Volcanos

Global Volcanic Activity – New Activity for the week of 12 June – 18 June 2019

Colima | Mexico : Centro Universitario de Estudios e Investigaciones de Vulcanologia – Universidad de Colima reported that intermittent steam-and-gas emissions mainly from the NE side of the crater and small explosions continued to be recorded during 8-14 June. Weather conditions often prevented visual observations of the crater.

Pavlof | United States : On 12 June AVO reported that elevated levels of seismicity at Pavlof, recorded since mid-May, had declined to background levels. The Aviation colour Code was lowered to Green and the Volcano Alert Level was lowered to Normal. The report noted that vapor plumes were occasionally visible in webcam views and elevated surface temperatures in the summit crater were sometimes identified in satellite images; both are common occurrences at Pavlof.

Piton de la Fournaise | Reunion Island (France) : The eruption at Piton de la Fournaise that began at 0635 on 11 June continued through 12 June from fissures on the SSE flank of Dolomieu Crater. The front of the lava flow had reached around 1,200-1,300 m elevation by 0620. OVPF stated that the eruption ended at 1200 on 13 June.

Sangeang Api | Indonesia : The Darwin VAAC reported that on 17 June multiple discrete emissions with increasing ash content over a period of about an hour rose from Sangeang Api to altitudes of 1.2-2.1 (4,000-7,000 ft) a.s.l. and drifted W and WNW, based on satellite images and weather models. A thermal anomaly was also visible. The Alert Level remained at 2 (on a scale of 1-4).

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Volcanos

Global Volcanic Activity – Ongoing Activity for the week of 5 June – 11 June 2019

Agung | Bali (Indonesia) : PVMBG reported that at 1212 on 10 June an explosion at Agung produced a gray ash plume that rose about 1 km and drifted SE and E. The Alert Level remained at 3 (on a scale of 1-4) with the exclusion zone set at a 4-km radius.

Aira | Kyushu (Japan) : JMA reported that during 3-10 June very small eruptive events at Minamidake crater (at Aira Caldera’s Sakurajima volcano) were recorded, as well as periodic crater incandescence. The Alert Level remained at 3 (on a 5-level scale).

Dukono | Halmahera (Indonesia) : Based on satellite and wind model data, and notices from PVMBG, the Darwin VAAC reported that during 5-11 June ash plumes from Dukono rose to an altitude of 2.1 km (7,000 ft) a.s.l. and drifted in multiple directions. The Alert Level remained at 2 (on a scale of 1-4), and the public was warned to remain outside of the 2-km exclusion zone.

Ebeko | Paramushir Island (Russia) : Volcanologists in Severo-Kurilsk (Paramushir Island), about 7 km E of Ebeko, observed explosions on 3 June that sent ash plumes up to 3 km (10,000 ft) a.s.l. The plumes drifted E. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Kerinci | Indonesia : PVMBG reported that at 0604 on 7 June a grayish ash emission from Kerinci rose 800 m above the summit and drifted E according to a ground observer. The Alert Level remained at 2 (on a scale of 1-4), and tourists were warned to remain outside of the 3-km exclusion zone.

Klyuchevskoy | Central Kamchatka (Russia) : On 12 June ash plumes from Klyuchevskoy rose to an altitude of 5 km (16,400 ft) a.s.l. and drifted 10 km N, prompting KVERT to raise the Aviation colour Code to Orange (the second highest level on a four-colour scale). Ash emissions continued later that day with plumes rising to 5 km a.s.l. and drifting 68 km WNW.

Krakatau | Indonesia : PVMBG reported that Anak Krakatau’s seismic network recorded one eruptive event at 0850 on 10 June. The event as not followed by visible ash emissions, though observations were hindered by weather conditions. The Alert Level remained at 2 (on a scale of 1-4), and the public was warned to remain outside of the 2-km radius hazard zone from the crater.

Manam | Papua New Guinea : The Darwin VAAC reported that during 7-8 June ash plumes from Manam rose to an altitude of 4.3 km (14,000 ft) a.s.l. and drifted SW, based on satellite data and weather models.

Merapi | Central Java (Indonesia) : PVMBG reported that during 3-10 June the lava-dome volume at Merapi did not change and was an estimated 458,000 cubic meters, based on analyses of drone footage. Extruded lava fell into the upper parts of the SE-flank, generating one block-and-ash flow that traveled 1 km down the Gendol drainage on 9 June. White plumes rose as high as 75 m above the summit. The Alert Level remained at 2 (on a scale of 1-4), and residents were warned to remain outside of the 3-km exclusion zone.

Rincon de la Vieja | Costa Rica : OVSICORI-UNA reported that a 10-minute-long eruption at Rincón de la Vieja began at 0343 on 11 June. Emissions were not visible due to weather conditions.

Sabancaya | Peru : Instituto Geofísico del Perú (IGP) reported that during 3-9 June an average of 12 explosion per day were recorded at Sabancaya. Ash plumes rose 2.9 km above the crater rim. On 7 June explosions generated ash plumes that drifted 30 km S and SW. The public was warned to not approach the crater within a 12-km radius.

Sheveluch | Central Kamchatka (Russia) : KVERT reported that a thermal anomaly over Sheveluch’s lava dome was identified daily in satellite images during 1-7 June. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Stromboli | Aeolian Islands (Italy) : INGV reported that during 3 and 6-9 June activity at Stromboli was characterized by ongoing Strombolian explosions and degassing from multiple vents within the crater terrace. Explosions from two vents (N1 and N2) in Area N (north crater area, NCA) occurred at a rate of 1-4 per hour, ejecting material 80 m high and producing ash plumes. Explosions from two vents (S1 and S2) in Area C-S (South Central crater area) occurred at a rate of 3-8 per hour, ejecting material 80-150 m high. Gas plumes rose from vent C.

Volcanos

Global Volcanic Activity – New Activity for the week of 5 June – 11 June 2019

Colima | Mexico : Centro Universitario de Estudios e Investigaciones de Vulcanologia – Universidad de Colima reported that small explosions and intermittent steam-and-gas emissions, originating mainly from the NE side of the crater, continued to be recorded during 1-7 June. Weather conditions often prevented visual observations of the crater.

Etna | Sicily (Italy) : INGV reported that explosions at the fissure segment at 2,850 m elevation on the SE base of Etna’s New Southeast Crater (NSEC) declined in frequency and intensity during 3-4 June; explosions ceased on 5 June. The lava flow from the fissure was active only near the vent on 5 June and by the next day had ceased and began cooling. Sporadic ash emissions rose from Northeast Crater (NEC) and quickly dissipated on 6 June. The report noted that the NE edge of the NSEC cone had dropped several meters, likely in conjunction with a period of ash emissions on 30 May. In addition, a hot zone high on the SE flank of the cone that was established prior to the recent eruption was extensively covered with coloured fumarolic deposits by 6 June.

Great Sitkin | Andreanof Islands (USA) : AVO reported that a small steam explosion at Great Sitkin was detected in seismic data at 1318 on 7 June. The Aviation colour Code remained at Yellow and the Volcano Alert Level remained at Advisory.

Piton de la Fournaise : OVPF reported that a seismic crisis at Piton de la Fournaise began at 0603 on 11 June and was accompanied by rapid deformation. Tremor began at 0635, indicating an eruption, though inclement weather conditions prevented visual confirmation; a gas plume was recorded in webcam images. Scientists observed the eruption during a field visit around 0930, describing at least five active fissures on the SSE flank of Dolomieu Crater. Weather conditions continued to hinder visual observations. Three fissures at relatively lower elevations produced 30-m-high lava fountains and lava flows. Two higher-elevation fissures were no longer active. By 1530 only the lowest-elevation fissure remained active.

