Volcanos

Roundup of Global Volcanic Activity – Ongoing Activity for the week of 4 July – 10 July 2018

Aira | Kyushu (Japan) : JMA reported that there were two events and three explosions at Minamidake crater (at Aira Caldera’s Sakurajima volcano) during 2-9 July, with ash plumes rising as high as 1.3 km above the crater rim and material ejected as far as 1.1 km. Crater incandescence was sometimes visible at night. The Alert Level remained at 3 (on a 5-level scale).

Cleveland | Chuginadak Island (USA) : AVO reported that unrest at Cleveland continued during 4-10 July, though nothing significant was detected in seismic or infrasound data. Meteorological cloud cover often prevented views of the crater. Weakly elevated surface temperatures were identified in satellite images during 7 and 9-10 July; a small steam cloud was visible on 7 July. The Aviation colour Code remained at Orange and the Volcano Alert Level remained at Watch.

Dukono | Halmahera (Indonesia) : Based on PVMBG observations and satellite data, the Darwin VAAC reported that during 4-10 July ash plumes from Dukono rose to altitudes of 1.5-2.1 km (5,000-7,000 ft) a.s.l. and drifted N, NE, and E.

Ebeko | Paramushir Island (Russia) : Volcanologists in Severo-Kurilsk (Paramushir Island), about 7 km E of Ebeko, observed explosions during 30 June-1 July that sent ash plumes as high as 3.2 km (10,500 ft) a.s.l. Satellite data showed ash plumes drifting 57 km SE on 1 July. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Fuego | Guatemala : INSIVUMEH and CONRED reported relatively quiet conditions at Fuego during 4-9 July characterized mainly by gas emissions and block avalanches on the flanks. During 7-8 July there was about one explosion detected every two hours, producing diffuse ash plumes that rose 500 m above the crater and drifted SW. Block avalanches descended the Seca (W), Cenizas (SSW), and Las Lajas (SE) drainages, while lahars were present in the El Jute (SE), Las Lajas, Cenizas, Taniluyá (SW), Seca, Mineral, and Pantaleón (W) drainages. Seismicity increased on 10 July. Explosions generated ash plumes that rose 2.3 km and drifted 12 km SE, causing ashfall in Morelia (9 km SW) and Panimaché (8 km SW). According to CONRED, as of 4 July, the number of people confirmed to have died due to the 3 June pyroclastic flows was 113, and 332 remained missing.

Kilauea | Hawaiian Islands (USA) : HVO reported that the eruption at Kilauea’s Lower East Rift Zone (LERZ) and at Overlook Crater within Halema`uma`u Crater continued during 4-10 July. Lava fountaining and spatter was concentrated at Fissure 8, feeding lava flows that spread through Leilani Estates and Lanipuna Gardens subdivisions, and built out the coastline at multiple ocean entries. Fissure 22 produced spattering 50-80 m above its spatter cone and fed short lava flows that traveled NE on 4 July; weak spattering was visible form the cone the rest of the week.

Inward slumping of the crater rim and walls of Halema`uma`u continued, adjusting from the withdrawal of magma and subsidence of the summit area. Explosions from collapse events occurred almost daily, producing gas-and-ash-poor plumes.

Fountaining at Fissure 8 continued; lava fountains rarely rose higher than the 55-m-high spatter cone. Pele’s hair and other volcanic glass from the fountaining fell within Leilani Estates. The fountains continued to feed the lava flow that traveled NE, and then SE around Kapoho Crater. Occasional overflows sent small flows down the sides of the channel that did not extend beyond areas previously covered in lava in the upper part of the channel; overflows further down traveled beyond the flow-field boundary. Small brush fires were ignited from some of the overflows. A thermal map from 6 July showed that lava was not entering the ocean from the main channel and that the open channel ended about 2 km inland. Lava was flowing into the ocean at the N part of the broad flow front. Observations on 9 July indicated that a blockage had formed upstream of Kapoho Crater, and by 10 July a small lobe was moving around the W side of the crater.

Pacaya | Guatemala : INSIVUMEH reported that during 5-10 July Strombolian explosions at Pacaya’s Mackenney Crater ejected material as high as 30 m above the crater rim. White gas plumes drifted SW. A lava flow originating from Mackenney Crater traveled 500 m down the N flank during 7-8 July, reaching the volcano’s base.

Sabancaya | Peru : Observatorio Vulcanológico del Sur del IGP (OVS-IGP) and Observatorio Vulcanológico del INGEMMET (OVI) reported that explosions at Sabancaya averaged 22 per day during 2-8 July. Hybrid earthquakes were infrequent and low magnitude. Gas-and-ash plumes rose as high as 2.5 km above the crater rim and drifted 30 km S, SE, and E. The MIROVA system detected nine thermal anomalies, and on 3 July the sulfur dioxide gas flux was high at 4,715 tons/day. The report noted that the public should not approach the crater within a 12-km radius.

Santa Maria | Guatemala : INSIVUMEH reported that during 5-10 July explosions at Santa María’s Santiaguito lava-dome complex generated ash plumes that rose 200-700 m and drifted SW and W. Local ashfall was reported. Avalanches of material descended the SE and W flanks of the lava dome.

