia : Based on PVMBG observations, webcam and satellite images, and wind data, the Darwin VAAC reported that during 23-27 August ash plumes from Sinabung rose 4-4.9 km (13,000-16,000 ft) a.s.l. and drifted E and ESE.

Suwanosejima | Ryukyu Islands (Japan) : Based on JMA notices and satellite-image analyses, the Tokyo VAAC reported that during 24-25 August ash plumes from Suwanosejima rose to altitudes of 2.1-3 km (7,000-10,000 ft) a.s.l. and drifted E and NE.

Turrialba | Costa Rica : OVSICORI-UNA reported that an event at Turrialba at 0715 on 24 August generated a plume that rose 400 m above the crater rim and drifted NW. Another event at 1025 on 28 August produced a plume that rose 300 m and drifted NW.

Volcanos

Roundup of Global Volcanic Activity – New Activity for the week of 23 August – 29 August 2017

Ibu | Halmahera (Indonesia) : Based on satellite images and model data, the Darwin VAAC reported that on 24 and 28 August ash plumes from Ibu rose 1.5-1.8 km (5,000-6,000 ft) a.s.l. and drifted W.

Pacaya | Guatemala : INSIVUMEH reported that during 21-28 August Strombolian explosions at Pacaya’s Mackenney cone ejected material as high as 75 m above the crater rim, and during 27-28 August as far as 100 m onto the W flank. Cloud cover sometimes prevented visual observations; explosions could be heard within a 5-km radius.

Sangay | Ecuador : Based on satellite data, the Washington VAAC reported that a plume from Sangay with possible ash content rose 7 km (23,000 ft) a.s.l. and drifted over 30 km SW. A thermal anomaly was identified on 23 August.

Volcanos

Roundup of Global Volcanic Activity – Ongoing Activity for the week of 16 August – 22 August 2017

Aira | Kyushu (Japan) : JMA reported 26 events at Showa Crater (at Aira Caldera’s Sakurajima volcano) during 18-21 August, one of which was explosive. Material was ejected as high and as far as 500 m. Ash plumes rose as high as 1.7 km above the crater rim. The Alert Level remained at 3 (on a 5-level scale).

Bezymianny | Central Kamchatka (Russia) : KVERT reported that during 11-18 August a daily thermal anomaly over Bezymianny was identified in satellite images. A lava flow continued to flow down the W flank of the dome; incandescence from the dome was visible at night. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Bogoslof | Fox Islands (USA) : AVO reported that photographs of Bogoslof taken during an overflight on 15 August showed that the vent area (which had dried out during the 7 August eruption) had refilled with water. Seismicity decreased on 16 August and remained low at least through 18 August. Weakly elevated surface temperatures consistent with a warm lake were identified in satellite data during 19-20 August. Satellite data acquired on 21 August showed an approximately 125-m-diameter lava dome within the intra-island lake, just W of the 1992 lava dome. A cold volcanic plume, likely from the lava dome, drifted about 55 km S of the island. Some minor explosions were detected in infrasound data at about 0410 on 22 August. The lava dome had grown to 160 m in diameter. The Aviation colour Code remained at Orange and the Volcano Alert Level remained at Watch.

Cleveland | Chuginadak Island (USA) : AVO reported that elevated surface temperatures at Cleveland were identified in satellite data during 17-21 August. Minor degassing from the summit was observed in satellite and webcam images during 20-21 August. A 1-minute-long moderate explosion was detected at 1043 on 22 August in infrasound and seismic data. The Aviation colour Code remained at Orange and the Volcano Alert Level remained at Watch.

Dukono | Halmahera (Indonesia) : Based on analyses of satellite imagery, wind model data, and notices from PVMBG, the Darwin VAAC reported that during 16-22 August ash plumes from Dukono rose to altitudes of 1.8-2.1 km (6,000-7,000 ft) a.s.l. and drifted E, NE, NW, and W. Ash plumes drifted as far as 150 km on 17 August.