Sinabung | Indonesia : PVMBG reported that at 1628 on 9 June an eruption at Sinabung produced a dense black-gray ash plume that rose around 7 km above the summit, drifted W and SW, and generated pyroclastic flows that traveled 3.5 km SE and 3 km S. Roaring was heard at the Sinabung observation post. Continuous emissions were visible rising 500 m above the summit for a period on 10 June. The Alert Level remained at 3 (on a scale of 1-4), with a general exclusion zone of 3 km and extensions to 5 km on the SE sector and 4 km in the NE sector.

Volcanos

Global Volcanic Activity – Ongoing Activity for the week of 29 May – 4 June 2019

Agung | Bali (Indonesia) : PVMBG reported that at 1142 on 31 May an explosion at Agung produced a dense gray ash plume that rose 2 km and drifted NE and E. Roaring was audible from the Agung Volcano Observatory in Rendang (about 8 km SW). The Alert Level remained at 3 (on a scale of 1-4) with the exclusion zone set at a 4-km radius.

Aira | Kyushu (Japan) : JMA reported that during 27 May-3 June very small eruptive events at Minamidake crater (at Aira Caldera’s Sakurajima volcano) were recorded as well as periodic crater incandescence. The Alert Level remained at 3 (on a 5-level scale).

Asosan | Kyushu (Japan) : JMA reported that very small eruptive events at Asosan’s Nakadake Crater on 29 and 31 May generated plumes that rose 400 m above the crater rim and, according to the Tokyo VAAC, drifted S and N, respectively. Sulfur dioxide emissions continued to be high at 2,000 tons per day. The Alert Level remained at 2 (on a scale of 1-5).

Dukono | Halmahera (Indonesia) : Based on satellite and wind model data, and notices from PVMBG, the Darwin VAAC reported that during 29 May-4 June ash plumes from Dukono rose to altitudes of 2.1-2.4 km (7,000-8,000 ft) a.s.l. and drifted NW and W. The Alert Level remained at 2 (on a scale of 1-4), and the public was warned to remain outside of the 2-km exclusion zone.

Ebeko | Paramushir Island (Russia) : Volcanologists in Severo-Kurilsk (Paramushir Island), about 7 km E of Ebeko, observed explosions during 25-28 May that sent ash plumes up to 3 km (10,000 ft) a.s.l. A thermal anomaly over the volcano was identified during 27-28 May. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Ibu | Halmahera (Indonesia) : The Darwin VAAC reported that on 31 May multiple ash plumes from Ibu rose to an altitude of 2.1 km (7,000 ft) a.s.l. and drifted W based on satellite data. On 2 June ash plumes rose to an altitude of 3 (10,000 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.

Karymsky | Eastern Kamchatka (Russia) : KVERT reported that an ash plume from Karymsky was identified in satellite images drifting 45 km NE on 24 May and a thermal anomaly was visible during 28-29 May. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Klyuchevskoy | Central Kamchatka (Russia) : KVERT reported that ash plumes from Klyuchevskoy were last observed on 22 April and a weak thermal anomaly was last identified on 15 May. KVERT lowered the Aviation colour Code to Yellow (the second lowest level on a four-colour scale) on 31 May.

Krakatau | Indonesia : PVMBG reported that Anak Krakatau’s seismic network detected two eruptive events on 29 May and two events on 2 June. None of the events were followed by visible ash emissions, though observations were hindered by weather conditions. The Alert Level remained at 2 (on a scale of 1-4), and the public was warned to remain outside of the 2-km radius hazard zone from the crater.

Merapi | Central Java (Indonesia) : PVMBG reported that during 24-30 May the lava-dome volume at Merapi did not change and was an estimated 458,000 cubic meters, based on analyses of drone footage. Extruded lava fell into the upper parts of the SE flank, generating one block-and-ash flow that traveled 1.1 km down the Gendol drainage. White plumes rose as high as 400 m above the summit. A news article stated that block-and-ash flows descended the Gendol drainage during 1-2 June, traveling as far as 1.2 km. In addition, incandescent dome material traveled 750 m on 2 June. The Alert Level remained at 2 (on a scale of 1-4), and residents were warned to remain outside of the 3-km exclusion zone.

Poas | Costa Rica : OVSICORI-UNA reported that multiple phreatic eruptions at Poás recorded during 29 May-1 June produced plumes that rose as high as 500 m above the vent.

Santa Maria | Guatemala : INSIVUMEH and CONRED reported that during 29-30 May lahars descended Santa María’s San Isidro drainage (tributary of El Tambor), carrying blocks 1-3 m in diameter and tree trunks. The lahars were 20 m wide and 1.5 m deep; CONRED noted that the 29 May lahar was hot and had a sulfur odor. Explosions recorded during 30 May-4 June generated ash plumes that rose as high as 800 m above the crater and drifted E and SE. Avalanches of material descended the E and SE flanks.

Sheveluch | Central Kamchatka (Russia) : KVERT reported that a thermal anomaly over Sheveluch’s lava dome was identified daily in satellite images during 24-31 May. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Suwanosejima | Ryukyu Islands (Japan) : JMA reported that crater incandescence at Suwanosejima’s Ontake Crater was occasionally visible at night during 24-31 May. An eruption at 1629 on 30 May generated a plume that rose 1.1 km above the crater rim. The Alert Level remained at 2 (on a 5-level scale).

Volcanos

Global Volcanic Activity – New Activity for the week of 29 May – 4 June 2019

Colima | Mexico : Centro Universitario de Estudios e Investigaciones de Vulcanologia – Universidad de Colima reported that during 25-31 May small explosions and intermittent steam-and-gas emissions mainly from the NE side of the crater continued to be recorded. During overflights conducted during 23-24 May scientists observed that the new feature (a crack or cavity) reported the previous week had become a hole due to the combination of excavation due to explosions and probable subsidence. The maximum temperature recorded with a portable thermal camera was 252 degrees Celsius, an increase of 80 degrees since recorded on 1 May.

Etna | Sicily (Italy) : INGV reported that at 0220 on 30 May a fissure opened at the N base of Etna’s NSEC at about 3,150 m elevation. The fissure produced Strombolian explosions and a lava flow that advanced towards the W wall of the Valle del Bove; by 0915 it had reached 2,050 m elevation near Monte Simone. The flow was 2 km in length. Two fissures opened a few hours later at the SE base of NSEC at an elevation of about 3,050 m, each producing lava flows that converged and traveled along the W wall of the Valle del Bove towards Serra Giannicola Grande, partially covering the 2018 lava flows. The flow reached 2,260 m elevation by 0915. The fissure activity was accompanied by ash emissions which were intense starting at 1150 but then decreased and almost stopped late in the evening. The lava flow reached the bottom of the valley in the early hours of 31 May and had a length of about 3 km. INGV volcanologists confirmed that lava continued to effuse from both fissures during a visual inspection in the morning of 1 June and that vigorous spatter was occurring at a fissure on the SE base of NSEC. By 1930 the lava flow from the N base was no longer being fed and was cooling. During a visual inspection of the eruption site on 2 June volcanologists confirmed explosive activity at a fissure segment at 2,850 m and continuing lava effusion. The lava traveled along the W wall of the Valle del Bove, overlapping flows from previous days.

Great Sitkin | Andreanof Islands (USA) : A small steam explosion at Great Sitkin was detected in seismic data at 2140 on 1 June, prompting AVO to raise the Aviation colour Code to Yellow and the Volcano Alert Level to Advisory. Low-level seismic activity was elevated just before and after the event.

