Ubinas, Peru

Based on pilot reports, SIGMET reports, and observations of satellite imagery, the Buenos Aires VAAC reported that ash plumes from Ubinas rose to altitudes of 5.5-7.6 km (18,000-25,000 ft) a.s.l. and drifted ESE and NE during 19-22 April.
Source: Buenos Aires Volcanic Ash Advisory Center (VAAC) - “Reports provided courtesy of the Smithsonian’s Global Volcanism Program [...]

Tungurahua, Ecuador

The IG reported that although visual observations were mostly limited due to cloud cover during 16-22 April, ash-and-steam plumes from Tungurahua were spotted on 16, 20, and 21 April and rose to altitudes of 6-8 km (19,700-26,200 ft) a.s.l. Strombolian activity at the crater was noted at night on 15 and 20 April. During 16-19 [...]

Suwanose-Jima, Ryukyu Islands, Japan

Based on information from JMA, the Tokyo VAAC reported that an explosion from Suwanose-jima occurred on 16 April. The altitude and direction of a possible resultant plume were not reported.
Source: Tokyo Volcanic Ash Advisory Center (VAAC) - “Reports provided courtesy of the Smithsonian’s Global Volcanism Program and the US Geological Survey’s Volcano Hazards Program.”

Soufriére Hills, Montserrat, West Indies

MVO reported that during 4-18 April the lava dome at Soufrière Hills changed very little, based on measurable parameters. Overflights on 9 and 16 April revealed that the E side of the lava dome continued to erode and exposed more resistant solid material below. A small pyroclastic flow traveled 500 m down the E flank [...]

Semeru, Eastern Java, Indonesia

Based on pilot observations, the Darwin VAAC reported that a plume from Semeru rose vertically to an altitude of 6.1 km (20,000 ft) a.s.l. on 21 April.
Source: Darwin Volcanic Ash Advisory Centre (VAAC)  - “Reports provided courtesy of the Smithsonian’s Global Volcanism Program and the US Geological Survey’s Volcano Hazards Program.”

Santa María, Guatemala

INSIVUMEH reported explosions from Santa María’s Santiaguito lava dome complex during 15-21 April. Resultant ash plumes rose to altitudes of 4.1-4.7 km (13,500-15,400 ft) a.s.l. and drifted SW. Constant avalanches on the W and S flanks were noted. Based on observations of satellite imagery, the Washington VAAC reported that an ash plume drifted SW on [...]

Sakura-Jima, Japan

Based on pilot reports and observations of satellite imagery, the Tokyo VAAC reported that an ash plume from Sakura-jima rose to an altitude of 4.6 km (15,000 ft) a.s.l. and drifted 100 km E on 19 April. The next day, the JMA reported that a plume rose to an altitude of 2.4 km (8,000 ft) [...]

Rabaul, Papua New Guinea

During 18-19 April, the Darwin VAAC reported that low-level ash-and-steam plumes from Rabaul were observed on satellite imagery drifting ESE. According to the VAAC, RVO advised that ash eruptions continued and rocks were expelled during explosions. RVO reported several explosions on 21 April. Billowing ash plumes drifted W and SE during 21-23 April, and caused [...]

Kilauea, Hawaii, USA

Based on observations during helicopter overflights, visual observations from HVO and National Park Service (NPS) crews, and web camera views, HVO reported that during 16-22 April lava flowed SE through a lava tube system underneath Kilauea’s Thanksgiving Eve Breakout (TEB) and rootless shield complex to the Waikupanaha ocean entries. The Ki ocean entry was inactive [...]

Karymsky, Russia

KVERT reported that seismic activity at Karymsky was above background levels during 11-18 April. Based on seismic interpretation, weak ash-and-gas explosions or hot avalanches may have occurred daily during 10-14. Observations of satellite imagery revealed that a thermal anomaly was present in the crater on 12 and 13 April. Based on information from KEMSD, the [...]