Fuego | Guatemala : INSIVUMEH reported that the eighth effusive episode at Fuego in 2017 began on 20 August. Constant explosions generated ash plumes that rose 2.3 km above the crater and drifted more than 50 km W and SW. Ashfall was reported in areas downwind including Panimaché I (8 km SW), Morelia (9 km SW), Santa Sofía (12 km SW), El Porvenir (8 km ENE), Sangre de Cristo (8 km WSW), and Yepocapa (8 km WNW). Two lava fountains, each 300 m high, fed lava flows that traveled 1.4 km SSW down the Ceniza ravine and 1.2 km W down the Seca (Santa Teresa) ravine. Incandescent block avalanches occurred throughout the crater. Some explosions generated shock waves that rattled nearby structures. Seismicity decreased on 21 August. Weak explosions generated ash plumes that rose 1 km and drifted 20 km. Suspended ash from explosions and pyroclastic flows was visible. The lava flows had lengthened 200 m in the Ceniza ravine and 100 m in the Santa Teresa ravine. The report warned that pyroclastic flows were concentrated in the Santa Teresa ravine, possibly filling the drainage with deposits (similar to activity from 5 May) and increasing the chances for lahars. Ash fell in San Pedro Yepocapa (8 km N) and Chimaltenango (21 km NNE). On 22 August INSIVUMEH noted that after 48 hours the effusive episode was over. Explosions produced ash plumes that rose 1.2 km and drifted SW, and continued to vibrate nearby structures. Incandescent material was ejected as high as 200 m above the crater rim.

Karymsky | Eastern Kamchatka (Russia) : A thermal anomaly over Karymsky was identified in satellite images on 11 August, as well as ash plumes drifting about 400 km SE during 12-13 August. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Kilauea | Hawaiian Islands (USA) : During 16-22 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. A breakout 120 m up-slope of the ocean entry began at 0410 on 19 August and lasted about 9.5 hours; it produced a lava fall over the sea cliff W of the ramp and a small ‘a’a flow on the W portion of the delta. At 2135 a large littoral explosion occurred near the front of the delta, producing spatter that was ejected higher than the sea cliff (about 28 m high). Another smaller explosion was observed five minutes later. HVO scientists documented ongoing littoral explosions on 21 August, as well as continued widening of the cracks running parallel to the coastline.

Klyuchevskoy | Central Kamchatka (Russia) : KVERT reported that ash plumes from Klyuchevskoy were identified in satellite images drifting 315 km E and NW during 11-12 and 15-17 August. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Langila | New Britain (Papua New Guinea) : Based on analyses of satellite imagery, the Darwin VAAC reported that on 16 August an ash plume from Langila rose 2.1 km (7,000 ft) a.s.l. and drifted NW.

Manam | Papua New Guinea : Based on analyses of satellite imagery and model data, the Darwin VAAC reported that on 21 August an ash plume from Manam rose to an altitude of 2.1 km (7,000 ft) a.s.l. and drifted NNW.

Piton de la Fournaise | Reunion Island (France) : Mainly based on seismicity, OVPF reported that the eruption at Piton de la Fournaise that began on 14 July continued during 16-22 August; weather clouds prevented visual and satellite observations most of the week. Volcanic tremor rapidly increased in the early evening on 15 August, concurrent with the presence of ephemeral lava fountains, at the cone and another area, visible in webcam images. The signal fluctuated at high levels until the evening of 19 August, when it began to stabilize at low levels. Satellite data from 19 August indicated a decreased lava-flow rate.

Poas | Costa Rica : OVSICORI-UNA reported that an event at Poás at 1517 on 22 August generated a plume that rose 300 m above the crater rim.

Sabancaya | Peru : Observatorio Vulcanológico del Sur del IGP (OVS-IGP) and Observatorio Vulcanológico del INGEMMET (OVI) reported that explosive activity at Sabancaya was similar to the previous week; there was an average of 41 explosions recorded per day during 14-20 August. The earthquakes were dominated by long-period signals, with fewer numbers of hybrid events recorded. Gas-and-ash plumes rose 3.4 km above the crater rim and drifted no more than 30 km SE. The report warned 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 in satellite images over Sheveluch during 11-18 August. Ash plumes drifted about 180 km E, NW, and NE during 12 and 15-16 August. The Aviation colour Code remained at Orange.

Sinabung | Indonesia : PVMBG reported that the lava dome in Sinabung’s crater that had been growing since April was destroyed during the 2-3 August events. The dome had grown to an estimated volume of 2.3 million cubic meters. Measurements on 6 August indicated that a new dome had a volume of 23,700 cubic meters. Based on PVMBG ground observations, the Darwin VAAC reported that on 16 August an ash plume from Sinabung rose to 2.7 km (9,000 ft) a.s.l. and drifted ESE.

