Eruptions

PVMBG reported that during 8-14 July the lava-dome volume at Merapi did not change and was an estimated 475,000 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 km down the Gendol drainage on 13 and 14 July. White plumes rose as high as 300 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.

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

ONEMI and SERNAGEOMIN reported that an explosive event at Nevados de Chillán?s Nicanor Crater recorded at 0657 on 14 July was associated with a long-period earthquake signal. The explosion ejected incandescent material onto areas near 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.

Sources: Oficina Nacional de Emergencia-Ministerio del Interior (ONEMI) ,Servicio Nacional de Geología y Minería (SERNAGEOMIN)

ONEMI and SERNAGEOMIN reported that an explosive event at Nevados de Chillán?s Nicanor Crater recorded at 0657 on 14 July was associated with a long-period earthquake signal. The explosion ejected incandescent material onto areas near 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.

Sources: Oficina Nacional de Emergencia-Ministerio del Interior (ONEMI) ,Servicio Nacional de Geología y Minería (SERNAGEOMIN)

CENAPRED reported that each day during 9-15 July there were 49-326 steam-and-gas emissions from Popocatépetl, some of which contained minor amounts of ash. As many as three explosions per day were recorded, though weather conditions often prevented visual characterization of ash emissions. An explosion at 1949 on 11 July generated an ash plume that rose 2.8 km above the crater rim. The Alert Level remained at Yellow, Phase Two (middle level on a three-color scale).

Source: Centro Nacional de Prevencion de Desastres (CENAPRED)

CENAPRED reported that each day during 9-15 July there were 49-326 steam-and-gas emissions from Popocatépetl, some of which contained minor amounts of ash. As many as three explosions per day were recorded, though weather conditions often prevented visual characterization of ash emissions. An explosion at 1949 on 11 July generated an ash plume that rose 2.8 km above the crater rim. The Alert Level remained at Yellow, Phase Two (middle level on a three-color scale).

Source: Centro Nacional de Prevencion de Desastres (CENAPRED)

IG reported that during 10-16 July seismic data from Reventador?s network indicated a high level of seismic activity, including explosions, long-period earthquakes, harmonic tremor, and signals indicating emissions. Weather often prevented views of the summit area, although during clear conditions ash plumes were visible rising at least 600 m above the crater rim and drifting W and N. Blocks were observed rolling 500-600 m down the flanks on 10 and 16 July.

Source: Instituto Geofísico-Escuela Politécnica Nacional (IG)

IG reported that during 10-16 July seismic data from Reventador?s network indicated a high level of seismic activity, including explosions, long-period earthquakes, harmonic tremor, and signals indicating emissions. Weather often prevented views of the summit area, although during clear conditions ash plumes were visible rising at least 600 m above the crater rim and drifting W and N. Blocks were observed rolling 500-600 m down the flanks on 10 and 16 July.

Source: Instituto Geofísico-Escuela Politécnica Nacional (IG)

The Darwin VAAC reported that during 10-16 July ash plumes from Sangeang Api were visible in satellite images rising to 2.1-3 km (7,000-10,000 ft) a.s.l. and drifting in multiple directions. The Alert Level remained at 2 (on a scale of 1-4).

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

The Darwin VAAC reported that on 10 July an ash plume from Semeru rose to an altitude of 4.3 km (14,000 ft) a.s.l. and drifted WNW based on satellite images and weather models. Ash plumes rose to 4 km (13,000 ft) a.s.l. on 13 July and drifted NW and W.

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

KVERT reported that a thermal anomaly over Sheveluch?s lava dome was identified daily in satellite images during 6-12 July. The Aviation Color Code remained at Orange (the second highest level on a four-color scale).

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)