Volcanos

Roundup of Global Volcanic Activity – New Activity for the week of 10 October – 16 October 2018

Cuicocha | Ecuador : IG reported that, after an earthquake swarm consisting of 62 volcano-tectonic events during 2-3 October, seismicity at Cuicocha returned to background levels on 4 October. Carbon dioxide levels were normal, and deformation data did not show any anomalies.

Gamalama | Halmahera (Indonesia) : On 10 October PVMBG reported only gas emissions (mostly water vapor) from Gamalama; the Aviation colour Code was lowered to Yellow. The Alert Level remained at 2 (on a scale of 1-4); visitors and residents were warned not to approach the crater within a 1.5-km radius.

Piton de la Fournaise | Reunion Island (France) : OVPF reported that the eruption at Piton de la Fournaise continued during 10-16 October, though webcam images indicated that the lava-flow front had not significantly progressed since 8 October. The lava lake in the cone was at a low level. Strong gas emissions rose from the main vent as well as from the lava tube, just downstream from the vent.

Sangeang Api | Indonesia : Based on a VONA from PVMBG an ash emission from Sangeang Api was generated at 1338 on 15 October; it rose 250 m above the summit and drifted SW, W, and NW. The VONA noted that the ash emission possibly rose higher than what a ground observer had estimated. Seismic data was dominated by signals indicating emissions as well as local tectonic earthquakes. The Aviation colour Code was changed from Yellow to Orange.

Sarychev Peak | Matua Island (Russia) : Based on Tokyo VAAC data and satellite images, KVERT reported that at 1330 on 10 October an ash plume from Sarychev Peak rose to 1.7-2 km (5,600-6,600 ft) a.s.l. and drifted 95 km E. SVERT reported that on 15 October an ash plume rose 2.1 km (7,000 ft) a.s.l. and drifted 65-70 km E. The Aviation colour Code remained at Orange.

Semisopochnoi | United States : On 11 October AVO reported that satellite data of Semisopochnoi indicated partial erosion of a tephra cone in the crater of Cerberus’s N cone. A crater lake about 90 m in diameter filled the vent. The data also suggested that the vent had not erupted since 1 October. Seismicity remained elevated and above background levels. The next day AVO lowered the Aviation colour Code to Yellow and the Volcano Alert Level to Advisory, noting the recent satellite data results and lack of tremor recorded during the previous week.

Soputan | Sulawesi (Indonesia) : On 16 October PVMBG issued a VONA noting only white emissions at Soputan; the Aviation colour Code was lowered to Yellow.

Ulawun | New Britain (Papua New Guinea) : RVO reported that during 1-12 October white and sometimes light gray emissions rose from Ulawun’s summit crater. Seismicity was low.

Volcanos

Roundup of Global Volcanic Activity – Ongoing Activity for the week of 3 October – 9 October 2018

Aira | Kyushu (Japan) : JMA reported that very small events at Minamidake crater (at Aira Caldera’s Sakurajima volcano) occurred during 1-5 October; no explosions had been detected since 23 September. Sulfur dioxide emissions were 400 tons per day on 1 October, and then increased to 3,400 tons per day on 4 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 3-9 October ash plumes from Dukono rose to altitudes of 1.5-2.1 km (5,000-7,000 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 28 September-5 October that sent ash plumes to 4.5 km (14,800 ft) a.s.l. Satellite images showed a thermal anomaly over the volcano on 27 and 28 September, and ash plumes drifting about 80 km SW, SE, and E during 27-30 September and 1 October. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Ibu | Halmahera (Indonesia) : Based on satellite images and model data, the Darwin VAAC reported that on 6 October an ash plume from Ibu rose to 1.8 km (6,000 ft) a.s.l. and drifted WSW.

Kadovar | Papua New Guinea : RVO reported quiet conditions at Kadovar during 1-20 September with only diffuse white plumes rising from the volcano. Activity increased on 21 September and remained elevated at least through 26 September, the date the last visual observation was received by RVO. During the period if increased activity dense dark gray and brown ash plumes rose several hundred meters above the summit crater (700-800 m) and drifted NW. Intense incandescence from Main Crater, the SE coastal vent, and other areas was visible. Minor amounts of ash fell on Blup Blup island. On 1 October an ash plume rose to 900 m (9,000 ft) a.s.l. and drifted W. An ash plume was visible in satellite images on 3 October drifting W at an altitude of 2.1 km (3,000 ft) a.s.l.

Karymsky | Eastern Kamchatka (Russia) : KVERT reported that a thermal anomaly over Karymsky was identified in satellite images on 28 September, and a narrow ash plume was visible drifting 135 km E on 30 September. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Krakatau | Indonesia : PVMBG reported that during 1 September-3 October the Strombolian eruption at Anak Krakatau continued, though foggy conditions often prevented visual observations. Ash plumes mainly rose 200-500 m above the crater rim and drifted NW to SW. On 22 September ash plumes rose as high as 2.5 km; ejected incandescent material mostly landed on the flanks (less than 1 km from the crater), and a small amount fell into the sea. Lava flows on the SSE flank also reached the sea. 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.

Manam | Papua New Guinea : RVO reported that on 1 October field observations after an eruption at Manam confirmed lava flows in the NE valley. There were two lava flow lobes, both stopping before inhabited areas; the smaller lobe flowed on the N side of the valley towards Koland Village and the larger flowed on the S side towards Boakure Village. Effects from ash and scoria fallout on the NW and NW sides of the island were minor. Based on analyses of satellite imagery and wind model data, the Darwin VAAC reported that on 3 October an ash plume rose 2.1 km (7,000 ft) a.s.l. and drifted NW. A thermal anomaly was also visible.

Merapi | Central Java (Indonesia) : PVMBG reported that during 28 September-4 October the lava dome in Merapi’s summit crater continued to slowly grow. By 4 October the volume of the lava dome was an estimated 135,000 cubic meters, and the growth rate was 1,000 cubic meters per day (similar to the previous week). White emissions of variable density rose a maximum of 75 m above the summit. The Alert Level remained at 2 (on a scale of 1-4), and resident were warned to remain outside of the 3-km exclusion zone.

Reventador | Ecuador : During 3-9 October IG reported a high level of seismic activity at Reventador, including explosions, long-period earthquakes, harmonic tremor, and signals indicating emissions. Steam, gas, and ash plumes sometimes rose higher than 1 km above the crater rim and drifted W, NW, N, and NE. Crater incandescence was visible at night, and incandescent blocks sometimes rolled down the flanks.

Sabancaya | Peru : Observatorio Vulcanológico del Sur del IGP (OVS-IGP) and Observatorio Vulcanológico del INGEMMET (OVI) reported that explosions at Sabancaya averaged 24 per day during 1-7 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 50 km SE, S, and SW. Ashfall was reported in Huanca (75 km SSE). The MIROVA system detected five thermal anomalies, and on 1 October the sulfur dioxide gas flux was high at 5,027 tons/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 data during 27-28 and 30 September; weather clouds prevented views on the other days during 29 September-5 October. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Turrialba | Costa Rica : OVSICORI-UNA reported that intense crater incandescence was visible at Turrialba the night of 3 October. At 0800 on 8 October an event produced an ash plume that rose 500 m above the crater and drifted N.