Sheveluch | Central Kamchatka (Russia) : KVERT reported that a weak thermal anomaly over Sheveluch was identified in satellite images during 4-5 July. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

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Volcanos

Roundup of Global Volcanic Activity – New Activity for the week of 27 June – 3 July 2018

Agung | Bali (Indonesia) : PVMBG reported that seismicity at Agung continued to be dominated by low-frequency events. The number of earthquakes increased from 15/day on 25 June to 69/day on 28 June; harmonic tremor emerged on 27 June, and at 2221 an event generated an ash plume that rose 2 km above the crater rim and drifted W. Gas-and-ash emissions were continuous during 28-29 June, rising around 2 km and drifting W and SW, and incandescence was reflected in the plume; satellite data confirmed that high-temperature (1,200 degrees Celsius) lava flowed onto the crater floor. The intensity of the thermal anomaly on 29 June was the largest recorded at Agung since the beginning of the eruption on 21 November 2017.

BNPB noted that the ash plumes on 28 June caused some airlines to cancel flights to Bali, and ashfall was reported in several villages on Bangli. The International Gusti Ngurah Rai (IGNR) airport (60 km SW) in Denpasar, the Blimbing Sari Airport (128 km W) in Banyuwangi, and the Noto Hadinegoro Airport (200 km W) in Jember closed for portions of the day on 29 June.

Lava continued to effuse, and by 1 July the estimated volume of new lava was 4-5 million cubic meters making the total volume erupted since 21 November 2017 around 27-28 million cubic meters (50% of the total crater volume). The height difference between the lowest part of the crater rim (SW side) and the highest part of the lava surface (in the center of the crater) was 85-90 m. Satellite data showed that the intensity of the thermal anomaly decreased during 28 June-2 July, though still remained at a high level. At 2104 on 2 July an explosion generated an ash plume that rose 7-9 km above the crater rim, and ejected incandescent lava as far as 2 km onto the flanks. News articles noted that the deposits caused forest fires on the upper flanks, and that the event prompted about 700 people to evacuate. An event at 0413 on 3 July generated an ash plume that rose around 2 km. The Alert Level remained at 3 (on a scale of 1-4) and the exclusion zone was stable at a 4-km radius.

Great Sitkin | Andreanof Islands (USA) : AVO reported that after the brief explosion at Great Sitkin on 10 June seismicity gradually declined to background levels. On 27 June AVO lowered the Volcano Alert Level to Normal and the Aviation colour Code to Green.

Ibu | Halmahera (Indonesia) : Based on satellite images and model data, the Darwin VAAC reported that on 27 June an ash plume from Ibu rose to 1.8 km (6,000 ft) a.s.l. and drifted W. The Alert Level remained at 2 (on a scale of 1-4), and the public was warned to stay at least 2 km away from the active crater, and 3.5 km away on the N side.

Krakatau | Indonesia : PVMBG reported that white plumes were seen rising as high as 100 m above Anak Krakatau during infrequent periods of clear weather from 27 June to 3 July. Incandescence from the summit was observed at night during 1-2 July. The Alert Level remained at 2 (on a scale of 1-4); residents and visitors were warned not to approach the volcano within 1 km of the crater.

Sierra Negra | Isla Isabela (Ecuador) : Based on video and photos shared by Parque Nacional Galápagos staff, IG reported that the eruption at Sierra Negra that began at 1340 on 26 June originated from several fissures on the N flank and one within the caldera. The flank flows reached the sea between Elizabeth Bay and Punta Morena. A gas-and-ash plume rose about 10.5 km and drifted W. Seismic and acoustic data indicated a gradual decrease but continuing activity on 27 June. A small seismic event was recorded at 1552 on 1 July, followed by at least four hours of tremor. At 1600 national park staff observed lava flows on the NW flank.

Yasur | Vanuatu : The Vanuatu Meteorology and Geo-hazards Department reported some stronger explosions at Yasur during 27-28 June. Based on webcam images the Wellington VAAC reported that on 29 June intermittent, low-level ash plumes rose to an altitude of 1.8 km (6,000 ft) a.s.l. and drifted NW. The Alert Level remained at 2 (on a scale of 0-4). 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 – Ongoing Activity for the week of 20 June – 26 June 2018

Aira | Kyushu (Japan) : JMA reported that there were four events and one explosion at Minamidake crater (at Aira Caldera’s Sakurajima volcano) during 18-25 June, with ash plumes rising as high as 1.9 km above the crater rim. Crater incandescence was visible at night on 18 June. The Alert Level remained at 3 (on a 5-level scale).

Cleveland | Chuginadak Island (USA) : AVO reported that a satellite image of Cleveland acquired on 25 June showed a small, circular lava flow about 80 m in diameter in the summit crater. The presence of a flow over the active vent increases the chances of an explosion, so AVO raised the Aviation colour Code to Orange and the Volcano Alert Level to Watch.

Copahue | Central Chile-Argentina border : The Buenos Aires VAAC reported that on 24 June diffuse steam emissions with possible ash were visible in webcam views rising to an altitude of 3.6 km (12,000 ft) a.s.l.

Dukono | Halmahera (Indonesia) : Based on PVMBG observations and satellite data, the Darwin VAAC reported that during 20-26 June ash plumes from Dukono rose to altitudes of 1.8-2.1 km (6,000-7,000 ft) a.s.l. and drifted NW, W, and SW.

