Volcanos

Roundup of Global Volcanic Activity – New Activity for the week of 5 December – 11 December 2018

Manam | Papua New Guinea : The Darwin VAAC reported that on 6 December ash plumes from Manam were identified in satellite images rising to an altitude of 5.2 km (17,000 ft) a.s.l. and drifting SE. RVO noted that at 1215 on 8 December seismicity increased and indicated an eruption had begun, according to a news article. The eruption was characterized by forceful ash emissions, explosions that ejected lava fragments above the crater, and rumbling and roaring noises. Around 1300, based on pilot observations, information from RVO, and satellite images, large ash plumes rose as high as 15.2 km (50,000 ft) a.s.l and drifted E. Island reports noted that ejections of material ceased around 1900; audible noises ended around 1930. Satellite data indicated that ash from the high-altitude plume had begun to dissipate by 2020, and that on-going ash emissions rose to 8.2 km (27,000 ft) a.s.l. Island residents described heavy ashfall and that the sun was blocked by airborne ash, based on second-hand social media posts. News reports indicated that residents in Bokure and Kolang (NE and ENE flanks, respectively) had evacuated. Seismicity had declined by the end of the day. Dark ash plumes continued to be visible the next day, rising as high as 7.6 km (25,000 ft) a.s.l. and drifting E, though were less frequent.

Mayon | Luzon (Philippines) : PHIVOLCS reported that during 5-11 December white steam plumes periodically emitted from Mayon drifted mainly WSW. Crater incandescence was sometimes visible at night. A four-minute long event recorded by the seismic network began at 1224 on 9 December, and produced a grayish-brown ash plume that drifted W. The Alert Level remained at 2 (on a 0-5 scale) and PHIVOLCS reminded residents to stay away from the 6-km-radius Permanent Danger Zone and the 7-km Extended Danger Zone on the SSW and ENE flanks.

Volcanos

Roundup of Global Volcanic Activity – New Activity for the week of 28 November – 4 December 2018

Aira | Kyushu (Japan) : JMA reported that nine events at Minamidake crater (at Aira Caldera’s Sakurajima volcano) were recorded during 26 November-3 December, producing ash plumes that rose as high as 1.8 km above the crater rim. Incandescence was periodically visible at night. An explosion at 0218 on 1 December generated a plume that rose 2.5 km and ejected tephra 1.1 km from the crater. The Alert Level remained at 3 (on a 5-level scale).

Bagana | Bougainville (Papua New Guinea) : On 1 December the Darwin VAAC reported that ash plumes from Bagana were visible in satellite images drifting SE at an altitude of 3 km (10,000 ft) a.s.l. The report also noted the presence of a strong thermal anomaly, and that ash plumes which previously rose to 6.1 km (20,000 ft) a.s.l. had dissipated. Steam plumes drifted SE on 2 December.

Chiles-Cerro Negro | Colombia-Ecuador : Servicio Geológico Colombiano (SGC) reported that a seismic swarm below Cerro Negro de Mayasquer and Chiles volcanoes began at 0100 on 3 December. The events were classified as volcano-tectonic, with epicenters located up to 6 km from the summit of Chiles volcano, at depths of less than 8 km (4.7 km a.s.l.). The maximum local magnitude was 2.3. From the beginning of the swarm until the time of the report posting (1640) there were about 5,400 recorded events, making the swarm the largest since 2015. The report also noted that seismicity had gradually been increasing in recent weeks. The Alert Level remained at Yellow (level 2 of 4).

Copahue | Central Chile-Argentina border : The Buenos Aires VAAC reported that on 2 December a narrow ash plume from Copahue was visible in satellite images drifting ESE.

Dukono | Halmahera (Indonesia) : Based on satellite data, wind model data, and notices from PVMBG, the Darwin VAAC reported that during 21-27 November ash plumes from Dukono rose to altitudes of 1.5-2.1 km (5,000-7,000 ft) a.s.l. and drifted NE, E, and SE. The Alert Level remained at 2 (on a scale of 1-4), and visitors were warned to remain outside of the 2-km exclusion zone.

Ebeko | Paramushir Island (Russia) : Volcanologists in Severo-Kurilsk (Paramushir Island), about 7 km E of Ebeko, observed explosions during 23-30 November that sent ash plumes to 4 km (13,100 ft) a.s.l. Ash plumes drifted E. A weak thermal anomaly was identified in satellite data on 24 November, and ashfall was reported in Severo-Kurilsk on 27 and 29 November. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Kadovar | Papua New Guinea : Based on satellite data and wind model data, the Darwin VAAC reported that during 27-28 November ash plumes from Kadovar rose to an altitude of 0.9 km (3,000 ft) a.s.l. and drifted SE and E. On 2 December ash plumes rose to 1.2 km (4,000 ft) a.s.l. and drifted WSW and W.

Kirishimayama | Kyushu (Japan) : JMA reported that vigorous fumarolic activity on the S side of Iwo-yama (also called Ioyama), on the NW flank of the Karakuni-dake stratovolcano in the Kirishimayama volcano group, continued during 30 November-3 December. Fumarolic plumes rose 100 m above the vent, and hot mud was ejected from the vent. A hot pool of water persisted on the S side of the area. Fumarolic plumes rose 50 m above a vent 500 m W of Iwo-yama. The Alert Level remained at 2 (the second lowest level on a scale of 1-5).

Krakatau | Indonesia : PVMBG reported that events at Anak Krakatau were recorded at 1131 on 1 December, at 1408 on 2 December, and at 0816 on 3 December, each lasting between 46 and 69 seconds. Ash plumes from the events rose 500-700 m and drifted NE and N. The Alert Level remained at 2 (on a scale of 1-4); residents and visitors were warned not to approach the volcano within 2 km of the crater.

Kuchinoerabujima | Ryukyu Islands (Japan) : JMA reported that during 28 November-3 December intermittent events at Kuchinoerabujima’s Shindake Crater generated plumes that rose as high as 1.5 km above the crater rim. The Alert Level remained at 3 (on a scale of 1-5).

Merapi | Central Java (Indonesia) : PVMBG reported that during 23-29 November the lava dome in Merapi’s summit crater grew at a rate of 2,500 cubic meters per day. By 29 November the volume of the dome, based on photos taken from the SE, was an estimated 329,000 cubic meters. White emissions of variable density rose a maximum of 400 m above the summit. The Alert Level remained at 2 (on a scale of 1-4), and residents were warned to remain outside of the 3-km exclusion zone.

Popocatepetl | Mexico : CENAPRED reported that each day during 28 November-3 December there were 16-79 steam-and-gas emissions from Popocatépetl. Periods of volcanic tremor were detected almost daily. Explosions at 0509 and 0922 on 2 December ejected incandescent material onto the upper flanks, and generated ash plumes that rose 2.5 km above the crater rim and drifted NE. More explosions at 1543 and 1745 produced ash plumes that rose 1.5 km and drifted NE. The Alert Level remained at Yellow, Phase Two (middle level on a three-colour scale).

Rincon de la Vieja | Costa Rica : OVSICORI-UNA reported a one-minute-long eruption at Rincón de la Vieja began at 1054 on 3 December. Weather conditions prevented webcam views and estimates of plume heights.

Sabancaya | Peru : Observatorio Vulcanológico del Sur del IGP (OVS-IGP) and Observatorio Vulcanológico del INGEMMET (OVI) reported that an average of 21 explosions per day occurred at Sabancaya during 26 November-2 December. Long-period seismic events were recorded, and hybrid earthquakes were infrequent and of low magnitude. Gas-and-ash plumes rose as high as 2.5 km above the crater rim and drifted 30 km N, E, and SE. MIROVA detected eight thermal anomalies, and on 28 November the sulfur-dioxide gas flux was high at 4,600 tons per day. The report noted that the public should not approach the crater within a 12-km radius.