Veniaminof | United States : AVO reported that the eruption at Veniaminof continued during 3-9 October based on periodic incandescence recorded by the FAA web camera in Perryville (35 km S), elevated surface temperatures in thermal satellite data, and elevated tremor levels. Minor steam-and-ash plumes were sometimes visible during clear daytime conditions. 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 3 October – 9 October 2018

Barren Island | Andaman Islands (India) : According to a news article, the Geological Survey of India reported a new eruption at Barren Island. Satellite data on 25 September confirmed ash emissions, and either lava flows or ejected tephra on the N flank.

Cuicocha | Ecuador : IG reported an increase in seismic activity at Cuicocha during 2-3 October, characterized by a total of 60 volcano-tectonic events recorded at the time of the report posting. The largest of these events, a M 2.5 at 1058 on 2 October, was reportedly slightly felt by a resident of Quiroga.

Gamalama | Halmahera (Indonesia) : PVMBG reported that an explosion from Gamalama at 1152 on 4 October was likely phreatic; it generated an ash plume that rose about 250 m above the summit and drifted NW. Eight volcanic earthquakes were recorded about an hour before the event. Based on satellite data and information from PVMBG, the Darwin VAAC reported that during 5-6 October ash plumes rose to 2.1 km (7,000 ft) a.s.l. and drifted W and NW. The Alert Level remained at 2 (on a scale of 1-4); visitors and residents were warned not to approach the crater within a 1.5-km radius.

Kilauea | Hawaiian Islands (USA) : On 5 October HVO reported that lava at Kilauea had not been active at the surface for 30 days. Seismicity was low, steady, relatively low rates of deformation across the volcano were recorded, and the summit and East Rift Zone (ERZ) produced only minor gas emissions. These data indicated that near-term resumption of activity at the summit or at the lower ERZ was unlikely; the Volcano Alert Level was lowered to Advisory and the Aviation colour Code was lowered to Yellow.

Piton de la Fournaise | Reunion Island (France) : OVPF reported that the eruption at Piton de la Fournaise continued during 2-9 October, though only weak and periodic surficial activity was observed. A lava lake in the cone continued to be active, and very minor amounts of lava were ejected above the cone’s rim. A few minor lava flows broke out from the main tube. The front of the N lava flow was 120 m from the S wall of the Enclos Fouqué.

Semisopochnoi | United States : AVO reported that during 3-9 October seismicity at Semisopochnoi remained elevated, with intermittent bursts of tremor. No volcanic activity was detected in infrasound or satellite data. The Aviation colour Code (ACC) remained at Yellow and Volcano Alert Level (VAL) remained at Advisory.

Soputan | Sulawesi (Indonesia) : Based on satellite images, information from PVMBG, and wind model data, the Darwin VAAC reported that on 4 October ash plumes from Soputan rose to 4.6 km (15,000 ft) a.s.l. and drifted W. The Alert Level remained at 3 (on a scale of 1-4); residents and tourists were advised not to approach the craters within a radius of 4 km, with an additional expansion to 6.5 km in WSW direction due to increased risk from a breach in the crater rim.

Ulawun | New Britain (Papua New Guinea) : According to the Darwin VACC, a steam-and-ash emission from Ulawun was identified in satellite images and reported by ground observers on 5 October, rising to an altitude of 4.6 km (15,000 ft) a.s.l. and drifting WSW.

Volcanos

Roundup of Global Volcanic Activity – Ongoing Activity for the week of 26 September – 2 October 2018

Aira | Kyushu (Japan) : JMA reported that occasional, very small, events at Minamidake crater (at Aira Caldera’s Sakurajima volcano) during 25 September-1 October generated plumes that rose 400 m above the crater rim. The Alert Level remained at 3 (on a 5-level scale).

Aira | Kyushu (Japan) : JMA reported that occasional, very small, events at Minamidake crater (at Aira Caldera’s Sakurajima volcano) during 25 September-1 October generated plumes that rose 400 m above the crater rim. 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 26 September-2 October ash plumes from Dukono rose to altitudes of 1.8-2.1 km (6,000-7,000 ft) a.s.l. and drifted NW, N, NE, and E.

Ebeko | Paramushir Island (Russia) : Volcanologists in Severo-Kurilsk (Paramushir Island), about 7 km E of Ebeko, observed explosions during 21-28 September that sent ash plumes to 4 km (13,100 ft) a.s.l. Satellite images showed a thermal anomaly over the volcano on 23 and 27 September, and ash plumes drifting as far as 68 km SE during 23-24 and 26-27 September. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Etna | Sicily (Italy) : INGV reported that during 24-30 September activity at Etna was characterized by gas emissions at the summit craters, with periodic Strombolian activity from vents in Bocca Nuova, Northeast Crater (NEC), and New Southeast Crater (NSEC). Strombolian activity at the N vent in Bocca Nuova (BN-1) ejected incandescent material almost as high as the W crater rim. No eruptive activity was observed at BN-2, though it produced explosions deep in the crater. A new high-temperature vent producing gas emissions was noted on 1 October in the same place a fumarole had been observed the previous week. Ash emissions from NSEC were sometimes accompanied by ejected incandescent material. Gas emissions increased at Voragine Crater from a vent that formed on 7 August 2016 on the E rim of the crater. NEC produced frequent brown-gray ash emissions, and ejected blocks and bombs, from a vent located in the W part of the crater floor.

Ibu | Halmahera (Indonesia) : Based on satellite images and wind model data, the Darwin VAAC reported that on 28 and 30 September ash plumes from Ibu rose to 1.8 km (6,000 ft) a.s.l. and drifted NE and N.

Kadovar | Papua New Guinea : An ash plume from Kadovar was visible in satellite images on 28 September drifting SE at an altitude of 2.1 km (7,000 ft) a.s.l. On 1 October an ash plume rose to 2.7 km (9,000 ft) a.s.l. and drifted W.

Karymsky | Eastern Kamchatka (Russia) : KVERT reported that a thermal anomaly over Karymsky was identified in satellite images during 22-24 September, and ash plumes were visible drifting 365 km E during 22-23 September. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Kilauea | Hawaiian Islands (USA) : HVO reported no significant incandescence from a collapse pit in the central part of Kilauea’s Fissure 8 cone during 26 September-2 October, though a small amount of fuming was visible during the day. Seismicity and ground deformation remain low at the summit, and small aftershocks from the M 6.9 earthquake in early May were located along faults on the south flank. Sulfur dioxide emissions from the summit and the LERZ were low. On 1 October a rockfall at Pu’u ‘O’o produced a small ash plume. The Volcano Alert Level remained at Watch and the Aviation colour Code remained at Orange.

Krakatau | Indonesia : Based on satellite data, wind model data, and notices from PVMBG, the Darwin VAAC reported that during 25 September-2 October ash plumes from Anak Krakatau rose to altitudes of 1.2-2.1 km (4,000-7,000 ft) a.s.l. and drifted W, WSW, and SW. 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.

