Volcanos

Roundup of Global Volcanic Activity – New Activity for the week of15 November – 21 November 2017

Agung | Bali (Indonesia) : PVMBG reported that a phreatic eruption at Agung began at 1705 on 21 November, following a low-frequency tremor signal. An ash plume rose 700 m above the crater rim and drifted ESE. The Alert Level remained at 3 (on a scale of 1-4), and the exclusion zones remained intact (at 6 km, and an additional expansion to 7.5 km in the NNE, SE, S, and SW directions).

Oraefajokull | Iceland : The Icelandic Meteorological Office (IMO) reported that on 17 November the Aviation colour Code for Öræfajökull was raised to Yellow because satellite images and photos showed that a new ice cauldron had formed within the caldera the previous week. The new cauldron was about 1 km in diameter and 15-20 m deep, and signified a recent increase in geothermal activity. Scientists conducted an overflight on 18 November; in addition, while on the ground, they took water samples, measurements of electrical conductivity, and gas levels at the Kvíárjökull outlet-glacier, a valley glacier on the SE flank of Öræfajökull. There was no obvious sign of flooding in the Kvíá river. A sulfur odor, which had been reported for about a week, was also noted. An increase in the seismic activity was recorded for the last few months (the largest earthquake, an M 3.4, occurred on the 3 October), but was low for the past few days. IMO noted that there were no signs of an imminent volcanic eruption, though there was considerable uncertainty about how the situation will evolve.

Sarychev Peak | Matua Island (Russia) : SVERT reported that weak steam-and-gas emissions from Sarychev Peak were observed on 13 November. Weather clouds prevented observations during 14-20 November. The Aviation colour Code remained at Green.

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Volcanos

Roundup of Global Volcanic Activity – Ongoing Activity for the week of 8 November – 14 November 2017

Agung | Bali (Indonesia) : PVMBG reported that white plumes from Agung rose as high as 500 m above the crater rim during 8-14 November. The Alert Level remained at 3 (on a scale of 1-4), and the exclusion zones remained intact (at 6 km, and an additional expansion to 7.5 km in the NNE, SE, S, and SW directions).

Aira | Kyushu (Japan) : JMA reported that an explosion at Minamidake summit crater (at Aira Caldera’s Sakurajima volcano) detected at 1025 on 7 November generated an ash plume that rose 1.3 km above the crater rim. A very small event occurred at the same crater on 13 November. The Alert Level remained at 3 (on a 5-level scale).

Cleveland | Chuginadak Island (USA) : AVO reported that during 8-13 November elevated surface temperatures in Cleveland’s summit crater were identified in satellite data, possibly indicative of a lava flow in the crater. No significant eruptive activity was detected by seismic or infrasound sensors; both sensors detected a signal associated with low-level emissions during 0056-0059 on 12 November. A small explosion was recorded at 0315 on 14 November. The Aviation colour Code remained at Orange and the Volcano Alert Level remained at Watch.

Dukono | Halmahera (Indonesia) : Based on analyses of satellite imagery, wind model data, and notices from PVMBG, the Darwin VAAC reported that during 8-14 November ash plumes from Dukono rose to an altitude of 2.1 km (7,000 ft) a.s.l. and drifted in multiple directions.

Ebeko | Paramushir Island (Russia) : Based on observations by volcanologists in Severo-Kurilsk (Paramushir Island), about 7 km E of Ebeko, explosions during 5 and 7-8 November generated ash plumes that rose as high as 2 km (6,600 ft) a.s.l. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Katmai | United States : On 13 November AVO reported that a cloud of ash, resuspended by strong winds in the vicinity of Katmai and the Valley of Ten Thousand Smokes, was blown about 120 km SE over Shelikof Strait and Kodiak Island at an altitude of up to 3 km (10,000 ft) a.s.l. The ash was originally deposited during the Novarupta eruption in 1912. The Volcano Alert Level remained at Normal and the Aviation colour Code remained at Green.

Kilauea | Hawaiian Islands (USA) : During 8-14 November HVO reported that the lava lake continued to rise, fall, and spatter in Kilauea’s Overlook crater. Webcams recorded incandescence from long-active sources within Pu’u ‘O’o Crater and from a small lava pond in a pit on the W side of the crater. The 61G lava flow, originating from a vent on Pu’u ‘O’o Crater’s E flank, ceased entering the ocean at Kamokuna on 8 November but then began reentering the ocean during 12-13 November. Surface lava flows were active above and on the pali, and on the coastal plain, and new breakouts were observed.

Sabancaya | Peru : Observatorio Vulcanológico del Sur del IGP (OVS-IGP) and Observatorio Vulcanológico del INGEMMET (OVI) reported that explosive activity at Sabancaya increased compared to the previous week; there was an average of 66 explosions recorded per day during 6-12 November. Seismicity was dominated by long-period events, with signals indicating emissions. Gas-and-ash plumes rose 4 km above the crater rim and drifted 50 km NE, E, and SE. The MIROVA system detected six thermal anomalies. The sulfur dioxide flux was high, at 2,763 tons per day on 8 November. The report noted that the public should not to approach the crater within a 12-km radius.

San Cristobal | Nicaragua : INETER reported that a series of 14 explosions at San Cristóbal began at 2134 on 7 November. The first explosion was the strongest, causing an increase in RSAM to 150 units; RSAM dropped to 50 after the last explosion. Ash fell in areas to the W and NE, including in the communities of Los Farallones, San Agustín, La Mora, El Naranjo, and Chinandega.

Sheveluch | Central Kamchatka (Russia) : KVERT reported that a thermal anomaly over Sheveluch was identified in satellite images on 3, 6, and 8 November; weather clouds prevented observations on the other days during 4-10 November. Explosions on 8 November generated ash plumes that rose 8 km (26,200 ft) a.s.l. and drifted 990 km NE. The Aviation colour Code remained at Orange.