Kurikomayama | Honshu (Japan) : JMA raised the Alert Level for Kurikomayama to 1 (the lowest level on a 5-level scale) on 30 May due to an undescribed potential for increased activity at the crater.

Midagahara | Honshu (Japan) : JMA raised the Alert Level for Midagahara to 1 (the lowest level on a 5-level scale) on 30 May due to an undescribed potential for increased activity at the crater.

Sinabung | Indonesia : PVMBG reported that white plumes from Sinabung rose as high as 500 m above the summit during 31 May-4 June. The Alert Level remained at 3 (on a scale of 1-4), with a general exclusion zone of 3 km and extensions to 5 km on the SE sector and 4 km in the NE sector.

Volcanos

Global Volcanic Activity – Ongoing Activity for the week of 22 May – 28 May 2019

Agung | Bali (Indonesia) : PVMBG reported that at 1923 on 24 May an explosion at Agung ejected incandescent material radially onto the flanks as far as 3 km from the crater rim, setting fire to some vegetation. A dense gray-white ash plume rose 2 km and, based on satellite data, drifted SW, causing thick ashfall in several villages to the S. Roaring was audible from the Agung Volcano Observatory in Rendang (about 8 km SW). According to a news article several flights to and from Australia were cancelled or diverted, though the International Gusti Ngurah Rai (IGNR) airport (60 km SW) in Denpasar was not closed. The Alert Level remained at 3 (on a scale of 1-4) with the exclusion zone set at a 4-km radius.

Aira | Kyushu (Japan) : JMA reported that during 22-23 May two explosions at Minamidake crater (at Aira Caldera’s Sakurajima volcano) produced plumes that rose 1.6 km above the crater rim and ejected material as far as 900 m. Crater incandescence was periodically visible. Very small eruptive events were recorded during 24-27 May. The Alert Level remained at 3 (on a 5-level scale).

Dukono | Halmahera (Indonesia) : Based on satellite and wind model data, and notices from PVMBG, the Darwin VAAC reported that during 22-28 May ash plumes from Dukono rose to altitudes of 2.1-3 km (7,000-10,000 ft) a.s.l. and drifted in multiple directions. The Alert Level remained at 2 (on a scale of 1-4), and the public was warned to remain outside of the 2-km exclusion zone.

Ebeko | Paramushir Island (Russia) : A thermal anomaly over Ebeko was identified in satellite images during 16-17 May. Volcanologists in Severo-Kurilsk (Paramushir Island), about 7 km E of Ebeko, observed explosions during 16-20 May that sent ash plumes up to 2.5 km (8,200 ft) a.s.l. Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Etna | Sicily (Italy) : INGV reported that gas emissions of variable intensity were observed rising from Etna’s summit craters during 20-26 May; weather conditions often prevented views. Weak and diffuse ash emissions occasionally rose from the New Southeast Crater (NSEC). An ash plume rose from Bocca Nuova Crater on 23 May.

Ibu | Halmahera (Indonesia) : The Darwin VAAC reported that during 23-24 May ash plumes from Ibu rose to altitudes of 2.4-2.7 km (8,000-9,000 ft) a.s.l. and drifted SE based on satellite data. 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.

Karymsky | Eastern Kamchatka (Russia) : KVERT reported that a thermal anomaly over Karymsky was visible in satellite images during 17-21 May. An ash plume drifted 9 km SW on 21 May. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Klyuchevskoy | Central Kamchatka (Russia) : KVERT reported that a weak thermal anomaly over Klyuchevskoy was identified in satellite images on 17, 19, and 21 May. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Krakatau | Indonesia : PVMBG reported that Anak Krakatau’s seismic network detected 26 eruptive events during 20-26 May. None of the events were followed by visible ash emissions, though observations were hindered by fog. The Alert Level remained at 2 (on a scale of 1-4), and the public was warned to remain outside of the 2-km radius hazard zone from the crater.

Merapi | Central Java (Indonesia) : PVMBG reported that on 11 May the lava dome at Merapi had an estimated volume of 458,000 cubic meters, based on analyses of drone footage, and remained unchanged at least through 26 May. The dome morphology remained relatively unchanged, as most of the extruded lava fell into the upper parts of the SE-flank Gendol River drainage. One block-and-ash flow traveled 1.1 km down the Gendol drainage. The Alert Level remained at 2 (on a scale of 1-4), and residents were warned to remain outside of the 3-km exclusion zone.

Sheveluch | Central Kamchatka (Russia) : KVERT reported that a thermal anomaly over Sheveluch’s lava dome was identified daily in satellite images during 17-24 May. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Soputan | Sulawesi (Indonesia) : PVMBG reported that during 22-28 May white plumes rose as high as 100 m above Soputan’s summit. On 27 May white-to-gray plumes rose 150 m high. The Alert Level remained at 3 (on a scale of 1-4). The public was advised not to approach the craters within a radius of 4 km, or 6.5 km on the WSW flank.

Volcanos

Global Volcanic Activity – New Activity for the week of 22 May – 28 May 2019

Colima | Mexico : Centro Universitario de Estudios e Investigaciones de Vulcanologia – Universidad de Colima reported that 51 low-magnitude explosions mainly from the NE part of Colima’s crater were recorded by the seismic and infrasound network during 11-24 May. Emissions from the explosions consisted mainly of water vapor and gas, and were the first surficial manifestations of activity since seismicity increased in the past few weeks. Footage from five drone overflights conducted on 22 May showed fumarolic activity on the inner wall of the NE part of the crater and a new small explosion crater near the center of the main crater.

Hakoneyama | Honshu (Japan) : JMA reported that the number of earthquakes at Hakoneyama increased on 18 May and remained elevated through 27 May. The epicenters were centered around the W bank of Lake Ashinoko and around Komagatake. Global Navigation Satellite Systems (GNSS) data continued to indicate a trend of inflation. The Alert Level remained at 2 (on a 5-level scale).

Sarychev Peak | Matua Island (Russia) : SVERT lowered the Alert Level for Sarychev Peak to Green on 22 May, noting that the last activity recorded was an ash plume on 16 May and a thermal anomaly on 17 May.

Sinabung | Indonesia : PVMBG reported that an eruption at Sinabung was recorded at 0253 on 25 May. An ash plume from the event drifted W and NW according to the Darwin VAAC; fog prevented ground-based visual observations. Ashfall was reported in several areas downwind according to a news article. At 0629 on 27 May a dense gray ash plume rose 2.5 km above the crater rim and drifted S. The VAAC reported that at 0700 an ash plume was visible in satellite images at an altitude of 6.1 km (20,000 ft) a.s.l., or 3.7 km above the crater rim. Eruptive events were recorded at 2323 on 27 May and 0118 on 28 May, though ash plumes were not visible. The Alert Level remained at 3 (on a scale of 1-4), with a general exclusion zone of 3 km and extensions to 5 km on the SE sector and 4 km in the NE sector.

Volcanos

Geologists Discover Large Underwater Volcano

A strange seismic event off the coast of Africa has led scientists to a mighty finding: the discovery of the largest underwater volcanic eruption ever recorded.

The eruption also may explain a weird seismic event recorded in November 2018 just off the island of Mayotte, located between Madagascar and Mozambique in the Indian Ocean. Researchers described that event as a seismic hum that circled the world, but no one could figure out what sparked it.

And, incredibly, investigations revealed that the island of Mayotte moved a few inches south and east after the mysterious event.