Fuego, Guatemala

INSIVUMEH reported that explosions (1-2 per hour) from Fuego produced ash plumes to altitudes of 4.3-4.7 km (14,100-15,400 ft) a.s.l. during 15-21 April. The plumes drifted 5-8 km SW and ashfall was reported from areas downwind. The explosions produced rumbling and degassing sounds, and shock waves that rattled windows and structures 5-15 km away. The [...]

Batu Tara, Komba Island, Indonesia

The Darwin VAAC reported that low-level ash-and-steam plumes from Batu Tara were observed on satellite imagery during 20-21 April.
Source: Darwin Volcanic Ash Advisory Centre - “Reports provided courtesy of the Smithsonian’s Global Volcanism Program and the US Geological Survey’s Volcano Hazards Program.”

Arenal, Costa Rica

In March, activity originating from Arenal’s Crater C consisted of gas emissions, sporadic Strombolian eruptions, and occasional avalanches from lava-flow fronts that traveled down the SW flanks. Volcanic activity was at relatively low levels and few eruptions occurred. Acid rain and small amounts of ejected pyroclastic material affected the NE and SE flanks. Eruptions produced [...]

Krakatau, Indonesia

CVGHM reported that seismicity from Anak Krakatau increased during 14-21 April; the number of events per day peaked on 20 April. Ash plumes accompanied by propelled incandescent rocks were noted during field observations on 16, 17, and 18 April. The eruption affected the summit and the E and S flanks. Booming noises were reported and [...]

Ibu, Halmahera, Indonesia

CVGHM reported that seismicity from Ibu increased during 6-14 April and remained elevated during 15-20 April. Plumes described as “eruption smoke” rose to altitude of 1.8-2.1 km (5,900-6,900 ft) a.s.l. during 12-21 April and were gray during 18-21 April. The Alert Level was increased to 3 (on a scale of 1-4) on 21 April. Residents [...]

Ubinas, Peru

Based on SIGMET advisories, the Buenos Aires VAAC reported that an ash plume from Ubinas rose to altitudes of 5.5-7 km (18,000-23,000 ft) a.s.l. and drifted ENE on 15 April.
Source: Buenos Aires Volcanic Ash Advisory Center (VAAC) - “Reports provided courtesy of the Smithsonian’s Global Volcanism Program and the US Geological Survey’s Volcano Hazards Program.”

Tungurahua, Ecuador

The IG reported that although visual observations were occasionally limited due to cloud cover, ash and ash-and-steam plumes from Tungurahua were spotted and rose to altitudes of 6-9 km (19,700-30,000 ft) a.s.l. during 9-15 April. Ash plumes drifted NW, W, and SW; ashfall was reported in areas downwind on 9, 11, and 14 April. Roaring [...]

Shiveluch, Russia

KVERT reported that seismic activity at Shiveluch was slightly above background levels and hot avalanches possibly descended the growing lava dome daily during 4-11 April. According to video footage and visual observations, fumarolic activity from the lava dome also occurred every day. Observations of satellite imagery revealed that a thermal anomaly was present in the [...]

Sakura-Jima, Japan

Based on information from JMA, the Tokyo VAAC reported that explosions from Sakura-jima during 11-15 April produced plumes that rose to altitudes of 2.1-3.4 km (7,000-11,000 ft) a.s.l. and drifted SW, NE, and SE.
Source: Tokyo Volcanic Ash Advisory Center (VAAC) - “Reports provided courtesy of the Smithsonian’s Global Volcanism Program and the US Geological Survey’s [...]

Rabaul, Papua New Guinea

RVO reported that during 9-13 April ash and steam-and-ash plumes rose to altitudes of 1.7-2.2 km (5,600-7,200 ft) a.s.l. and drifted W and NW. Ashfall was reported in areas downwind, including Rabaul Town (3-5 km NW). Incandescence at night at the summit and intermittent roaring noises were reported. A large explosion on 10 April showered [...]