Volcanos

Roundup of Global Volcanic Activity – Ongoing Activity for the week of 4 October – 10 October 2017

Aira | Kyushu (Japan) : JMA reported that during 2-10 October there were 19 events detected at Showa Crater (at Aira Caldera’s Sakurajima volcano), three of which were explosive. Plumes rose as high as 1.6 km above the crater rim. An explosion on 5 October ejected material as far as 800 m. The Alert Level remained at 3 (on a 5-level scale).

Bezymianny | Central Kamchatka (Russia) : On 6 October KVERT reported that a thermal anomaly at Bezymianny was identified in satellite images during 1-2 and 4-5 October, and that lava probably continued to flow down the W flank of the dome. The Aviation Color Code was lowered to Yellow (the second lowest level on a four-color scale).

Cleveland | Chuginadak Island (USA) : AVO reported that no significant activity at Cleveland was observed in seismic or infrasound data during 4-10 October, though elevated surface temperatures identified in satellite data on 6 October suggested that the lava dome in the summit crater (first noted on 30 September) continued to grow. Elevated surface temperatures were identified during 8-9 October. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.

Dukono | Halmahera (Indonesia) : Based on analyses of satellite imagery, model data, and notices from PVMBG, the Darwin VAAC reported that during 4-10 October 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, W, and SW. Ash plumes drifted 140-170 km on 8 October.

Ebeko | Paramushir Island (Russia) : Based on observations by volcanologists in Severo-Kurilsk (Paramushir Island), about 7 km E of Ebeko, explosions during 29-30 September and 1 and 5 October generated ash plumes that rose 1.5 km (4,900 ft) a.s.l. The Aviation Color Code remained at Orange (the second highest level on a four-color scale).

Fuego | Guatemala | 14.473°N, 90.88°W : CONRED and INSIVUMEH reported that during 4-6 October increased explosive activity (8-12 explosions per hour) at Fuego generating ash plumes that rose as high as 1.3 km above the crater. Ash plumes drifted more than 20 km S, SW, and W; ashfall was reported in areas downwind including Panimaché I and II (8 km SW), Santa Sofía (12 km SW), Morelia (9 km SW), and El Porvenir. Incandescent material rose 300 m above the crater, and avalanches of material traveled as far as 1.5 km W down the Seca (Santa Teresa) ravine and SSW down the Ceniza ravine. Shockwaves vibrated local structures. An average of 4-6 explosions per hour were detected during 7-8 October. Ash plumes rose around 1 km and drifted 12 km W, NW, and N. Incandescent material was ejected 150 m above the crater, causing avalanches that were confined to the crater. Ash fell in local communities including San Pedro Yepocapa (8 km N), Sangre de Cristo (8 km WSW), and La Soledad. Vulcanian explosions during 8-9 October produced ash plumes that rose 1 km and drifted 15 km SW, W, and NW, again causing ashfall in Panimaché, Santa Sofía, Morelia, El Porvenir, San Pedro Yepocapa, and Sangre de Cristo. Block avalanches traveled 2 km down the flanks.

Karymsky | Eastern Kamchatka (Russia) : KVERT reported that an ash cloud was identified in satellite images drifting about 85 km ENE from Karymsky on 3 October. The Aviation Color Code was raised to Orange (the second highest level on a four-color scale).

Kilauea | Hawaiian Islands (USA) : During 4-10 October 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 although the plume at the entry was weaker. Surface lava flows were active above and on the pali, and on the coastal plain.

Langila | New Britain (Papua New Guinea) : Based on analyses of satellite imagery and model data, the Darwin VAAC reported that on 4 October a minor ash emission from Langila rose 1.8 km (6,000 ft) a.s.l. and drifted N.

Reventador | Ecuador : During 3-10 October 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 sometimes higher that 1.1 km above the crater rim and drifted mainly NW, W, and SW. Incandescent blocks rolled as far as 800 m down the flanks. Weather clouds sometimes prevented visual observations.