The underwater volcano is enormous, rising nearly a half mile (0.8 kilometers) from the ocean floor. It’s the length of a 3.1-mile (5 km) race and lies about 31 miles (50 km) off Mayotte’s eastern coast. And it came into being in just six months.

Researchers used multibeam sonar to find the underwater volcano. The reflected sonar waves revealed the outline of the underwater volcano (red) and the gassy plume rising from it.

Screen Shot 2019 05 24 at 1 25 35 PM

Global Volcanic Activity – Ongoing Activity for the week of 15 May – 21 May 2019

Agung | Bali (Indonesia) : PVMBG reported that at 1409 on 18 May an explosion at Agung ejected incandescent material radially onto the flanks as far as 2.5 km from the crater rim. A dense gray-white ash plume rose 2 km and drifted NE, E, and SE, causing ashfall in hamlets downwind including Cutcut, Tongtongan, Bonyoh, and Temakung. A weak roar was audible from the Agung Volcano Observatory in Rendang (about 8 km SW). The Alert Level remained at 3 (on a scale of 1-4) with the exclusion zone set at a 4-km radius.

Aira | Kyushu (Japan) : JMA reported that on 13 May two explosions at Minamidake crater (at Aira Caldera’s Sakurajima volcano) produced plumes that rose 1.8 km above the crater rim and ejected material as far as 1.3 km. Crater incandescence from the crater was visible. Very small non-explosive events were recorded by the seismic network during 17-20 May. The Alert Level remained at 3 (on a 5-level scale).

Asosan | Kyushu (Japan) : JMA reported that during 15-20 May sulfur dioxide emission levels were somewhat high at Asosan’s Nakadake Crater. At 1028 on 15 May an eruption produced a plume that rose 700 m above the crater rim. White plumes rose 200 m during 17-20 May. The Alert Level remained at 2 (on a scale of 1-5).

Dukono | Halmahera (Indonesia) : Based on satellite and wind model data, and notices from PVMBG, the Darwin VAAC reported that during 15-21 May ash plumes from Dukono rose to altitudes of 2.1-3 km (7,000-10,000 ft) a.s.l. and drifted in multiple directions. The Alert Level remained at 2 (on a scale of 1-4), and the public was warned to remain outside of the 2-km exclusion zone.

Ebeko | Paramushir Island (Russia) : A thermal anomaly over Ebeko was identified in satellite images during 12-13 May. Volcanologists in Severo-Kurilsk (Paramushir Island), about 7 km E of Ebeko, observed explosions during 13-15 May that sent ash plumes up to 2.5 km (8,200 ft) a.s.l. Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Etna | Sicily (Italy) : INGV reported that gas emissions of variable intensity were observed rising from Etna’s summit craters during 14 and 17-19 May; weather conditions prevented views on the other days during 13-19 May. Ash emissions periodically rose from vents in the S and E parts of New Southeast Crater (NSEC). Several Strombolian explosions at NSEC ejected incandescent pyroclastic material a few dozen meters above the crater rim during 17-18 May.

Fuego | Guatemala : INSIVUMEH reported that there were 15-20 explosions per hour recorded at Fuego during 16-17 and 19-20 May, generating ash plumes that rose as high as 1.1 km above the crater rim and drifted 10-25 km S, SW, and W. Explosions sometimes produced shock waves that rattled houses in nearby communities. Incandescent material was ejected 300-400 m high and caused avalanches of material that occasionally traveled long distances (reaching vegetated areas) down Seca (W), Taniluyá (SW), Ceniza (SSW), Trinidad (S), and Las Lajas (SE) ravines. Ashfall was reported in areas downwind including Santa Sofía (12 km SW), Morelia (9 km SW), Panimaché I and II (8 km SW), and El Porvenir (8 km ENE). A lava flow on the W flank was 300 m long. On 16 May lahars carrying variously-sized blocks and tree branches and trunks descended the Las Lajas ravine. On 20 May hot lahars with a sulfur odor descended the Ceniza, El Jute, and Las Lajas drainages, carrying blocks 1-3 m in diameter.

Ibu | Halmahera (Indonesia) : The Darwin VAAC reported that during 14-16 and 18-19 May ash plumes from Ibu rose to 2.1-3 km (7,000-10,000 ft) a.s.l. and drifted NW, N, ENE, and SE based on satellite data. 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.

Karymsky | Eastern Kamchatka (Russia) : KVERT reported that a thermal anomaly over Karymsky was visible in satellite images during 10-14 May. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Klyuchevskoy | Central Kamchatka (Russia) : KVERT reported that a weak thermal anomaly over Klyuchevskoy was identified in satellite images on 10 and 15 May. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Krakatau | Indonesia : PVMBG reported that Anak Krakatau’s seismic network detected 22 eruptive events during 13-19 May, though none of the events were followed by ash emissions. Dense white plumes were visible rising as high as 200 m above the summit during periods of clear weather. The Alert Level remained at 2 (on a scale of 1-4), and the public was warned to remain outside of the 2-km radius hazard zone around the crater.

Merapi | Central Java (Indonesia) : PVMBG reported that on 11 May the lava dome at Merapi had an estimated volume of 458,000 cubic meters, based on analyses of drone footage. The dome morphology remained relatively unchanged during 12-19 May, as most of the extruded lava fell into the upper parts of the SE-flank Gendol River drainage. Two block-and-ash flows traveled as far as 1.2 km down the Gendol drainage. The Alert Level remained at 2 (on a scale of 1-4), and residents were warned to remain outside of the 3-km exclusion zone.

Popocatepetl | Mexico : CENAPRED reported that each day during 15-21 May there were 22-72 steam-and-gas emissions from Popocatépetl, some of which contained ash (19-21 May). Two explosions, at 0817 and 0831 on 16 May, generated ash plumes that rose 1.6 and 1 km above the crater rim, respectively. During 20-21 May crater incandescence was visible during some emissions. The Alert Level had returned to Yellow, Phase Two (middle level on a three-colour scale) on 7 May and remained there through 21 May.

Reventador | Ecuador : IG reported that during 14-21 May seismic data from Reventador’s network indicated a high level of seismic activity, including explosions, long-period earthquakes, harmonic tremor, and signals indicating emissions. Weather conditions often prevented views of the summit area, although when clear (during 17-18 and 20-21 May) several ash plumes were visible rising as high as 1 km above the crater rim and drifting W and NW. Crater incandescence was visible on some mornings and evenings. On 19 May a 500-m-long pyroclastic flow deposit on the N flank was visible. Blocks were observed rolling 800 m down the flanks on 21 May.

Rincon de la Vieja | Costa Rica : OVSICORI-UNA reported that phreatic eruptions at Rincón de la Vieja were recorded at 1703 on 14 May and 0357 on 17 May, though dense fog prevented visual confirmation of both events with webcams. On 15 May a local observer noted a diffuse plume of steam, gas, and particulates rising from the crater and photographed milky-gray deposits on the N part of the crater rim, ejected from the event the day before.

Sabancaya | Peru : Instituto Geofísico del Perú (IGP) and Instituto Geológico Minero y Metalúrgico (INGEMMET) reported that an average of 33 low-to-medium intensity explosions per day occurred at Sabancaya during 13-19 May. Gas-and-ash plumes rose as high as 2.5 km above the crater rim and drifted NW, N, and NE. There were 10 thermal anomalies identified in satellite data. The report noted that the public should not approach the crater within a 12-km radius.

Santa Maria | Guatemala : INSIVUMEH reported that during 16-17 May there were two explosions per hour detected at Santa María’s Santiaguito lava-dome complex. Ash plumes rose 700 m above the complex and drifted SW. Eight weak explosions were recorded during 19-20 May, generating ash plumes that rose 700 m and drifted SW. Avalanches of material descended the E and SE flanks of the lava dome.