Sheveluch | Central Kamchatka (Russia) : KVERT reported that a thermal anomaly over Sheveluch was identified in satellite images on 23 November; weather clouds prevented views of the volcano during 24-30 November. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Suwanosejima | Ryukyu Islands (Japan) : JMA reported that four explosions at Suwanosejima’s Ontake Crater were recorded during 22-30 November. The highest ash plume rose 2 km, and material was ejected 300 m from the crater. Ashfall was reported in an area 4 km SSW on 23 November. Crater incandescence was visible at night. The Alert Level remained at 2 (on a 5-level scale).

Turrialba | Costa Rica : OVSICORI-UNA reported intermittent pulses of ash and some periods of continuous ash emissions from Turrialba during 28 November-3 December. Ash plumes rose as high as 500 m above the crater rim and drifted N, NW, and SW. Ashfall was reported in Santo Domingo (36 km WSW) on 2 December.

Volcanos

Roundup of Global Volcanic Activity – Ongoing Activity for the week of 28 November – 4 December 2018

Mayon | Luzon (Philippines) : PHIVOLCS reported that during 27 November-4 December white steam plumes rose from Mayon daily, and crater incandescence was visible almost nightly. At 0533 on 27 November a phreatic event generated a grayish-white ash plume that rose 300-500 m and drifted SW. A one-minute-long event that began at 0941 on 30 November produced another grayish-white ash plume. The Alert Level remained at 2 (on a 0-5 scale) and PHIVOLCS reminded residents to stay away from the 6-km-radius Permanent Danger Zone and the 7-km Extended Danger Zone on the SSW and ENE flanks.

Veniaminof | United States : AVO reported that the eruption of lava from the cone in Veniaminof’s ice-filled summit caldera continued during 27 November-3 December. Satellite and webcam data showed elevated surface temperatures. Steam and diffuse ash plumes were periodically identified in webcam and satellite images. During 27-28 November acoustic waves were recorded by regional infrasound sensors. Continuous low-amplitude tremor was recorded until the network went offline following a M 7 tectonic earthquake near Anchorage on 30 November. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale) and the Volcano Alert Level remained at Watch (the second highest level on a four-level scale).

Volcanos

Roundup of Global Volcanic Activity – Ongoing Activity for the week of 21 November – 27 November 2018

Aira | Kyushu (Japan) : JMA reported that four events at Minamidake crater (at Aira Caldera’s Sakurajima volcano) were recorded during 19-22 November, producing ash plumes that rose as high as 1.6 km above the crater rim. Material was ejected 500-700 m from the crater. Occasional, very small events occurred during 22-26 November. Crater incandescence was visible at night during 20-21 November, for the first time since 20 September, and continued through 26 November. The Alert Level remained at 3 (on a 5-level scale).

Dukono | Halmahera (Indonesia) : Based on satellite data, wind model data, and notices from PVMBG, the Darwin VAAC reported that during 21-27 November ash plumes from Dukono rose to altitudes of 1.5-2.1 km (5,000-7,000 ft) a.s.l. and drifted NE, E, and SE.

Ebeko | Paramushir Island (Russia) : Volcanologists in Severo-Kurilsk (Paramushir Island), about 7 km E of Ebeko, observed explosions during 15-23 November that sent ash plumes to 3.2 km (10,500 ft) a.s.l. Ash plumes drifted NE and S. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Ibu | Halmahera (Indonesia) : The Darwin VAAC reported that on 26 November an ash plume from Ibu was identified in satellite images rising to 1.8 km (6,000 ft) a.s.l. and drifting SE. The Alert Level remained at 2 (on a scale of 1-4), and the public was warned to stay at least 2 km away from the active crater, and 3.5 km away on the N side.

Krakatau | Indonesia : PVMBG reported that events at Anak Krakatau were recorded at 0611 on 24 November, at 0810 on 25 November, and at 0900 and 1037 on 26 November, each lasting between 30 and 42 seconds. Ash plumes from the events rose 300-600 m and drifted NE and SW; the ash plumes from the 1037 event were dense and black. The Alert Level remained at 2 (on a scale of 1-4); residents and visitors were warned not to approach the volcano within 2 km of the crater.

Kuchinoerabujima | Ryukyu Islands (Japan) : JMA reported that during 22-26 November intermittent events at Kuchinoerabujima’s Shindake Crater generated plumes that rose as high as 2.1 km above the crater rim. The Alert Level remained at 3 (on a scale of 1-5).

Merapi | Central Java (Indonesia) : PVMBG reported that during 16-22 November the lava dome in Merapi’s summit crater grew at a rate of 2,600 cubic meters per day, slower than the previous week. By 21 November the volume of the dome, based on photos taken from the SE, was an estimated 308,000 cubic meters. White emissions of variable density rose a maximum of 125 m above the summit. The Alert Level remained at 2 (on a scale of 1-4), and residents were warned to remain outside of the 3-km exclusion zone.

Pacaya | Guatemala : INSIVUMEH reported that during 24-27 November Strombolian explosions at Pacaya’s Mackenney Crater ejected material as high as 25 m above the crater rim. As many as three lava flows were active on the NW flanks, advancing towards Cerro Chino. Minor avalanches of material descended the SE flank during 26-27 November.

Rincon de la Vieja | Costa Rica : OVSICORI-UNA reported that at 0237 on 27 November a hydrothermal explosion at Rincón de la Vieja produced a plume of water vapor and gas that rose 600 m above the crater rim and drifted SW.

Sabancaya | Peru : Observatorio Vulcanológico del Sur del IGP (OVS-IGP) and Observatorio Vulcanológico del INGEMMET (OVI) reported that an average of 20 explosions per day occurred at Sabancaya during 19-25 November. Long-period seismic events were recorded, and hybrid earthquakes were infrequent and of low magnitude. Gas-and-ash plumes rose as high as 2.7 km above the crater rim and drifted 40 km NW and N. MIROVA detected six thermal anomalies, and on 22 November the sulfur-dioxide gas flux was high at 3,000 tons per day. The report noted that the public should not approach the crater within a 12-km radius.

Sangay | Ecuador : IG reported that since 8 August activity at Sangay was characterized by the extrusion of lava flows on the ESE flank and ash emissions that rose between 500 and 1,500 m and mainly drifted W and NW. Lava flows were 1-2 km long, though block avalanches from the flow fronts traveled additionally as far as 5 km. The seismic network recorded more than 50 signals per day indicating explosions. The activity continued at least through 21 November; the report noted that this phase has lasted longer than any other since 2015.

Santa Maria | Guatemala : INSIVUMEH reported that during 24-27 November explosions at Santa María’s Santiaguito lava-dome complex generated ash plumes that rose 700-900 m and drifted SW, causing ashfall in Monte Claro. Avalanches of material descended the SE and NE flanks of the lava dome.

Semisopochnoi | United States : AVO reported that no evidence of activity at Semisopochnoi had been detected since an explosion was recorded in infrasound data on 31 October. The satellite link for transmitting seismic data failed on 1 November, though no activity was observed in satellite or infrasound data since then. As a result, the Aviation colour Code was lowered to Yellow and Volcano Alert Level was lowered to Advisory (both are the second lowest levels on four-level scales) on 21 November.

Sheveluch | Central Kamchatka (Russia) : KVERT reported that a weak thermal anomaly over Sheveluch was identified in satellite images during 16-17 and 19-20 November. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Turrialba | Costa Rica : OVSICORI-UNA reported that at 0710 on 22 November an event at Turrialba generated an ash plume that rose 100 m above the crater rim and drifted W. The next day there were frequent pulses of ash. During 23-25 November occasional Strombolian explosions ejected lava bombs that were deposited near the crater; residents of Cascajal de Coronado reported hearing several booming sounds. Ash plumes rose as high as 500 m. During 26-27 November passive emissions with small quantities of ash were visible. Minor ashfall was reported in San Jose (Cascajal de Coronado and Dulce Nombre), San Pedro Montes de Oca, and neighborhoods of Heredia.