Sinabung | Indonesia : Based on observations by PVMBG, satellite and webcam images, and model data, the Darwin VAAC reported that during 9 and 11-12 November ash plumes from Sinabung rose 4.6-4.9 km (15,000-16,000 ft) a.s.l. and drifted E and ESE. The Alert Level remained at 4 (on a scale of 1-4).

Suwanosejima | Ryukyu Islands (Japan) : Based on JMA notices and satellite data, the Tokyo VAAC reported that on 10 November an event at Suwanosejima produced a plume that rose 1.8 km (6,000 ft) a.s.l. and drifted NW.

Turrialba | Costa Rica : OVSICORI-UNA reported that an ash emission at Turrialba began before 0730 on 13 November and intensified around 0830. An ash plume rose 500 m above the crater rim and drifted SW.

Volcanos

Roundup of Global Volcanic Activity – New Activity for the week of 8 November – 14 November 2017

Aoba | Vanuatu : Based on analyses of satellite images and model data, the Wellington VAAC reported that during the morning of 8 November low-level ash plumes from Aoba rose 3 km (10,000 ft) a.s.l. and drifted W.

Dempo | Indonesia : According to PVMBG a three-minute-long phreatic eruption at Dempo began at 1651 on 9 November, and generated a dense ash plume that rose 4.2 km (13,800 ft) a.s.l., about 1 km above the crater rim, and drifted S. The Alert Level remained at 2 (on a scale of 1-4).

Sarychev Peak | Matua Island (Russia) : SVERT reported that a thermal anomaly over Sarychev Peak was identified in satellite images during 6-7 November. Weak steam-and-gas emissions were observed on 8 November. Weather clouds prevented observations during 9-13 November. The Aviation Colour Code remained at Green.

Volcanos

Roundup of Global Volcanic Activity – Ongoing Activity for the week of 1 November – 7 November 2017

Aira | Kyushu (Japan) : JMA reported that sulfur dioxide flux at Aira Caldera’s Sakurajima volcano was just under 800 tons per day on 30 October. An explosion at Minamidake summit crater at 1221 on 31 October generated an ash plume that rose 1 km above the crater rim. The Alert Level remained at 3 (on a 5-level scale).

Bagana | Bougainville (Papua New Guinea) : Based on analyses of satellite imagery and model data, the Darwin VAAC reported that on 3 November an ash plume from Bagana rose to an altitude of 2.4 km (8,000 ft) a.s.l. and drifted NE.

Cleveland | Chuginadak Island (USA) : AVO reported that small explosions at Cleveland on 28 and 30 October partly destroyed the lava dome within the summit crater. Elevated surface temperatures were identified in satellite data during clear views during 1 and 5-7 November, possibly indicative of a lava flow in the crater. Otherwise no significant eruptive activity was recorded by seismic or infrasound sensors. The Aviation colour Code remained at Orange and the Volcano Alert Level remained at Watch.

Dukono | Halmahera (Indonesia) : Based on analyses of satellite imagery, wind model data, and notices from PVMBG, the Darwin VAAC reported that during 1-7 November 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, E, and ESE. Ash plumes drifted as far as 170 km during 4-5 November.

Ebeko | Paramushir Island (Russia) : Based on observations by volcanologists in Severo-Kurilsk (Paramushir Island), about 7 km E of Ebeko, explosions during 27 October-3 November generated ash plumes that rose as high as 2 km (6,600 ft) a.s.l. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Fuego | Guatemala : INSIVUMEH reported that during 2-3 November tremor at Fuego increased. Explosions (6-8 per hour) generated ash plumes that rose as high as 1.3 km above the crater and drifted 15 km W and SW. During 4-5 November there were 5-8 explosions per hour producing ash plumes that rose 1.2 km and drifted 10-15 km W and SW. Incandescent material was ejected 300 m above the crater, causing avalanches that were confined to the crater. The 11th effusive eruption phase in 2017 began on 5 November. Lava flowed 1-1.2 km W down the Seca drainage and 800 m SSW down the Ceniza drainage. Avalanches of material from the ends of the lava flows descended the flanks and reached vegetated areas. About 6-8 explosions per hour generated ash plumes that rose as high as 1.1 km and drifted 10-15 km W and SW. Ashfall was reported in areas downwind including Panimaché I and II (8 km SW), Santa Sofía (12 km SW), Morelia (9 km SW), and El Porvenir. The effusive phase ended on 7 November.

Kilauea | Hawaiian Islands (USA) : During 1-7 November HVO reported that the lava lake continued to rise, fall, and spatter in Kilauea’s Overlook crater. Webcams recorded incandescence from long-active sources within Pu’u ‘O’o Crater and from a small lava pond in a pit on the W side of the crater. The 61G lava flow, originating from a vent on Pu’u ‘O’o Crater’s E flank, continued to enter the ocean at Kamokuna. Surface lava flows were active above and on the pali, and on the coastal plain.

Langila | New Britain (Papua New Guinea) : Based on analyses of satellite imagery and wind model data, the Darwin VAAC reported that on 5 October an ash plume from Langila rose 3.7 km (12,000 ft) a.s.l. and drifted SE and ESE.

Pacaya | Guatemala : INSIVUMEH reported that during 4-7 November Strombolian explosions at Pacaya’s Mackenney cone ejected material as high as 40 m above the crater rim.

Poas | Costa Rica : OVSICORI-UNA reported that an event at Poás at 0915 on 6 November generated a plume that rose 300 m above the crater rim.

