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.

Volcanos

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

Aira | Kyushu (Japan) : JMA reported occasional, very small events at Minamidake crater (at Aira Caldera’s Sakurajima volcano) during 9-15 October. Sulfur dioxide emissions decreased from 3,400 tons/day on 4 October to 600 tons/day on 10 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 10-12 October ash plumes from Dukono rose to altitudes of 1.5-2.1 km (5,000-7,000 ft) a.s.l. and drifted W and SW.

Ebeko | Paramushir Island (Russia) : Volcanologists in Severo-Kurilsk (Paramushir Island), about 7 km E of Ebeko, observed explosions during 5-12 October that sent ash plumes to 4.5 km (14,800 ft) a.s.l. Satellite images showed ash plumes drifting about 125 km SE on 5 and 8 October, and a thermal anomaly over the volcano on 8 October. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Fuego | Guatemala : INSIVUMEH and CONRED reported that on 12 October a new phase of activity began at Fuego, characterized by lava fountains rising as high as 400 m above the crater rim, avalanches of incandescent material down the W and SSW flanks, increased rumbling, and a lava flow traveling 1 km down the Santa Teresa (W) drainage. Very frequent explosions generated ash plumes that rose 850 m and drifted 12 km S and SE. On 13 October a steaming lahar descended the Ceniza (SSW) drainage, carrying blocks up to 2 m in diameter, and branches and tree trunks. During 13-16 October explosions (8-18 per hour) produced ash plumes that rose almost 1 km and drifted 8-12 km S, SW, and W. Ashfall was reported in areas downwind including Sangre de Cristo (8 km WSW), Finca Palo Verde, and Panimaché I and II (8 km SW). Incandescent material was ejected 150-200 m high, causing avalanches of material within the crater, though some of the avalanches traveled long distances, reaching vegetated areas. The lava flow on the W flank was still visible but by 14 October no longer active.

Kadovar | Papua New Guinea : Based on satellite data and wind model data, the Darwin VAAC reported that during 10-12 October ash plumes from Kadovar rose to an altitude of 2.4 km (8,000 ft) a.s.l. and drifted NW and W.

Manam | Papua New Guinea : RVO reported that during 2-12 October brown, gray-brown, and dark gray ash emissions rose as high as 1 km above Manam’s Southern Crater rim and drifted NW. Main Crater produced occasional white emissions, though on 2 October plumes were gray-brown and contained ash. Bluish vapor was noted during 3-4 October.

Merapi | Central Java (Indonesia) : PVMBG reported that during 5-11 October the lava dome in Merapi’s summit crater grew slowly at a rate of 3,100 cubic meters per day, though faster than the previous week. By 11 October the volume of the dome was an estimated 160,000 cubic meters. 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 residents were warned to remain outside of the 3-km exclusion zone.

Pacaya | Guatemala : INSIVUMEH reported that during 11-15 October Strombolian explosions at Pacaya’s Mackenney Crater ejected material as high as 25 m above the crater rim, and gas plumes rose 200-700 m. A lava flow that first emerged on 11 October traveled NW towards Cerro Chino, and by 15 October was 250 m long.

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 8-14 October. 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 NE, E, SE, and SW. The MIROVA system detected six thermal anomalies, and on 14 October the sulfur dioxide gas flux was high at 3,132 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 data during 8-10 October; weather clouds prevented views on the other days during 5-12 October. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Turrialba | Costa Rica : OVSICORI-UNA reported that most days during 10-16 October intermittent, passive gas-and-ash emissions at Turrialba rose as high as 1 km above the crater rim. The emissions drifted W, SW, S, and NE. There were also some explosive events; an energetic explosion was recorded at 1712 on 14 October, though cloudy weather prevented estimates of a plume height.

Veniaminof | United States : AVO reported that the eruption at Veniaminof continued during 10-16 October, as evidenced by elevated surface temperatures in satellite data, and low-level continuous tremor. Satellite data indicated that the E part of the S-flank flow field remained active. 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 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.