Volcanos

Roundup of Global Volcanic Activity – New Activity for the week of 21 November – 27 November 2018

Fuego | Guatemala : colourOn 23 November INSIVUMEH reported that during the previous few days moderate explosions at Fuego generated shock waves that vibrated structures within 20 km. Ash plumes from the explosions rose 1.3 km above the cone in the summit crater and drifted 20 km W and SW, causing ashfall in areas downwind including Panimaché (8 km SW), El Porvenir (8 km ENE), Morelia (9 km SW), Santa Sofia (12 km SW), Sangre de Cristo (8 km WSW), Palo Verde Estate, and San Pedro Yepocapa (8 km NW). Incandescent material was ejected 150 m high, causing avalanches, some that traveled long distances in the Las Lajas (SE), Ceniza (SSW), and Seca (W) drainages and reached vegetated areas. During 24-25 November there were 12-15 weak-to-moderate explosions per hour, generating ash plumes that rose as high as 1.1 km and drifted 20-25 km W and SW. Shock waves continued to vibrate local structures, and ashfall was again reported in Panimaché, El Porvenir, Morelia, Santa Sofia, Sangre de Cristo, Palo Verde Estate, and San Pedro Yepocapa. Moderate-to-strong Vulcanian explosions on 26 November generated ash plumes that rose as high as 1.2 km and drifted N. The explosions were heard, and shock waves felt, mostly within 25 km, though some explosions were audible to residents of Guatemala City (city center is about 40 km ENE). Explosions continued the next day at a rate of 10-15 per hour. Ash plumes rose as high as 1.3 km and drifted 20-25 km W and SW. Incandescent material was ejected 200 m high, and avalanches of material descended multiple drainages. Ashfall was reported in areas downwind.

Karangetang | Siau Island (Indonesia) : PVMBG reported that at 1314 on 25 November an eruption at Karangetang produced an ash plume that rose at least 500 m above the crater rim; weather clouds prevented clear views of the plume. The Aviation colour Code was raised to Orange, though the Alert Level remained at 2 (on a scale of 1-4).

Mayon | Luzon (Philippines) : PHIVOLCS reported that during 21-26 November white steam plumes periodically emitted from Mayon rose as high as 750 m and drifted WSW and SW. Crater incandescence was visible at night during 24-27 November. Two phreatic explosions were recorded during 0759 and 0805 on 26 November. The events generated grayish ash plumes that rose 300-500 m and drifted SW. The Alert Level remained at 2 (on a 0-5 scale) and PHIVOLCS reminded residents to stay away from the 6-km-radius Permanent Danger Zone and the 7-km Extended Danger Zone on the SSW and ENE flanks.

Suwanosejima | Ryukyu Islands (Japan) : JMA reported that 16 explosions at Suwanosejima’s Ontake Crater were recorded during 16-22 November. The highest ash plume rose 2 km, and material was ejected 300 m from the crater. Ashfall was reported in an area 4 km SSW on 17 November. The Alert Level remained at 2 (on a 5-level scale).

Veniaminof | United States : Ash emissions from the cone in Veniaminof’s ice-filled summit caldera significantly increased overnight during 20-21 November, prompting AVO to raise the Aviation colour Code to Red and the Volcano Alert Level to Warning (the highest levels on four-level scales). Ash emissions rose to below 4.6 km (15,000 ft) a.s.l. and drifted more than 240 km SE. On 21 November observers and webcam views in Perryville (35 km SE) indicated continuous ash emissions through most of the day; ash plumes drifted SE, extending as far as 400 km by around 1445. A short eruptive pulse was recorded during 1526-1726, and then afterwards ash plumes rose to below 3 km (10,000 ft) a.s.l. Low-altitude ash emissions on 22 November drifted 100 km S. Minor ashfall was reported in Perryville. AVO lowered the Aviation colour Code and Volcano Alert Level to Orange and Watch, respectively, because of decreased ash emissions. Elevated thermal anomalies were identified in satellite data overnight, and incandescence was visible from a Perryville webcam, suggesting continuing lava effusion which had been obscured by the increased period of ash emissions. Lava effusion was persistent through 27 November.

Volcanos

Roundup of Global Volcanic Activity – Ongoing Activity for the week of 14 November – 20 November 2018

Aira | Kyushu (Japan) : JMA reported that an explosion at Minamidake crater (at Aira Caldera’s Sakurajima volcano) was recorded at 0043 on 14 November, producing a large ash cloud that rose over 4 km above the crater rim. Incandescent material was ejected more than 1 km from the crater. The report noted that this was the first occurrence of an ash plume rising above 4 km since 16 July 2018. Two events occurred during 16-19 November with the larger plume rising 1.6 km into the clouds. The Alert Level remained at 3 (on a 5-level scale).

Ambrym | Vanuatu : On 15 November the Vanuatu Meteorology and Geo-hazards Department (VMGD) reported that the lava lakes in Ambrym’s Benbow and Marum craters continued to be active during October and November, and produced substantial and sustained gas-and-steam emissions. The Alert Level remained at 2 (on a scale of 0-5); the report reminded the public to stay outside of the Permanent Danger Zone defined as a 1-km radius from Benbow Crater and a 2.7-km radius from Marum Crater.

Dukono | Halmahera (Indonesia) : Based on satellite data and wind model data, the Darwin VAAC reported that during 14-15 and 19-20 November 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.

Ebeko | Paramushir Island (Russia) : Volcanologists in Severo-Kurilsk (Paramushir Island), about 7 km E of Ebeko, observed explosions during 9-15 November that sent ash plumes to 4.5 km (14,800 ft) a.s.l. Ash plumes drifted E. A weak thermal anomaly was identified in satellite data during 12-13 November. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Kadovar | Papua New Guinea : The Darwin VAAC reported that discrete, low-level events at Kadovar regularly occurred on 14 November based on satellite data. Ash plumes rose to an altitude of 2.4 km (8,000 ft) a.s.l. and drifted E.

Krakatau | Indonesia : PVMBG reported that seven events at Anak Krakatau were recorded between 0840 on 14 November and 0601 on 15 November. Each event lasted for 33-175 seconds, based on the seismic data, and produced ash plumes that rose 0.3-1 km above the crater rim and drifted N, ENE, and E. A 212-second-long event at 0524 on 16 November generated a dense black ash plume that rose 600 m and drifted NE. An event at 0532 lasted 207 seconds and generated an ash plume that rose 300 m and drifted NE. The Alert Level remained at 2 (on a scale of 1-4); residents and visitors were warned not to approach the volcano within 2 km of the crater.

Kuchinoerabujima | Ryukyu Islands (Japan) : JMA reported that intermittent events at Kuchinoerabujima’s Shindake Crater had been recorded since 21 October, and crater incandescence began to be periodically visible on 6 November. Ash plumes rose as high as 1.2 km above the crater rim during 12-19 November and, according to the Tokyo VAAC, drifted in multiple directions. During fieldwork on 14 and 15 November observers noted no changes to the thermal areas in the crater. The Alert Level remained at 3 (on a scale of 1-5).

Merapi | Central Java (Indonesia) : PVMBG reported that during 9-15 November the lava dome in Merapi’s summit crater grew at a rate of 2,400 cubic meters per day, slower than the previous week. By 14 November the volume of the dome, based on photos from the SE sector, was an estimated 290,000 cubic meters. White emissions of variable density rose a maximum of 200 m above the summit. The Alert Level remained at 2 (on a scale of 1-4), and residents were warned to remain outside of the 3-km exclusion zone.