Ebeko | Paramushir Island (Russia) : KVERT reported that on 15 June an ash plume from Ebeko was visible in satellite images drifting 14 km SE. Video data from SVERT and KBGS RAS (Kamchatka Branch, Geophysical Service, Russian Academy of Sciences) showed ash explosions during 17-18 June that sent ash plumes to 2.5-3 km (8,200-10,000 ft) a.s.l. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Fuego | Guatemala : INSIVUMEH and CONRED reported that during 20-26 June multiple lahars at Fuego were often hot, steaming, and had a sulfur odor, and were generated from heavy rains and the recent accumulation of pyroclastic-flow deposits from the 3 June events. Lahars remained a significant hazard, and descended the Cenizas (SSW), Las Lajas (SE), Santa Teresa (W), and Taniluyá (SW) drainages. They were 25-45 m wide, as deep as 3 m, and often carried blocks up to 3 m in diameter, tree trunks, and branches. The agencies warned that because the Las Lajas drainage is full of deposits, lahars can continue to descend that drainage or create new channels in San Miguel Los Lotes (one of the hardest-hit areas).

Explosions continued, producing ash plumes that rose as high as 1.3 km above the crater and drifted as far as 15 km in multiple directions. Ashfall was reported in Panimache, Morelia, Sangre de Cristo, and finca Palo Verde on 22 June. Avalanches of material descended the SE, S, and W flanks (Santa Teresa, Las Lajas, and Cenizas drainages). According to CONRED, as of 26 June, the number of people confirmed to have died due to the 3 June pyroclastic flows was 112, and 197 more were missing. In addition, 12,823 remained evacuated.

Kilauea | Hawaiian Islands (USA) : HVO reported that the eruption at Kilauea’s Lower East Rift Zone (LERZ) and at Halema`uma`u Crater continued during 20-26 June. Lava fountaining and spatter was concentrated at Fissure 8, feeding lava flows that spread through Leilani Estates and Lanipuna Gardens subdivisions, and built out the coastline where the fast-moving flow entered the ocean in the area of the former Kapoho Bay. Fissure 16/18 was often incandescent, and lava effusion was visible at Fissure 6 on 21 June. Fissure 22 produced weak lava fountains on 22 June, and weak spattering and small lava flows on 26 June.

Inward slumping of the crater rim and walls of Halema`uma`u continued, adjusting from the withdrawal of magma and subsidence of the summit area. Steam plumes rose from areas in the crater as well as from circumferential cracks adjacent to the crater. Explosions from collapse events occurred daily, producing gas-and-ash-poor plumes that rose less than 1.8 km (6,000 ft) a.s.l. and drifted SW. On 24 June HVO noted that since late May these plumes rarely rose higher than 3 km (10,000 ft) a.s.l. where they can cause an aviation hazard; the Aviation colour Code was reduced to Orange.

Fountaining at Fissure 8 continued; lava fountains rose occasionally higher than the 55-m-high spatter cone. Pele’s hair and other volcanic glass from the fountaining fell within Leilani Estates. The fountains continued to feed the fast-moving lava flow that traveled NE, and then SE around Kapoho Crater, and into the ocean. Occasional overflows sent small flows down the sides of the channel. The lava-flow front at the ocean was almost 3.2 km wide by 25 June, with lava entering the ocean on the S side of the flow front mainly through an open channel, but also along a 1-km-long area marked with billowing laze plumes.

Kirishimayama | Kyushu (Japan) : JMA reported that at Shinmoedake (Shinmoe peak), a stratovolcano of the Kirishimayama volcano group, an explosive eruption at 0909 on 22 June generated an ash plume that rose 2.6 km above the crater rim and drifted E. Tephra was ejected 1.1 km away, and shock waves were felt in the Miyazaki region. Minor amounts of ash fell in Kirishima prefecture and Kagoshima prefecture to the S, Miyakonojo city (Miyazaki prefecture) to the E, and Takahara Town. The Alert Level remained at 3 (on a scale of 1-5).

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

Langila | New Britain (Papua New Guinea) : Based on analyses of satellite imagery and model data, the Darwin VAAC reported that during 20-21 June ash plumes from Langila rose to an altitude of 2.4 km (8,000 ft) a.s.l. and drifted W and NW.

Mauna Loa | Hawaiian Islands (USA) : On 21 June HVO reported that seismicity and deformation at Mauna Loa had been at near-background levels for at least the previous six months. The Aviation colour Code was lowered to Green and the Volcano Alert Level was lowered to Normal. During 2014 through most of 2017 seismicity was variable but elevated, and ground deformation was consistent with an influx of magma in the shallow reservoir.

Nishinoshima | Japan : JMA reported that seismic, thermal, RADAR, and sulfur dioxide data all showed no eruptive activity at Nishinoshima since mid-August 2017. During an overflight on 14 June the Japan Coast Guard noted white fumarolic plumes rising about 20 m from the E side of main cone’s inner wall and from the center of the crater. Ocean water all around the island was discoloured, especially in the N-to-NW quadrant where the yellowish brown water extended 200-300 m from the shore. On 20 June the JMA reduced the warning level for the island, specifying hazards were less severe “around the crater” (encompassing areas within 500 m).