Rincon de la Vieja | Costa Rica : OVSICORI-UNA reported that at 1048 on 9 October a small eruption at Rincón de la Vieja produced a plume that rose 700 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 slightly declined; there was an average of 42 explosions recorded per day during 2-8 October. The earthquakes were dominated by long-period events, with fewer numbers of signals indicating emissions and hybrid events. Gas-and-ash plumes rose 3.5 km above the crater rim and drifted no more than 40 km N, NW, and W. The MIROVA system detected 10 thermal anomalies. The report warned the public not to approach the crater within a 12-km radius.

Sangay | Ecuador : In a special report from 4 October IG stated that the current eruption at Sangay which began on 20 July continued, and that the activity had not changed significantly during the previous two months. Activity was characterized by explosions at the central vent and lava from the Ñuñurco lava dome flowing down the E and ESE flanks. On each day during the previous week there were about 65 explosions, 25 long-period events, and a few harmonic tremor signals. Ash plumes rose 1 km above the crater rim and caused ashfall in areas to the W and NW (Culebrillas and Licto (35 km NW)).

Sheveluch | Central Kamchatka (Russia) : KVERT reported that a thermal anomaly over Sheveluch was identified daily in satellite images on 2 and 5 October. The Aviation Color Code remained at Orange.

Sinabung | Indonesia : Based on observations by PVMBG and BMKG, webcam and satellite images, and model data, the Darwin VAAC reported that during 4-5 and 7-9 October ash plumes from Sinabung rose 3-5.8 km (10,000-19,000 ft) a.s.l. and drifted in multiple directions.

Turrialba | Costa Rica : OVSICORI-UNA reported that an event at Turrialba at 0815 on 6 October produced a plume that rose 50 m above the crater rim and drifted NW. An event at 1040 on 9 October generated a plume that rose 200 m and drifted NW.

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Volcanos

Roundup of Global Volcanic Activity – New Activity for the week of 4 October – 10 October 2017

Agung | Bali (Indonesia) : On 5 October PVMBG reported that the rate of volcanic earthquakes at Agung had not increased during the previous 12 days, but continued to fluctuate at a high level. The seismic network detected 1-3 earthquakes per minute on average, with a total more than 600 events per day. The number of shallow volcanic earthquakes increased to 200 per day during 24 September-5 October, possibly indicating that magmatic activity at shallow depths was still high. The number of earthquakes felt by staff at the Mt. Agung Volcano Observatory in Rendang village, 12.5 km SSW, peaked on 27 September and then decreased afterwards. Gas plumes rose 50-200 m above the crater rim. Satellite data indicated an area of water expulsion near the solfatara field on the crater floor thought to reflect a disturbance to the hydrologic system in response to intruded magma at depth. On 5 October BNPB reported that the number of evacuees reached 146,797 (spread out in 427 shelters), though about 28 villages (70,000 people) were located within the evacuation zone. About 10,000 farm animals had also been evacuated. On 7 October a white plume likely composed mostly of water vapor rose 1.5 km above the crater rim and slowly drifted E. During 8-10 October fumarolic plumes rose 50-200 m above the rim. The Alert Level remained at 4 (the highest level on a scale of 1-4) with the exclusion zone at 9 km, and an additional expansion to 12 km in the SE, S, and SW directions.

Aoba | Vanuatu : Vanuatu Geohazards Observatory (VGO) stated that photographs and thermal infrared images taken on 30 September, and 1, 3, and 5 October during overflights of Aoba’s Lake Voui confirmed that the eruption was ongoing. Activity consisted of small explosions ejecting hot rock from vents on a new small island in the lake, and a small lava flow that traveled from the vent into the lake. On 6 October VGO noted that there was no evidence of the eruption escalating; the Alert Level was lowered to 3 (the middle level on a scale of 0-5) and residents and tourists were reminded to stay outside of the Red Zone defined as a 3 km radius around the active cone. Based on analyses of satellite imagery and model data, the Wellington VAAC reported that during 10-11 October ash plumes rose as high as 3.7 km (12,000 ft) a.s.l. and drifted N. On 11 October a news article stated that the government extended a state of emergency on the island to 24 October, delaying the return of the 11,000 residents that had been evacuated.