Sheveluch | Central Kamchatka (Russia) : KVERT reported that a thermal anomaly over Sheveluch’s lava dome was identified daily in satellite images during 10-17 May. Plumes of re-suspended ash were visible drifting 16 km SE on 13 May. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Turrialba | Costa Rica : On 19 May OVSICORI-UNA reported that passive, short-duration emissions with small amounts of ash had been sporadically occurring at Turrialba over the previous week. Prolonged and intermittent periods of emissions with minor amounts of ash were visible during 19-20 May.

Villarrica | Chile : POVI reported continuing activity at Villarrica during 5-6 May when Strombolian explosions ejected lava 50 m above the crater rim. On 14 May the webcam recorded 24-m-wide lava fountains rising as high as 70 m. An explosion later that day at 2220 ejected a mushroom-shaped fountain 70 m high. POVI noted it was one of the largest lava explosions since 2015.

Volcanos

Global Volcanic Activity – New Activity for the week of 15 May – 21 May 2019

Azumayama | Honshu (Japan) : The number of volcanic earthquakes at Azumayama increased on 5 May and data from a tiltmeter about 1 km SE of Ohana Crater showed inflation on 9 May, prompting JMA to raise the Alert Level to 2 (on a 5-level scale). Field observations on 7 and 10 May indicated no changes in the fumarolic and thermal areas around Ohana. Seismicity began to decrease on 10 May, though continued to fluctuate through 20 May. Deformation continued but at a slower rate.

Hakoneyama | Honshu (Japan) : JMA reported that the number of earthquakes at Hakoneyama increased during 18-19 May, with epicenters centered around the W bank of Lake Ashinoko and around Komagatake. Fumaroles in the Owakudani hot springs area continued to be active. Global Navigation Satellite Systems (GNSS) data showed changes in deformation beginning in mid-March. On 19 May JMA raised the Alert Level to 2 (on a 5-level scale). Elevated seismicity continued to be recorded through 21 May.

Pavlof | United States : AVO reported that low-frequency tremor was detected at Pavlof during 14-15 May and a vigorous steam plume rising from the summit was visible in webcam images on 15 May. The Aviation colour Code was raised to Yellow and the Volcano Alert Level was raised to Advisory primarily because of increased seismicity. Steam plumes recorded by the webcam, low levels of seismic tremor, and warm surface temperatures identified in satellite data continued during 16-19 May; AVO noted that steam emissions and warm surface temperatures are common at Pavlof.

Sangay | Ecuador : IG reported that a new eruption at Sangay began on 7 May and was continuing as of 21 May. Activity was concentrated at two eruptive centers; the Central Crater and the Ñuñurcu dome (located 190 m SSE of Central Crater). Explosive activity at Central Crater produced ash plumes that rose an average of 1 km above the crater rim and drifted W and NW. Ejected blocks rolled as far as 2.5 km down the SE flank. The Ñuñurcu dome produced a lava flow that had a maximum width of 175 m and traveled about 470 m down the SE flank. Collapses of the lava-flow front generated small pyroclastic flows and numerous block flows; one of the pyroclastic flows traveled 340 m.

Sarychev Peak | Matua Island (Russia) : SVERT reported that a weak thermal anomaly over Sarychev Peak was visible in satellite images on 10, 12, and 17 May. At 0830 on 16 May satellite images showed an ash plume drifting 50 km SE at an altitude as high as 2.5 km (8,200 ft) a.s.l. The Aviation colour Code was raised to Yellow on 16 May.

Sinabung | Indonesia : PVMBG reported that white plumes rose as high as 700 m above Sinabung’s crater rim during 13-21 May. On 20 May the Alert Level was lowered to 3 (on a scale of 1-4), with a general exclusion zone of 3 km and extensions to 5 km on the SE sector and 4 km in the NE sector. PVMBG noted that the seismic activity surrounding the recent ash emissions during 7 and 11-12 May were not indicative of renewed activity.

Volcanos

Global Volcanic Activity – Ongoing Activity for the week of 8 May – 14 May 2019

Agung | Bali (Indonesia) : PVMBG and BNPB reported that an eruptive event at Agung was recorded by the seismic network at 2229 on 12 May, accompanied by a loud bang audible at the Agung Volcano Observatory in Rendang (about 8 km SW). Dense fog prevented height estimates of the ash plume. A photo posted along with the report showed that incandescent material was deposited on the flanks. The Alert Level remained at 3 (on a scale of 1-4) with the exclusion zone set at a 4-km radius.

Aira | Kyushu (Japan) : JMA reported that incandescence from Minamidake crater (at Aira Caldera’s Sakurajima volcano) was occasionally visible at night during 7-13 May. Explosions on 7 and 13 May generated plumes that rose 1.6 and 2.9 km above the crater rim, respectively. The Alert Level remained at 3 (on a 5-level scale).

Dukono | Halmahera (Indonesia) : Based on satellite and wind model data, and notices from PVMBG, the Darwin VAAC reported that during 8-14 May ash plumes from Dukono rose to an altitude of 2.1 km (7,000 ft) a.s.l. and drifted mainly NE, E, and SE. The Alert Level remained at 2 (on a scale of 1-4), and visitors were warned to remain outside of the 2-km exclusion zone.

Fuego | Guatemala : INSIVUMEH reported that there were 13-24 explosions per hour recorded at Fuego during 9-10 and 12-14 May, generating ash plumes that rose as high as 1.1 km above the crater rim and drifted 10-15 km S and SW. Explosions sometimes produced shock waves that rattled houses in areas to the S and SW. Incandescent material was ejected 200-300 m high and caused avalanches of material that occasionally traveled long distances (and reached vegetated areas) down the Seca (W), Taniluyá (SW), Ceniza (SSW), Trinidad (S), and Las Lajas (SE) ravines. Ashfall was reported in areas downwind including Santa Sofía (12 km SW), Morelia (9 km SW), Panimaché (8 km SW), El Porvenir (8 km ENE), and Sangre de Cristo (8 km WSW). Lava flows were 500-600 m long on the W flank. On 11 May steaming lahars descended the Las Lajas, Seca, Ceniza, and Mineral drainages, carrying variously-sized blocks and tree parts. Lahars on 14 May carried blocks and tree trunks down the Ceniza drainage.

Ibu | Halmahera (Indonesia) : The Darwin VAAC reported that on 8 May an ash plume from Ibu rose to 2.4 km (8,000 ft) a.s.l. and drifted ESE based on satellite data. PVMBG noted that at 1821 on 9 May an ash plume rose 600 m above the crater rim and drifted S. Seismic activity was characterized by explosions, tremor, and signals indicating rock avalanches. According to the VAAC an ash plume drifted ESE at an altitude of 1.8 (6,000 ft) a.s.l. on 10 May. A 14 May VONA stated that at 1846 an ash plume rose 800 m and drifted N. 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.

Karymsky | Eastern Kamchatka (Russia) : KVERT reported that a thermal anomaly over Karymsky was visible in satellite images during 6-8 May. A gas-and-steam plume containing ash was also visible drifting 105 km SE and SW during 6-7 May. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Kerinci | Indonesia : PVMBG reported that at 1804 on 10 May a brown ash emission from Kerinci rose 700 m and drifted ESE. Seismic activity was characterized by continuous volcanic tremor and gas emissions. The Alert Level remained at 2 (on a scale of 1-4) with a 3-km exclusion zone.