Sabancaya | Peru : Observatorio Vulcanológico del Sur del IGP (OVS-IGP) and Observatorio Vulcanológico del INGEMMET (OVI) reported that explosions at Sabancaya averaged 29 per day during 18-24 June. Hybrid earthquakes were infrequent and low magnitude. Gas-and-ash plumes rose as high as 1.8 km above the crater rim and drifted 30 km S, SE, and E. The MIROVA system detected 11 thermal anomalies, and on 21 June the sulfur dioxide gas flux was high at 4,900 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 weak thermal anomaly over Sheveluch was identified in satellite images during 16-17 and 19 June. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Sinabung | Indonesia : Based on observations by PVMBG, satellite and webcam images, and model data, the Darwin VAAC reported that during 20-22 June ash plumes from Sinabung rose 3-3.7 km (10,000-12,000 ft) a.s.l. and drifted SE and E. The Alert Level remained at 4 (on a scale of 1-4), with a general exclusion zone of 3 km and extensions of 7 km on the SSE sector, 6 km in the ESE sector, and 4 km in the NNE sector.

Yasur | Vanuatu : Based on webcam images and local visual observations the Wellington VAAC reported that during 20-21 June intermittent, low-level ash plumes from Yasur rose to an altitude of 1.5 km (5,000 ft) a.s.l. and drifted SE.

Volcanos

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

Ambae | Vanuatu : On 18 March the Vanuatu Geohazards Observatory (VGO) reported that eruptive activity at Ambae’s Lake Voui during February-March was similar to activity observed at the end of October 2017, but with more sustained ash emissions from explosions at the vent. The ongoing ash-and-gas emissions were impacting local villages, prompting VGO to raise the Alert Level to 3 (on a scale of 0-5) and to warn residents and tourists to stay outside of the Danger Zone defined as a 3-km radius around the active vent in Lake Voui. A news article noted that ashfall was reported in the NW, W, SW, and S parts of the island.

Kick ’em Jenny | North of Grenada : The University of the West Indies (UWI) Seismic Research Centre (SRC) and the National Disaster Management Agency (NaDMA) reported that during 12-15 March seismicity at Kick ’em Jenny significantly decreased. The Alert Level remained at Orange (the second highest level on a four-colour scale) with a 5-km maritime exclusion zone.

Kikai | Japan : JMA reported that one small-amplitude, short-duration volcanic tremor was detected on 16 March at Satsuma Iwo-jima, a subaerial part of Kikai’s NW caldera rim. The number of volcanic earthquakes increased on 19 March, prompting JMA to raise the Alert Level to 2 (on a 5-level scale), and then decreased the next day. The report noted increased thermal activity since February, with occasional visual observations of incandescence.

Kirishimayama | Kyushu (Japan) : JMA reported that the eruption at Shinmoedake (Shinmoe peak), a stratovolcano of the Kirishimayama volcano group, continued during 13-19 March. Lava effusion possibly stopped on 9 March, though the lava flow on the NW flank continued to advance. An explosion at 1413 on 15 March generated a gray-white plume that rose 2.1 km above the crater and ejected material 1 km from the crater. A high number of volcanic earthquakes continued to be recorded, in addition to many low-frequency earthquakes with shallow hypocenters. Volcanic tremor was occasionally recorded. The Alert Level remained at 3 (on a scale of 1-5).

Stromboli | Aeolian Islands (Italy) : INGV reported that during 12-17 March activity at Stromboli was at normal levels, characterized by explosive activity and gas emissions from two vents (N1 and N2) in Area N and two vents in Area C-S (C and S2). Explosions at N1 ejected lapilli, bombs, and sometimes ash less than 120 m high, and less intense explosions at N2 emitted ash no higher than 80 m. The frequency of explosions in Area N was 3-8 events/hour. Continuous gas emissions rose from C. Explosions at S2 emitted ash no higher than 80 m at a rate of 2-5 explosions/hour. A high-energy explosive sequence began at vent C at 2027 on 19 March and lasted about 40 seconds. The first explosion ejected ash and incandescent material that fell in a radial distribution around the crater. Two subsequent explosions ejected incandescent material as high as 80 m. Tephra fell along the Sciara del Fuoco, towards the NE parts of the island. At 2028 an explosion at N2 ejected lapilli 100-120 m high.

Volcanos

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

Kadovar | Papua New Guinea : RVO reported that the eruption at Kadovar continued during 18-19 and 21-22 January. Main Crater produced ash plumes that rose as high as 800 m above the summit and drifted tens of kilometers E, SE, S, and SW. Vulcanian activity was continuous, though no discrete explosions were detected. Steam plumes from the SE Coastal Vent rose 800 m above the island, and a lava dome which strongly and continuously glowed at night slowly extruded from the vent. Strong sulfur dioxide emissions were detected.

