KVERT reported that a strong explosive eruption at Chikurachki during 29-31 March generated ash plumes that rose to a maximum altitude of 4 km (13,100 ft) a.s.l. and drifted 570 km NE, S, and SW. The volcano was quiet afterwards; the Aviation Color Code was lowered to Yellow on 2 April, and then to Green on 5 April.

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

PHIVOLCS reported that long-duration tremor began at Kanlaon at 0130 on 30 March. The tremor was accompanied by gas-and-steam plumes that rose 600-700 m and drifted SW and SSW during 30 March-1 April. On 31 March minor ashfall was reported in areas downwind including in parts of La Carlota City (14 km W), La Castellana, and Bago City in Negros Occidental. The tremor continued during 2-4 April, though the energy decreased, and steam plumes rose 400-500 m. On 5 April steam plumes rose 800 m and drifted SW. The Alert Level remained at 1 (on a scale of 0-5).

Source: Philippine Institute of Volcanology and Seismology (PHIVOLCS)

Based on satellite images and ground reports from PVMBG, the Darwin VAAC reported that during 31 March-2 April and 4-5 April ash plumes from Kerinci rose to altitudes of 4.3-4.9 km (14,000-16,000 ft) a.s.l., and drifted NW, N, and E.

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

KVERT reported strong gas-and-steam activity at Klyuchevskoy during 25 March-1 April. A weak thermal anomaly was detected over the volcano during 25 and 29-30 March. Strong Strombolian activity began at 2325 on 3 April, and satellite images on 5 April began registering a bright thermal anomaly. The Aviation Color Code remained at Yellow.

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Based on analyses of satellite imagery, the Darwin VAAC reported that during 2-3 April ash plumes from Langila rose to an altitude of 2.1 km (7,000 ft) a.s.l. and drifted 35-65 km N NE, and E.

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

AVO reported that the intensity of the eruption at Pavlof greatly decreased during 29-30 March, though a news article noted that ash from the eruption had caused more flights in and out of Yellowknife and Regina, Canada, to be cancelled. Elevated surface temperatures identified in satellite data and visual observations of low-level, intermittent ash plumes were noted during brief breaks in poor weather conditions. Seismicity remained elevated above background levels through 4 April, and was characterized by occasional short-duration tremor bursts. Cloud cover obscured satellite and web-cam views, though weakly elevated surface temperatures were detected in a few satellite images during 1-5 April. Airwave signals, indicative of small explosions at the summit, were recorded by the seismic stations at 1842 on 3 April. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.

Sources: US Geological Survey Alaska Volcano Observatory (AVO), CityNews

At 1200 on 30 March CENAPRED reported that during the previous 24 hours the seismic network at Popocatépetl recorded 179 emissions and four explosions. Ash plumes from the explosions rose as high as 3.5 km above the crater; ash from the explosions caused Puebla's airport to close from 2000 on 29 March to 0600 on 30 March.

During 30 March-5 April there were 38-136 emissions and as many as six explosions detected daily; some emissions corresponded with increased crater incandescence. An explosion at 0103 on 31 March produced an ash plume that rose 1.8 km and drifted ENE, and ejected incandescent fragments 1 km away onto the ESE flank. An explosion at 1521 generated an ash plume that rose 2 km and drifted ENE. With the assistance of the Federal Police, on 2 April CENAPRED scientists conducted an overflight of the crater and observed an inner crater that was 325 m in diameter and 50 m deep; the crater had previously been filled with a lava dome, destroyed in January, which had grown to an estimated volume of 2,000,000 cubic meters. Small landslides had occurred on the E wall of the inner crater. An explosion at 2031 on 3 April generated an ash plume that rose 2 km and drifted NE. Incandescent fragments were ejected as far as 3.5 km onto the E and SE flanks, generating fires in that part of the forest. Ash fell in the towns of Juan C. Bonilla (32 km ENE) and Coronango (35 km ENE), both in the state of Puebla. SINAPRED noted that the explosion was the strongest recorded in the previous three years. The Alert Level remained at Yellow, Phase Two.