Lewotolo | Lomblen Island (Indonesia) : The number of shallow and deep volcanic earthquakes at Lewotolo recently increased, prompting PVMBG to raise the Alert Level from 1 to 2 (on a scale of 1-4) on 7 October. The report noted that the public should not enter the 2-km-radius exclusion zone around the crater. Solfatara emissions rose as high as 500 m above the crater rim on 9 October; emissions during 1 August-6 October rose 50-600 m. BNPB reported that five earthquakes recorded by Badan Meteorologi, Klimatologi, dan Geofisika (BMKG) on 10 October ranged in magnitude between 3.9 and 4.9, and were located 10-30 km below Lewotolo. The events were felt by local populations, causing an evacuation of 723 people. Preliminary data suggested that five homes were damaged from rock avalanches, triggered by the earthquakes.

Volcanos

Roundup of Global Volcanic Activity – Ongoing Activity for the week of 27 September – 3 October 2017

Aira | Kyushu (Japan) : JMA reported that at 0055 on 29 September an explosive event at Showa Crater (at Aira Caldera’s Sakurajima volcano) produced a plume that rose 2.8 km above the crater rim, and ejected material as far as 1,300 m. Two of eight events were explosive during 30 September-2 October; plumes rose 2.8 km and material was ejected 1,300 m away. The Alert Level remained at 3 (on a 5-level scale).

Bezymianny | Central Kamchatka (Russia) : KVERT reported that during 22-29 September lava continued to flow down the W flank of Bezymianny’s dome, and 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) : On 27 September AVO reported that the last explosion at Bogoslof was detected on 30 August, and no new volcanic activity was observed in satellite, seismic, or infrasound data since then. The Aviation colour Code was lowered to Yellow and the Volcano Alert Level was lowered to Advisory.

Cleveland | Chuginadak Island (USA) : AVO reported that two small explosions at Cleveland were detected at 0516 and 0558 on 28 September in infrasound and seismic data. Elevated surface temperatures were identified in satellite data, and a weak plume rising from the summit crater was recorded by the webcam. Satellite data indicated that lava effusion in the summit crater began on 30 September, and by 1 October the new lava dome had grown to about 4,200 square meters. The Aviation colour Code remained at Orange and the Volcano Alert Level remained at Watch.

Dieng Volcanic Complex | Central Java (Indonesia) : PVMBG reported that since 20 September tremor and water temperature at Sileri Crater lake (Dieng Volcanic Complex) both declined. The Alert Level was lowered to 1 (on a scale of 1-4) on 2 October. PVMBG warned the public to stay at least 100 m away from the crater rim.

Dukono | Halmahera (Indonesia) : Based on analyses of satellite imagery, wind model data, and notices from PVMBG, the Darwin VAAC reported that during 27 September-3 October ash plumes from Dukono rose to an altitude of 2.1 km (7,000 ft) a.s.l. and drifted in multiple directions.

Ebeko | Paramushir Island (Russia) : Based on observations by volcanologists in Severo-Kurilsk (Paramushir Island), about 7 km E of Ebeko, explosions on 24 September generated ash plumes that rose 2 km (6,600 ft) a.s.l. Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Karymsky | Eastern Kamchatka (Russia) : KVERT reported that a weak thermal anomaly over Karymsky was identified in satellite images during 23-25 September. An ash cloud drifted about 54 km E on 23 September. The Aviation colour Code was raised to Orange (the second highest level on a four-colour scale).

Kilauea | Hawaiian Islands (USA) : During 27 September-3 October 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, although during 1-3 October the plume at the entry waxed and waned. Surface lava flows were active above and on the pali, and on the coastal plain.