Manam | Papua New Guinea : RVO reported that pale-gray-to-brown ash plumes rose from Manam’s Southern Crater during 20 September-1 October. Activity was most intense on 24 September, with an increased amount of ash emissions, and occasional weak roaring and rumbling noises. Based on seismic data an eruption at Main Crater began during 0100-0130 on 1 October, peaked around 0200, and ended at 1200 (though a sharp decline was recorded at 1215). Ash plumes rose at least several hundred meters above the crater rim, though darkness obscured visual observations. Islanders described loud roaring and rumbling noises, as well as loud banging noises. Residents of Tabele on the SW side of the island observed bright summit incandescence, which was also visible from the Bogia Government Station on the mainland (22 km SSW). Scoria and minor amounts of ash fell in Jogari and villages to the N.

Merapi | Central Java (Indonesia) : PVMBG reported that during 21-27 September the new lava dome in Merapi’s summit crater continued to slowly grow. By 27 September the volume of the lava dome was an estimated 129,000 cubic meters, and the growth rate was 1,000 cubic meters per day (slower than the previous week). White emissions of variable density rose a maximum of 450 m above the summit. The Alert Level remained at 2 (on a scale of 1-4), and resident 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 explosions at Sabancaya averaged 21 per day during 24-30 September. 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 50 km E, SE, and SW. The MIROVA system detected six thermal anomalies, and on 29 September the sulfur dioxide gas flux was high at 3,250 tons/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 data during 20, 23, and 27 September; weather clouds prevented views on the other days during 21-28 September. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Turrialba | Costa Rica : OVSICORI-UNA reported that at 0915 on 27 September an event at Turrialba produced a passive ash plume that rose 200 m above the crater and drifted NW. During 30 September-1 October ash emissions rose as high as 500 m above the crater rim and drifted NW and NE.

Volcanos

Roundup of Global Volcanic Activity – New Activity for the week of 26 September – 2 October 2018

Kerinci | Indonesia : Based on satellite and wind model data, the Darwin VAAC reported that during 28-30 September and 2 October ash plumes from Kerinci rose to an altitude of 4.3 km (14,000 ft) a.s.l. and drifted SW and W.

Langila | New Britain (Papua New Guinea) : Based on analyses of satellite imagery and model data, the Darwin VAAC reported that on 29 September an ash plume from Langila rose to an altitude of 2.4 km (8,000 ft) a.s.l. and drifted NE.

Piton de la Fournaise | Reunion Island (France) : OVPF reported that the eruption at Piton de la Fournaise continued during 26 September-2 October, and tremor levels were stable. The cone continued to grow; one vent was active and ejected spatter. Lava flows were mostly confined to lava tubes, emerging 150-200 m downstream, S of the cone. During a field inspection on 29 September OVPF staff observed a small lava flow at the foot of the cone.

Sarychev Peak | Matua Island (Russia) : KVERT reported that a thermal anomaly over Sarychev Peak was visible in satellite images on 22 September. The Aviation colour Code remained at Orange.

Semisopochnoi | United States : AVO reported that during 19-25 September seismicity at Semisopochnoi remained elevated, alternating between periods of continuous and intermittent bursts of tremor. Tremor bursts at 1319 on 21 September and at 1034 on 22 September produced airwaves detected on a regional infrasound array on Adak Island; no ash emissions were identified above the low cloud deck in satellite data, and the infrasound detections likely reflected an atmospheric change instead of volcanic activity. The Aviation colour Code (ACC) remained at Yellow and Volcano Alert Level (VAL) remained at Advisory.

Soputan | Sulawesi (Indonesia) : PVMBG reported that increased seismicity at Soputan was notable on 2 October, characterized by an increased number of signals indicating emissions and avalanches (which began in September and mid-July, respectively), increased RSAM values, and a higher number of volcanic earthquakes (since September). Data from a thermal camera showed increased summit temperatures, indicating the presence of lava. The Alert Level was increased to 3 (on a scale of 1-4) on 3 October; residents and tourists were advised not to approach the craters within a radius of 4 km, with an additional expansion to 6.5 km in WSW direction due to increased risk from a breach in the crater rim. An eruption commenced at 0847 on 3 October, producing a dense ash plume that rose 4 km above the summit and drifted W and NW. Based on seismic data the event lasted six minutes. Events at 1044, 1112, and 1152 produced ash plumes that rose 2 km, 2.5 km , and 5 km above the crater rim, respectively. A thermal anomaly identified in satellite data significantly increased, and incandescent ejecta at the summit was clearly observed by residents. Avalanches of material traveled 2.5 km down the NE flank.

Veniaminof | United States : AVO reported that the eruption at Veniaminof continued during 26 September-2 October, as evidenced by nighttime incandescence recorded by the FAA web camera in Perryville (35 km S), elevated surface temperatures in thermal satellite data, and elevated tremor levels. A gas plume was occasionally visible during clear daytime conditions. On 26 September lava fountains, visible in webcam images, rose from a second vent located 75 m N of the vent producing lava flows. Minor ash emissions associated with lava fountaining possibly rose as high as km (15,000 ft) a.s.l. and quickly dispersed. The lava flow had traveled 1 km down the S flank of the summit cone by 1 October. The Aviation colour Code remained at Orange and the Volcano Alert Level remained at Watch.

Volcanos

Roundup of Global Volcanic Activity – Ongoing Activity for the week of 19 September – 25 September 2018

Aira | Kyushu (Japan) : JMA reported that there were eight events and an additional five explosions at Minamidake crater (at Aira Caldera’s Sakurajima volcano) during 18-25 September, with ash plumes rising as high as 2.1 km above the crater rim and material ejected as far as 1.1 km. Crater incandescence was occasionally visible at night. The Alert Level remained at 3 (on a 5-level scale).

Ambae | Vanuatu : On 21 September the Vanuatu Meteorology and Geo-hazards Department reported that during September activity at Ambae’s Lake Voui was characterized only by steam emissions; the eruption had ceased. The Alert Level was lowered to 2 (on a scale of 0-5).

Dukono | Halmahera (Indonesia) : Based on satellite data, wind model data, and notices from PVMBG, the Darwin VAAC reported that during 19-25 September ash plumes from Dukono rose to an altitude of 1.8 km (6,000 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 14-21 September that sent ash plumes to 4.2 km (13,800 ft) a.s.l. A thermal anomaly over the volcano was occasionally visible in satellite data, and an ash plume was identified drifting about 80 km E on 14 September. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Fuego | Guatemala : INSIVUMEH reported that during 20-21 and 24-25 September explosions at Fuego generated ash plumes that rose almost as high as 1 km above the crater and drifted 12 km W and SW. Incandescent material was ejected 150 m above the crater rim, and caused avalanches of material within the crater area. Ashfall was reported in areas downwind including Sangre de Cristo (8 km WSW), Finca Palo Verde, Panimaché (8 km SW), and San Pedro Yepocapa (8 km NW). On 25 September hot, steaming lahars descended the El Jute (SE) and Las Lajas (SE) drainages, carrying blocks up to 2 m in diameter, and branches and tree trunks.