Sabancaya | Peru : Observatorio Vulcanológico del Sur del IGP (OVS-IGP) and Observatorio Vulcanológico del INGEMMET (OVI) reported that an average of 20 explosions per day occurred at Sabancaya during 12-18 November. Long-period seismic events were recorded, and hybrid earthquakes were infrequent and of low magnitude. Gas-and-ash plumes rose as high as 3 km above the crater rim and drifted 40 km NW, SW, and S. MIROVA detected seven thermal anomalies, and on 13 November the sulfur-dioxide gas flux was high at 3,000 tons per day. The report noted that the public should not approach the crater within a 12-km radius.

Sheveluch | Central Kamchatka (Russia) : KVERT reported that explosions at Sheveluch on 9 November generated ash plumes that drifted as far as 460 km E. A weak thermal anomaly was identified in satellite images during 9-11 and 15 November. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Turrialba | Costa Rica : OVSICORI-UNA reported that periodic, passive ash emissions at Turrialba continued to be visible in webcam images or during cloudy conditions inferred from the seismic data during 13-19 November.

Veniaminof | United States : AVO reported that the eruption from the cone in Veniaminof’s ice-filled summit caldera, continued at low levels during 14-20 November. Satellite and webcam data showed elevated surface temperatures from minor lava spattering and lava effusion. Relatively continuous low-amplitude tremor was recorded. Steam and diffuse ash plumes were periodically identified in webcam and satellite images; plumes rose as high as 4.9 km (16,000 ft) a.s.l. on 16 November. Recent satellite data showed that the lava flows had traveled as far as 1.2 km from the vent. Fractures in the ice sheet adjacent to the lava flow continued to grow due to meltwater flowing beneath the ice sheet. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale) and the Volcano Alert Level remained at Watch (the second highest level on a four-level scale).

Yasur | Vanuatu : On 15 November the Vanuatu Meteorology and Geo-hazards Department (VMGD) reported that ongoing explosions at Yasur were sometimes strong during October and November, based on visual observations and seismic data. The Alert Level remained at 2 (on a scale of 0-4). VMGD reminded residents and tourists that hazardous areas were near and around the volcanic crater, within a 395-m-radius permanent exclusion zone, and that volcanic ash and gas could reach areas impacted by trade winds.

Volcanos

Roundup of Global Volcanic Activity – New Activity for the week of 14 November – 20 November 2018

Fuego | Guatemala : INSIVUMEH and CONRED reported that activity at Fuego increased on 18 November, heralding the fifth effusive phase of 2018. Incandescent material was ejected 200-300 m above the crater rim and a lava flow in the Ceniza (SSW) drainage reached 2.5 km in length. Avalanches of material from the lava flow reached vegetated areas. Explosions occurring at a rate of 8-17 per hour generated ash plumes that rose at least 1.2 km and drifted 20-25 km W and SW. Ashfall was reported in areas downwind including Morelia (9 km SW), Santa Sofia (12 km SW), Sangre de Cristo (8 km WSW), Panimaché I and II (8 km SW), and Finca Palo Verde. Volcanic material also accumulated in the Taniluyá (SW) and Seca (W) drainages causing increased risk of avalanches. Later that day explosions became stronger, and incandescent material was ejected 400 m high. Ashfall continued to be reported in local communities. CONRED reported that a portion of National Route 14 was closed, and evacuations began in some local areas. Strombolian activity continued to intensify on 19 November with stronger explosions and increased seismicity. Incandescent material was ejected as high as 1 km above the crater. Ash plumes rose as high as 3.2 km and drifted 20-60 km W, SW, and NE. Pyroclastic flows descended the Seca drainage, and, along with ash emissions from the crater, caused ashfall in multiple areas including Santa Sofia, Sangre de Cristo, Panimaché I and II, and Finca Palo Verde. The lava flow in the Ceniza drainage advanced to 3 km long and produced avalanches from the flow front. Avalanches of tephra also descended the Seca, Ceniza, Taniluyá, Las Lajas, and Honda (E) drainages, reaching vegetated areas. CONRED noted that 3,925 people had been evacuated. INSIVUMEH noted that the effusive phase was over at 1800 on 19 November, having lasted for 32 hours. Explosions continued during 19-20 November, generating ash plumes which rose 0.8-1 km and drifted 10-15 km NW, W, and SW. Ash fell in areas downwind including El Porvenir (8 km ENE), Morelia, Santa Sofia, Sangre de Cristo, Panimaché I and II, and Finca Palo Verde. Incandescent material was ejected 100-300 m high, casing avalanches, some that traveled long distances. Some explosions generated shock waves that rattled nearby structures.

Mayon | Luzon (Philippines) : PHIVOLCS reported that during 14-20 November white steam plumes emitted from Mayon drifted downslope and then in multiple directions. Crater incandescence was visible at night. The Alert Level remained at 2 (on a 0-5 scale) and PHIVOLCS reminded residents to stay away from the 6-km-radius Permanent Danger Zone and the 7-km Extended Danger Zone on the SSW and ENE flanks.

Suwanosejima | Ryukyu Islands (Japan) : JMA reported that four explosions at Suwanosejima’s Ontake Crater were recorded during 9-16 November. The highest ash plume rose 2 km, the first time a plume from Ontake Crater rose that high since 4 April. Material was ejected 700 m from the crater. Ashfall was reported in an area 4 km SSW on 15 November. The Alert Level remained at 2 (on a 5-level scale).

Volcanos

Roundup of Global Volcanic Activity – Ongoing Activity for the week of 7 November – 13 November 2018

Aira | Kyushu (Japan) : JMA reported that the sulfur dioxide emission rate at Minamidake crater (at Aira Caldera’s Sakurajima volcano) was high at 1,100 tons/day on 6 November, an increase from the previous measurement of 1,000 tons/day recorded on 23 October. Very small eruptive events were occasionally recorded during 9-12 November. The Alert Level remained at 3 (on a 5-level scale).

Dukono | Halmahera (Indonesia) : PVMBG reported that an event at Dukono, recorded by the seismic network at 0824 on 8 November, generated an ash plume that rose 200 m above the crater rim and drifted SW. The Darwin VAAC reported that during 12-13 November ash plumes rose to an altitude of 1.8 km (6,000 ft) a.s.l. and drifted E and NE.

Ebeko | Paramushir Island (Russia) : Volcanologists in Severo-Kurilsk (Paramushir Island), about 7 km E of Ebeko, observed explosions during 2-9 November that sent ash plumes to 3.7 km (12,400 ft) a.s.l. Ash plumes drifted in multiple directions and caused ashfall in Severo-Kurilsk. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Fuego | Guatemala : INSIVUMEH reported that 7-18 explosions per hour were detected at Fuego during 8-12 November. Ash plumes from the explosions rose as high as 1.1 km above the crater rim and drifted 8-20 km W and SW. Ash fell in areas downwind including Morelia (9 km SW), Santa Sofia (12 km SW), Sangre de Cristo (8 km WSW), Panimaché (8 km SW), El Porvenir, Finca Palo Verde, and San Pedro Yepocapa (8 km NW). Incandescent material was ejected 150-300 m high and caused avalanches that traveled far, reaching vegetated areas in multiple drainages. Lava flows as long as 1.2 km advanced in the Ceniza (SSW) drainage, though lava-flow activity greatly decreased by 12 November.

Kadovar | Papua New Guinea : According to the Darwin VAAC an ash plume from Kadovar was identified in satellite data on 9 November drifting WNW at an altitude of 1.8 km (6,000 ft) a.s.l.

