Report for Ulawun
RVO reported that RSAM values at Ulawun steadily increased during 24-25 June, and then sharply increased at around 0330 on 26 June. The RSAM values reflect an increase in seismicity dominated by volcanic tremor. An eruption began in the morning hours of 26 June with emissions of gray ash that over time became darker and more energetic. The plumes rose 1 km and drifted NW, causing minor ashfall in NW and SW areas. Locals heard roaring and rumbling during 0600-0800.
The Darwin VAAC issued several notices about ash plumes visible in satellite data. These stated that during 1130-1155 ash plumes rose to 6.7-8.5 km (22,000-28,000 ft) a.s.l. and drifted W, while ash plumes that rose to 12.8-13.4 km (42,000-44,000 ft) a.s.l. drifted S and SW. A new pulse of activity generated ash plumes that by 1512 rose to 16.8 km (55,000 ft) a.s.l. and drifted S and SE. By 1730 the ash plume had risen to 19.2 km (63,000 ft) a.s.l. and spread over 90 km in all directions. Ash from earlier ejections continued to drift S at 13.4 km a.s.l. and W at 8.5 km a.s.l. RVO stated that RSAM values peaked at about 2,500 units during 1330-1600, and then dropped to 1,600 units as the eruption subsided.
RVO stated that parts of the ash plume at lower altitudes drifted W, causing variable amounts of ashfall in areas to the NW and SW. A pyroclastic flow descended the N flank. Residents evacuated to areas to the NE and W; a news article noted that around 3,000 people had gathered at a local church. According to another news source an observer in a helicopter reported a column of incandescent material rising from the crater, residents noted that the sky had turned black, and a main road in the N part of the island was blocked by volcanic material. Residents also reported a lava flow near Noau village and Eana Valley. RVO reported that the eruption ceased between 1800 and 1900. Incandescence visible on the N flank was either from a lava flow or pyroclastic flow deposits.
Report for Krakatau
PVMBG reported that Anak Krakatau’s seismic network recorded at least four eruptive events during 17-24 June. The events were not followed by visible ash emissions, though observations were hindered by weather conditions. A Surtseyan eruption was recorded by a local webcam around 0909 on 25 June. 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.
Report for Merapi
PVMBG reported that during 17-23 June the lava-dome volume at Merapi did not change and was an estimated 458,000 cubic meters, based on analyses of drone images. Extruded lava fell into the upper parts of the SE-flank, generating two block-and-ash flows that traveled 1.2 km down the Gendol drainage on 17 and 20 June. White plumes rose as high as 500 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.
Report for Semeru
The Darwin VAAC reported that on 20 June an ash plume from Semeru rose to an altitude of 4.3 km (14,000 ft) a.s.l. and drifted E based on satellite images.
Report for Dukono
Based on satellite and wind model data, and notices from PVMBG, the Darwin VAAC reported that during 19-25 June ash plumes from Dukono rose to altitudes of 1.8-2.1 km (6,000-7,000 ft) a.s.l. and drifted in multiple directions. The Alert Level remained at 2 (on a scale of 1-4), and the public was warned to remain outside of the 2-km exclusion zone.
Report for Ibu
The Darwin VAAC reported that on 21 June ash plumes from Ibu rose to 1.8 km (6,000 ft) a.s.l. and drifted N and NE based on satellite images and weather models. During 24-25 June ash plumes rose to 1.5-2.4 km (5,000-8,000 ft) a.s.l. and drifted SE and 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.
Report for Aira
JMA reported that during 17-21 June very small eruptive events at Minamidake crater (at Aira Caldera’s Sakurajima volcano) were recorded, as well as periodic crater incandescence through 24 June. An explosion recorded on 24 June generated a plume that rose 1.6 km above the crater rim. The Alert Level remained at 3 (on a 5-level scale).