Popocatepetl | Mexico : Each day during 1-7 November CENAPRED reported 200-361 emissions from Popocatépetl, some of which contained ash. Crater incandescence was noted almost nightly. Increased seismicity at 0146 on 3 November coincided with a period of Strombolian activity that ended at 0535; gas, water vapor, and ash emissions rose from the carter and incandescent material was ejected 500 m onto the flanks. An explosion was detected at 1027. On 4 November explosions were detected at 0145 and 0608. Following the second explosion a continuous gas plume with minor ash drifted WSW. Beginning at 0735 ashfall was reported in municipalities of Yecapixtla (31 km SW) and Zacualpan de Amilpas (30 km SW), in the state of Morelos. A Strombolian period began at 1029 and lasted for 80 minutes, causing ashfall in Tetela del Volcán (20 km SW). Explosions at 1440 and 2231 ejected incandescent material 200 m onto the flanks. Another explosion was recorded at 0411 on 5 November. An explosion at 1653 on 6 November generated a gas-and-ash plume that rose 2.5 km above the crater rim and drifted SW. Fragments were ejected 500 m onto the flanks. An explosion at 0100 on 7 November generated a gas-and-ash plume that rose almost 2 km above the crater rim and drifted SW. The Alert Level remained at Yellow, Phase Two.

Reventador | Ecuador : IG reported that during the last week of October the intensity of explosions at Reventador slightly increased; ash plumes, generated from 4-5 explosions per hour, rose to more than 2.5 km above the crater rim and had a higher ash content. Plumes typically drifted W, but also occasionally S and N. Loud “cannon shot” sounds accompanying some explosions were heard in nearby towns. IG volcanologists conducting fieldwork on 23 and 25 October noted strong explosions producing “cannon shots” that vibrated windows in Hostería Reventador, 7.2 km away. On 27 October ash plumes rose as high as 4.9 km. During 30-31 October ashfall was reported in multiple towns in the Napo Province to the S, mainly due to a change in wind direction and not increased activity.

Sabancaya | Peru : Observatorio Vulcanológico del Sur del IGP (OVS-IGP) and Observatorio Vulcanológico del INGEMMET (OVI) reported that explosive activity at Sabancaya increased compared to the previous week; there was an average of 57 daily explosions during 30 October-5 November. Seismicity was dominated by long-period events, with signals indicating emissions. Gas-and-ash plumes rose 3.8 km above the crater rim and drifted 40 km N, NE, and E. The MIROVA system detected five thermal anomalies. The sulfur dioxide flux was high, at 3,996 tons per day, on 30 October. The report noted that the public should not to approach the crater within a 12-km radius.

Sheveluch | Central Kamchatka (Russia) : KVERT reported that a thermal anomaly over Sheveluch was identified in satellite images during 26-30 October and 1-2 November. Explosions on 2 November generated ash plumes that rose 8 km (26,200 ft) a.s.l. and drifted NE. The Aviation colour Code remained at Orange.

Sinabung | Indonesia : Based on observations by PVMBG, satellite and webcam images, and model data, the Darwin VAAC reported that during 2 and 5-7 November ash plumes from Sinabung rose 3.4-4.9 km (11,000-16,000 ft) a.s.l. and drifted E, ESE, and SSE.

Stromboli | Aeolian Islands (Italy) : INGV reported that a 3-minute-long explosive sequence began at the central vents of Stromboli’s southern crater area (Area CS) at 2129 on 1 November. The explosions ejected coarse pyroclastic material onto the Sciara del Fuoco, in the direction of Pizzo Sopra la Fossa, and produced a dense ash plume that quickly dissipated to the S. Seismicity returned to normal levels after the events.

Suwanosejima | Ryukyu Islands (Japan) : Based on JMA notices and satellite data, the Tokyo VAAC reported explosions at Suwanosejima during 31 October, and 1, 3, and 5 November; plumes rose 1.5 km (5,000 ft) a.s.l. and drifted NW and W.

Turrialba | Costa Rica : The Washington VAAC reported that an ash emission from Turrialba was observed in webcam images on 4 November. Ash was not identified in satellite images, though weather cloud cover was increasing and may have obscured views.

Ulawun | New Britain (Papua New Guinea) : Based on analyses of satellite imagery, the Darwin VAAC reported that on 3 November an ash plumes from Ulawun rose to an altitude of 3 km (10,000 ft) a.s.l. and drifted NNE, though a RVO report noted only vapor emissions.

Volcanos

Roundup of Global Volcanic Activity – New Activity for the week of 1 November – 7 November 2017

Agung | Bali (Indonesia) : PVMBG reported that white plumes from Agung rose as high as 500 m above the crater rim during 1-7 November. The Alert Level remained at 3 (on a scale of 1-4), and the exclusion zones remained at 6 km, with an additional expansion to 7.5 km in the NNE, SE, S, and SW directions.

Aoba | Vanuatu : Based on analyses of satellite and webcam images, and model data, the Wellington VAAC reported that during 6-7 November ash plumes from Aoba rose 2.1-4.3 km (7,000-14,000 ft) a.s.l. and drifted E, NW, W, and SW.

Kirishimayama | Kyushu (Japan) : JMA reported that during 2-6 November activity at Shinmoedake (Shinmoe peak), a stratovolcano of the Kirishimayama volcano group, continued to be slightly elevated. White plumes rose 300-400 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 25 October – 31 October 2017

Aira | Kyushu (Japan) : JMA reported that sulfur dioxide flux at Aira Caldera’s Sakurajima volcano was high at 1,000 and 1,400 tons per day on 23 and 27 October, respectively. Very small events at Minamidake summit crater were detected during 24-25 and 29-30 October. A thermally anomalous area on the SE flank, near Showa Crater, was identified on 25 October using a thermal camera. The Alert Level remained at 3 (on a 5-level scale).

Bagana | Bougainville (Papua New Guinea) : Based on analyses of satellite imagery and model data, the Darwin VAAC reported that on 27 October an ash plume from Bagana rose to an altitude of 2.1 km (7,000 ft) a.s.l. and drifted E and NE.