Suwanosejima | Ryukyu Islands (Japan) : Based on JMA notices, the Tokyo VAAC reported explosions at Suwanosejima during 19-20 August.

Turrialba | Costa Rica : OVSICORI-UNA reported that an event at Turrialba at 1012 on 21 August generated a plume that rose 200 m above the crater rim and drifted NW.

Volcanos

Roundup of Global Volcanic Activity – New Activity for the week of 16 August – 22 August 2017

Kanlaon | Philippines : PHIVOLCS reported that between 24 June and 18 August the seismic network at Kanlaon detected 244 volcanic earthquakes. The report stated that the increased seismic activity could be followed by phreatic explosions at the summit crater, despite the absence of visible degassing or steaming from the active vent during 2017. The Alert Level was raised to 1 (on a scale of 0-5), and the public was warned to not enter the 4-km-radius Permanent Danger Zone (PDZ).

Pacaya | Guatemala : INSIVUMEH reported that during 20-22 August Strombolian explosions at Pacaya’s Mackenney cone ejected material as high as 75 m above the crater rim and onto the flanks, generating avalanches mainly on the W flank.

San Cristobal | Nicaragua : According to a news report, at 0518 on 18 August SINAPRED received reports of ash fall in some communities near San Cristóbal, including La Grecia, and the municipalities of El Viejo (18 km WSW) and El Realejo (25 km SW). Based on analysis of satellite images and information from INETER, the Washington VAAC reported that a small ash puff from the volcano rose 300 m above the crater rim and drifted NW. Later that day a gas emission possibly containing ash rose 300 m and drifted W. An ash plume identified in satellite images extended as far as 265 km W. Seismicity was elevated. Steam-and-gas emissions continued through the rest of the day.

Sangay | Ecuador : Based on information from IG, the Guayaquil MWO, and satellite data the Washington VAAC reported continuing ash emissions at Sangay. On 16 August an ash plume drifted W. On 17 August an ash plume rose to an altitude of 8.2 km (27,000 ft) a.s.l. and drifted NW, and was followed by several more ash puffs. During 19-20 August ash plumes rose to 5.8 km (19,000 ft) a.s.l. and drifted SW and W. A thermal anomaly was identified in satellite images on 20 August.

Ulawun | New Britain (Papua New Guinea) : Based on analyses of satellite imagery and wind model data, the Darwin VAAC reported that during 17-18 August ash plumes from Ulawun rose to 2.7 km (9,000 ft) a.s.l. and drifted W.

Volcanos

Roundup of Global Volcanic Activity – Ongoing Activity for the week of 9 August – 15 August 2017

Aira | Kyushu (Japan) : JMA reported 44 events at Showa Crater (at Aira Caldera’s Sakurajima volcano) during 10-14 August, one of which was explosive. Material was ejected as high as 500 m and as far as 300 m. Ash plumes rose as high as 1.8 km above the crater rim. The Alert Level remained at 3 (on a 5-level scale).

Bagana | Bougainville (Papua New Guinea) : Based on analyses of satellite imagery and model data, the Darwin VAAC reported that during 9-10 and 13 August ash plumes from Bagana rose to an altitude of 2.4 km (8,000 ft) a.s.l. and drifted W and NW. Plumes drifted 120 km W on 13 August.

Bezymianny | Central Kamchatka (Russia) : KVERT reported that during 4-11 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; incandescence from the dome was visible at night. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Bogoslof | Fox Islands (USA) : AVO reported that on 9 August seismic and infrasound data suggested low-level eruptive activity at Bogoslof; weakly elevated surface temperatures and a minor steam emission were identified in satellite images. No significant activity was observed in cloudy satellite images, and no activity was detected in seismic, infrasound, or lightning data during 10-13 August. Two short pulses of tremor were detected (at 0853, lasting five minutes, and at 0913, lasting three minutes) in seismic data; seismicity returned to baseline levels afterwards. A sequence of seismic events began at 0000 on 15 August; no activity was observed in infrasound, lightning, or satellite data. The Aviation colour Code remained at Orange and the Volcano Alert Level remained at Watch.