Sources: Centro Nacional de Prevencion de Desastres (CENAPRED), Sistema Nacional para la Prevención, Mitigación y Atención de Desastres (SINAPRED)

Based on satellite images and notices from the Guayaquil MWO, the Washington VAAC reported that on 1 April an ash plume from Sangay rose to an altitude of 6.7 km (22,000 ft) a.s.l. and drifted SW. The next day an ash plume rose to an altitude of 5.5 km (18,000 ft) a.s.l., and a continuing thermal anomaly was detected. On 4 April satellite images detected an ash plume that drifted about 18 km N at an altitude of 5.5 km (18,000 ft) a.s.l.

Source: Washington Volcanic Ash Advisory Center (VAAC)

OVDAS-SERNAGEOMIN reported that at 0750 on 3 April the seismic stations at Villarrica began recording more energetic volcanic tremor. In addition, the webcam recorded increased surficial activity characterized by Strombolian explosions and intensifying crater incandescence. The Alert Level was raised to Yellow (the second lowest level on a four-color scale) and the public was warned to stay outside of a 1-km radius around the crater and away from drainages.

Source: Servicio Nacional de Geología y Minería (SERNAGEOMIN)

JMA reported that on 1 April an explosion at Aira Caldera’s Sakurajima volcano generated an ash plume that rose 2 km above Showa's crater rim. An explosion at Minamidake summit crater also produced an ash plume which rose 800 m above its crater rim. Three of five explosions detected at Showa during 1-4 April generated ash plumes that rose as high as 3.5 km, and ejected tephra as far as 1,300 m. Reports of falling tephra, 2 cm in diameter, came from a town 3 km away. At 0608 on 3 April an ash plume from an explosion rose 700 m above Minamidake. The Alert Level remained at 3 (on a 5-level scale).

Source: Japan Meteorological Agency (JMA)

KVERT reported that moderate activity at Alaid continued during 25 March-1 April. Satellite images showed an intense daily thermal anomaly over the volcano. A gas-and-steam plume continaing minor amounts of ash drifted about 60 km S and SW during 26 and 30-31 March. The Aviation Color Code remained at Orange (the second highest level on a four-color scale).

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

SVERT reported that satellite images detected a thermal anomaly over Snow, a volcano of Chirpoi, during 29-30 March and 1 April. The Aviation Color Code remained at Yellow.

Source: Sakhalin Volcanic Eruption Response Team (SVERT)

Based on satellite and webcam images, the Washington VAAC reported that during 30 March and 1-2 April ash plumes from Colima rose to altitudes of 4-5.5 km (13,000-18,000 ft) a.s.l. and drifted E and NE.

Source: Washington Volcanic Ash Advisory Center (VAAC)

Based on analyses of satellite imagery and wind data, the Darwin VAAC reported that during 30 March-5 April ash plumes from Dukono rose to altitudes of 1.5-2.1 km (5,000-7,000 ft) a.s.l. and drifted as far as 175 km NE, ESE, S, and SW.

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Based on INGV webcam views, and VONA and SIGMET notices, the Toulouse VAAC reported a small eruption at Etna on 31 March which ended the next day.

Source: Toulouse Volcanic Ash Advisory Centre (VAAC)

KVERT reported that moderate activity at Karymsky continued during 25 March-1 April. Fresh ash deposits from the previous week were noted near the volcano. The Aviation Color Code remained at Orange.