Cleveland | Chuginadak Island (USA) : Based on satellite observations, AVO reported that the lava dome in Cleveland’s summit crater continued to grow, and by 23 October it had dimensions of 140 x 110 m. A small, 30-second-long explosion was recorded at 1045 on 28 October in seismic and infrasound data. Weather conditions were overcast with clouds at approximately 4.6 km (15,000 ft) a.s.l.; no volcanic plumes associated with the explosion were identified in satellite images emerging above the cloud level. A small explosion was recorded at 0320 on 30 October, though no ash plume was observed rising above the weather clouds at 2.4 km (8,000 ft) a.s.l. in satellite data. Slightly elevated surface temperatures were detected the next day. The Aviation colour Code remained at Orange and the Volcano Alert Level remained at Watch.

Dukono | Halmahera (Indonesia) : Based on analyses of satellite imagery, wind model data, and notices from PVMBG, the Darwin VAAC reported that during 25-31 October ash plumes from Dukono rose to an altitude of 2.1 km (7,000 ft) a.s.l. and drifted NE, E, and SE.

Ebeko | Paramushir Island (Russia) : Based on observations by volcanologists in Severo-Kurilsk (Paramushir Island), about 7 km E of Ebeko, explosions during 20-27 October generated ash plumes that rose as high as 2 km (6,600 ft) a.s.l. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Karymsky | Eastern Kamchatka (Russia) : On 27 October KVERT reported that gas-and-steam activity at Karymsky continued, and that the last ash-bearing explosions occurred on 3 October. The Aviation colour Code was lowered to Green (the lowest level on a four-colour scale).

Kilauea | Hawaiian Islands (USA) : During 25-31 October HVO reported that the lava lake continued to rise, fall, and spatter in Kilauea’s Overlook crater. Webcams recorded incandescence from long-active sources within Pu’u ‘O’o Crater and from a small lava pond in a pit on the W side of the crater. The 61G lava flow, originating from a vent on Pu’u ‘O’o Crater’s E flank, continued to enter the ocean at Kamokuna. Surface lava flows were active above the pali and on the coastal plain.

Sabancaya | Peru : Observatorio Vulcanológico del Sur del IGP (OVS-IGP) and Observatorio Vulcanológico del INGEMMET (OVI) reported that explosive activity at Sabancaya slightly decreased compared to the previous week; there was an average of 43 explosions recorded per day during 23-29 October. Seismicity was dominated by long-period events, with a relatively steady rate of signals indicating emissions and an increasing number of hybrid events. Gas-and-ash plumes rose 3.9 km above the crater rim and drifted 30 km NW, NE, E, and SE. The MIROVA system detected eight thermal anomalies. The sulfur dioxide flux was high, at 2,635 tons per day on 29 October. The report noted that the public should not to approach the crater within a 12-km radius.

Sheveluch | Central Kamchatka (Russia) : KVERT reported that a thermal anomaly over Sheveluch was identified in satellite images during 20-22 and 25 October. The Aviation colour Code remained at Orange.

Sinabung | Indonesia : Based on observations by PVMBG, satellite images, and model data, the Darwin VAAC reported that on 31 October ash plumes from Sinabung rose 4 km (13,000 ft) a.s.l.

Stromboli | Aeolian Islands (Italy) : INGV reported that a strong explosive sequence began at the vents of Stromboli’s southern crater area (Area CS) at 1604 on 23 October. The explosions ejected coarse pyroclastic material onto the Pizzo Sopra la Fossa, and produced a dense ash plume that quickly dissipated to the SE.

Turrialba | Costa Rica : OVSICORI-UNA reported that events at Turrialba at 1030, 1105, and 1445 on 30 October generated ash plumes that rose 200-500 m above the crater rim and drifted NW, W, and SW. Ashfall was reported in the community of Pacayas (about 12 km SSW). OVSICORI-UNA noted that the ash emissions from the event at 1445 rose from the reddish crater.

Ulawun | New Britain (Papua New Guinea) : Based on analyses of satellite imagery, the Darwin VAAC reported that during 26-27 October ash plumes from Ulawun rose to an altitude of 2.4 km (8,000 ft) a.s.l. and drifted 130 km S and SE.

Yasur | Vanuatu : On 31 October the Vanuatu Geohazards Observatory stated that the Alert Level for Yasur remained at 2 (on a scale of 0-4) and that, based on seismic data, explosions continued to be intense. VGO 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 25 October – 31 October 2017

Agung | Bali (Indonesia) | 8.343°S, 115.508°E | Elevation 2995 m

On 29 October PVMBG lowered the Alert level for Agung to 3 (on a scale of 1-4), noting a decline in activity, especially since 20 October. The thermal anomaly in the crater identified in satellite data was less intense in October than in September. Beginning on 20 October GPS data showed a slower deformation rate. Seismic signals decreased in number and amplitude, though low-frequency events continued to indicate magma movement. White fumarolic plumes rose as high as 500 m above the crater rim during 20-29 October; a comparison of video taken by drones on 20 and 29 October showed a relative decrease in the intensity of fumarolic emissions. BNPB stated that, despite the decreased Alert Level, the exclusion zones remained intact (at 6 km, and an additional expansion to 7.5 km in the NNE, SE, S, and SW directions). The number of evacuees was 133,457 (spread out in 385 shelters).

Aoba | Vanuatu : Based on analyses of satellite imagery and model data, the Wellington VAAC reported that on 29 October ash plumes from Aoba rose 6.1 km (20,000 ft) a.s.l. and drifted S and SE.