Cleveland | Chuginadak Island (USA) : AVO reported that elevated surface temperatures at Cleveland were identified in satellite data during 9-15 August; weather clouds occasionally obscured views. No significant activity was observed in seismic and infrasound data. On 11 August AVO noted that lava-dome growth had stopped or slowed, based on satellite observations. Steam emissions from the summit crater were occasionally visible in webcam images. The Aviation colour Code remained at Orange and the Volcano Alert Level remained at Watch.

Dukono | Halmahera (Indonesia) : Based on analyses of satellite imagery, wind model data, and notices from PVMBG, the Darwin VAAC reported that during 9-15 August ash plumes from Dukono rose to an altitude of 2.1 km (7,000 ft) a.s.l. and drifted NW and W.

Fuego | Guatemala : CONRED reported that during 8-9 August the lava flow that had descended Fuego’s Ceniza (SSW) drainage was still active, producing avalanches of material and emissions. Explosions generated ash plumes that rose 650 m above the crater. According to INSIVUMEH ash plumes from explosions during 11-12 and 14-15 August rose 650-850 m and drifted 7-8 km W and SW. Ashfall was reported in areas downwind including in Panimache (8 km SW), Morelia (9 km SW), Santa Sofía (12 km SW), El Porvenir (8 km ENE), Yepocapa, and Sangre de Cristo (8 km WSW). Incandescent material was ejected 100-150 m above the crater rim, and caused avalanches of material that traveled down multiple ravines.

Ibu | Halmahera (Indonesia) : Based on PVMBG observations, the Darwin VAAC reported that on 15 August an ash plume from Ibu rose to an altitude of 1.8 km (6,000 ft) a.s.l. and drifted N.

Karymsky | Eastern Kamchatka (Russia) : A thermal anomaly over Karymsky was identified in satellite images during 4 and 6-10 August, as well as ash plumes drifting about 70 km NE and SW during 4 and 7-9 August. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Kilauea | Hawaiian Islands (USA) : During 9-15 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 warned of the potential for larger-scale delta collapses.

Klyuchevskoy | Central Kamchatka (Russia) : KVERT reported that ash plumes from Klyuchevskoy were identified in satellite images drifting 300 km SW, SE, and NE during 4 and 7-11 August. A thermal anomaly was identified on 4 and 7 August. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Langila | New Britain (Papua New Guinea) : Based on analyses of satellite imagery, the Darwin VAAC reported that on 9 August a minor ash emission from Langila rose 1.8 km (6,000 ft) a.s.l. and drifted N.

Manam | Papua New Guinea : Based on analyses of satellite imagery and model data, the Darwin VAAC reported that on 13 August an ash plume from Manam rose to an altitude of 2.1 km (7,000 ft) a.s.l. and drifted almost 40 km NW.

Nevado del Ruiz | Colombia : Servicio Geológico Colombiano’s (SGC) Observatorio Vulcanológico y Sismológico de Manizales reported that during 8-14 August seismicity at Nevado del Ruiz continued to indicate unrest; seismicity decreased as compared to the previous week. Plumes of water vapor and gas continued to be emitted from the volcano. A gas-and-steam plume rose 450 m above the crater rim on 8 August and drifted NW. A thermal anomaly was identified on 14 August. The Alert Level remained at III (Yellow; the second lowest level on a four-colour scale).

Poas | Costa Rica : OVSICORI-UNA reported that during 11-14 August seismicity at Poás was characterized by low-amplitude tremor, some volcano-tectonic earthquakes, and high-frequency signals indicating gas emissions. Weather clouds mostly prevented visual observations.

Popocatepetl | Mexico : Each day during 9-13 and 15 August CENAPRED reported 97-355 and steam and gas emissions from Popocatépetl; the daily count increased to 702 on 14 June. Crater incandescence was visible on some nights. A small explosion at 0815 on 14 August produced a plume with low ash content that rose 500 m above the crater rim and drifted SW. Explosions at 1759 and 1805 generated ash plumes that rose 0.8 and 1.5 km, respectively, and drifted W. On 15 August an explosion produced an ash plume that rose 1 km and drifted WNW. The Alert Level remained at Yellow, Phase Two.

Reventador | Ecuador : During 9-15 August IG reported a high level of seismic activity including explosions, long-period earthquakes, harmonic tremor, and signals indicating emissions at Reventador. Steam, gas, and ash plumes rose as high as 550 m above the crater rim and drifted mainly W and SW. Incandescent blocks rolled as far as 800 m down the flanks. During 10-12 August pyroclastic flows traveled as far as 600 m down the ESE and W flanks. Weather clouds sometimes prevented visual observations.