Kusatsu-Shiranesan | Honshu (Japan) : JMA reported that at 0959 on 23 January an eruption began at Kusatsu-Shiranesan coincident with the onset of volcanic tremor; there were no indications of an impending eruption. The Alert Level was raised to 3 (on a scale of 1-5). Skiers at the popular ski resort Kusatsu Kokusai took video showing a plume of tephra and ejected bombs rising from a vent on the Motoshiranesan edifice, about 2 km SSE of Yagama Crater on Shiranesan (where all previous historical activity has been). The eruption also caused what appeared to be an avalanche. Photos and video posted in news articles showed tephra drifting E and blanketing the nearby hillside; JMA noted ashfall in Nakanojo-machi, in the Gunma Prefecture. Tephra hit a gondola, shattering glass and injuring four skiers. Material crashed through the roof of a lodge, where about 100 people had already been evacuated. Ground Self-Defense Force troops were engaging in ski training at the time of the event; one member died and seven others were injured. Emergency responders gathered at the Sanroku Station to assist. On 24 January JMA noted that volcanic earthquakes were numerous but decreasing in number, and two 2-3-minute-long periods of volcanic tremor were detected at 1015 and 1049.

Mayon | Luzon (Philippines) : PHIVOLCS reported that during 16-17 January Mayon’s seismic network recorded 143 lava collapse events associated with rockfalls along the front and margins of advancing lava and pyroclastic flows in the Miisi (S), Matanag (SE), and Buyuan (SE) drainages. These events generated ash plumes that drifted SW. During 17-20 January effusion of lava at the summit and collapse events continued. Two pyroclastic flows traveled around 3 km down the Miisi drainage. Rockfall events were generated by the collapsing lava front and margins of the advancing 3-km-long lava flow in the Miisi drainage, and from the summit into the Matanag, Buyuan, and Bonga (SE) drainages. Ash plumes continued to drift SW. Sulfur dioxide gas emissions were 1,478 tonnes/day on 18 January and 1,131 tonnes/day on 19 January. During 20-21 January there were 14 rockfall events and 10 pyroclastic flows recorded by the seismic network.

During 21-22 January there were 64 rockfall events and one pyroclastic flow recorded. Strombolian activity generated lava fountains 500 and 200 m high at 1045 on 21 January and at 0225 on 22 January, respectively. Ash plumes rose 1.3 km high and drifted SW, causing ashfall in Oas and Guinobatan (12 km SW). Lava flowed more voluminously, adding to the advancing Miisi lava flow (over 3 km long) and feeding two new lava flows on the Bonga and upper Buyuan drainages.

At 1243 on 22 January an eight-minute-long phreatomagmatic event generated a dense, 5-km-high ash plume that drifted W. Ashfall was reported in the municipalities of Guinobatan, Camalig (11 km SSW), Oas, Polangui (20 km WNW), and Iriga City (34 km NW). The event also generated pyroclastic flows that traveled as far as 4 km down multiple drainages including Miisi, Bonga, Buyuan, Basud, San Andres, Buang, Anoling. PHIVOLCS raised the Alert Level to 4 (on a 0-5 scale) and extend the Danger Zone to an 8-km radius. A minor event at 1725 produced a 500-m-high ash plume. Between 2137 on 22 January and 0525 on 23 January there were five episodes of intense and sporadic lava fountaining, each lasting 3-30 minutes. The lava fountains rose 500-700 m high, and generated ash plumes that rose 2.5-3 km above the crater. The events fed lava flows on the Miisi and Bonga drainages, sprayed near-vent lava spatter, and fed incandescent rockfalls around the summit area. The Buyuan lava flow was 200 m long. According to news articles posted on 23 January about 40,000 people have been evacuated, and airports in the cities of Legazpi City (13 km SSE) and Naga (66 km NW), and on the nearby island of Masbate (100 km S) were closed.

Nevados de Chillan | Chile : Servicio Nacional de Geología and Minería (SERNAGEOMIN) Observatorio Volcanológico de Los Andes del Sur (OVDAS) reported continuing explosive activity during 1-15 January associated with a low rate of lava-dome growth in the active crater. Gas plumes from the explosions rose less than 1 km above the crater rim, and sporadic incandescence associated with some explosions was recorded at night. The lava-dome growth rate was low at 1,360 m3/day, determined by photos taken during overflights on 9 and 12 January. The total volume of the lava dome was an estimated 37,000 m3. 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 4-km radius.

San Miguel | El Salvador : SNET reported that during 14-17 January there were four gas-and-ash emissions from San Miguel that rose no higher than 300 m above the crater rim. The report noted that prior to each emission seismicity decreased and then suddenly increased.

Volcanos

Roundup of Global Volcanic Activity – Ongoing Activity for the week of 11 January-17 January 2017 – Cont.

Nevados de Chillan | Chile : The Buenos Aires VAAC reported that on 13 January an ash puff recorded by a webcam rose from Nevados de Chillán and quickly dissipated. On 15 January a narrow ash plume observed in satellite images, by a pilot, and recorded by a webcam drifted W and dissipated.

Sheveluch | Central Kamchatka (Russia) : KVERT reported that during 6-13 January lava-dome extrusion onto Sheveluch’s N flank was accompanied by strong fumarolic activity, dome incandescence, ash explosions, and hot avalanches. Satellite images showed a daily thermal anomaly over the dome. The Aviation Color Code remained at Orange.

Sinabung | Indonesia : Based on PVMBG observations, webcam views, and satellite images, the Darwin VAAC reported that during 11-17 January ash plumes from Sinabung rose to altitudes of 4-7.3 km (13,000-24,000 ft) a.s.l. and drifted N, NNE, E, SE, and S.

