Eruptions

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.

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

JMA reported that incandescence from Minamidake crater (at Aira Caldera?s Sakurajima volcano) was occasionally visible at night during 22-29 April. Three events and one explosion during 22-26 April generated plumes that rose as high as 1.4 km above the crater rim. A small event was recorded on 27 April. The Alert Level remained at 3 (on a 5-level scale).

Source: Japan Meteorological Agency (JMA)

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.

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

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 Color Code remained at Orange (the second highest level on a four-color scale).

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

KVERT reported that a weak thermal anomaly over Karymsky was visible in satellite images during 18-21 April. The Aviation Color Code remained at Orange (the second highest level on a four-color scale).

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

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.

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

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.

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

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-color 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-color scale) for the communities of Pinto, Coihueco, and San Fabián.

Source: Servicio Nacional de Geología y Minería (SERNAGEOMIN)

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.

Source: Observatorio Vulcanologico y Sismologico de Costa Rica-Universidad Nacional (OVSICORI-UNA)

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.

Source: Instituto Geofísico-Escuela Politécnica Nacional (IG)