Sabancaya | Peru : Observatorio Vulcanológico del Sur del IGP (OVS-IGP) and Observatorio Vulcanológico del INGEMMET (OVI) reported that explosive activity at Sabancaya decreased compared to the previous week; there was an average of 49 explosions recorded per day during 7-13 August. The earthquakes were dominated by long-period signals, with fewer numbers of hybrid and tremor events recorded. Gas-and-ash plumes rose 3.2 km above the crater rim and drifted no more than 40 km NE and E. Sulfur dioxide flux was as high as 912 tons per day, recorded on 8 August. The MIROVA system detected 12 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 in satellite images over Sheveluch during 4-11 August. Strong explosions on 8 August produced a large ash cloud (300 x 400 km in size) that rose as high as 10 km (32,800 ft) a.s.l. and drifted more than 550 km SSE during 8-9 August. Ashfall was reported in Klyuchi Village (50 km SW) on 8 August. The Aviation colour Code remained at Orange.

Sinabung | Indonesia : Based on PVMBG ground observations, the Jakarta MWO, satellite images, and wind data, the Darwin VAAC reported that during 9-10 and 13 August ash plumes from Sinabung rose 3.4-5.2 km (11,000-17,000 ft) a.s.l. and drifted W and ESE.

Turrialba | Costa Rica : OVSICORI-UNA reported that an event at Turrialba at 1607 on 9 August generated a plume that rose 200 m above the crater rim and drifted NW. The report noted that since 6 August a monitoring station in Coronado San José had been detecting the presence of ash in emissions. Sporadic and passive emissions of ash, water vapor, magmatic gases, and aerosols continued to be observed at least through 14 August.

Volcanos

Roundup of Global Volcanic Activity – New Activity for the week of 9 August – 15 August 2017

Kerinci | Indonesia : Based on satellite data, the Darwin VAAC reported that on 13 August an ash plume from Kerinci rose to an altitude of 4.3 km (14,000 ft) a.s.l. and drifted WSW. Plumes drifted almost 30 km on 17 November.

Pacaya | Guatemala : On 12 August INSIVUMEH reported that Strombolian explosions at Pacaya’s Mackenney cone were observed. During 12-13 August the number of Strombolian explosions increased to a rate of 5-7 per hour, and ejected incandescent material was mainly visible at night. Explosions vibrated structures in communities within a 5-km radius. Activity continued at a similar level on 15 August.

Piton de la Fournaise | Reunion Island (France) : OVPF reported that the eruption at Piton de la Fournaise that began on 14 July continued through 15 August. Weather clouds often prevented visual confirmation of activity, though observers periodically noted that small amounts of material were ejected from a small vent on the N flank of the eruptive vent. Some active pahoehoe flows were visible at a distance of 2 km from the cone, though most of the flow activity was confined to lava tubes.

Sangay | Ecuador : Based on information from the Guayaquil MWO, the Washington VAAC reported that on 12 August an emission from Sangay rose to altitudes of 6.1-6.4 km (20,000-21,000 ft) a.s.l. and drifted SW and NW. Ash in the emission was not detected in satellite data. On 13 August satellite data showed a well-defined thermal anomaly over the volcano, and an ash plume drifting 55 km SW.

Sangeang Api | Indonesia : Based on analyses of satellite imagery, the Darwin VAAC reported that on 12 August an ash plume from Sangeang Api rose to 2.7 km (9,000 ft) a.s.l. and drifted NW.

Ulawun | New Britain (Papua New Guinea) : Based on analyses of satellite imagery and wind model data, the Darwin VAAC reported that during 9-10 August ash plumes from Ulawun rose to 2.4 km (8,000 ft) a.s.l. and drifted NW and W.

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.

Volcanos

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

Piton de la Fournaise | Reunion Island (France) colour: 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.

Sangay | Ecuador : 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.

Sangeang Api | Indonesia : Based on analyses of satellite imagery, the Darwin VAAC reported that during 7-8 August minor emissions from Sangeang Api rose 2.4 km (8,000 ft) a.s.l. and drifted WSW.

Sinabung | Indonesia : 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.