Kirishimayama | Kyushu (Japan) : JMA reported that during 25-31 October activity at Shinmoedake (Shinmoe peak), a stratovolcano of the Kirishimayama volcano group, continued to be slightly elevated. White plumes rose 100-500 m above the crater rim, though weather clouds sometimes prevented visual observations. Almost daily field surveys revealed no particular changes in the fumarolic and fissure areas near the cracks on the W flank of Shinmoedake, nor to the thermally anomalous zone below the crack. Sulfur dioxide fluxes were as high as 200 tons/day. The Alert Level remained at 3 (on a scale of 1-5).

Sarychev Peak | Matua Island (Russia) : SVERT reported that a thermal anomaly over Sarychev Peak was identified in satellite images on 29 October. Weather clouds prevented observations on the other days during 24-30 October. The Aviation colour Code remained at Green.

Tinakula | Solomon Islands : Based on satellite data and information from ground-based observers, the Wellington VAAC reported that during 25 October and the early part of 26 October a low-level eruption at Tinakula was ongoing. Ash emission rose 2.1 km (7,000 ft) a.s.l. and drifted S and SE. A news article from 1 November noted that significant ashfall had covered crops, and the water supplies for an estimated 11,500 people had been contaminated.

Volcanos

Roundup of Global Volcanic Activity – Ongoing Activity for the week of 18 October – 24 October 2017

Aira | Kyushu (Japan) : JMA reported that a very small event at Showa Crater (at Aira Caldera’s Sakurajima volcano) was detected on 17 October. The Alert Level remained at 3 (on a 5-level scale).

Cleveland | Chuginadak Island (USA) : AVO reported that the lava dome in Cleveland’s summit crater continued to grow, and by 15 October it covered an area of about 9,500 square meters with dimensions of 125 x 100 m. No significant change in the size of the dome was identified in satellite data from 15 to 19 October. During 16 and 21-23 October satellite data showed moderately elevated surface temperatures and a small steam plume was visible in web camera images. The Aviation colour Code remained at Orange and the Volcano Alert Level remained at Watch.

Dukono | Halmahera (Indonesia) : Based on analyses of satellite imagery, wind model data, and notices from PVMBG, the Darwin VAAC reported that during 19-20 and 22-23 October ash plumes from Dukono rose to altitudes of 1.5-2.1 km (5,000-7,000 ft) a.s.l. and drifted NNE, NE, and E.

Ebeko | Paramushir Island (Russia) : Based on observations by volcanologists in Severo-Kurilsk (Paramushir Island), about 7 km E of Ebeko, explosions during 13-20 October generated ash plumes that rose as high as 2.5 km (8,200 ft) a.s.l. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Karymsky | Eastern Kamchatka (Russia) : On 19 October KVERT reported that gas-and-steam activity at Karymsky continued, and that quiet or cloudy conditions had been observed in satellite data since 3 October. The Aviation colour Code was lowered to Yellow (the second highest level on a four-colour scale).

Kilauea | Hawaiian Islands (USA) : During 18-24 October HVO reported that the lava lake continued to rise, fall, and spatter in Kilauea’s Overlook crater. Webcams recorded incandescence from long-active sources within Pu’u ‘O’o Crater and from a small lava pond in a pit on the W side of the crater. The 61G lava flow, originating from a vent on Pu’u ‘O’o Crater’s E flank, continued to enter the ocean at Kamokuna. Surface lava flows were active above the pali and on the coastal plain.

Langila | New Britain (Papua New Guinea) : Based on analyses of satellite imagery and wind model data, the Darwin VAAC reported that during 17-18 and 20 October ash plumes from Langila rose 1.5-1.8 km (5,000-6,000 ft) a.s.l. and drifted S, W, and NW.

Sabancaya | Peru : Observatorio Vulcanológico del Sur del IGP (OVS-IGP) and Observatorio Vulcanológico del INGEMMET (OVI) reported that explosive activity at Sabancaya slightly increased compared to the previous week; there was an average of 47 explosions recorded per day during 16-22 October. Seismicity was dominated by long-period events, with an increase in signals indicating emissions and a low number of hybrid events. Gas-and-ash plumes rose 3.8 km above the crater rim and drifted 60 km NE, E, and SE. The MIROVA system detected four thermal anomalies. The report warned the public not to approach the crater within a 12-km radius.

Sheveluch | Central Kamchatka (Russia) : KVERT reported that a plume comprised of re-suspended ash drifted about 230 km SE from the vicinity of the Sheveluch on 13 October. A thermal anomaly was identified in satellite images during 15-19 October. The Aviation colour Code remained at Orange.

Sinabung | Indonesia : Based on observations by PVMBG, webcam and satellite images, and model data, the Darwin VAAC reported that during 17-18 and 21-23 October ash plumes from Sinabung rose 2.4-4.6 km (8,000-15,000 ft) a.s.l. and drifted in multiple directions.

Turrialba | Costa Rica : OVSICORI-UNA reported that an event at Turrialba at 0825 on 20 October generated 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 18 October – 24 October 2017

Agung | Bali (Indonesia) : PVMBG reported that although foggy conditions at Agung occasionally prevented visual observations, during 18-24 October dense white plumes were seen rising as high as 500 m above the crater rim. Seismicity fluctuated but remained high, though BNPB reported that overall seismicity had decreased. According to BNPB a team launched a drone on 19 October and were able to capture video of the fumarolic emissions from several vents and cracks in the crater. The Alert Level remained at 4 (the highest level on a scale of 1-4) with the exclusion zone at 9 km, and an additional expansion to 12 km in the SE, S, and SW directions.

Aoba | Vanuatu : According to a news article posted on 20 October, residents that had evacuated from Aoba after the eruption from a vent in Lake Voui were returning home. Based on analyses of satellite imagery and model data, the Wellington VAAC reported that during 22-23 October intermittent events generated low-level ash plumes that rose 2.4-3.7 km (8,000-12,000 ft) a.s.l. and drifted E.