Suwanosejima | Ryukyu Islands (Japan) : Based on JMA notices and satellite-image analyses, the Tokyo VAAC reported that on 17 January an ash plume from Suwanosejima rose to an altitude of 1.2 km (4,000 ft) a.s.l. and drifted S.

Volcanos

Roundup of Global Volcanic Activity – New Activity

Bogoslof (United States, Aleutian Islands): Another (the 6th) large explosion seems to be occurring this morning at the volcano. The Alaska Volcano Observatory reported detecting a strong seismic signal (captured on neighboring islands) and a swarm of lightnings typical for large eruption ash plumes near the volcano and extending north (as the ash plume drifts in this direction). Weather cloud tops at 30,000 ft prevent visual and other satellite conformation (so far) of the likely ash plume which could have reached similar altitudes. The eruption started presumably at 22:30 local time (07:30 UTC Dec 29) and is continuing at the time of writing.

Ongoing Activity for the week of 21 December-27 December 2016

Bagana | Bougainville (Papua New Guinea) : Based on analyses of satellite imagery and model data, the Darwin VAAC reported that during 22 and 25-27 December ash plumes from Bagana rose to altitudes of 2.1-2.4 km (7,000-8,000 ft) a.s.l. and drifted 45-85 km S, SW, and WSW.

Copahue | Central Chile-Argentina border : Based on satellite and webcam images, the Buenos Aires VAAC reported that during 21-23 December gas-and-ash plumes from Copahue rose to altitudes of 3.6-3.9 km (12,000-13,000 ft) a.s.l. and drifted SE and ESE.

Dukono | Halmahera (Indonesia) : Based on analyses of satellite imagery and model data, the Darwin VAAC reported that during 21-26 December ash plumes from Dukono rose to altitudes of 2.1-2.4 km (7,000-8,000 ft) a.s.l. and drifted as far as 185 km NE, ENE, E, and SE.

Fuego | Guatemala : In a special bulletin from 21 December, INSIVUMEH reported the beginning of the 16th Strombolian episode in 2016 at Fuego. Ash plumes rose 1.5 km above the crater and drifted 18 km S, SW, W, and NW, and ashfall was reported in nearby areas including Morelia (9 km SW), Santa Sofía (12 km SW), Panimaché I and II (8 km SW), and Sangre de Cristo (8 km WSW). Lava fountains rose 200-300 m above the crater and fed three lava flows: the first traveled 2.5 km W down the Santa Teresa drainage, the second traveled 2 km SW down the Taniluyá Canyon, and the last traveled 1.8 km SE down the Las Lajas drainage. Shock waves from explosions rattled structures within a 12-km radius. During 24-27 December weak explosions generated ash plumes that rose 450-750 m and drifted 5-10 km W and SW.

Volcanos

Roundup of Global Volcanic Activity – Ongoing Activity for the week of 14 December-20 December 2016

Bogoslof (United States, Aleutian Islands): Another explosive eruption occurred at the volcano a few hours ago (at around 09:30 AKST local time), the Alaska Volcano Observatory reported. The alert level of Bogoslof was raised back to red. “A Coast Guard ship in the vicinity reported ash emission as well as ejection of lava and fragmental material. The eruption cloud did not penetrate the regional cloud tops at 30,000 ft and winds are to the north-northeast. According to the Coast Guard, ash emission subsided at about 10:37 AKST (19:37 UTC). On the basis of this information, the Aviation Colour Code is raised to RED and the Alert Level to WARNING.” (AVO)

Suwanosejima | Ryukyu Islands (Japan) : Based on JMA notices and satellite-image analyses, the Tokyo VAAC reported that during 17-18 December ash plumes from Suwanosejima rose to an altitude of 1.8 km (6,000 ft) a.s.l. and drifted SE and SW.

Sinabung | Indonesia : Based on PVMBG observations, webcam views, and satellite images, the Darwin VAAC reported that on 15, 17, and 19 December ash plumes from Sinabung rose 3-5.8 km (10,000-19,000 ft) a.s.l. and drifted E and S.

Sheveluch | Central Kamchatka (Russia) : KVERT reported that during 10-16 December lava-dome extrusion onto Sheveluch’s N flank was accompanied by strong fumarolic activity, dome incandescence, ash explosions, and hot avalanches. Satellite images showed a daily thermal anomaly over the dome. The Aviation Color Code remained at Orange.

Sabancaya | Peru : IGP’s OVS reported that during 12-18 December seismicity at Sabancaya continued to be dominated by long-period earthquakes; hybrid earthquakes decreased from 14 events per day to 6. Gas-and-ash plumes rose as high as 3.5 km above the crater and drifted more than 35 km NW, E, SE, and S.

Based on webcam and satellite views, the Buenos Aires VAAC reported that during 14-20 December gas-and-water-vapor emissions and sporadic ash puffs rose 6.4-8.2 km (21,000-27,000 ft) a.s.l. (2.3 km above the crater) and drifted SW, WSW, W, and NW.

Nevados de Chillan | Chile : According to ONEMI on 16 December, OVDAS-SERNAGEOMIN reported that in recent days there had been sporadic explosions at craters formed at Nevados de Chillán in 2016. 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.