Krakatau | Indonesia : PVMBG reported that four events at Anak Krakatau occurred between 1620 and 1710 on 9 November. Each event lasted for 42-55 seconds, based on the seismic data, and produced ash plumes that rose 300-500 m above the crater rim and drifted N. An event at 0939 on 10 November generated an ash plume that rose 500 m and drifted N. There were 10 events recorded during 1029-1656 on 12 November, each lasting 38-117 seconds, and producing ash plumes that rose 200-700 m and drifted N. Four events were recorded during 0546-0840 on 13 November, each lasting 44-175 seconds, and producing ash plumes that rose as high as 800 m. The Alert Level remained at 2 (on a scale of 1-4); residents and visitors were warned not to approach the volcano within 2 km of the crater.

Merapi | Central Java (Indonesia) : PVMBG reported that during 2-8 November the lava dome in Merapi’s summit crater grew slowly at a rate of 3,500 cubic meters per day, faster than the previous week. By 7 November the volume of the dome, based on photos from the SE sector, was an estimated 273,000 cubic meters. White emissions of variable density rose a maximum of 100 m above the summit. The Alert Level remained at 2 (on a scale of 1-4), and residents were warned to remain outside of the 3-km exclusion zone.

Rincon de la Vieja | Costa Rica : OVSICORI-UNA reported a two-minute-long eruption at Rincón de la Vieja began at 1703 on 9 November. Weather conditions prevented webcam views and estimates of plume heights.

Sabancaya | Peru : Observatorio Vulcanológico del Sur del IGP (OVS-IGP) and Observatorio Vulcanológico del INGEMMET (OVI) reported that an average of 18 explosions per day occurred at Sabancaya during 5-11 November. Hybrid earthquakes were infrequent and of low magnitude. Gas-and-ash plumes rose as high as 3.7 km above the crater rim and drifted 40 km N, NW, and W. MIROVA detected seven thermal anomalies, and on 8 November the sulfur-dioxide gas flux was high at 2,500 tons per day. The report noted that the public should not approach the crater within a 12-km radius.

Semisopochnoi | United States : AVO reported that three possible small explosions at Semisopochnoi were detected in infrasound data between 1951 and 2004 on 9 November. No associated ash clouds were observed in partly cloudy satellite images, and no other activity was noted during 7-11 November also in partly cloudy images. Images were cloudy during 12-13 November. The Aviation colour Code remained at Orange and Volcano Alert Level remained at Watch (both are the second highest levels on four-level scales).

Sheveluch | Central Kamchatka (Russia) : KVERT reported that a weak thermal anomaly over Sheveluch was identified in satellite data on 2 and 6 November. Explosions at 1510 on 9 November generated ash plumes that rose to 7 km (23,000 ft) a.s.l. and drifted 5 km NE. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Turrialba | Costa Rica : OVSICORI-UNA reported that during 6-11 November low-level ash-and-gas emissions at Turrialba were continuous, though occasionally punctuated by energetic explosions which elevated the plumes as high as 500 m above the crater rim. The emission drifted towards the Valle Central. Ashfall was reported in several areas downwind including Cascajal de Coronado, Desamparados (35 km WSW), San Antonio, Guadalupe (32 km WSW), Sabanilla, San Pedro Montes de Oca, Moravia (31 km WSW), Heredia (38 km W), and Coronado (San José, 35 km WSW). Emissions likely continued on 12 November, though inclement weather did not allow for visual confirmation.

Veniaminof | United States : AVO reported that the eruption from the cone in Veniaminof’s ice-filled summit caldera, continued at low levels during 7-13 November. Satellite and webcam data showed elevated surface temperatures from minor lava spattering and lava effusion. Continuous low-amplitude tremor was recorded. Steam and diffuse ash plumes periodically identified in webcam and satellite images rose as high as 3 km (10,000 ft) a.s.l. and drifted S and W. Recent satellite data showed that the lava flows had traveled as far as 1.2 km from the vent. Fractures in the ice sheet adjacent to the lava flow continued to grow due to meltwater flowing beneath the ice sheet. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale) and the Volcano Alert Level remained at Watch (the second highest level on a four-level scale).

Volcanos

Roundup of Global Volcanic Activity – New Activity for the week of 7 November – 13 November 2018

Mayon | Luzon (Philippines) : PHIVOLCS reported that at 1243 on 8 November and at 0739 on 12 November small, short-lived brownish ash plumes from Mayon, associated with a degassing events, drifted WSW and SW, respectively. There was no accompanying seismic or infrasound record from these events. On 11 November a volcanic earthquake was associated with a short-lived lava fountaining event at 0840. The event lasted for 36 seconds based on the seismic record and produced a brownish-gray ash plume that drifted SW. Crater incandescence was visible most nights during 7-13 November. The Alert Level remained at 2 (on a 0-5 scale) and PHIVOLCS reminded residents to stay away from the 6-km-radius Permanent Danger Zone and the 7-km Extended Danger Zone on the SSW and ENE flanks.

Suwanosejima | Ryukyu Islands (Japan) : JMA reported that an explosion at Suwanosejima’s Ontake Crater was recorded at 0428 on 9 November. A plume could not be confirmed because weather clouds obscured views, but large pieces of pumice were observed being ejected 700 m S. Explosions had not been recorded since 2 June. The Alert Level remained at 2 (on a 5-level scale).

Volcanos

Roundup of Global Volcanic Activity – Ongoing Activity for the week of 31 October – 6 November 2018

Aira | Kyushu (Japan) : JMA reported that at 1022 on 30 October an event at Minamidake crater (at Aira Caldera’s Sakurajima volcano) generated a plume that rose 1 km above the crater rim. Two explosions occurred during 2-5 November; the larger of the two sent a plume to 2.6 km and ejected material as far as 700 m from the crater. The Alert Level remained at 3 (on a 5-level scale).

Dukono | Halmahera (Indonesia) : Based on satellite data, wind model data, and notices from PVMBG, the Darwin VAAC reported that during 30-31 October ash plumes from Dukono rose to an altitude of 2.1 km (7,000 ft) a.s.l. and drifted W and N.

Ebeko | Paramushir Island (Russia) : Volcanologists in Severo-Kurilsk (Paramushir Island), about 7 km E of Ebeko, observed explosions during 26 October-2 November that sent ash plumes to 3.7 km (12,400 ft) a.s.l. Ash plumes drifted in multiple directions and caused ashfall in Severo-Kurilsk during 29-31 October. A thermal anomaly was visible in satellite images on 24 and 29 October. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Etna | Sicily (Italy) : INGV reported that during 29 October-4 November activity at Etna was characterized by gas emissions at the summit craters, with periodic Strombolian activity from vents in Bocca Nuova, Northeast Crater (NEC), SE Crater (SEC), and New Southeast Crater (NSEC). Strombolian explosions at NSEC were interspersed with long pauses from a few minutes to a few hours. The explosions sometimes produced ash emissions that quickly dispersed; ashfall was deposited around the crater and in the Valle del Bove. Strombolian activity and gas emissions were characteristic of the N vent in the W part of Bocca Nuova’s (BN-1) crater floor. Spattering from the southernmost vent was also visible, as well as gas emissions. Gas emissions at Voragine Crater from a vent on the E rim of the crater were less intense compared to previous months. NEC activity was characterized by Strombolian explosions sometimes accompanied by minor ash emissions.