Kirishimayama | Kyushu (Japan) : JMA reported that the eruption at Shinmoe-dake (Shinmoe peak), a stratovolcano of the Kirishimayama volcano group, began on 11 October and lasted almost continuously until the morning of 17 October. The eruption plume usually rose several hundred meters about the crater rim, though on 14 October the plume rose as high as 2.3 km. Sulfur dioxide flux exceeding 10,000 tons/day was also recorded. Cloudy weather conditions prevented webcam views during 19-20 October. Plumes rose 200-600 m on 21, 23, and 24 October. During an overflight on 24 October scientists observed a white plume rising from the active vent on the E side of the crater, and puddles in multiple low areas of the crater. The Alert Level remained at 3 (on a scale of 1-5).

Tinakula | Solomon Islands : Based on satellite data, the Wellington VAAC reported that an eruption at Tinakula began around 0620 on 21 October, producing a sulfur dioxide signature, and an ash plume that rose to an altitude of 4.6 km (15,000 ft) a.s.l. and drifted N. Another eruption at 1040 generated an ash plume that rose significantly higher that the first, to an altitude of 10.7 (35,000 ft) a.s.l. and drifted SE. Later that day ash plumes rose to 6.1 km (20,000 ft) a.s.l. Ash emissions continued through at least 24 October, rising to altitudes of 3-3.7 (10,000-12,000 ft) a.s.l. and drifting E and W on 22 October, 2.4 km (8,000 ft) a.s.l. and drifting S and SE on 23 October, and 1.8 km (6,000 ft) a.s.l. with a SW drift on 24 October. A news article from 24 October stated that water supplies in the Reef Islands had been contaminated with ashfall, and that ashfall was also reported in Fenualoa, and likely in Nupani.

Volcanos

Roundup of Global Volcanic Activity – Ongoing Activity for the week of 11 October – 17 October 2017

Aira | Kyushu (Japan) : JMA reported that during 10-16 October there were 18 events detected at Showa Crater (at Aira Caldera’s Sakurajima volcano), two of which were explosive. Plumes rose as high as 1.9 km above the crater rim, and material was ejected as far as 800 m. The Alert Level remained at 3 (on a 5-level scale).

Cleveland | Chuginadak Island (USA) : On 13 October AVO reported that the lava dome in Cleveland’s summit crater, first observed in satellite data on 30 September, had doubled in size during 1-11 October. The lava dome covered an area of 8,300 square meters, and had approximate dimensions of 115 x 95 m. The number and intensity of elevated surface temperatures identified in satellite data had declined during the week, possibly indicating slowed or paused dome growth. A small steam plume was observed in mostly clear web camera views during 15-16 October, and moderately elevated surface temperatures were identified in satellite images on 16 October; these observations suggested continuing dome growth. The Aviation colour Code remained at Orange and the Volcano Alert Level remained at Watch.

Dukono | Halmahera (Indonesia) : Based on analyses of satellite imagery, wind model data, and notices from PVMBG, the Darwin VAAC reported that during 11-14 October ash plumes from Dukono rose to an altitude of 2.1 km (7,000 ft) a.s.l. and drifted SE, E, and NE.

Ebeko | Paramushir Island (Russia) : Based on observations by volcanologists in Severo-Kurilsk (Paramushir Island), about 7 km E of Ebeko, explosions during 6-7, 9, and 12 October generated ash plumes that rose as high as 3 km (10,000 ft) a.s.l. Ash fell in Severo-Kurilsk on 7, 9, and 12 October. Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Karymsky | Eastern Kamchatka (Russia) : KVERT reported that a plume comprised of re-suspended ash was identified in satellite images drifting about 320 km E from Karymsky during 11-12 October. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Kilauea | Hawaiian Islands (USA) : During 11-17 October HVO reported that the lava lake continued to rise, fall, and spatter in Kilauea’s Overlook crater. Webcams recorded incandescence from long-active sources within Pu’u ‘O’o Crater and from a small lava pond in a pit on the W side of the crater. The 61G lava flow, originating from a vent on Pu’u ‘O’o Crater’s E flank, continued to enter the ocean at Kamokuna. Surface cracks on the delta that had been covered up by new flows had begun to reemerge and become visible. Surface lava flows were active above and on the pali, and on the coastal plain.

Langila | New Britain (Papua New Guinea) : Based on analyses of satellite imagery and wind model data, the Darwin VAAC reported that during 11 and 15-16 October ash plumes from Langila rose 1.8-2.1 km (6,000-7,000 ft) a.s.l. and drifted NE, NNW, and NW.

Nevados de Chillan : Servicio Nacional de Geología and Minería (SERNAGEOMIN) Observatorio Volcanológico de Los Andes del Sur (OVDAS) reported that a series of six pulsating gas-and-tephra emissions from low-energy explosions began at 0843 on 11 October. The plumes rose 1 km and drifted SW. The Alert Level remained at Yellow, the middle level on a three-colour scale, and the public was reminded not to approach the craters within a 3-km radius.

Pacaya | Guatemala : INSIVUMEH reported that during 13-14 October Strombolian explosions at Pacaya’s Mackenney cone ejected material as high as 25 m above the crater rim.

Sabancaya | Peru : Observatorio Vulcanológico del Sur del IGP (OVS-IGP) and Observatorio Vulcanológico del INGEMMET (OVI) reported that explosive activity at Sabancaya was similar to the previous week; there was an average of 41 explosions recorded per day during 9-15 October. The earthquakes were dominated by long-period events, with fewer numbers of signals indicating emissions and hybrid events. Gas-and-ash plumes rose 3.1 km above the crater rim and drifted more than 35 km S and SE. The MIROVA system detected four thermal anomalies. The report warned the public not to approach the crater within a 12-km radius.

