Aira (Japan) | 22 April-28 April 2015 | Continuing ActivityCite this Report

JMA reported that 29 explosions from Showa Crater at Aira Caldera’s Sakurajima volcano ejected tephra as far as 1,300 m during 20-24 April. Nine of the explosions generated ash plumes that rose 3 km above the crater rim; one explosion, on 24 April, produced an ash plume that rose 4 km. Incandescence from the crater was visible on one night. The Alert Level remained at 3 (on a scale of 1-5). Based on JMA notices, the Tokyo VAAC reported that explosions during 22-28 April generated plumes which rose to altitudes of 1.5-4.9 km (5,000-16,000 ft) a.s.l. and drifted S, SE, E, NE, and N.

Sources: Japan Meteorological Agency (JMA), Tokyo Volcanic Ash Advisory Center (VAAC)

Asosan (Japan) | 22 April-28 April 2015 | Continuing ActivityCite this Report

JMA reported that, based on seismic data, the eruption from Asosan’s Nakadake Crater that began on 25 November 2014 continued during 20-24 April. A plume rose 1.5 km above the crater rim and incandescence from the vent was observed at night. Field surveys confirmed that ash emissions from the active vent rose as high as 200 m above the crater rim. High-amplitude tremor continued. The Alert Level remained at 2 (on a scale of 1-5).

Source: Japan Meteorological Agency (JMA)

Bardarbunga (Iceland) | 22 April-28 April 2015 | Continuing ActivityCite this Report

On 26 April the Icelandic Met Office (IMO) lowered the Aviation Color Code for Bárdarbunga to Green (the lowest on a four-color scale). No further signs of unrest had been noted since the end of the eruption on 27 February; seismicity within the caldera and the associated dyke intrusion continued to decline.

Source: Icelandic Meteorological Office (IMO)

Chikurachki (Russia) | 22 April-28 April 2015 | Continuing ActivityCite this Report

KVERT reported that, based on analysis of satellite images of Chikurachki from 18 April, a thermal anomaly and ash plumes were not detected; an observer from Severo-Kurilsk (60 km NW, Paramushir Island) had reported a minor ash plume. The Aviation Color Code was lowered back to Green on 24 April.

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Chirpoi (Russia) | 22 April-28 April 2015 | Continuing ActivityCite this Report

SVERT reported that satellite images over Snow, a volcano of Chirpoi, detected steam-and-gas emissions on 20 April. Cloud cover obscured views during 21-27 April. The Aviation Color Code remained at Yellow.

Source: Sakhalin Volcanic Eruption Response Team (SVERT)

Colima (Mexico) | 22 April-28 April 2015 | Continuing ActivityCite this Report

Based on satellite images, and webcam views, Mexico City MWO notices, and wind data, the Washington VAAC reported multiple ash emissions from Colima during 21-26 and 28 April. Ash plumes rose to altitudes of 5.5-7.3 km (15,000-24,000 ft) a.s.l. and drifted NW to NE. On 25 April ashfall was reported in areas 85 km N.

Source: Washington Volcanic Ash Advisory Center (VAAC)

Dukono (Indonesia) | 22 April-28 April 2015 | Continuing ActivityCite this Report

PVMBG reported that during March-22 April dense white-gray plumes rose as high as 2 km above Dukono's Malupang Warirang Crater and were accompanied by rumbling and roaring. Seismicity remained high and consisted of explosion signals, volcanic earthquakes, and tremor. The Alert Level remained at 2 (on a scale of 1-4). Residents and tourists were advised not to approach the crater within a radius of 2 km. Based on analyses of satellite imagery and wind data, the Darwin VAAC reported that on 26-28 April ash plumes from Dukono rose to altitudes of 2.7-3 km (9,000-10,000 ft) a.s.l. and drifted 35-150 km E.

Sources: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM), Darwin Volcanic Ash Advisory Centre (VAAC)

Gamalama (Indonesia) | 22 April-28 April 2015 | Continuing ActivityCite this Report

PVMBG reported that during March-22 April diffuse white plumes rose as high as 50 m above Gamalama; on 7 April the plumes became dense and rose 100 m. Seismicity fluctuated but remained generally low. The Alert Level remained at 2 (on a scale of 1-4); visitors and residents were warned not to approach the crater within a radius of 1.5 km.

Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)

Karangetang (Indonesia) | 22 April-28 April 2015 | Continuing ActivityCite this Report

PVMBG reported that during 15-22 April diffuse white and bluish-white plumes rose as high as 300 m above Karangetang's main crater and 25 m above Crater II. Incandescence from the lava dome was observed at night. Seismicity indicated lava-dome growth and an overall decline in activity compared to February data. The Alert Level remained at 3 (on a scale of 1-4); visitors and residents were warned not to climb Karangetang any higher than 500 a.s.l.

Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)

Karymsky (Russia) | 22 April-28 April 2015 | Continuing ActivityCite this Report

KVERT reported moderate activity at Karymsky during 17-24 April. Satellite images detected a thermal anomaly over the volcano during 16-17 and 23 April, and ash plumes drifting 35 km SE on 23 April. The Aviation Color Code remained at Orange.

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Klyuchevskoy (Russia) | 22 April-28 April 2015 | Continuing ActivityCite this Report

KVERT reported that moderate gas-and-steam activity at Klyuchevskoy was recorded by the webcam during 16-17, 19, 21, and 23 April. Satellite images detected a weak thermal anomaly over the volcano during 16-17 and 23 April. A gas plume containing a small amount of ash drifted 147 km E on 21 April. On 26 April the Aviation Color Code was lowered to Yellow; KVERT noted that gas-and-steam activity and tremor continued.

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Krakatau (Indonesia) | 22 April-28 April 2015 | Continuing ActivityCite this Report

PVMBG reported that during 1 March-21 April diffuse white plumes rose 25-50 m above Anak Krakatau, although foggy weather often prevented observations. Seismicity continued to be dominated by shallow and deep volcanic earthquakes, as well as signals indicating emissions. 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.

Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)

Manam (Papua New Guinea) | 22 April-28 April 2015 | Continuing ActivityCite this Report

Based on observations of satellite imagery and wind data analyses, the Darwin VAAC reported that during 27-28 April ash plumes from Manam rose to an altitude of 2.4 km (8,000 ft) a.s.l. and drifted 75-130 km W.

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Nevado del Ruiz (Colombia) | 22 April-28 April 2015 | Continuing ActivityCite this Report

Based on satellite image analyses, the Washington VAAC reported that on 22 April a small puff of gas with minor amounts of ash from Nevado del Ruiz drifted over 40 km W and dissipated.

Source: Washington Volcanic Ash Advisory Center (VAAC)

Papandayan (Indonesia) | 22 April-28 April 2015 | Continuing ActivityCite this Report

PVMBG reported that during 1 March-21 April seismicity at Papandayan was dominated by shallow volcanic earthquakes but also consisted of volcanic earthquakes, low-frequency earthquakes, and local and remote tectonic earthquakes. Visual monitoring occurred from the Pakuwon Village post; observers noted white plumes rising at most 100 m above the crater. The Alert Level remained at 2 (on a scale of 1-4); residents and tourists were reminded not to approach the craters within a 1-km radius.

Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)

Popocatepetl (Mexico) | 22 April-28 April 2015 | Continuing ActivityCite this Report

CENAPRED reported that during 22-28 April the seismic network at Popocatépetl recorded 25-91 daily emissions mostly consisting of water vapor and gas. Cloud cover sometimes prevented observations of the crater, although gas plumes and nighttime crater incandescence were noted daily. On 22 April an explosion at 0121 produced diffuse gas and water vapor emissions. Explosions at 1643 and 1758 generated ash plumes. The Alert Level remained at Yellow, Phase Two.

Source: Centro Nacional de Prevencion de Desastres (CENAPRED)

Santa Maria (Guatemala) | 22 April-28 April 2015 | Continuing ActivityCite this Report

INSIVUMEH reported that during 23-24 and 27-28 April grayish-white ash plumes rose 400-500 m from Santa María's Santiaguito lava-dome complex and drifted SW. An explosion at 0450 on 24 April generated a small plume that drifted SW, and explosions at 0517 and 0602 on 28 April generated plumes that rose 500 m and drifted SW.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)

Semeru (Indonesia) | 22 April-28 April 2015 | Continuing ActivityCite this Report

PVMBG reported that white plumes and grayish white plumes from Semeru rose as high as 600 m above the crater during January-20 April, although inclement weather often prevented observations. Seismicity fluctuated, and was dominated by explosions and emission signals. During January incandescent avalanches from lava-flow fronts traveled 100-300 m. Eruptions were heard five times during 16-28 February. Nine explosions were heard during 1-15 March; minor ashfall from one of the explosions fell on the observation post. The Alert Level remained at 2 (on a scale from 1-4); visitors and residents were warned to avoid the SE flank within 4 km of the crater.

Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)

Sheveluch (Russia) | 22 April-28 April 2015 | Continuing ActivityCite this Report

KVERT reported that during 17-24 April lava-dome extrusion onto Sheveluch’s N flank was accompanied by incandescence, hot block avalanches, and fumarolic activity. A thermal anomaly was detected during 16-18 and 23 April; cloud cover obscured views on the other days. The Aviation Color Code remained at Orange.

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Shishaldin (United States) | 22 April-28 April 2015 | Continuing ActivityCite this Report

AVO reported that seismicity at Shishaldin continued to be elevated over background levels 22-28 April, indicating that low-level eruptive activity confined to the summit crater likely continued. Cloud cover frequently prevented satellite and webcam observations. Slight steaming was recorded by the webcam on 26 April and elevated temperatures were detected in satellite images during 27-28 April. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

Suwanosejima (Japan) | 22 April-28 April 2015 | Continuing ActivityCite this Report

Based on JMA notices, the Tokyo VAAC reported that explosions at Suwanose-jima during 24-25 April generated plumes that rose to altitudes of 1.8-2.1 km (6,000-7,000 ft) a.s.l. and drifted N and SE.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)

Tengger Caldera (Indonesia) | 22 April-28 April 2015 | Continuing ActivityCite this Report

PVMBG reported that during January-10 April white plumes from Tengger Caldera's Bromo cone rose 50-100 m above the crater. A sulfur dioxide odor was noted at the Bromo observation post. Seismicity was dominated by tremor, but also included volcanic earthquakes. The Alert Level remained at 2 (on a scale of 1-4). Residents and visitors were warned not to approach the crater within a radius of 1 km.

Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)

Turrialba (Costa Rica) | 22 April-28 April 2015 | Continuing ActivityCite this Report

Based on webcam views, and observers at the Tobías Bolaños and Juan Santamaría international airports, the Washington VAAC reported that gas emissions with minor ash content rose from Turrialba and drifted W during 23-24 April.

Source: Washington Volcanic Ash Advisory Center (VAAC)

Villarrica (Chile) | 22 April-28 April 2015 | Continuing ActivityCite this Report

OVDAS-SERNAGEOMIN reported that during 15-28 April seismicity at Villarrica fluctuated but remained at moderate levels. Intermittent crater incandescence was observed and diffuse gas plumes mostly consisting of water vapor rose from the crater. Data from monitoring stations and pictures taken during an overflight on 21 April confirmed the presence of a lava lake and Strombolian explosions. During 23-27 April Strombolian explosions ejected material that remained mostly within the crater or no more than 100 m away. The Alert Level remained at Orange (the second highest level on a four-color scale) and the public was warned to stay outside of a 5-km radius around the crater and 200 m away from drainages.

Source: Servicio Nacional de Geología y Minería (SERNAGEOMIN)

Yasur (Vanuatu) | 22 April-28 April 2015 | Continuing ActivityCite this Report

On 27 April, the Vanuatu Geohazards Observatory stated that Yasur continued in a state of unrest; the Alert Level remained at 1 (on a scale of 0-4). VGO reminded residents and tourists that hazardous areas were in proximity to and around the volcanic crater, and in volcanic ash and gas prone areas exposed to trade winds.

Source: Vanuatu Meteorology and Geohazards Department (VMGD)

Zhupanovsky (Russia) | 22 April-28 April 2015 | Continuing ActivityCite this Report

KVERT reported that strong gas-and-steam activity was observed at Zhupanovsky during 10-17 April. A thermal anomaly over the volcano was observed in satellite images during 16-17 and 23 April; cloud cover obscured views during 18-22 and 24 April. The Aviation Color Code remained at Orange.

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)