Popocatepetl | Mexico : Each day during 26 September-3 October CENAPRED reported 21-61 emissions from Popocatépetl and 2-6 volcano-tectonic earthquakes. Cloud cover often prevented visual observations. Periods of harmonic tremor and as many as 10 explosions per day were detected during 26-30 September. Beginning at 0315 on 27 September an episode of Strombolian activity that lasted for six hours and sixteen minutes ejected incandescent tephra as far as 1 km onto the flanks. Ash plumes rose 1.5 km above the crater rim and drifted W. Ash fell in the towns of Ecatzingo and Atlautla in Estado de México, and in Atlatlahuacán, Ocuituco, Oaxtepec, Jiutepec, and Yautepec in Estado de Morelos. An explosion at 2257 on 30 September ejected incandescent tephra no more than 800 m onto the flanks, and produced an ash plume that rose 2 km. An explosion was detected at 1417 on 3 October. The Alert Level remained at Yellow, Phase Two. 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 on 19 September.

Rincon de la Vieja | Costa Rica : OVSICORI-UNA reported that at 0858 on 29 September a small phreatic explosion at Rincón de la Vieja produced a plume that rose 1 km above the crater rim; material also flowed down the S flank. On 3 October events at 0848 and 1445 generated plumes that rose 700 m and 1,500 m, respectively.

Sabancaya | Peru : Observatorio Vulcanológico del Sur del IGP (OVS-IGP) and Observatorio Vulcanológico del INGEMMET (OVI) reported that explosive activity at Sabancaya increased; there was an average of 45 explosions recorded per day during 25 September-1 October. The earthquakes were dominated by long-period events, with fewer numbers of signals indicating emissions and hybrid events. Gas-and-ash plumes rose 3.5 km above the crater rim and drifted no more than 40 km E and NE. The MIROVA system detected seven 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 22-29 September. 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 27-29 September and 1-2 October ash plumes from Sinabung rose 3.7-5.5 km (12,000-18,000 ft) a.s.l. and drifted in multiple directions.

Suwanosejima | Ryukyu Islands (Japan) : Based on JMA notices and satellite-image analyses, the Tokyo VAAC reported an explosion on 29 September which generated a plume that rose 2.4 km (8,000 ft) a.s.l. and drifted E.

Turrialba | Costa Rica : OVSICORI-UNA reported that daily events at Turrialba during 27 September-1 October and on 3 October generated plumes that rose as high as 1 km above the crater rim and drifted NW, W, SW, and S. On 30 September explosions ejected hot material out of West Crater and minor ashfall was reported in Coronado (San José). Ash fell in Santa Cruz (7 km SE), Las Verbenas, Santa Teresita, Calle Vargas, Guayabito, and La Isabel on 3 October.

Volcanos

Roundup of Global Volcanic Activity – New Activity for the week of 27 September – 3 October 2017

Agung | Bali (Indonesia) : On 29 September PVMBG reported that earthquakes at Agung were becoming stronger with more felt by local residents, and larger ones felt in areas 45-55 km SW including Denpasar and Kuta. Fumarolic emissions were identified in satellite data, as well as hot areas on the crater floor that had enlarged over the previous week. A new fracture on the crater floor emitted steam. After a M 4.2 earthquake was detected at 1627 on 26 September emissions intensified and rose 500 m above the crater rim. On 4 October BNPB reported that seismicity continued to fluctuate at high levels, and weak emissions rose above the crater rim. The number of evacuees reached 141,213 (spread out in 416 shelters) from 78 villages, though about 2,600 in locations outside of the evacuation zone were returning home; there were 28 villages (about 70,000 people) within the evacuation zone. The Alert Level remained at 4 (the highest level on a scale of 1-4) with the exclusion zone at 9 km, and an additional expansion to 12 km in the SE, S, and SW directions.