Fuego | Guatemala : INSIVUMEH and CONRED reported an increase in seismicity and in the number of explosions at Fuego on 31 October. Ash plumes during 31 October-5 November rose 1 km above the summit and drifted 15 km W and SW. Ashfall was reported in areas downwind including Morelia (9 km SW), Santa Sofia (12 km SW), Sangre de Cristo (8 km WSW), Panimaché (8 km SW), and San Pedro Yepocapa (8 km NW). By 2 November a lava flow had traveled 300 m down the Ceniza (SSW) drainage, and by 4 November lava flows 600 m long descended the Ceniza and Taniluyá (SW) drainages. Explosions on 4 November produced shock waves that rattled nearby structures, and on 5 November ejected incandescent material 200 m high. INSIVUMEH reported another increase of activity on 6 November characterized by a period of constant explosions, and ash plumes rising over 1 km and drifting 20 km W and SW. Ashfall was reported in multiple areas including Panimaché, El Porvenir, Morelia, Santa Sofia, Sangre de Cristo, Finca Palo Verde, and San Pedro Yepocapa. Incandescent material was ejected 200-300 m high and caused avalanches that reached vegetated areas in the Seca and Taniluyá drainages. A 1-km-long lava flow was active in the Ceniza drainage. Shock waves from explosions vibrated local houses.

Krakatau | Indonesia : PVMBG reported that a 37-second-long event at Anak Krakatau at 0223 on 6 November generated an ash plume that, based on a ground observation, rose 500 m and drifted N. At 1000 a dense ash plume rose 600 m above the summit and drifted N. The Alert Level remained at 2 (on a scale of 1-4); residents and visitors were warned not to approach the volcano within 2 km of the crater.

Merapi | Central Java (Indonesia) : PVMBG reported that during 26 October-1 November the lava dome in Merapi’s summit crater grew slowly at a rate of 2,900 cubic meters per day, slower than the previous week. By 31 October the volume of the dome, based on photos from the SE sector, was an estimated 248,000 cubic meters. White emissions of variable density rose a maximum of 50 m above the summit. The Alert Level remained at 2 (on a scale of 1-4), and residents were warned to remain outside of the 3-km exclusion zone.

Nevados de Chillan | Chile : Servicio Nacional de Geología and Minería (SERNAGEOMIN) Observatorio Volcanológico de Los Andes del Sur (OVDAS) and ONEMI reported the continuing, slow growth of the lava dome in Nevados de Chillán’s Nicanor Crater during 30 October-6 November. Seismicity was characterized by moderate levels of long-period and tremor events, often associated with explosion signals. Gas emissions persisted, and sometimes contained ash. Periodic explosions sometimes ejected material that was deposited around the crater. At night incandescence emanated from the lava dome as well as from ejected ballistics. The Alert Level remained at Orange, the second highest level on a four-colour scale, and residents were reminded not to approach the crater within 3 km. ONEMI maintained an Alert Level Yellow (the middle level on a three-colour scale) for the communities of Pinto, Coihueco, and San Fabián.

Piton de la Fournaise | Reunion Island (France) : OVPF reported that seismicity associated with the eruption at Piton de la Fournaise that began on 15 September had ceased by 1 November and no further signs of activity were recorded.

Popocatepetl | Mexico : CENAPRED reported that each day during 31 October-6 November there were 89-192 steam-and-gas emissions from Popocatépetl, some of which contained minor amounts of ash. Periods of volcanic tremor were detected almost daily. Explosions at 1638 and 1727 on 3 November ejected material NE and generated plumes that rose 1.5 and 1.6 km above the crater rim, respectively. The Alert Level remained at Yellow, Phase Two (middle level on a three-colour scale).

Rincon de la Vieja | Costa Rica : OVSICORI-UNA reported that an eruptive sequence at Rincón de la Vieja began at 1945 on 4 November and consisted of at least three two-minute-long episodes. Weather conditions prevented webcam views and estimates of plume heights. The next day at 1511 a plume of water vapor and diffuse gas, recorded by a webcam and visible to residents to the N, rose about 100 m above the crater rim and drifted W.

Sabancaya | Peru : Observatorio Vulcanológico del Sur del IGP (OVS-IGP) and Observatorio Vulcanológico del INGEMMET (OVI) reported that an average of 30 explosions per day occurred at Sabancaya during 29 October-4 November. Hybrid earthquakes were infrequent and of low magnitude. Gas-and-ash plumes rose as high as 3.4 km above the crater rim and drifted 40 km W, SW, and S. MIROVA detected seven thermal anomalies, and on 2 November the sulfur-dioxide gas flux was high at 2,300 tons per day. The report noted that the public should not approach the crater within a 12-km radius.

Santa Maria | Guatemala : CONRED and INSIVUMEH reported that the number of avalanches at Santa María’s Santiaguito lava-dome complex increased on 2 November. The avalanches traveled long distances from the crater, down the S and SE flanks, to the volcano’s base. Some avalanches generated ash plumes. Explosions during 2-6 November produced ash plumes that rose 500-800 m above the crater rim and drifted SW, causing local ashfall. Avalanches descended the SE and NE flanks during 4-5 November.

Semisopochnoi | United States : AVO reported that two small explosions at Semisopochnoi were detected in seismic and infrasound data on 31 October. Intermittent seismic tremor was recorded on 1 November but later that day the satellite link that transmits seismic data failed. Weather clouds obscured views of the volcano during 31 October-4 November. Nothing was observed in satellite data during 5-6 November. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale) and Volcano Alert Level remained at Watch (the second highest level on a four-level scale).

Sheveluch | Central Kamchatka (Russia) : KVERT reported that a weak thermal anomaly over Sheveluch was identified in satellite data during 31 October-2 November. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Turrialba | Costa Rica : On 1 November OVSICORI-UNA reported that since 24 October emissions at Turrialba were continuous with plumes rising 500 m above the crater rim. In addition, seismicity was characterized by banded volcanic tremor, long-period earthquakes, and low-amplitude volcano-tectonic earthquakes. Passive ash emissions were visible during 1-6 November. A 70-minute-long event began at 0530 and generated plumes that rose 500 m and drifted SW. Several short-duration (2-3 minutes) events were recorded at 1523 and 1703 on 2 November and at 0109 on 3 November; they generated ash plumes that rose 500 m. Ashfall was reported in Coronado. Seismic activity remained high, with moderate-to-high amplitude banded tremor. At 0620 on 5 November a plume rose 600 m and drifted NW.

Veniaminof | United States : AVO reported that the eruption from the cone in Veniaminof’s ice-filled summit caldera, continued during 31 October-6 November. Satellite data showed elevated surface temperatures from minor lava spattering and flows. Low-amplitude continuous tremor was recorded. The webcam in Perryville, 35 km SE, periodically recorded diffuse ash emissions and incandescence from the cone. Based on a pilot observation and satellite data, a diffuse ash plume rose to 4.3 km (14,000 ft) a.s.l. and drifted E on 5 November. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale) and the Volcano Alert Level remained at Watch (the second highest level on a four-level scale).

Volcanos

Roundup of Global Volcanic Activity – New Activity for the week of 31 October – 6 November 2018

Sarychev Peak | Matua Island (Russia) : KVERT reported that an ash explosion at Sarychev Peak was last noted on 10 October and a thermal anomaly was last identified on 15 October. The volcano was quiet or obscured by clouds during 16-31 October. KVERT lowered the Aviation Colour Code to Yellow (the second lowest level on a four-colour scale).

Kuchinoerabujima | Ryukyu Islands (Japan) : JMA reported that during 31 October-5 November there were very small events recorded at Kuchinoerabujima’s Shindake Crater. Plumes rose 500-1,200 m above the crater rim. The Alert Level remained at 3 (on a scale of 1-5).

Volcanos

Roundup of Global Volcanic Activity – Ongoing Activity for the week of 24 October – 30 October 2018

Aira | Kyushu (Japan) : JMA reported that during 22-26 October seven events at Minamidake crater (at Aira Caldera’s Sakurajima volcano) produced eruption plumes that rose as high as 1.6 km above the crater rim. Small scale events were occasionally detected through 29 October. The Alert Level remained at 3 (on a scale of 1-5).