Kilauea | Hawaiian Islands (USA) :During 14-20 December HVO reported that the lava lake continued to rise and fall, circulate, and spatter in Kilauea’s Overlook vent; the lake level rose as high as 13 m below the Halema’uma’u floor. Webcams recorded incandescence from long-active sources within Pu’u ‘O’o Crater and from a vent high on the NE flank of the cone. The 61G lava flow, originating from a vent on Pu’u ‘O’o Crater’s E flank, continued to enter the ocean near Kamokuna at the easternmost lava delta. An active branch of 61G remained active E of Pu’u ‘O’o and advanced slowly E at a rate of only a few tens of meters per day.

Volcanos

Roundup of Global Volcanic Activity

Pacaya (Guatemala): The volcano’s activity has been comparably calm recently, characterized by strong degassing from the intra-crater cone that formed during the latest period (2015-16) of strombolian activity and has become impressively large, filling a good part of the crater now. On a recent video, no ejections of lava fragments are visible, but rather near-continuous, pulsating emissions of steam and ash. These probably reflect an activity weaker than, but essentially similar to what we observed in Dec last year: spattering-type degassing (“bubbling”) from the magma column inside the cone, generating near-continuous small strombolian explosions. The only real difference would be that this time the effusion rate is too low and activity too deep to eject incandescent lava spatter.

Turrialba (Costa Rica): The volcano continues to be restless with intermittent mild eruptive phases. After 5 days of no visible activity, it restarted to emit low-energy plumes of gas, steam and ash yesterday. According to OVSICORI-UNA, the new phase of eruptive activity began at 7 am local time and was accompanied by a weak tremor signal, which increased from 11:30 am to fluctuating medium to high levels. The observed ash emissions have been weak and produced a plume that did not exceed 500 m. Easterly winds have been carrying the ashes into nearby areas west and northwest of the volcano

Cayambe (Ecuador): The volcano has become restless. Scientists from Ecuador’s Institute of Geophysics (IGEPN) recorded an increased number of earthquakes under the volcano a new report shows. The increased seismicity could be (but not must be) a precursor of renewed activity in the medium-term future (weeks, months?). An increase of earthquakes began on 5 June this year when a seismic swarm of earthquakes started which totalled more than 2300 events by the end of the month. The quakes occurred concentrated in an area NE of the volcano and were volcano-tectonic in origin, likely caused by a magma intrusion at depth causing pressurization and fracturing of rocks. After the June swarm, the volcano returned to calm again first. New earthquakes started to appear in increased numbers from September and have been continuing. Different from in June, the quakes have been concentrated under the summit area of the volcano and been showing an upward trend in depth. In addition, there have been increased reports of strong sulfur smell from climbers who visited the volcano, suggesting that there has been an increase in SO2 emission.

Volcanos

Roundup of Global Volcanic Activity

Sinabung (Sumatra, Indonesia): No significant changes have occurred in the ongoing effusive-explosive eruption of the volcano. The slow lava dome growth continues to feed a prominent lava lobe on the upper ESE flank that sheds glowing avalanches. Occasional larger collapses of this lava lobe produce more violent pyroclastic flows. In addition, the volcano continues to produce explosions, caused by trapped, pressurized gasses contained in the magma from the upper conduit or the dome itself. These vertical explosions have been occurring at rates of one per day on average recently. This morning, an ash plume rose to 15,000 ft (4.5 km) altitude, i.e. approx. 2 km above the summit.

Bromo (East Java, Indonesia): Mild to moderate ash emissions continue, generating a plume that rises up to 500-1000 m and drifts mostly northwest before dissipating.

Kilauea (Hawai’i): The latest mapping of the active lava flow in the coastal plain shows that the leading tip was about 870 m from the coast yesterday. Most of the activity in recent days has been the overriding and widening of the lava flow field, with only little net advance of the farthest lava front towards ocean. However, if the feeding of fresh lava through the main tube into the lava field in the coastal plain continues, and eventually establishes itself over increasing distance, it is more and more likely that the lava eventually reaches the sea. This is likely to occur in the near or medium-term future (days to weeks).

Santiaguito (Guatemala): A strong explosion (another in the ongoing series) occurred at the Caliente lava dome yesterday at 13:30 local time. According to INSIVUMEH, it generated an ash column that rose to approx. 5 km altitude, i.e. about 2500 m above the dome.

Piton de la Fournaise (La Réunion): The volcano is showing signs of unrest that could be (but not necessarily) precursors of a new eruption. Since the beginning of the month, shallow (0-2 km depth) volcanic earthquakes of rock-fracturing type under the Dolomieu crater (the main vent of the volcano) have been more frequent, probably caused by a new magma intrusion. The volcano observatory’s (OVPF) latest statement mentions that 111 “collapses” have occurred recently on the Dolomieu crater, the Enclos and on the lava flow of Aug-Oct 2015. In addition, it seems that new deformation has started during the past days, which would fit into the picture that the volcano is likely preparing itself for a new eruption, although the trend was still unclear and needs to be confirmed.

Volcanos

Roundup of Global Volcanic Activity

Kuchinoerabu-jima (Ryukyu Islands): The Japan Meteorological Agency (JMA), the official government body in charge of monitoring volcanoes, lowered the alert level for the island, after no more significant activity has occurred at the volcano since 19 June 2015 (i.e. almost one year). Current level was lowered from the second highest on the scale (4: “prepare for evacuation”) to now 3 (“Do not approach the volcano”).