Karymsky | Eastern Kamchatka (Russia) : KVERT reported that a thermal anomaly over Karymsky was identified in satellite images on 19 September; the volcano was obscured by weather clouds the rest of the days during 14-21 September. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Kilauea | Hawaiian Islands (USA) : HVO reported no incandescence from a collapse pit in the central part of Kilauea’s Fissure 8 cone during 19-25 September, though a small amount of fuming was visible during the day. Seismicity and ground deformation remain low at the summit, and small aftershocks from the M 6.9 earthquake in early May were located along faults on the south flank. The combined rate of sulfur dioxide emission from the summit and the LERZ (less than 1,000 tonnes/day) were lower than any time since late 2007. The Volcano Alert Level remained at Watch and the Aviation colour Code remained at Orange.

Krakatau | Indonesia : Based on satellite data, wind model data, and notices from PVMBG, the Darwin VAAC reported that during 18-24 September ash plumes from Anak Krakatau rose to altitudes of 0.9-3.7 km (3,000-12,000 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.

Manam | Papua New Guinea : Based on analyses of satellite imagery and model data, the Darwin VAAC reported that at 2050 on 23 September a short-lived eruption at Manam produced an ash plume that rose 8.5 km (28,000 ft) a.s.l. and drifted NW.

Merapi | Central Java (Indonesia) : PVMBG reported that during 17-23 September the new lava dome in Merapi’s summit crater continued to slowly grow. By 22 September the volume of the lava dome was an estimated 113,000 cubic meters, and the growth rate was 3,000 cubic meters per day. White emissions of variable density rose 100 m above the summit. The Alert Level remained at 2 (on a scale of 1-4), and resident were warned to remain outside of the 3-km exclusion zone.

Pacaya | Guatemala : INSIVUMEH reported that during 17-18, 20-21, and 24-25 September Strombolian explosions at Pacaya’s Mackenney Crater ejected material as high as 25 m above the crater rim. As many as four lava flows originating from Mackenney Crater traveled 50-250 m NW.

Sabancaya | Peru : Observatorio Vulcanológico del Sur del IGP (OVS-IGP) and Observatorio Vulcanológico del INGEMMET (OVI) reported that explosions at Sabancaya averaged 16 per day during 17-23 September. Hybrid earthquakes were infrequent and of low magnitude. Gas-and-ash plumes rose as high as 3.5 km above the crater rim and drifted 40 km N, NE, and SE. The MIROVA system detected eight thermal anomalies, and on 17 September the sulfur dioxide gas flux was high at 1,600 tons/day. The report noted that the public should not approach the crater within a 12-km radius.

Sangay | Ecuador : Based on satellite images and wind model data, the Washington VAAC reported that during 19-20 September ash emissions from Sangay rose to 5.8-6.1 km (19,000-20,000 ft) a.s.l., drifted WNW and W, and became diffuse after 37 km.

Santa Maria | Guatemala : INSIVUMEH reported that heavy rain at Santa María on 20 September produced hot lahars in the San Isidro-Tambor River (S), a tributary of Salamá River. The lahars were 25 m wide, 2 m deep, had a sulfur odor, and carried branches, tree trunks, and blocks up to 2 m in diameter. Lahars also descended the Nimá I (S) drainage. On 21 September explosions generated ash plumes that rose 800 m above the crater rim and drifted W and SW; minor amounts of ash fell locally. Lahars descended the Nimá I, Salamá, and San Isidro drainages. During 24-25 September explosions produced ash plumes that rose 500-700 m and drifted SW. Avalanches of material traveled down the SE and NE flanks.

Semeru | Eastern Java (Indonesia) : Based on analysis of satellite images, the Darwin VAAC reported that on 19 September a possible ash-and-steam plume from Semeru rose to an altitude of 4 km (13,000 ft) a.s.l. and drifted SSW.

Sheveluch | Central Kamchatka (Russia) : KVERT reported that a thermal anomaly over Sheveluch was identified in satellite data during 14, 16-17, and 19-20 September. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Volcanos

Roundup of Global Volcanic Activity – New Activity for the week of 19 September – 25 September 2018

Ketoi | Kuril Islands (Russia) : Based on a report from SVERT the Tokyo VAAC reported that on 21 September an ash plume from Ketoi drifted NE.

Piton de la Fournaise | Reunion Island (France) : OVPF reported that, based on visual observations and satellite data, a lava flow at Piton de la Fournaise had traveled 2.8 km S and then SE, and was 500 m from the S wall of Enclos Fouqué by 18 September. It was 660 m wide at the widest part. Volcanic tremor was at a low level and relatively stable on 19 September, and then decreased on 20 September. During fieldwork on 21 September volcanologists observed three active lava fountains that were continuing to build the cone. The E wall was 30 m high, particularly vertical, and appeared unstable with numerous fractures. The lava flows were well-channeled and had advanced several hundred meters since 19 September, threatening an OVPF seismic station. Volcanic tremor levels fluctuated during 21-22 September. Deposits of Pele’s hair were noted in the Grand Coude area (8-10 km SW) on 22 September. During an overflight that same day volcanologists noted that the three lava fountains in the cone were visible, and lava tubes had formed near the uppermost part of the channel. Volcanic tremor had doubled in intensity on 23 September. Compared to the beginning of the eruption on 15 September the sulfur dioxide emissions had decreased by a factor of six; gas plumes were small and drifted S and W, but were confined to the Enclos Fouqué.

Sarychev Peak | Matua Island (Russia) : KVERT reported a continuing eruption at Sarychev Peak (the NW part of Mantua Island) through 21 September. Island observers reported explosions at 1010 on 18 September that sent ash plumes to 4.5 km (14,800 ft) a.s.l. Ash plumes identified in satellite images during 17-18 September drifted 265 km E. The Aviation Color Code remained at Orange.

Semisopochnoi | United States : AVO reported that during 19-25 September seismicity at Semisopochnoi remained elevated, alternating between periods of continuous and intermittent bursts of tremor. Tremor bursts at 1319 on 21 September and at 1034 on 22 September produced airwaves detected on a regional infrasound array on Adak Island; no ash emissions were identified above the low cloud deck in satellite data, and the infrasound detections likely reflected an atmospheric change instead of volcanic activity. The Aviation Color Code (ACC) remained at Yellow and Volcano Alert Level (VAL) remained at Advisory.

Ulawun | New Britain (Papua New Guinea) : According to the Darwin VACC, a pilot observed an ash plume from Ulawun rising to an altitude of 3.7 km (12,000 ft) a.s.l. and drifting W. Ash was not confirmed in satellite images, though weather clouds obscured views.

Veniaminof | United States : AVO reported that the eruption at Veniaminof continued during 19-25 September, as evidenced by nighttime incandescence recorded by the FAA web camera in Perryville (35 km S), elevated surface temperatures in thermal satellite data, and elevated seismic activity. A gas plume was occasionally visible during clear daytime conditions. A lava flow had traveled 800 m down the S flank of the summit cone by 14 September, though satellite images from 18 September indicated no further advancement. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.

Volcanos

Roundup of Global Volcanic Activity – Ongoing Activity for the week of 12 September -18 September 2018

Aira | Kyushu (Japan) : JMA reported that there were 13 events and also 13 explosions at Minamidake crater (at Aira Caldera’s Sakurajima volcano) during 10-18 September, with ash plumes rising as high as 1.8 km above the crater rim and material ejected as far as 1.1 km. Crater incandescence was visible at night. 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 12-18 September ash plumes from Dukono rose to altitudes of 1.8-2.1 km (6,000-7,000 ft) a.s.l. and drifted in multiple directions.