Ambrym | Vanuatu : On 28 September the Vanuatu Geohazards Observatory (VGO) reported that minor eruptive activity continued at Ambrym. The Alert Level remained at 3 (on a scale of 0-5). Areas deemed hazardous were within a 2-km radius from Benbow Crater and a 3-km radius from Marum Crater.

Aoba | Vanuatu : On 28 September the Vanuatu Geohazards Observatory (VGO) stated that activity at Aoba remained at a moderate level. The Alert Level remained at (the second highest level on a scale of 0-5) and VGO reminded residents and tourists to stay outside of the Red Zone defined as a 6.5 km radius around Manaro Lakua cone (Manaro Voui). According to news sources, island officials ordered the evacuation of all of the island inhabitants, and by 4 October about 11,600 people had been evacuated. A 4 October news article noted that during the past week tephra had fallen on local villages.

Volcanos

Roundup of Global Volcanic Activity – Ongoing Activity for the week of 20 September-26 September 2017

Aira | Kyushu (Japan) : JMA reported that 29 events at Showa Crater (at Aira Caldera’s Sakurajima volcano) detected during 19-22 September sometimes produced plumes that rose 1.8 km. At 0445 on 24 September an eruption plume rose 1 km. The Alert Level remained at 3 (on a 5-level scale).

Bezymianny | Central Kamchatka (Russia) : KVERT reported that during 15-22 September lava continued to flow 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 15-19 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 20-26 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 22-23 September, indicating ongoing unrest. The Aviation colour Code remained at Orange and the Volcano Alert Level remained at Watch.

Cleveland | Chuginadak Island (USA) : AVO reported that during 20-24 September nothing significant was observed in satellite images and web camera views of Cleveland, and nothing noteworthy was detected in seismic or infrasound data. Minor steaming was noted during 22-24 September. A three-minute-long explosion that began at 1747 on 25 September was detected by seismic and infrasound sensors. Satellite data 30 minutes later suggested that a volcanic cloud likely containing ash rose to 4.6 km (15,000 ft) a.s.l. and drifted S. 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 20-26 September ash plumes from Dukono rose to an altitude of 2.1 km (7,000 ft) a.s.l. and drifted in multiple directions.

Ebeko | Paramushir Island (Russia) : Based on observations by volcanologists in Severo-Kurilsk (Paramushir Island), about 7 km E of Ebeko, explosions during 15-17 September generated ash plumes that rose 3 km (10,000 ft) a.s.l. Minor amounts of ash fell in Severo-Kurilsk on 16 and 18 September. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Karymsky | Eastern Kamchatka (Russia) : KVERT reported that a weak thermal anomaly over Karymsky was identified in satellite images during 15-16 September. An ash cloud rose 7 km (23,000 ft) a.s.l. and drifted for about 100 km NE on 19 September. The Aviation colour Code was raised to Orange (the second highest level on a four-colour scale).

Kilauea | Hawaiian Islands (USA) : During 20-26 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. During 23-24 September a short-lived breakout above the ocean entry disrupted the ramp and produced a brief “firehose” of lava.

Klyuchevskoy | Central Kamchatka (Russia) : KVERT reported that during 16-17 September a weak thermal anomaly at Klyuchevskoy was identified in satellite images. KVERT noted that the last time ash was emitted from the volcano was on 7 September; 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 wind model data, the Darwin VAAC reported that during 22-23 September ash plumes from Langila rose 2.1 km (7,000 ft) a.s.l. and drifted NNW.

Nevados de Chillan | Chile : Servicio Nacional de Geología and Minería (SERNAGEOMIN) Observatorio Volcanológico de Los Andes del Sur (OVDAS) reported that a phreatic explosion at Nevados de Chillán’s Volcán Arrau dome complex was recorded by a webcam on 21 September. An explosion ejected gas and tephra on 23 September. 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.

Pacaya | Guatemala : INSIVUMEH reported that during 21-22 September Strombolian explosions at Pacaya’s Mackenney cone ejected material as high as 100 m above the crater rim. During 23-24 September the seismic network recorded Strombolian explosion signals.