Sangay | Ecuador : The Washington VAAC reported that during 12-13 October ash emissions from Sangay rose to an altitude of 6.1 km (20,000 ft) a.s.l. and drifted S.

Santa Maria | Guatemala : INSIVUMEH reported that on 11 October a moderate lahar descended the Cabello de Ángel and the Nimá I drainages, both tributaries of the Salama river. During 12-13 October ash plumes generated by explosions rose 500 m above the crater rim and drifted SE, causing ashfall in Finca San José. Avalanches of material descended the SE part of the lava dome. On 13 October the seismic network detected moderate-to-strong lahars in the Cabello de Ángel and the Nimá I drainages triggered by heavy rain. Explosions during 13-14 October produced ash plumes that drifted SW, causing ashfall in La Florida (5 km S) ranch. Ash plumes from explosions detected during 15-16 October rose 600 m and drifted S. Ash fell locally around the volcano. Avalanches of material descended the NE and SE parts of the lava dome.

Sheveluch | Central Kamchatka (Russia) : KVERT reported that a thermal anomaly over Sheveluch was identified in satellite images during 9-11 October. Explosions on 10 October generated ash plumes that rose 10 km (32,800 ft) a.s.l. and drifted about 250 km N. A plume comprised of re-suspended ash drifted about 350 km SE from the vicinity of the volcano on 12 October. The Aviation colour Code remained at Orange.

Sinabung | Indonesia : BNPB stated that at 1051 on 11 October an event at Sinabung generated an ash plume that rose 1.5 km above the crater and drifted ESE, causing ashfall in several local villages. At 0245 on 12 October an event produced an ash plume that rose 2 km above the crater, and was followed by pyroclastic flows traveling 1.5 and 2 km down the S and ESE flanks, respectively. The report noted that activity remained high. Based on observations by PVMBG and information from the Jakarta MWO, the Darwin VAAC reported that during 13-15 October ash plumes rose as high as 3 km above the crater. The Alert Level remained at 4 (on a scale of 1-4), with an exclusion zone of 7 km from the volcano on the SSE sector, and 6 km in the ESE sector, and 4 km in the NNE sector.

Suwanosejima | Ryukyu Islands (Japan) : Based on JMA notices and satellite data, the Tokyo VAAC reported that on 11 October an explosion at Suwanosejima generated a plume that rose 2.7 km (9,000 ft) a.s.l. and drifted NE.

Turrialba | Costa Rica : OVSICORI-UNA reported that an event at Turrialba at 0927 on 11 October generated an ash plume that rose 200 m above the crater rim and drifted N.

Volcanos

Roundup of Global Volcanic Activity – New Activity for the week of 11 October – 17 October 2017

Agung | Bali (Indonesia) : PVMBG reported that although foggy conditions at Agung sometimes prevented visual observations, during 11-17 October dense white plumes were seen rising 200 m above the crater rim. On 14 October BNPB stated that seismicity remained high; PVMBG noted that seismicity was dominated by shallow volcanic events, and the number of volcanic earthquakes remained steady. The governor of Bali extended the state of emergency to 26 October, noting that the Alert Level remained at 4 (the highest level on a scale of 1-4). The number of evacuees was 139,199 (spread out in 389 shelters).

Ambrym | Vanuatu : The Vanuatu Geohazards Observatory (VGO) reported that aerial observations of Ambrym on 24 and 30 September, and 1 and 6 October, and the analysis of seismic data, confirmed that minor eruptive activity within the caldera was characterized by hot volcanic gas and steam emissions. The Alert Level remained at 3 (on a scale of 0-5). Areas deemed hazardous were within a 2-km radius from Benbow Crater and a 3-km radius from Marum Crater.

Aoba | Vanuatu : Based on analyses of satellite, video, and model data, the Wellington VAAC reported that during 13-14 October ash plumes from Aoba rose 2.1-4.6 km (7,000-15,000 ft) a.s.l. and drifted NW, N, and NE, though a short-lived event generated ash plumes that rose as high as 9.1 (30,000 ft) a.s.l.

Kirishimayama | Kyushu (Japan) : JMA reported that an eruption at Shinmoedake (Shinmoe peak), a stratovolcano of the Kirishimayama volcano group, began at 0534 on 11 October, prompting the agency to raise the Alert Level to 3 (on a scale of 1-5). Ash plumes rose 300 m above the crater rim (2 km a.s.l.) and drifted NE, though some news sources stated that plumes rose 2 km above the crater rim. Volcanic-tremor amplitude increased and inflation was detected. Ashfall was noted in at least four towns in the Miyazaki and Kagoshima prefectures. On 12 October ash plumes rose as high as 2 km. Based on JMA notices, pilot observations, and satellite data, the Tokyo VAAC reported that ash plumes rose 1.8-2.1 (6,000-7,000 ft) a.s.l. on 11 October and 3.4 km (11,000 ft) a.s.l. on 12 October. Gas measurements taken during field surveys on 12 and 13 October showed that the sulfur dioxide flux was 1,400 tons/day, an increase from 800 tons/day measured on 11 October. Volcanic tremor fluctuated but the amplitude was slightly lower. During 0823-1420 on 14 October an event produced a tall plume which rose 2.3 km above the crater rim. Another event, at 1505, generated a grayish-white plume that rose 1 km and then blended into the weather clouds. Ashfall was reported in Kirishima and Sono in the Kagoshima prefecture, and from Kobayashi in the Miyazaki prefecture to Hyuga city. An event was detected at 1300 on 15 October, and an increase in low-frequency earthquakes was recorded on 16 October.

Lewotolo | Lomblen Island (Indonesia) : PVMBG reported that white plumes rose as high as 50 m above Lewotolo’s summit crater rim. The Alert Level remained at 2 (on a scale of 1-4).