Ebeko | Paramushir Island (Russia) : KVERT reported that a thermal anomaly over Ebeko was identified in satellite images during 7, 9, and 12-13 September. Volcanologists in Severo-Kurilsk (Paramushir Island), about 7 km E, observed explosions that sent ash plumes to 3.4 km (11,200 ft) a.s.l. and occasional incandescence during 10-13 September; ash plumes visible in satellite data drifted 113 km SE and NE. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Karymsky | Eastern Kamchatka (Russia) : KVERT reported that a thermal anomaly over Karymsky was identified in satellite images on 7 September. Dense and continuous ash emissions from the crater were visible on 10 September. Explosions during 10-11 September generated ash plumes identified in satellite images rising 5-6 km (16,400-19,700 ft) a.s.l. and drifting about 860 km NE. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Kilauea | Hawaiian Islands (USA) : HVO reported minor incandescence from a collapse pit in the central part of Kilauea’s Fissure 8 cone during 12-15 September, and that small amounts of fuming rose from a small spatter cone located towards the back of the Fissure 8 cone during 12-18 September. Seismicity and ground deformation remain low at the summit, and aftershocks from the M 6.9 earthquake in early May were located along faults on the south flank. The combined rate of sulfur dioxide emission from the summit and the LERZ (less than 1,000 tonnes/day) were lower than any time since late 2007. Small collapses at Pu’u ‘O’o Crater during 12-14 September generated visible dust plumes. The Volcano Alert Level remained at Watch and the Aviation colour Code remained at Orange.

Krakatau | Indonesia : Based on satellite data, the Darwin VAAC reported that during 11-13 and 17-18 September ash plumes from Anak Krakatau rose to altitudes of 1.5-1.8 km (5,000-6,000 ft) a.s.l. and drifted NW, W, and SW. 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 10-16 September the new lava dome in Merapi’s summit crater continued to slowly grow. By 16 September the volume of the lava dome was an estimated 112,000 cubic meters, and the growth rate was 1,600 cubic meters per day. White emissions of variable density rose 20 m above the summit. The Alert Level remained at 2 (on a scale of 1-4), and resident 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 11-17 September. Gas emissions persisted, and sometimes contained ash. Periodic explosions sometimes ejected material that was deposited around the crater. Notably, at 0057 on 12 September, an explosion associated with a partial dome-collapse event ejected incandescent material 700 m above the crater rim and onto the flanks. An explosion at 2224 on 13 September generated ash plumes that rose 2.5 km above the crater rim. The event also ejected incandescent material to the SE, and generated a pyroclastic flow that traveled as most 400 m E. 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.

Popocatepetl | Mexico : CENAPRED reported that each day during 12-17 September there were 64-189 steam-and-gas emissions from Popocatépetl, some of which contained minor amounts of ash. Nighttime crater incandescence was sometimes visible. Explosions were detected almost every day: eight on 12 September; one on 14 September; five on 15 September; three on 16 September. A series of emissions and explosions accompanied by tremor began at 0425 on 17 September and lasted for 365 minutes; incandescent tephra was ejected. The Alert Level remained at Yellow, Phase Two.

Sabancaya | Peru : Observatorio Vulcanológico del Sur del IGP (OVS-IGP) and Observatorio Vulcanológico del INGEMMET (OVI) reported that explosions at Sabancaya averaged 13 per day during 10-16 September. 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, NE, and SE. The MIROVA system detected seven thermal anomalies, and on 12 September the sulfur dioxide gas flux was high at 2,060 tons/day. The report noted that the public should not approach the crater within a 12-km radius.

Sangay | Ecuador : Based on satellite images and wind model data, the Washington VAAC reported that on 11, 13, 15, and 17 September ash emissions from Sangay rose to 5.8-6.4 km (19,000-21,000 ft) a.s.l. and drifted SW and W. A thermal anomaly was visible each day, and also on 16 September.

Sheveluch | Central Kamchatka (Russia) : KVERT reported that a thermal anomaly over Sheveluch was identified in satellite data during 7-8 and 12-13 September. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Suwanosejima | Ryukyu Islands (Japan) : JMA reported that during 12-13 September eruptive events at Suwanosejima’s Ontake Crater generated plumes that rose 1.1 km above the crater rim. Tremor increased, and nighttime crater incandescence was also visible. The Alert Level remained at 2 (on a 5-level scale).

Turrialba | Costa Rica : OVSICORI-UNA reported that passive gas-and-ash emissions from Turrialba were continuous in September through the 13th. Events during 17-18 September produced plumes that rose 300 m above the crater and drifted SW and NW.

Volcanos

Roundup of Global Volcanic Activity – New Activity for the week of 12 September -18 September 2018

Ioto | Japan : During an overflight of Ioto (Iwo-jima) on 12 September the Japan Maritime Self Defense Force observed seawater jetting 5-10 m above the sea surface on the S coast, suggestive of a submarine eruption.

Piton de la Fournaise | Reunion Island (France) : OVPF reported that after several hours of increased seismicity at Piton de la Fournaise a seismic crisis began at 0145 on 15 September, accompanied by rapid deformation. Tremor began at 0425, contemporaneous with the opening of fissures on the S flank near Rivals Crater. Around 1000 an estimate of the lava flow rate, based on satellite data, was 30 cubic meters per second. During an overflight about an hour later observers noted five fissures. The central fissure was the most active, producing lava fountains 30 m high; two lava flows that merged downstream had already flowed more than 2 km towards the wall of the Enclos Fouqué. By the afternoon of 16 September the estimated flow rate was between 2.5 and 7 cubic meters per second. Only three vents were active and a cone had started to form. Lava flows continued to advance during 16-18 September.

Sarychev Peak | Matua Island (Russia) : SVERT and KVERT reported increased activity and ash emissions at Sarychev Peak in mid-September. A thermal anomaly had been periodically visible since 7 May 2018, though more recently anomalies were detected during 8 and 11-12 September. Explosions sometimes occurred during 11 and 13-15 September, and ash emissions rose 3-4 km (10,000-13,100 ft) a.s.l. On 14 September ash plumes drifted as far as 120 km. On 14 September KVERT stated that the Aviation Color Code was raised to Orange, though on 17 September SVERT noted that the Aviation Color Code was at Yellow. KVERT reported that explosions at 0910 on 17 September generated ash plumes that rose as high as 4.5 km (14,800 ft) a.s.l. and drifted 21 km NE.

Semisopochnoi | United States : On 16 September AVO raised the Aviation Color Code (ACC) for Semisopochnoi to Yellow and Volcano Alert Level (VAL) to Advisory after increased seismicity was detected at 0831. Retrospective analysis of satellite data acquired on 10 September revealed small ash deposits on the N flank of Mount Cerberus, possibly associated with two bursts of tremor recorded on 8 September. This new information coupled with intensifying seismicity and a strong tremor signal recorded at 1249 on 17 September prompted AVO to raise the ACC to Orange and the VAL to Watch. Seismicity remained elevated on 18 September with nearly constant tremor being recorded by local sensors.