Sabancaya | Peru : Observatorio Vulcanológico del Sur del IGP (OVS-IGP) and Observatorio Vulcanológico del INGEMMET (OVI) reported that explosive activity at Sabancaya increased; there was an average of 45 explosions recorded per day during 18-24 September. The earthquakes were dominated by long-period events, with fewer signals indicating emissions and hybrid events. Gas-and-ash plumes rose 3.5 km above the crater rim and drifted no more than 40 km E and SE. The MIROVA system detected seven 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 15-22 September. 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 22-23 September ash plumes from Sinabung rose 3.4-4 km (11,000-13,000 ft) a.s.l. and sometimes drifted E and SE. On 25 September ash plumes rose 6.4 km (21,000 ft) a.s.l. and drifted ESE.

Turrialba | Costa Rica : OVSICORI-UNA reported that events at Turrialba at 1112 on 25 September and 0910 on 26 September generated plumes that rose 300 m above the crater rim and drifted NW.

Ulawun | New Britain (Papua New Guinea) : Based on analyses of satellite imagery and model data, the Darwin VAAC reported that on 25 September a minor ash plume from Ulawun rose 3 km (10,000 ft) a.s.l. and drifted WSW.

Volcanos

Roundup of Global Volcanic Activity – New Activity for the week of 20 September-26 September 2017

Agung | Bali (Indonesia) : BNPB noted that as of 1300 on 22 September there were 9,421 people displaced from the evacuation zones at Agung. Seismicity continued to increase, therefore later that day on 22 September PVMBG raised the Alert Level to 4 (the highest level on a scale of 1-4) and expanded the exclusion zone to 9 km, with an additional expansion to 12 km in the SE, S, and SW directions. On 24 September BNPB reported that the number of refugees continued to grow, as residents were leaving the expanded evacuation zones; there were 34,931 people in 238 shelters. The report noted that some evacuees were returning home in the daytime to feed their livestock. On 27 September the number of evacuees reached 96,086 (spread out in 430 shelters), seismic activity continued to escalate, and diffuse white plumes rose 50 m above the crater rim.

Aoba | Vanuatu : On 23 September the Vanuatu Geohazards Observatory (VGO) stated that activity at Aoba continued to increase, prompting them to raise the Alert Level to 4 (the second highest level on a scale of 0-5). On 24 September photos showed an ash plume rising above the crater rim, and ashfall was reported in areas across the island. One report noted that ashfall had been reported for a few weeks. The Vanuatu government’s Council of Ministers declared a state of emergency on the island on 26 September; about 36 schools were closed. That same day the New Zealand Defence Force conducted an overflight and posted a video showing an ash plume and lava fountains rising from the vent. On 27 September a news article stated that about 8,000 residents were in 35 evacuation shelters, mostly evacuated from the N and S parts of the island to the E and W areas.

Lopevi | Vanuatu : Increased activity at Lopevi prompted the Vanuatu Geohazards Observatory to increase the Alert Level to 2 (on a scale of 0-4). The report noted that all visitors should not approach the crater area.

San Cristobal | Nicaragua : Based on seismic data INETER reported that a period of tremor recorded at San Cristóbal during 1939-2005 on 9 September ended with an explosion signal.

Telica | Nicaragua : INETER reported that a small gas explosion was heard by local residents on 10 September. INETER warned the public to stay at least 2 km away from the crater.

Volcanos

Indonesia – Mount Agung

Nearly 50 000 people have evacuated their homes amid fears of an imminent volcanic eruption on the Indonesian resort island of Bali, disaster officials said on Monday.

Mount Agung, about 75 km from the tourist hub of Kuta, has been rumbling since August, threatening to erupt for the first time in more than 50 years. In 1963, more than 1 000 people died in the previous eruption.

Indonesia’s disaster mitigation agency said Monday 48 540 people had fled, although the number was expected to rise because more than 60 000 people lived in the danger zone.

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.

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.