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

HVO reported that seismicity beneath Kīlauea's summit, upper East Rift Zone, and Southwest Rift Zone was at background levels during 30 March-5 April. The lava lake continued to circulate and spatter in the Overlook vent. Webcams recorded outgassing from multiple spatter cones on the Puʻu ʻŌʻō Crater floor. A very small lava flow briefly erupted onto the crater floor during 31 March-1 April, and on 3 and 4 April. The June 27th NE-trending lava flow continued to be active within 7.6 km NE of Puʻu ʻŌʻō Crater.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)

On 30 March INETER reported that the lava lake rose in Masaya's Santiago crater and several landslide deposits from the precious few days were visible in the NE crater. RSAM values were at moderate-to-high levels. On 4 April SINAPRED noted that tremor continued and the widening of the vent in the SE part of the crater persisted.

Sources: Instituto Nicaragüense de Estudios Territoriales (INETER), Sistema Nacional para la Prevención, Mitigación y Atención de Desastres (SINAPRED)

SINAPRED reported that on 2 April explosions at Momotombo produced gas-and-ash plumes and ejected incandescent tephra.

Source: Sistema Nacional para la Prevención, Mitigación y Atención de Desastres (SINAPRED)

Servicio Geológico Colombiano’s (SGC) Observatorio Vulcanológico y Sismológico de Manizales reported that at 0804 on 31 March an episode of short-duration volcanic tremor was associated with an ash emission that rose 3.5 km above Nevado del Ruiz. According to the Washington VAAC the ash plume drifted NW and SW. The Alert Level remained at III (Yellow; "changes in the behavior of volcanic activity").

Sources: Servicio Geológico Colombiano (SGC), Washington Volcanic Ash Advisory Center (VAAC)

INSIVUMEH reported that during 30 March-3 April cloud cover prevented visual observations of Caliente cone, part of Santa María's Santiaguito lava-dome complex, though sounds of small avalanches were noted. At 1000 on 3 April INSIVUMEH issued a special report stating that a strong explosion occurred, and pyroclastic flows descended the E and SE flanks. Parts of the E and W crater rim collapsed, and a mushroom-shaped ash cloud rose 4 km and drifted 30 km S, SW, W, and NW. During 4-5 April white plumes drifted SW and SE, and weak avalanches traveled short distances.

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

KVERT reported that during 25 March-1 April lava-dome extrusion onto Sheveluch’s N flank was accompanied by strong fumarolic activity, dome incandescence, ash explosions, and hot avalanches. Satellite images detected an intense daily thermal anomaly over the dome. The Aviation Color Code remained at Orange.

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Based on satellite images and information from PVMBG, the Darwin VAAC reported that during 30 March-2 April and 4 April ash plumes from Sinabung rose to altitudes of 3.3-4.2 km (11,000-14,000 ft) a.s.l. and drifted W and NW.

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

On 30 March INETER reported that micro-seismicity at Telica remained high and was characterized by small, high-energy earthquakes. Incandescence emanated from the crater floor. On 4 April SINAPRED noted that seismicity continued at a high level and warned the public to stay away from the crater.

Sources: Instituto Nicaragüense de Estudios Territoriales (INETER), Sistema Nacional para la Prevención, Mitigación y Atención de Desastres (SINAPRED)

Based on satellite images, wind data, and ground reports from PVMBG, the Darwin VAAC reported that during 2-5 April ash plumes from Tengger Caldera's Bromo cone rose to altitudes of 2.1-3.6 km (7,000-12,000 ft) a.s.l. and drifted 25-45 km SW and W.

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

OVSICORI-UNA reported that at 0859 on 3 April an explosion at Turrialba lasting less than one minute generated an ash-and-gas plume that rose about 100 m and drifted S and SW. A small amount of ash and a sulfur odor was reported in an area 2 km NW of the volcano.

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

On 31 March, the Vanuatu Geohazards Observatory stated that the Alert Level for Yasur remained at 2 (on a scale of 0-4) and that explosions were intense. VGO reminded residents and tourists that hazardous areas were near and around the volcanic crater, and that volcanic ash and gas could reach areas impacted by trade winds.

Source: Vanuatu Meteorology and Geohazards Department (VMGD)

KVERT reported that moderate activity at Zhupanovsky continued during 25 March-1 April. The Aviation Color Code remained at Orange.

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)