Veniaminof | United States : AVO reported that the eruption at Veniaminof continued during 12-18 September. A lava flow had traveled 800 m down the S flank of the summit cone by 14 September, remaining confined to the ice-filled summit caldera. A webcam in Perryville (35 km S) recorded nighttime incandescence, and sporadic gas emissions in the day during clear conditions. Elevated surface temperatures were identified in satellite images, and seismicity remained elevated. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.

Volcanos

Roundup of Global Volcanic Activity – Ongoing Activity for the week of 5 September -11 September 2018

Aira | Kyushu (Japan) : JMA reported that there were two events and four explosions at Minamidake crater (at Aira Caldera’s Sakurajima volcano) during 3-10 September, with ash plumes rising as high as 1.7 km above the crater rim. Crater incandescence was occasionally visible at night. An explosion at 0304 on 9 September ejected material as far as 700 m. 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 5-10 September ash plumes from Dukono rose to altitudes of 1.8-2.1 km (6,000-7,000 ft) a.s.l. and drifted SSE, SE, and E.

Ebeko | Paramushir Island (Russia) : Volcanologists in Severo-Kurilsk (Paramushir Island), about 7 km E of Ebeko, observed explosions during 31 August-7 September that sent ash plumes to 4.5 km (14,800 ft) a.s.l. Ash plumes were identified in satellite images drifting about 75 km N and S on 31 August and 4 September, and a thermal anomaly over the volcano was visible during 4-5 September. The Aviation Color Code remained at Orange (the second highest level on a four-color scale).

Karymsky | Eastern Kamchatka (Russia) : KVERT reported that a thermal anomaly over Karymsky was identified in satellite images on 31 August and 5 September. The Aviation Color Code remained at Orange (the second highest level on a four-color scale).

Kilauea | Hawaiian Islands (USA) : HVO reported that during 5-11 September weak lava activity at Kilauea’s Fissure 8 was characterized by occasional incandescence; during 9-10 September a small collapse pit formed and exposed hot material underneath. Seismicity and ground deformation remain low at the summit, and aftershocks from the M 6.9 earthquake in early May were located along faults on the south flank. The combined rate of sulfur dioxide emission from the summit and the LERZ (<1,000 tonnes/day) were lower than any time since late 2007. A series of small collapses at Pu’u ‘O’o Crater during 8-10 September generated visible brown plumes. The Volcano Alert Level remained at Watch and the Aviation Color Code remained at Orange.

Sabancaya | Peru : Observatorio Vulcanológico del Sur del IGP (OVS-IGP) and Observatorio Vulcanológico del INGEMMET (OVI) reported that explosions at Sabancaya averaged 17 per day during 3-9 September. Hybrid earthquakes were infrequent and of low magnitude. Gas-and-ash plumes rose as high as 3.5 km above the crater rim and drifted 50 km SW, E, and NE. The MIROVA system detected seven thermal anomalies, and on 3 September the sulfur dioxide gas flux was high at 2,380 tons/day. The report noted that the public should not approach the crater within a 12-km radius.

Sangay | Ecuador : Based on satellite images and wind model data, the Washington VAAC reported that during 5-8 and 10 September ash emissions from Sangay rose to 4.3-6.7 km (14,000-22,000 ft) a.s.l. and drifted at least 170 km W. A thermal anomaly was visible on 5 September.

Semeru | Eastern Java (Indonesia) : Based on analysis of satellite images and wind model data, the Darwin VAAC reported that during 6-7 September ash plumes from Semeru rose to an altitude of 4.3 km (14,000 ft) a.s.l. and drifted SW.

Sheveluch | Central Kamchatka (Russia) : KVERT reported that a thermal anomaly over Sheveluch was identified in satellite data during 1-7 September. The Aviation Color Code remained at Orange (the second highest level on a four-color scale).

Stromboli | Aeolian Islands (Italy) : INGV reported that during 3-9 September activity at Stromboli was characterized by ongoing Strombolian activity and degassing from multiple vents within the crater terrace. Explosions mainly from two vents (N1 and N2) in Area N (north crater area, NCA) and three vents (C, S1, and S2) in Area C-S (South Central crater area) occurred at a rate of 2-15 per hour. Low-to-medium-intensity explosions from the N1 vent ejected lapilli and bombs mixed with ash as high as 120 m. Explosions of variable intensity at the N2 vent ejected tephra 150 m high. Vent C produced gas emissions, and periodic low-intensity explosions ejected tephra 80 m high. Incandescent material from S1 jetted 120 m above the crater. Low-intensity explosions at S2 ejected tephra less than 80 m high.

Turrialba | Costa Rica : OVSICORI-UNA reported that passive gas-and-ash emissions from Turrialba were continuous during 27 August-5 September, with plumes rising 100 m above the vent. Emissions on 6 September were mostly gas, punctuated by small and sporadic ash plumes. At 1210 on 10 September an event produced an ash plume that rose 300 m above the crater rim and drifted NW.

Volcanos

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

Etna | Sicily (Italy) : INGV reported that during 3-9 September activity at Etna was characterized by gas emissions at the summit craters, with periodic Strombolian activity from vents in Bocca Nuova, Northeast Crater (NEC), and New Southeast Crater (NSEC). A few Strombolian explosions at NSEC were recorded on 5 September; an explosion at 0536 generated an ash plume that produced local ashfall around the vent and in the Valle del Bove, and quickly dispersed. A similar but less intense event occurred earlier that day, at 0316. Similar Strombolian events continued during 6-9 September, at intervals of a few hours. Strombolian activity at the N vent (BN-1) in Bocca Nuova occurred at 3-5-minute intervals, ejecting incandescent material that fell within the crater confines. Gas emissions were sometimes punctuated with ash emissions. Intense degassing was characteristic of the second vent (BN-2). Strombolian activity occurred at NEC, and a few times explosions were accompanied by ash emissions.

Krakatau | Indonesia : Based on satellite data, the Darwin VAAC reported that on 8 September ash plumes from Anak Krakatau rose to altitudes of 4.9-5.5 km (16,000-18,000 ft) a.s.l. and drifted W and NW. During 9-10 September ash plumes rose to 1.5 km (5,000 ft) a.s.l. and drifted W. 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.

Veniaminof | United States : On 4 September low-level ash emissions (less than 3 km or 10,000 ft a.s.l.) from Veniaminof were evident in webcam images and confirmed by observers in Perryville (35 km S), prompting AVO to raise the Aviation colour Code to Orange and the Volcano Alert Level to Watch. Seismicity was elevated. During 4-6 September pulsating, low-altitude ash plumes were visible from a Perryville webcam and reported by a pilot, and a small thermal anomaly was visible in satellite data. On 7 September the thermal signal increased, suggesting lava fountaining at the summit. Webcam images the next day showed minor ash or steam near the summit cone. Ash deposits on the snowfield formed a “V” shape from the summit, extending to the SSW and SE. On 9 September a lava flow, about 800 m long, was identified on the S flank in satellite data. Witnesses aboard a ferry passing Veniaminof early the next morning noted lava fountaining and an active lava flow. Lava flows continued on 11 September, though were confined to the summit caldera.