Bezymianny | Central Kamchatka (Russia) : KVERT reported that a thermal anomaly over Bezymianny was identified in satellite images during 20 and 22-25 October. Gas-and-steam emissions continued to rise from the crater. The Aviation colour Code remained at Yellow (the second lowest level on a four-colour scale).

Dukono | Halmahera (Indonesia) : Based on satellite data, wind model data, and notices from PVMBG, the Darwin VAAC reported that during 24-28 October ash plumes from Dukono rose to altitudes of 1.5-1.8 km (5,000-6,000 ft) a.s.l. and drifted E and NE.

Ebeko | Paramushir Island (Russia) : Volcanologists in Severo-Kurilsk (Paramushir Island), about 7 km E of Ebeko, observed explosions during 19-26 October that sent ash plumes to 4.7 km (15,400 ft) a.s.l. Ash plumes drifted eastward, and caused ashfall in Severo-Kurilsk during 19-20 and 23-24 October; ash plumes drifted about 80 km E on 20 October. A thermal anomaly was visible in satellite images on 24 October. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Kadovar | Papua New Guinea : The Darwin VAAC reported that during 29-30 October intermittent ash plumes from Kadovar rose to altitudes of 1.8-2.1 km (6,000-7,000 ft) a.s.l. and drifted SW, S, and SE.

Karymsky | Eastern Kamchatka (Russia) : KVERT reported that a thermal anomaly over Karymsky was last identified in satellite images on 28 September, and an ash plume was last visible on 30 September. The volcano was either quiet or obscured by weather clouds during 1-25 October. On 26 October the Aviation colour Code was lowered to Yellow (the second lowest level on a four-colour scale).

Krakatau | Indonesia : Based on satellite data, the Darwin VAAC reported that during 24-28 October ash plumes from Anak Krakatau rose to altitudes of 0.9-2.1 km (3,000-7,000 ft) a.s.l. and drifted SW, NW, and N. The Alert Level remained at 2 (on a scale of 1-4); residents and visitors were warned not to approach within 2 km of the crater.

Merapi | Central Java (Indonesia) : PVMBG reported that during 19-25 October the lava dome in Merapi’s summit crater grew slowly at a rate of 6,100 cubic meters per day, similar to the previous week. By 21 October the volume of the dome, based on photos from the SE sector, was an estimated 219,000 cubic meters. White emissions of variable density rose a maximum of 50 m above the summit. The Alert Level remained at 2 (on a scale of 1-4), and residents were warned to remain outside of the 3-km exclusion zone.

Nevado del Ruiz | Colombia : Servicio Geológico Colombiano’s (SGC) Observatorio Vulcanológico y Sismológico de Manizales reported that during 24-30 October seismicity at Nevado del Ruiz continued to indicate unrest. Seismicity increased during 26-27 October, with signals concentrated in an area 4.6 km WSW of Arenas Crater at depths of 4-6 km. Plumes of water vapor, ash, and gas continued to rise from the volcano, and on 26 October a plume rose as high as 1.5 km above the crater rim. A weak thermal anomaly was identified in satellite data. The Alert Level remained at 3 (Yellow; the second lowest level on a four-colour scale).

Piton de la Fournaise | Reunion Island (France) : OVPF reported that on 24 October satellite observations of Piton de la Fournaise suggested minimal change to the lava-flow field. During 25-26 October a breakout from the main tube emerged about 1 km downstream from the vent and remained visible through 28 October. Weather conditions prevented views on 29 October.

Sabancaya | Peru : Observatorio Vulcanológico del Sur del IGP (OVS-IGP) and Observatorio Vulcanológico del INGEMMET (OVI) reported that an average of 30 explosions per day occurred at Sabancaya during 22-28 October. Hybrid earthquakes were infrequent and of low magnitude, and long-period events were detected. Gas-and-ash plumes rose as high as 3.4 km above the crater rim and drifted 40 km SE, E, and NE. MIROVA detected five thermal anomalies, and on 27 October the sulfur-dioxide gas flux was high at 2,671 tons per day. The report noted that the public should not approach the crater within a 12-km radius.

Semisopochnoi | United States : AVO reported that an eruptive event at Semisopochnoi began at 2047 on 25 October based on seismic data; strong volcanic tremor lasted about 20 minutes and was followed by 40 minutes of weak tremor pulses. A weak infrasound signal was detected by instruments on Adak Island (260 km SE). The Aviation colour Code was raised to Orange (the second highest level on a four-colour scale) and Volcano Alert Level was raised to Watch (the second highest level on a four-level scale). A dense meteorological cloud deck prevented observations below 3 km (10,000 ft) a.s.l.; a diffuse cloud was observed in satellite data rising briefly above the cloud deck, though it was unclear if it was related to eruptive activity. Tremor ended after the event, and seismicity returned to low levels. Small explosions were detected by the seismic network at 2110 and 2246 on 26 October and 0057 and 0603 on 27 October. No ash clouds were identified in satellite data, but the volcano was obscured by high meteorological clouds. Additional small explosions were detected in seismic and infrasound data during 28-29 October; no ash clouds were observed in partly-cloudy-to-cloudy satellite images.

Sheveluch | Central Kamchatka (Russia) : KVERT reported that a weak thermal anomaly over Sheveluch was identified in satellite data on 20, 22, and 25 October; weather clouds prevented views on the other days during 19-26 October. Moderate levels of gas-and-steam emissions rose from the volcano. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Turrialba | Costa Rica : OVSICORI-UNA reported that when weather conditions allowed for observations gas and periodic ash emissions rising from Turrialba were recorded by the webcam during 25-30 October. An event at 0134 on 26 October produced an ash plume that rose 500 m above the crater rim and drifted NE, causing ashfall in the neighborhoods of Coronado (San José, 35 km WSW) and San Isidro de Heredia (Heredia, 38 km W). Events at 0231 on 29 October and 1406 on 30 October produced plumes that rose 500 m and drifted NW and W respectively.

Veniaminof | United States : AVO reported that the eruption from the cone in Veniaminof’s ice-filled summit caldera, continued during 24-30 October. Satellite data showed elevated surface temperatures from minor lava fountaining and flows. Low-amplitude continuous tremor was detected. The webcam in Perryville, 35 km SE, periodically recorded diffuse ash emissions that often rapidly dissipated; minor ashfall was recorded in Perryville on 25 October. Based on satellite data acquired on 25 October the lava flows had traveled as far as 1.2 km from the vent, and the area of the flow field had doubled in the past month. Fractures in the ice sheet adjacent to the lava flow continued to grow due to meltwater flowing beneath the ice sheet. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale) and the Volcano Alert Level remained at Watch (the second highest level on a four-level scale).

Volcanos

Roundup of Global Volcanic Activity – New Activity for the week of 24 October – 30 October 2018

Ambae | Vanuatu : At 1832 on 30 October an eruption at Ambae’s Lake Voui generated ash plumes that rose to altitudes of 3-10.7 km (10,000-35,000 ft) a.s.l. and drifted mainly E and SE, based on satellite data, ground-based observations, wind model data, Vanuatu Meteorology and Geo-hazards Department (VMGD), and the Wellington VAAC. According to the VAAC the ash cloud was about 3,400-5,100 square kilometers in area.

Kuchinoerabujima | Ryukyu Islands (Japan) : Based on satellite images and information from JMA, the Tokyo VAAC reported that during 24-28 October ash plumes from Kuchinoerabujima’s Shindake Crater rose to altitudes of 0.9-1.5 km (3,000-5,000 ft) a.s.l. and drifted in multiple directions. JMA scientists noted no changes in the thermal anomalies at the crater during a field observation on 28 October. The Alert Level remained at 3 (on a scale of 1-5).