Sarychev Peak | Matua Island (Russia) : A NOAA/NESDIS scientist noted that a thermal anomaly at Sarychev Peak was identified in satellite images on 12 October. Robust thermal anomalies were identified on 14 October, and were accompanied by a plume of unknown composition. Thermal anomalies were also recorded by the MODVOLC and MIROVA thermal detection systems.

Volcanos

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

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

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

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

Dukono | Halmahera (Indonesia) : Based on analyses of satellite imagery, model data, and notices from PVMBG, the Darwin VAAC reported that during 4-10 October ash plumes from Dukono rose to altitudes of 1.8-2.1 km (6,000-7,000 ft) a.s.l. and drifted N, NW, W, and SW. Ash plumes drifted 140-170 km on 8 October.

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

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

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

Kilauea | Hawaiian Islands (USA) : During 4-10 October HVO reported that the lava lake continued to rise, fall, and spatter in Kilauea’s Overlook crater. Webcams recorded incandescence from long-active sources within Pu’u ‘O’o Crater and from a small lava pond in a pit on the W side of the crater. The 61G lava flow, originating from a vent on Pu’u ‘O’o Crater’s E flank, continued to enter the ocean at Kamokuna although the plume at the entry was weaker. Surface lava flows were active above and on the pali, and on the coastal plain.

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

Reventador | Ecuador : During 3-10 October IG reported a high level of seismic activity including explosions, long-period earthquakes, harmonic tremor, and signals indicating emissions at Reventador. Steam, gas, and ash plumes rose sometimes higher that 1.1 km above the crater rim and drifted mainly NW, W, and SW. Incandescent blocks rolled as far as 800 m down the flanks. Weather clouds sometimes prevented visual observations.

Rincon de la Vieja | Costa Rica : OVSICORI-UNA reported that at 1048 on 9 October a small eruption at Rincón de la Vieja produced a plume that rose 700 m above the crater rim.

Sabancaya | Peru : Observatorio Vulcanológico del Sur del IGP (OVS-IGP) and Observatorio Vulcanológico del INGEMMET (OVI) reported that explosive activity at Sabancaya slightly declined; there was an average of 42 explosions recorded per day during 2-8 October. The earthquakes were dominated by long-period events, with fewer numbers of signals indicating emissions and hybrid events. Gas-and-ash plumes rose 3.5 km above the crater rim and drifted no more than 40 km N, NW, and W. The MIROVA system detected 10 thermal anomalies. The report warned the public not to approach the crater within a 12-km radius.

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

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

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

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

Volcanos

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

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

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

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

Volcanos

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

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

Bezymianny | Central Kamchatka (Russia) : KVERT reported that during 22-29 September lava continued to flow down the W flank of Bezymianny’s dome, and incandescence from the dome was visible at night. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Bogoslof | Fox Islands (USA) : On 27 September AVO reported that the last explosion at Bogoslof was detected on 30 August, and no new volcanic activity was observed in satellite, seismic, or infrasound data since then. The Aviation colour Code was lowered to Yellow and the Volcano Alert Level was lowered to Advisory.

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

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

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

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

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

Kilauea | Hawaiian Islands (USA) : During 27 September-3 October HVO reported that the lava lake continued to rise, fall, and spatter in Kilauea’s Overlook crater. Webcams recorded incandescence from long-active sources within Pu’u ‘O’o Crater and from a small lava pond in a pit on the W side of the crater. The 61G lava flow, originating from a vent on Pu’u ‘O’o Crater’s E flank, continued to enter the ocean at Kamokuna, although during 1-3 October the plume at the entry waxed and waned. Surface lava flows were active above and on the pali, and on the coastal plain.

Popocatepetl | Mexico : Each day during 26 September-3 October CENAPRED reported 21-61 emissions from Popocatépetl and 2-6 volcano-tectonic earthquakes. Cloud cover often prevented visual observations. Periods of harmonic tremor and as many as 10 explosions per day were detected during 26-30 September. Beginning at 0315 on 27 September an episode of Strombolian activity that lasted for six hours and sixteen minutes ejected incandescent tephra as far as 1 km onto the flanks. Ash plumes rose 1.5 km above the crater rim and drifted W. Ash fell in the towns of Ecatzingo and Atlautla in Estado de México, and in Atlatlahuacán, Ocuituco, Oaxtepec, Jiutepec, and Yautepec in Estado de Morelos. An explosion at 2257 on 30 September ejected incandescent tephra no more than 800 m onto the flanks, and produced an ash plume that rose 2 km. An explosion was detected at 1417 on 3 October. The Alert Level remained at Yellow, Phase Two. CENAPRED stated that there was no significant increase in activity at Popocatépetl related to the M 7.1 earthquake, centered beneath Puebla (45 km E), that occurred at 1314 on 19 September.

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

Sabancaya | Peru : Observatorio Vulcanológico del Sur del IGP (OVS-IGP) and Observatorio Vulcanológico del INGEMMET (OVI) reported that explosive activity at Sabancaya increased; there was an average of 45 explosions recorded per day during 25 September-1 October. The earthquakes were dominated by long-period events, with fewer numbers of signals indicating emissions and hybrid events. Gas-and-ash plumes rose 3.5 km above the crater rim and drifted no more than 40 km E and NE. The MIROVA system detected seven thermal anomalies. The report warned the public not to approach the crater within a 12-km radius.

Sheveluch | Central Kamchatka (Russia) : KVERT reported that a thermal anomaly over Sheveluch was identified daily in satellite images during 22-29 September. The Aviation colour Code remained at Orange.

Sinabung | Indonesia : Based on observations by PVMBG, webcam and satellite images, and model data, the Darwin VAAC reported that during 27-29 September and 1-2 October ash plumes from Sinabung rose 3.7-5.5 km (12,000-18,000 ft) a.s.l. and drifted in multiple directions.

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

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

Volcanos

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

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

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

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