Santiaguito (Guatemala): Heavy rainfalls in recent days generated strong lahars (mud flows) through the Nima I River bed, remobilizing some of the recently erupted loose volcanic debris. The turbulent hot flows reached 30 m width and carried blocks up to 50 to 70 cm in diameter, tree trunks and large branches.

Volcanos

Roundup of Global Volcanic Activity

Alaid (Northern Kuriles): A new eruption is occurring at the volcano, satellite images show. A pronounced steam plume with possible ash content can be seen drifting west from the volcano, at estimated 13,000 ft (4 km) altitude. In addition, NASA’s MODIS and VIIRS sensors have been detecting an intense heat source from the volcano’s summit lately. Tokyo VAAC raised the aviation color code to orange.

Manam (Papua New Guinea): New activity has been reported from the volcano this morning. A pilot reported an ash plume at approx. 10,000 ft (3 km) altitude extending 50 km to the SE. A plume, along with a thermal signal, can also be seen on the latest satellite image.

Bromo (East Java, Indonesia): The latest eruptive cycle of the volcano might have ended. No more eruptions (explosions, ash emissions) have been observed during the past 2 weeks and seismic activity has returned to normal levels as well.

Masaya (Nicaragua): The activity of the lava lake in the Santiago crater has been increasing in the past week. In a recent bulletin, INETER mentions that the previously two ponds in two adjacent vents have now joined, probably as a result of erosion by the violently degassing and convective lava.

Tungurahua (Ecuador): The volcano is in a phase of mild to moderate strombolian activity. Incandescent bombs are ejected to the upper slopes of the volcano, generating avalanches. Ash plumes rise up to a few km above the crater and drift mostly in westerly directions. Apparently, the large vent-clearing explosion on 27 Feb has opened the conduit to allow a sustained slow rise of magma and more gradual release of gas pressure in small discrete explosions (= strombolian activity).

Nevados de Chillán (Central Chile): A small eruption occurred at the volcano again yesterday, the first activity since the mild explosive activity on 7 February. Starting around noon, the volcano began to emit a steam plume of variable intensity, sometimes mixed with ash. The activity took place at one of the new craters that had formed in early February. According to SERNAGEOMIN, seismicity and other monitored parameters had shown little fluctuations during most of February, but then started to increase at the end of the month, possibly related to a slowly ascending body of magma. Yesterday’s new activity is likely the result of this and could be a precursor of more activity in the near to medium future.

Volcanos

Roundup of Global Volcanic Activity

Etna (Sicily, Italy): On November 1st a quite energetic seismo-volcanic event occurred most probably from the Bocca Nuova crater. Since that time there has been a change in the seismic tremor. During last weekend cloud cover prevented direct observations but today it was possible to observe very weak ash emissions most probably due to the activity inside the Voragine crater.

Volcanos

Roundup of Global Volcanic Activity

Aso (Kyushu): Activity has been low during the past days, with only intense steaming and dilute ash emissions from the Nakadake crater. Incandescence continues to be visible from the main vent, suggesting magma remains close to the surface.

Sangeang Api (Indonesia): A thermal hot spot of moderate intensity from the volcano’s summit continues to be visible on satellite data, suggesting some weak activity continues there. A steam plume can be seen rising from the volcano’s summit where a small lava dome might be growing.

Ubinas (Peru): A series of small explosions occurred today, producing ash plumes that rose up to approx. 700 m above the crater and drifted northeast.

Piton de la Fournaise (La Réunion): A new eruption started at the volcano this evening. Following a brief seismic crisis that triggered an eruption alarm, an eruptive fissure opened south of Dolomieu crater at 18:50 local time. It is producing impressive lava fountains and a branching lava flow.

Volcanos

Roundup of Global Volcanic Activity

Karymsky (Kamchatka): An ash plume from an explosion produced an ash plume that rose to 14,000 ft (4.2 km) altitude and drifted north this morning. The volcano continues to produce intermittent strombolian- to vulcanian-type explosive eruptions.

Chirinkotan (Northern Kuriles): Ash emissions were recorded on satellite imagery on 26 July, producing a plume that rose to 15,000 ft (4.5 km) altitude and drifted NW. During yesterday and today, the plume dissipated and no new emissions were detected (VAAC Tokyo).

Akan (Hokkaido): A swarm of shallow volcanic earthquakes under the Ponmachineshiri crater of Mt Meakan volcano has been occurring since yesterday. This event triggered the Japanese Meteorological Agency (JMA) to raise the volcanic alert status to 2 (eruption alert, on a scale of 1-5) today. The swarm follows a gradual increase in seismicity under the volcano noted since April this year. JMA thinks the most likely outcome is a very small (phreatic) eruption in the near future and recommends not to approach the crater within 500 m.

Raung (East Java): The eruption, now over 4 weeks old, continues with no significant changes. Strong lava effusion inside the summit caldera is accompanied by near-constant ash emissions rising 1-2 km and drifting up to 100-200 km in mostly westerly directions.

Dukono (Halmahera): Strong ash emissions continue at the volcano. VAAC Darwin reported an ash plume extending 25 km north of the volcano yesterday.