Volcanos

Roundup of Global Volcanic Activity – Ongoing Activity for the week of 29 August -2 September 2018

Aira | Kyushu (Japan) : JMA reported that there were 14 events and 15 explosions at Minamidake crater (at Aira Caldera’s Sakurajima volcano) during 27 August-3 September, with ash plumes rising as high as 2.8 km above the crater rim and material ejected as far as 1.3 km. Crater incandescence was occasionally visible at night. The sulfur dioxide emission rate was 1,500 tons/day on 27 August. The Alert Level remained at 3 (on a 5-level scale).

Ambae | Vanuatu : The Vanuatu Meteorology and Geo-hazards Department reported that at 2015 on 1 September explosions at Ambae’s Lake Voui generated ash plumes that rose 4-11 km above the crater rim. According to the Wellington VAAC the ash plumes were visible in satellite images rising as high as 10.7 km (35,000 ft) a.s.l. and drifting E; the ash quickly dissipated. Moderate ashfall was likely produced in areas NE and E. The Alert Level remained at 3 (on a scale of 0-5).

Dukono | Halmahera (Indonesia) : Based on satellite data, wind model data, and notices from PVMBG, the Darwin VAAC reported that during 29 August-4 September ash plumes from Dukono rose to altitudes of 1.8-2.1 km (6,000-7,000 ft) a.s.l. and drifted N, NE, and E.

Ebeko | Paramushir Island (Russia) : Volcanologists in Severo-Kurilsk (Paramushir Island), about 7 km E of Ebeko, observed explosions during 24-31 August that sent ash plumes to 3-6 km (17,100 ft) a.s.l. A thermal anomaly was visible in satellite data during 24-25 and 30 August. Ash plumes drifted about 135 km SE, S, and SW during 24-25 and 27-30 August, producing ashfall on 29 and 30 August. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Fuego | Guatemala : INSIVUMEH reported that heavy rain generated lahars during 29 August-1 September that descended Fuego’s El Jute (SE), Las Lajas (SE), Cenizas (SSW), Taniluyá (SW), Seca (W), Mineral, Honda, and Pantaleón (W) drainages. The lahars were hot, had a sulfur odor, and carried tree branches and blocks (2-3 m in diameter). On 1 September lahars disrupted roads between San Pedro Yepocapa (8 km NW) and Sangre de Cristo (8 km WSW), and from Finca Palo Verde and El Porvenir (8 km ENE). During 2-4 September explosions produced ash plumes that rose as high as 950 m above the crater rim and drifted 10-15 km W and SW. Avalanches of incandescent material were confined to the crater. Ashfall was reported in areas downwind including San Pedro Yepocapa, Sangre de Cristo, Panimaché I and II (8 km SW), Morelia (9 km SW), and Finca Palo Verde.

Karymsky | Eastern Kamchatka (Russia) : KVERT reported that an ash plume from Karymsky was identified in satellite images drifting about 40 km S on 25 August. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Kilauea | Hawaiian Islands (USA) : HVO reported a break in visible lava activity at Kilauea’s Fissure 8 during 26-31 August. On 1 September incandescence at Fissure 8 was evident in the afternoon; spattering from a small area produced lava flows that slowly covered the 15 x 65 m crater floor by the evening. Lava continued to fill the Fissure 8 crater on 3 September. The Volcano Alert Level remained at Watch and the Aviation colour Code remained at Orange.

Mayon | Luzon (Philippines) : PHIVOLCS reported that at 0653 on 27 August a short-lived degassing event at Mayon produced a light-brown ash plume that rose 200 m above the summit rim and drifted NE. During 28 August-3 September white steam plumes rose as high as 1 km and drifted in multiple directions. Crater incandescence was visible nightly. 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.

Reventador | Ecuador : During 29 August-3 September IG reported a high level of seismic activity at Reventador, including explosions, long-period earthquakes, harmonic tremor, and signals indicating emissions. Steam, gas, and ash plumes rose as high as 600 m above the crater rim and drifted NE, NW, and W. Crater incandescence was visible.

Rincon de la Vieja | Costa Rica : OVSICORI-UNA reported two distinct, two-minute-long eruptions at Rincón de la Vieja beginning at 0434 and 1305 on 31 August. 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 explosions at Sabancaya averaged 25 per day during 27 August-2 September. Hybrid earthquakes were infrequent and of low magnitude. Gas-and-ash plumes rose as high as 3 km above the crater rim and drifted 50 km SE, E, and NE. The MIROVA system detected six thermal anomalies, and on 2 September the sulfur dioxide gas flux was high at 3,970 tons/day. The report noted that the public should not approach the crater within a 12-km radius.

Sangay | Ecuador : Based on satellite images and wind model data, the Washington VAAC reported that during 28 August-3 September ash emissions from Sangay rose to 5.8-6.7 km (19,000-22,000 ft) a.s.l. and drifted over 45 km in multiple directions. A thermal anomaly was sometimes visible.

Santa Maria | Guatemala : INSIVUMEH reported that during 1-4 September weak explosions at Santa María’s Santiaguito lava-dome complex generated ash plumes that rose 600-700 m and drifted SW. Avalanches of material descended the SE flanks of the lava dome. Ashfall was reported to the south in Monte Claro.

Semeru | Eastern Java (Indonesia) : Based on analysis of satellite images and wind model data, the Darwin VAAC reported that on 4 September a discrete eruption at Semeru generated an ash plume that rose to an altitude of 4.3 km (14,000 ft) a.s.l. and drifted W.

Sheveluch | Central Kamchatka (Russia) : KVERT reported that a thermal anomaly over Sheveluch was identified in satellite data during 25 and 28-30 August; cloudy weather prevented views of the volcano on the other days during 24-31 August. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Sierra Negra | Isla Isabela (Ecuador) : IG reported that the eruption at Sierra Negra that began on 26 June was divided into two main phases. The first and most energetic phase lasted one day (26 June) and was characterized by the opening of five fissures and lava flows traveling as far as 7 km from the vents. Lava was only produced from fissure 4 during the 57-day-long second phase (27 June-23 August), with lava reaching the sea on 6 July and expanding the coastline. By 25 August the lava flows in total covered an area of 30.6 square kilometers. Activity continued to decline the last week of August with decreased seismicity, gas emission, and no surficial activity visible.

Turrialba | Costa Rica : OVSICORI-UNA reported that at 1340 on 30 August an event at Turrialba produced an ash plume that passively rose 200 m above the crater rim and drifted SW. Gas-and-ash emissions became continuous during 31 August-1 September, with plumes rising 200 m and drifting SW and W.

Volcanos

Roundup of Global Volcanic Activity – New Activity for the week of 29 August -2 September 2018

Krakatau | Indonesia : Based on satellite data, the Darwin VAAC reported that during 29-30 August and during 3-4 September ash plumes from Anak Krakatau rose to altitudes of 1.2-1.5 km (4,000-5,000 ft) a.s.l. and drifted SW, W, NW, 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.

Manam | Papua New Guinea : RVO reported that during 26 August-3 September white plumes rose from Manam’s Main and Southern craters. Seismicity was at low levels.

Veniaminof | United States: Late on 2 September seismic activity at Veniaminof increased, indicative of unrest, prompting AVO to raise the Aviation colour Code to Yellow and the Volcano Alert Level to Advisory. The report noted no other signs of eruptive activity.