Ulawun | New Britain (Papua New Guinea) : Based on analyses of satellite imagery and wind model data, the Darwin VAAC reported that during 4-8 August ash plumes from Ulawun rose 2.4-2.7 km (8,000-9,000 ft) a.s.l. and drifted NW, W, and SW.

Volcanos

Roundup of Global Volcanic Activity – Ongoing Activity for the week of 26 July – 1 August 2017

Aira | Kyushu (Japan) : colourJMA reported two events at Showa Crater (at Aira Caldera’s Sakurajima volcano) during 24-28 July. One of the events generated an ash plume that rose 2 km above the crater rim. The Alert Level remained at 3 (on a 5-level scale).

Bagana | Bougainville (Papua New Guinea) : Based on analyses of satellite imagery and model data, the Darwin VAAC reported that on 1 August an ash plume from Bagana drifted W at an altitude of 2.1 km (7,000 ft) a.s.l.

Bezymianny | Central Kamchatka (Russia) : KVERT reported that during 21-28 July a thermal anomaly was identified daily 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 26 July-1 August no activity at Bogoslof was observed in partly cloudy to clear satellite images, and no activity was detected in seismic, infrasound, or lightning data. The Aviation colour Code remained at Orange and the Volcano Alert Level remained at Watch.

Cleveland | Chuginadak Island (USA) : AVO reported that during 26 July-1 August no activity was observed in seismic or infrasound data at Cleveland. The small lava dome on the floor of the crater had grown from 30 m in diameter to 42, and continued to inflate; the surface area of the dome was at least 50 x 45 m (~2,100 square meters), which was an increase of about 75% since 25 July (~1,200 square meters). Steam plumes rising from the crater were recorded by the webcam during 25 and 29-30 July, and elevated surface temperatures (consistent with lava-dome growth) were identified in satellite images during 30 July-1 August. The Aviation colour Code remained at Orange and the Volcano Alert Level remained at Watch.

Colima | Mexico : On 2 June the Centro Universitario de Estudios e Investigaciones de Vulcanologia – Universidad de Colima reported that during the previous week seismic data revealed 45 high-frequency events, 12 long-period events, 1.2 hours of tremor, 3 landslides, and one low-intensity explosion. Two lahars descended the La Lumbre ravine (SW) and three descended the Montegrande ravine (SSE); both ravines are in Colima state.

Dukono | Halmahera (Indonesia) : Based on analyses of satellite imagery, wind model data, and notices from PVMBG, the Darwin VAAC reported that during 26 July-1 August ash plumes from Dukono rose to altitudes of 2.1-2.7 km (7,000-9,000 ft) a.s.l. and drifted in multiple directions.

Kilauea | Hawaiian Islands (USA) : During 26 July-1 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. Several large cracks running parallel to the coastline spanned the width of the delta. Surface lava flows were active above the pali and on the coastal plain about 2 km upslope from the gravel emergency route.

Klyuchevskoy | Central Kamchatka (Russia) : KVERT reported that during 22-27 July ash plumes from Klyuchevskoy were identified in satellite images drifting 120 km E and NE. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Poas | Costa Rica : OVSICORI-UNA reported that on 1 August an event at Poás passively produced a plume that rose 500 m above the crater.

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 40 explosions recorded per day during 24-30 July. Gas-and-ash plumes rose 5 km above the crater rim and drifted more than 50 km NW and SE. Sulfur dioxide flux was as high as 2,530 tons per day, recorded on 28 July. The MIROVA system detected nine thermal anomalies.

Sheveluch | Central Kamchatka (Russia) : KVERT reported that a thermal anomaly was identified daily during 21-28 July in satellite images over Sheveluch. Strong explosions on 23 July generated ash plumes that rose 11-12 km (36,100-39,400 ft) a.s.l. and during 23-24 July drifted 1,400 km E. The Aviation colour Code remained at Orange.

Sinabung | Indonesia : Based on PVMBG observations, satellite images, and wind data, the Darwin VAAC reported that during 26-29 and 31 July ash plumes from Sinabung rose 3.3-4.6 km (11,000-15,000 ft) a.s.l. and drifted NE, ENE, and ESE.

Turrialba | Costa Rica : OVSICORI-UNA reported that on 26 July an event at Turrialba passively produced a plume that rose 300 m above the crater and drifted SW.