Langila | New Britain (Papua New Guinea) : Based on analyses of satellite imagery and wind-model data, the Darwin VAAC reported that on 30 October an ash plume from Langila rose to an altitude of 2.7 km (9,000 ft) a.s.l. and drifted SE.

Volcanos

Roundup of Global Volcanic Activity – Ongoing Activity for the week of 17 October – 23 October 2018

Aira | Kyushu (Japan) : JMA reported that occasional, very small events occurred at Minamidake crater (at Aira Caldera’s Sakurajima volcano) during 12-19 October. Sulfur dioxide emissions were slightly less than 400 tons per day on 17 October. The Alert Level remained at 3 (on a 5-level scale).

Dukono | Halmahera (Indonesia) : Based on satellite data, wind model data, and notices from PVMBG, the Darwin VAAC reported that during 18-23 October ash plumes from Dukono rose to altitudes of 1.5-2.1 km (5,000-7,000 ft) a.s.l. and drifted E and NE.

Ebeko | Paramushir Island (Russia) : Volcanologists in Severo-Kurilsk (Paramushir Island), about 7 km E of Ebeko, observed explosions during 12-19 October that sent ash plumes to 4.5 km (14,800 ft) a.s.l. Ash plumes drifted in multiple directions, and caused ashfall in Severo-Kurilsk during 14-16 October. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Etna | Sicily (Italy) : INGV reported that during 15-21 October activity at Etna was characterized by gas emissions at the summit craters, with periodic Strombolian activity from vents in Bocca Nuova, Northeast Crater (NEC), Southeast Crater (SEC), and New Southeast Crater (NSEC). Strombolian activity at the N vent in the W part of Bocca Nuova’s (BN-1) crater floor ejected incandescent material higher that the crater rim. Spattering from the southernmost vent was also visible. Gas emissions increased at Voragine Crater from a vent that formed on 7 August 2016 on the E rim of the crater, and the crater continued to gradually widen and deepen. NEC activity was characterized by gas emissions and explosive activity of variable frequency and intensity. Fumarolic plumes rose from the rim and crater walls of NSEC and SEC. The E vent in NSEC produced Strombolian explosions and ash emissions which rapidly dispersed.

Fuego | Guatemala : INSIVUMEH and CONRED reported that on 20 October hot lahars descended Fuego’s Las Lajas (SE) and Mineral drainages, carrying blocks up to 2 m in diameter along with branches and tree trunks. The lahars were 20-30 m wide and 2 m deep. During 20-23 October there were 8-15 weak explosions recorded per hour, producing gray ash plumes that rose 750-850 m above the crater rim and drifted 12 km W and SW. Ashfall was reported in areas downwind, including Morelia (9 km SW), Santa Sofia (12 km SW), Sangre de Cristo (8 km WSW), Finca Palo Verde, Panimaché (8 km SW), and San Pedro Yepocapa (8 km NW). Lava fountains rose 100-200 m high. Avalanches of blocks descended the El Jute (SE), Ceniza (SSW), and Las Lajas (SE) drainages, with material reaching vegetated areas.

Ibu | Halmahera (Indonesia) : PVMBG reported that at 1223 on 19 October an event at Ibu generated an ash plume that rose 400 m above the crater rim and drifted E. Another event at 1809 on 22 October generated an ash plume that rose 400 m above the crater rim and drifted N. On both days seismic signals indicated explosions and rock avalanches. The Alert Level remained at 2 (on a scale of 1-4), and the public was warned to stay at least 2 km away from the active crater, and 3.5 km away on the N side.

Kadovar | Papua New Guinea : According to the Darwin VAAC, ash plumes from Kadovar were visible in satellite images on 21 October drifting NE at an altitude of 2.4 km (8,000 ft) a.s.l.

Krakatau | Indonesia : Based on satellite data, the Darwin VAAC reported that during 17-19 October ash plumes from Anak Krakatau rose to altitudes of 1.5-2.4 km (5,000-8,000 ft) a.s.l. and drifted in multiple directions. The Alert Level remained at 2 (on a scale of 1-4); residents and visitors were warned not to approach the volcano within 2 km of the crater.

Merapi | Central Java (Indonesia) : PVMBG reported that during 12-18 October the lava dome in Merapi’s summit crater grew at a rate of 6,200 cubic meters per day, faster than the previous week. By 18 October the volume of the dome, based on photos from the SE sector, was an estimated 201,000 cubic meters. White emissions of variable density rose a maximum of 100 m above the summit. The Alert Level remained at 2 (on a scale of 1-4), and residents were warned to remain outside of the 3-km exclusion zone.

Piton de la Fournaise | Reunion Island (France) : OVPF reported that the eruption at Piton de la Fournaise continued during 17-23 October. Strong gas emissions rose from the main vent as well as from areas along the lava tube. Periodic field surveys indicated active lava flows, several tens of meters long, at the base of the cone, and possibly active lava in the main vent.

Sabancaya | Peru : Observatorio Vulcanológico del Sur del IGP (OVS-IGP) and Observatorio Vulcanológico del INGEMMET (OVI) reported that explosions at Sabancaya averaged 23 per day during 15-21 October. Hybrid earthquakes were infrequent and of low magnitude. Gas-and-ash plumes rose as high as 3 km above the crater rim and drifted 40 km W, NE, and SE. The MIROVA system detected five thermal anomalies, and on 19 October the sulfur dioxide gas flux was high at 2,200 tons per day. The report noted that the public should not approach the crater within a 12-km radius.

Santa Maria | Guatemala : INSIVUMEH reported that during 20-23 October explosions at Santa María’s Santiaguito lava-dome complex generated ash plumes that rose 500-700 m and drifted SW and W. Avalanches of material descended the W and E flanks of the lava dome.

Sheveluch | Central Kamchatka (Russia) : KVERT reported that a weak thermal anomaly over Sheveluch was identified in satellite data during 14-15 October; weather clouds prevented views on the other days during 12-19 October. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Turrialba | Costa Rica : OVSICORI-UNA reported frequent Strombolian events at Turrialba since 5 October. Periodic gas-and-ash emissions rose 200-500 m above the crater rim and drifted E, NW, and SW during 17-23 October.

Veniaminof | United States : AVO reported that the eruption at Veniaminof continued during 10-16 October, as evidenced by elevated surface temperatures from lava fountains and flows visible in satellite and webcam data, and low-level continuous tremor. Satellite data indicated that the W part of the S-flank flow field was active. A persistent steam plume, visible in webcam views, also contained sulfur dioxide and possible ash. The plume was particularly robust on 18 October, drifting 30 km NE; plumes drifted NE on 19 October and S the next morning. The Aviation colour Code remained at Orange and the Volcano Alert Level remained at Watch.

Volcanos

Roundup of Global Volcanic Activity – New Activity for the week of 17 October – 23 October 2018

Kerinci | Indonesia : Based on satellite images, ground observers, and wind model data, the Darwin VAAC reported that during 18-22 October ash plumes from Kerinci rose to an altitude of 4.3 km (14,000 ft) a.s.l. and drifted N, W, WSW, and SW.

Kuchinoerabujima | Ryukyu Islands (Japan) : JMA reported that a very small eruption at Kuchinoerabujima’s Shindake Crater was recorded at 1831 on 21 October, with additional activity between 2110 on 21 October and 1350 on 22 October. Plumes rose 200 m above the crater rim. During an overflight on 22 October observers noted ash in the emissions, though no morphological changes to the crater nor ash deposits were seen. The Alert Level remained at 3 (on a scale of 1-5).

Sarychev Peak | Matua Island (Russia) : KVERT reported that a thermal anomaly over Sarychev Peak was visible in satellite images on 15 October. Weather clouds obscured views on the other days during 12-19 October. The Aviation colour Code remained at Orange.