Klyuchevskoy | Central Kamchatka (Russia) : KVERT reported that a weak thermal anomaly over Klyuchevskoy was identified in satellite images during 6 and 8-9 May. The Aviation colour Code was raised to Orange (the second highest level on a four-colour scale).

Krakatau | Indonesia : PVMBG reported that Anak Krakatau’s seismic network detected eruptive events at 1254 and 1446 on 10 May, 0555 on 11 May, 1003 and 1220 on 12 May, and 0021 on 14 May. An observer estimated that an ash plume rose 150 m above the summit and drifted NE at 1446 on 10 May, but noted that visibility was difficult. The Alert Level remained at 2 (on a scale of 1-4), and residents were warned to remain outside of the 2-km radius hazard zone from the crater.

Manam | Papua New Guinea : The Darwin VAAC reported that on 10 May an ash plume from Manam rose to an altitude of 5.5 km (18,000 ft) a.s.l. and drifted NE, based on satellite data and weather models. A sulfur dioxide plume and a thermal anomaly were also identified. The next day diffuse plumes drifted NE and E at an altitude of 2.4 (8,000 ft) a.s.l.

Nevados de Chillan | Chile : ONEMI and SERNAGEOMIN reported that an explosive event at Nevados de Chillán’s Nicanor Crater was recorded at 2003 on 12 May associated with a long-period earthquake signal. The explosion partially destroyed the lava dome, ejecting incandescent material onto the N flank. The Alert Level remained at Orange, the second highest level on a four-colour scale, and residents were reminded not to approach the crater within 3 km. ONEMI maintained an Alert Level Yellow (the middle level on a three-colour scale) for the communities of Pinto, Coihueco, and San Fabián.

Rincon de la Vieja | Costa Rica : OVSICORI-UNA reported that an eruption at Rincón de la Vieja recorded at 0720 on 11 May produced a white gas-and-steam plume that rose 600 m above the crater rim.

Sheveluch | Central Kamchatka (Russia) : KVERT reported that a thermal anomaly over Sheveluch’s lava dome was identified daily in satellite images during 3-10 May. Gas-and-steam plumes containing some ash was visible drifting 50 km SE and SW. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Suwanosejima | Ryukyu Islands (Japan) : JMA reported that crater incandescence at Suwanosejima’s Ontake Crater was visible at night during 3-10 May. A very small eruption on 5 May generated a plume that rose 500 m above the crater rim. The Alert Level remained at 2 (on a 5-level scale).

Volcanos

Global Volcanic Activity – Ongoing Activity for the week of 1 May – 7 May 2019

Agung | Bali (Indonesia) : PVMBG reported that an event at Agung was recorded by the seismic network at 1859 on 3 May. An ash plume was not visible from the Agung Volcano Observatory in Rendang (about 8 km SW), although the Darwin VAAC report a growing thermal anomaly and possible ash near the summit. About 30 minutes later the VAAC reported that an ash plume rose to 4.3 km (14,000 ft) a.s.l. and drifted NE; a thermal anomaly continued to be visible. On 6 May at 2255 a gray ash plume rose to around 2 km above the crater rim and drifted W. The Alert Level remained at 3 (on a scale of 1-4) with the exclusion zone set at a 4-km radius.

Aira | Kyushu (Japan) : JMA reported that incandescence from Minamidake crater (at Aira Caldera’s Sakurajima volcano) was occasionally visible at night during 29 April-7 May. Five explosions generated plumes that rose as high as 1.6 km above the crater rim. The Tokyo VAAC noted that plumes drifted E, SE, and SW during 1-2, 4, and 6 May. The Alert Level remained at 3 (on a 5-level scale).

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

Ebeko | Paramushir Island (Russia) : Volcanologists in Severo-Kurilsk (Paramushir Island), about 7 km E of Ebeko, observed explosions during 26 April-3 May that sent ash plumes up to 3 km (10,000 ft) a.s.l. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Etna | Sicily (Italy) : INGV reported that during 22-28 April ash emissions rose from Etna’s Bocca Nuova Crater, Northeast Crater (NEC), and from the E vent in New Southeast Crater (NSEC). Pulsating incandescence from NSEC’s E vent was recorded at night by webcams. A new vent on the inner wall of Voragine Crater was noted on 30 April. Strombolian activity from the BN-1 crater deep within the Bocca Nuova Crater was visible on 28 April and continued through 5 May; field inspections on 30 April revealed that two vents in BN-1 were active and producing explosions at a rate of one every 2-3 seconds. Bombs and lapilli were ejected above the crater rim but deposits remained mostly within the confines of the crater or near the rim. Strombolian activity was visible at NSEC during 29 April-5 May. On 2 May, beginning at 0131, discontinuous explosions at the E vent produced emissions of fine tephra that rose as high as 1 km above the crater rim and quickly dissipated. During 5-6 May the frequency of explosions increased for brief periods in conjunction with a slight increases in volcanic tremor amplitude.

Ibu | Halmahera (Indonesia) : The Darwin VAAC reported that on 7 May an ash plume from Ibu was visible in satellite data rising to an altitude of 2.4 km (8,000 ft) a.s.l. and drifting ESE. 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.

Karymsky | Eastern Kamchatka (Russia) : KVERT reported that a weak thermal anomaly over Karymsky was visible in satellite images during 27 and 30 April and 1 May. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Kerinci | Indonesia : In a Volcano Observatory Notice for Aviation (VONA) PVMBG noted that local residents reported ashfall from Kerinci in areas 7 km S and NE. According to a news article at least five villages were affected late on 2 May, including Tanjung Bungo, Sangir, Sangir Tengah, Sungai Rumpun, and Bendung Air. A brown ash emission was observed at 1836 on 3 May rising 800 m above the crater rim and drifting ESE. Seismicity was dominated by continuous volcanic tremor and signals indicating gas emissions. The next day at 1708 a brown ash emission rose 300 m and drifted SE. According to the Darwin VAAC an ash emission was observed by a pilot at 0610 on 5 May drifting NE at an altitude of 6.7 km (22,000 ft) a.s.l. The Alert Level remained at 2 (on a scale of 1-4), and tourists were warned to remain outside of the 3-km exclusion zone.

Krakatau | Indonesia : PVMBG reported that an event at 0519 on 6 May was recorded by Anak Krakatau’s seismic network, although no emission was visually observed. The Alert Level remained at 2 (on a scale of 1-4), and residents were warned to remain outside of the 2-km radius hazard zone from the crater.

Merapi | Central Java (Indonesia) : PVMBG reported that during 22-28 April the lava dome at Merapi continued to grow slowly, with any extruded material channeled into the SE-flank Gendol River drainage. White emissions rose 70 m. Five block-and-ash flows traveled as far as 1.2 km in the Gendol drainage on 24 April. The Alert Level remained at 2 (on a scale of 1-4), and residents were warned to remain outside of the 3-km exclusion zone.

Nyamuragira | DR Congo : The Observatoire Volcanologique de Goma (OVG) reported that during early April Nyamuragira’s lava lake, which had returned in April 2018 after almost a year of quiet, continued to be active. Beginning on 12 April seismic and lava-lake activity both declined. MIROVA data showed that the thermal radiative power was at moderate levels the first half of the month then declined to low levels during the second half.

Nyiragongo | DR Congo : The Observatoire Volcanologique de Goma (OVG) reported that during 1-28 April Nyiragongo’s lava lake continued to be active, extending the episode of ongoing activity to almost 17 years. A secondary cone which had formed on 29 February 2016 was also active, as well as three other vents surrounding it. Sulfur dioxide emissions reached a high of at least 5,000 tonnes per day, greater than March highs of 2,900 tonnes per day, but still below the alert threshold.