Report for Raikoke
A powerful eruption at Raikoke that began on 22 June (after 95 years of dormancy) was identified based on satellite observations, prompting KVERT and SVERT to raise the Aviation Color Code to Red. A series of at least nine explosions (six within the first 25 minutes) beginning at 0505 and continuing to about 1900 produced ash plumes, with a significant sulfur dioxide component, that rose 10-13 km (32,800-42,700 ft) a.s.l. and drifted E and NE. Lightning was detected in the eruption plumes. Strong explosions at 1640 on 22 June generated ash plumes that rose to 10-11 km (32,800-36,100 ft) a.s.l. The ash and gas was entrained by jet streams and by a cyclone around the Komandorskiye Islands, causing parts of the material to spiral counterclockwise as it drifted farther NE. By 23 June the leading edge of the plume had drifted 2,000 km ENE. According to a news article, at least 40 flights in that region were diverted.
On 23 June ash plumes continued to be visible, rising to 4.5 km and drifting NE. The Aviation Color Code was lowered to Orange. Gas-and-steam plumes possibly with some ash rose to 4.5 km (14,800 ft) a.s.l. and drifted 60 km NW. That same day observers on a passing ship approached the island from the W side; they photographed the island and sent out a drone. An expedition member noted that the entire island was mantled with light-colored ash deposits up to several dozen centimeters thick. In some of the drainages and at the base of some drainages deposits were several meters thick. In some areas along the shoreline waves interacted with the deposits, causing steam explosions and dark brown steam emissions. Gas-and-ash plumes rose 1.5 km above the summit crater rim and drifted W. Minor ashfall was reported in Severo-Kurilsk (340 km NE) during 1830-1920. On 25 June ash plumes continued to be produced, rising as high as 2 km (6,600 ft) a.s.l. and drifting NW.
Report for Ebeko
Volcanologists in Severo-Kurilsk (Paramushir Island), about 7 km E of Ebeko, observed explosions during 14-15 June that sent ash plumes up to 2.5 km (8,200 ft) a.s.l. The plumes drifted NW and NE. The Aviation Color Code remained at Orange (the second highest level on a four-color scale).
Report for Karymsky
KVERT reported that a weak thermal anomaly over Karymsky was identified in satellite images during 14-15 June. The Aviation Color Code remained at Orange (the second highest level on a four-color scale).
Report for Klyuchevskoy
KVERT reported that a weak thermal anomaly over Klyuchevskoy was visible in satellite images on 14 June. The Aviation Color Code remained at Orange (the second highest level on a four-color scale).
Report for Sheveluch
KVERT reported that a thermal anomaly over Sheveluch’s lava dome was identified daily in satellite images during 14-21 June. The Aviation Color Code remained at Orange (the second highest level on a four-color scale).
Report for Colima
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 14-21 June. Weather conditions often prevented visual observations of the crater.
Report for Popocatepetl
CENAPRED reported that each day during 19-25 June there were 26-201 steam-and-gas emissions from Popocatépetl, some of which contained minor amounts of ash. An explosion at 2058 on 21 June produced an ash plume that rose 2.5 km above the crater rim and drifted W, and ejected incandescent material less than 1 km onto the flanks. Minor ashfall was reported in areas downwind including the municipalities of Ozumba (18 km W), Atlautla (16 km W), and Ecatzingo (15 km SW) in the State of Mexico, and in Tetela del Volcán (20 km SW) in the State of Morelos. The Alert Level remained at Yellow, Phase Two (middle level on a three-color scale).
Report for Poas
On 21 June OVSICORI-UNA reported that small, frequent phreatic eruptions from vent A (Boca Roja) were visible during good viewing conditions at Poás ejecting material less than 10 m high.
Report for Ubinas
Instituto Geofísico del Perú (IGP) reported that seismic activity at Ubinas increased suddenly on 18 June with signals indicting rock fracturing. During 21-24 June signals indicating fluid movement emerged and, beginning at 0700 on 24 June, webcams recorded ash, gas, and water vapor plumes rising from the crater. The plumes were visible in satellite images rising to 6.1 km (20,000 ft) a.s.l. and drifting N, NE, and E. IGP recommended that the authorities raise the Alert Level to Yellow (on a 4 level scale).
Report for Villarrica
According to POVI, observers near Villarrica during 20-21 June reported hearing noises from the volcano. The webcam recorded incandescent material ejected above the crater rim.