Volcanos

Roundup of Global Volcanic Activity – Ongoing Activity for the week of 22 August -28 August 2018

Aira | Kyushu (Japan) : JMA reported that there were three events and 12 explosions at Minamidake crater (at Aira Caldera’s Sakurajima volcano) during 20-27 August, with ash plumes rising as high as 2.1 km above the crater rim and material ejected as far as 1.3 km. Crater incandescence was sometimes visible at night. The Alert Level remained at 3 (on a 5-level scale).

Ambrym | Vanuatu : On 22 August the Vanuatu Meteorology and Geo-hazards Department reported that the lava lakes in Ambrym’s Benbow and Marum craters continued to be active, and produced sustained and substantial 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.

Cleveland | Chuginadak Island (USA) : Low-level unrest at Cleveland continued, though on 22 August AVO noted a pause in activity and lowered the Aviation colour Code to Yellow and the Volcano Alert Level to Advisory. The report noted that elevated surface temperatures were identified in satellite images the previous day, suggestive of hot gas emissions from the summit crater vents.

Dukono | Halmahera (Indonesia) : Based on satellite data, wind model data, and notices from PVMBG, the Darwin VAAC reported that during 22-23 and 25-28 August ash plumes from Dukono rose to altitudes of 1.8-2.1 km (6,000-7,000 ft) a.s.l. and drifted in multiple directions.

Ebeko | Paramushir Island (Russia) : Volcanologists in Severo-Kurilsk (Paramushir Island), about 7 km E of Ebeko, observed explosions during 17-24 August that sent ash plumes as high as 5.2 km (17,100 ft) a.s.l. Ash plumes drifted 235 km SE during 21-22 August, and a thermal anomaly was visible during 21-23 August. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Ibu | Halmahera (Indonesia) : PVMBG reported that at 0838 on 24 August an event at Ibu generated an ash plume that rose 800 m above the crater rim and drifted S. Seismicity was characterized by 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.

Kilauea | Hawaiian Islands (USA) : HVO reported that during an overflight on 25 August a small lava pond was visible deep within the vent at Kilauea’s Fissure 8 cone; the pond was no longer visible on 27 August. Lava continued to ooze into the ocean and produce minimal laze plumes, but by 27 August only a small single breakout from the Kapoho Bay lobe was active. The Volcano Alert Level remained at Watch and the Aviation colour Code remained at Orange.

Pacaya | Guatemala : Based on information from INSIVUMEH, CONRED reported a slight increase in explosive activity at Pacaya, with 3-5 explosions per hour recorded by the seismic network. A 600-m-long lava flow originating from Mackenney Crater was visible on NW flank.

Sabancaya | Peru : Observatorio Vulcanológico del Sur del IGP (OVS-IGP) and Observatorio Vulcanológico del INGEMMET (OVI) reported that explosions at Sabancaya averaged 25 per day during 20-26 August. Hybrid earthquakes were infrequent and low magnitude. Gas-and-ash plumes rose as high as 4.5 km above the crater rim and drifted 50 km SE, E, NE, and N. The MIROVA system detected seven thermal anomalies, and on 25 August the sulfur dioxide gas flux was high at 2,230 tons/day. The report noted that the public should not approach the crater within a 12-km radius.

Semeru | Eastern Java (Indonesia) : Based on analysis of satellite images and wind model data, the Darwin VAAC reported that during 23-27 August ash plumes from Semeru rose to an altitude of 4.3 km (14,000 ft) a.s.l. and drifted SW, W, NW, and SE.

Sheveluch | Central Kamchatka (Russia) : KVERT reported that satellite images showed a thermal anomaly over Sheveluch on 17, 19, and 23 August; cloudy weather prevented views of the volcano on the other days during 17-24 August. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Sierra Negra | Isla Isabela (Ecuador) : IG reported that during 20-21 August both steam-and-gas emissions and incandescence from lava flows were visible on the Sierra Negra webcam. No activity was noted when the weather was clear during 22-28 August.

Turrialba | Costa Rica : OVSICORI-UNA reported that during 27-28 August emissions from Turrialba rose continuously to 200 m above the crater rim, and drifted SW.

Yasur | Vanuatu : The Vanuatu Meteorology and Geo-hazards Department reported that ongoing explosions at Yasur were sometimes strong during August. 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 22 August -28 August 2018

Etna | Sicily (Italy) : INGV reported that during 20-26 August activity at Etna was characterized by gas emissions at the summit craters, Strombolian activity, and ash emissions. Strombolian explosions continued from vents in Bocca Nuova (including from a vent that had opened on 16 August) and Northeast Crater (NEC). Activity at New Southeast Crater (NSEC) was characterized by modest and occasional explosions and Strombolian activity. Beginning at 1700 on 23 August Strombolian activity from the cone in the saddle between the Southeast Crater (SEC) and NSEC cone complex rapidly intensified; explosions ejected tephra 100-150 m above the vent rim. At 1730 Strombolian activity occurred at NSEC’s E vent, and a lava flow from the same vent traveled a few hundred meters towards the Valle del Bove. Just after 1730 lava overflowed the vent in the saddle cone and flowed N; Strombolian activity at that vent continued through the night and then stopped no later than 0620 on 24 August. At 0622 Strombolian activity from a vent on the S flank of NSEC produced a small lava flow that traveled a few dozen meters. During 25-26 August the activity at the saddle cone gradually decreased, and ash emissions were weak and occasional.

Krakatau | Indonesia : PVMBG reported that at 1807 on 23 August an event at Anak Krakatau generated a dense, black ash plume that rose about 700 m above the crater rim. Based on satellite data, the Darwin VAAC reported that during 27-28 August ash plumes rose to altitudes of 1.2-1.5 km (4,000-5,000 ft) a.s.l. and drifted SW and WSW. 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.

Manam | Papua New Guinea : RVO reported that an eruption at Manam began at around 0600 on 25 August after island residents reported increased activity beginning an hour before. According to the Darwin VAAC ash plumes visible in satellite data rose to 15.2 km (50,000 ft) a.s.l. and drifted WSW. The plume drifted W and NW, causing ash and scoria to fall in areas from Dangale in the NNE to Jogari in the SW part of the island. The most affected areas were Baliau and Kuluguma; residents reported fallen tree branches from the deposits, and conditions so dark that flashlights were needed to move around. Lava flows traveled down the NE valley and pyroclastic-flow deposits were evident in the NE valley all the way to the sea. The pyroclastic flows buried six houses in Boakure village though the occupants escaped to the nearby Abaria village. According to a news article about 2,000 people evacuated. The eruption ceased around 1030 with dense white emissions visible afterwards. During brief periods of good visibility after the eruption, and through 26 August, observers noted dense white vapor emissions and occasional light gray ash plumes.

Merapi | Central Java (Indonesia) : PVMBG reported that the new lava dome within the fracture of Merapi’s 2010 dome grew at a rate of 4,300 cubic meters per day during 18-28 August, and by 28 August the volume of the lava dome was an estimated 44,000 cubic meters. The Alert Level remained at 2 (on a scale of 1-4), and resident were warned to remain outside of the 3-km exclusion zone.