Poas | Costa Rica : OVSICORI-UNA reported a period of continuous emissions from Poás during 30 April-1 May with plumes rising 300 m above the crater rim and drifting SW. Ash emissions were visible for a few hours on 30 April, and incandescence was visible at night.

Sheveluch | Central Kamchatka (Russia) : KVERT reported that a thermal anomaly over Sheveluch’s lava dome was identified daily in satellite images during 26 April-3 May. Plumes of re-suspended ash were visible drifting 200 km SE during 30 April-2 May. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Volcanos

Global Volcanic Activity – New Activity for the week of 1 May – 7 May 2019

Asosan | Kyushu (Japan) : JMA reported that sulfur dioxide emissions at Asosan’s Nakadake Crater continued to be very high at 3,200 tons per day on 2 May. At night during 2-3 May webcams recorded weak incandescence from the crater. At 1540 on 3 May a very small eruption produced an off-white plume that rose 600 m above the crater rim. Later that day, at 1948, an ash plume rose 2 km and, according to the Tokyo VAAC, drifted S. Emissions from eruptive events continued until 0620 on 5 May, rising to 500 m. Afterwards white plumes rose as high as 1.1 km, at least through 7 May. Crater incandescence continued to be visible. During a field survey on 4 May ashfall was confirmed in areas downwind including parts of Takamori (7 km SSE), Minamiaso village (8 km SW), and Yamato (24 km SSW). Sulfur dioxide emissions were 4,000 tons per day on 4 May, and 3,100 tons per day on 6 May. The Alert Level remained at 2 (on a scale of 1-5).

Colima | Mexico : Centro Universitario de Estudios e Investigaciones de Vulcanologia – Universidad de Colima reported increased seismicity at Colima during 20-26 April characterized by a considerable increase in the number of high-frequency and volcano-tectonic events. On 26 April a consensus was reached to raise the Alert Level to Yellow (the second lowest level on a four-colour scale) and extend the exclusion zone to a 8-km radius during a meeting of the Coordinación Nacional de Protección Civil (CNPC), the Unidad Estatal de Protección Civil Colima (UEPC), the Unidad Estatal de Protección Civil y Bomberos de Jalisco (UEPCBJ), the Universidad de Colima (UdeC), and la Universidad de Guadalajara (UdeG). Seismicity continued to be elevated through 3 May. The largest events (M 2.4-3) were located 0.5-3 km deep in the N and NE parts of the volcano.

Klyuchevskoy | Central Kamchatka (Russia) : KVERT reported that a weak thermal anomaly over Klyuchevskoy was identified in satellite images during 26 April-3 May. The Aviation colour Code was raised to Orange (the second highest level on a four-colour scale).

Sinabung | Indonesia : PVMBG and BNPB reported that an eruption at Sinabung at 0641 on 7 May generated a dense ash plume that rose 2 km above the crater rim and drifted SW, causing the sky to turn dark in some areas. The eruption lasted 42 minutes and 49 seconds according to the seismic data. Ashfall was reported on farms in many villages in the Simpang Empat (7 km SE), Namanteran, Kabanjahe, and Berastadi districts. The Alert Level remained at 4 (on a scale of 1-4), with a general exclusion zone of 3 km and extensions to 7 km on the SSE sector, 6 km in the ESE sector, and 4 km in the NNE sector.

Volcanos

Global Volcanic Activity – Ongoing Activity for the week of 24 April – 30 April 2019

Agung | Bali (Indonesia) : PVMBG reported that at 0534 on 30 April a dense gray ash plume from Agung rose 1 km above the crater rim and drifted E. The Alert Level remained at 3 (on a scale of 1-4) with the exclusion zone set at a 4-km radius.

Dukono | Halmahera (Indonesia) : Based on satellite and wind model data, and information from PVMBG, the Darwin VAAC reported that during 24-27 and 29-30 April ash plumes from Dukono rose to altitudes of 1.5-2.1 km (5,000-7,000 ft) a.s.l. and drifted in multiple directions. The Alert Level remained at 2 (on a scale of 1-4), and visitors were warned to remain outside of the 2-km exclusion zone.

Ebeko | Paramushir Island (Russia) : Volcanologists in Severo-Kurilsk (Paramushir Island), about 7 km E of Ebeko, observed explosions during 21-22 and 24 April that sent ash plumes up to 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) : KVERT reported that a weak thermal anomaly over Karymsky was visible in satellite images during 18-21 April. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Krakatau | Indonesia : PVMBG reported that there were 19 events during 22-28 April recorded by Anak Krakatau’s seismic network; no emissions from the events were visually observed, even though the visibility was a mix of clear and foggy conditions. The Alert Level remained at 2 (on a scale of 1-4), and residents were warned to remain outside of the 2-km radius hazard zone from the crater.

Merapi | Central Java (Indonesia) | 7.54°S, 110.446°E | Elevation 2910 m

PVMBG reported that during 22-28 April the lava dome at Merapi continued to grow slowly, with any extruded material channeled into the SE-flank Gendol River drainage. White emissions rose 70 m. Five block-and-ash flows traveled as far as 1.2 km in the Gendol drainage on 24 April. The Alert Level remained at 2 (on a scale of 1-4), and residents were warned to remain outside of the 3-km exclusion zone.

Nevados de Chillan | Chile : SERNAGEOMIN reported that the lava dome in Nevados de Chillán’s Nicanor Crater continued a cycle of slow growth and partial destruction from explosions during 23-30 April. The pulsating, generally white, emissions were sometimes gray and rose no higher than 900 m above the crater rim and drifted NW, S, and SE. Nighttime webcam data showed incandescent ejecta around the crater. The Alert Level remained at Orange, the second highest level on a four-colour scale, and residents were reminded not to approach the crater within 3 km. ONEMI maintained an Alert Level Yellow (the middle level on a three-colour scale) for the communities of Pinto, Coihueco, and San Fabián.

Poas | Costa Rica : OVSICORI-UNA reported that on 24 April a very diffuse ash emission rose from Poás. Incandescence from vent A (Boca Roja) was sometimes visible during 24 and 27-28 April.

Reventador | Ecuador : IG reported that during 23-30 April periodic seismic data from Reventador’s network indicated a high level of seismic activity, including explosions, long-period earthquakes, harmonic tremor, and signals indicating emissions. Steam, gas, and ash plumes sometimes rose higher than 1 km above the crater rim and drifted N, NW, W, and SW. Incandescent blocks were observed rolling 500-800 m down the flanks. Inclement weather sometimes prevented visual observations.

Ruapehu | North Island (New Zealand) : GeoNet reported that the period of high water temperatures at Ruapehu’s summit Crater Lake along with elevated tremor levels was over. Tremor levels began to decline on 16 April and by 29 April was described as weak. The lake water reached a peak temperature of 44 degrees Celsius on 19 April and then began cooling; the temperature was 39 degrees Celsius by 29 April. The report noted that the probability of an eruption during a heating cycle had decreased with the decreasing activity. The Volcanic Alert Level remained at 1 (minor volcanic unrest) and the Aviation colour Code remained at Green.

Sheveluch | Central Kamchatka (Russia) : KVERT reported that a thermal anomaly over Sheveluch’s lava dome was identified daily in satellite images during 18-26 April. Ash plumes were visible drifting 300 km NE during 22-23 April. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Turrialba | Costa Rica : OVSICORI-UNA reported that a diffuse ash emission rose from Turrialba on 24 April, and an emission with low ash content drifted N on 26 April. At 0722 on 27 April a small, short-duration eruption generated an ash plume that rose less than 100 m above the crater rim.

Veniaminof | United States : On 30 April AVO lowered the Aviation colour Code for Veniaminof to Green and the Volcano Alert Level to Normal, noting that signs of unrest had continued to decline over the previous four months since the eruption ended in early January. Low-level tremor, slightly elevated surface temperatures, and minor steam emissions continued and considered typical activity for a post-eruptive period.

Volcanos

Global Volcanic Activity – New Activity for the week of 24 April – 30 April 2019

Asosan | Kyushu (Japan) : JMA reported that during 24-29 April white plumes from Asosan’s Nakadake Crater rose 200-800 m above the crater rim. Many low-amplitude tremors and volcanic earthquakes were recorded. Sulfur dioxide emissions were generally high but on 25 April the gas emissions were very high at 4,000 tons/day, a value not exceeded since 12 March. Emissions were 3,300 tons/day on 25 April. Weak incandescence from Nakadake Crater was visible at night during 27-28 April. The Alert Level remained at 2 (on a scale of 1-5).

Klyuchevskoy | Central Kamchatka (Russia) : KVERT reported that during 21-22 April a weak thermal anomaly over Klyuchevskoy was identified in satellite images along with gas-and-steam plumes containing ash drifting 160 km E. The Aviation colour Code was raised to Orange (the second highest level on a four-colour scale).

Tengger Caldera | Eastern Java (Indonesia) : The Darwin VAAC reported that during 24-26 April white plumes of variable density rose 300-500 m above Tengger Caldera’s Bromo cone. White-to-black emissions rose 500 m above the cone on 27 April, and white-to-gray emissions rose 600 m above the cone on 29 April. The Alert Level remained at 2 (on a scale of 1-4), and visitors were warned to stay outside of a 1-km radius of the crater.

Volcanos

Global Volcanic Activity – Ongoing Activity for the week of 17 April – 23 April 2019

Agung | Bali (Indonesia) : PVMBG reported two explosive eruptions at Agung on 21 April. The first was recorded at 0321 and produced a dense gray ash plume that rose 2 km above the crater rim and drifted W and S. Ashfall was reported in areas downwind including Besakih (7 km SW), Rendang (12 km NW), Klungkung (~40 km S), Gianyar (20 km WSW), Bangli (17 km WNW), Tabanan (51 km WSW), and the International Gusti Ngurah Rai (IGNR) airport (60 km SW) in Denpasar. The second event was recorded at 1856 and generated a dense ash plume that rose 3 km and drifted S. Minor ashfall was reported in Besakih, Rendang, Sebudi (6 km SW), and Selat (12 km SSW). The eruptions were accompanied by a boom heard at both the Rendang and Batulompeh observation posts. Ejected incandescent material from the two events fell on the flanks in all directions within a radius of 4 km. The Alert Level remained at 3 (on a scale of 1-4) with the exclusion zone set at a 4-km radius.

Aira | Kyushu (Japan) : JMA reported that the sulfur dioxide emission rate at Minamidake crater (at Aira Caldera’s Sakurajima volcano) was somewhat high on 16 April at 1,600 tons/day. An explosion on 17 April generated a plume that rose 2 km above the crater rim and ejected material as far as 900 m. During 19-22 April plumes from two events rose as high as 1.4 km. The Alert Level remained at 3 (on a 5-level scale).

Ambrym | Vanuatu : On 24 April the Vanuatu Meteorology and Geo-Hazards Department (VMGD) reported ongoing seismic activity at Ambrym and steam emissions. The lava lakes in Benbow and Marum craters had ceased to be active on 16 December 2018, one day after a fissure eruption began in the ESE part of the summit caldera near the Lewlembwi crater, and continued to be inactive. The Alert Level remained at 2 (on a scale of 0-5); the report reminded the public to stay outside of the Permanent Danger Zone defined as a 1-km radius from Benbow Crater and a 2-km radius from Marum Crater. An additional Danger Zone was defined as a 1-km radius around the December 2018 fissures.

Dukono | Halmahera (Indonesia) : Based on satellite and wind model data, the Darwin VAAC reported that during 17-23 April ash plumes from Dukono rose as high as 2.1 km (7,000 ft) a.s.l. and drifted in multiple directions. The Alert Level remained at 2 (on a scale of 1-4), and visitors were warned to remain outside of the 2-km exclusion zone.

Ebeko | Paramushir Island (Russia) : Volcanologists in Severo-Kurilsk (Paramushir Island), about 7 km E of Ebeko, observed explosions during 12-15 April that sent ash plumes up to 3.2 km (10,500 ft) a.s.l. A thermal anomaly was identified in satellite images on 13 April. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Fuego | Guatemala : INSIVUMEH reported that on 18 April steaming hot lahars descended Fuego’s Ceniza (SSW) and Taniluyá (SW) drainages, carrying variously-sized material including blocks up to 2 m in diameter. The lahars were 1 m deep, 15 m wide, and had a sulfur odor. During 20-23 April there were 17-22 explosions per hour, generating ash plumes that rose almost as high as 1.1 km and drifted 15-20 km S, SW, and W. Shock waves vibrated local structures. Incandescent material was ejected 300-450 m high and caused avalanches of material that occasionally traveled long distances down Seca, Taniluyá, Ceniza, Trinidad, Las Lajas, and Honda ravines. A lava flow, 600 m long, advanced in the Seca drainage. Ashfall was reported in reported in Yepocapa (8 km N), Morelia (9 km SW), Santa Sofia (12 km SW), Sangre de Cristo (8 km WSW), and Panimache (8 km SW).

Ibu | Halmahera (Indonesia) : The Darwin VAAC reported that on 18 April an ash plume from Ibu was identified in satellite images drifting E at an altitude of 2.1 km (7,000 ft) a.s.l. 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.

Karymsky | Eastern Kamchatka (Russia) : KVERT reported that a weak thermal anomaly over Karymsky was visible in satellite images during 13-14 April. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Krakatau | Indonesia : PVMBG reported that there were four eruptive events during 15-22 April and multiple events on 23 April recorded by Anak Krakatau’s seismic network, though no emissions were visible. The Alert Level remained at 2 (on a scale of 1-4), and residents were warned to remain outside of the 2-km radius hazard zone from the crater.

Merapi | Central Java (Indonesia) : PVMBG reported that during 15-21 April the lava dome at Merapi continued to grow slowly, with any extruded material channeled into the SE-flank Gendol River drainage. White emissions rose 70 m. Block-and-ash flows traveled as far as 1.5 km in the Gendol drainage on 21 April. The Alert Level remained at 2 (on a scale of 1-4), and residents were warned to remain outside of the 3-km exclusion zone.

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

Sheveluch | Central Kamchatka (Russia) : KVERT reported that a thermal anomaly over Sheveluch’s lava dome was identified daily in satellite images during 12-18 April. Ash plumes were visible on 13 and 15 April drifting 83 km SE. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Stromboli | Aeolian Islands (Italy) : INGV reported that during 15-21 April activity at Stromboli was characterized by ongoing Strombolian activity and degassing from multiple vents within the crater terrace, though activity intensified on 19 April. Explosions originated at a rate of 3-16 per hour mainly from two vents (N1 and N2) in Area N (north crater area, NCA) and at least four vents (including C, S1, and S2) in Area C-S (South Central crater area). Explosions from the N1 vent ejected lapilli and bombs mixed with ash no more than 150 m high. Low-intensity explosions at the N2 vent ejected tephra to heights under 80 m. Vent C produced gas emissions. Incandescent material from S1 jetted as high as 150 m above the crater. Explosions from two vents at S2 ejected tephra more than 150 m high.