Roundup of Global Volcanic Activity – New Activity for the week of 24 May – 30 May 2017
Poas | Costa Rica : OVSICORI-UNA reported that tremor amplitude at Poás fluctuated between low and high levels during 23-30 May, often corresponding to the vigor of emissions of water vapor, magmatic gases, and material from fumarolic vents. During 25-26 May ashfall was reported in some communities around the volcano. Low magnitude volcano-tectonic earthquakes and small phreatic eruptions were recorded sporadically during 27-30 May.
Rincon de la Vieja | Costa Rica : OVSICORI-UNA reported that a small hydrothermal explosion occurred at 1020 on 23 May in Rincón de la Vieja’s crater lake, producing a small lahar that traveled down the N flank of the crater.
Sheveluch | Central Kamchatka (Russia) : KVERT reported that during 23-25 May powerful explosions at Sheveluch generated ash plumes that rose 8 km (26,200 ft) a.s.l. and drifted 715 km in different directions. At 0830 on 25 May explosions generated ash plumes that rose 9-10 km (29,500-32,800 ft) a.s.l. and drifted 16 km NE. The Aviation colour Code (ACC) was raised to Red (the highest colour on a four-colour scale). Around 30 minutes later the ash plume was identified in satellite images drifting 45 km ENE. Strong steam-and-gas emissions rose from the lava dome. The ACC was lowered to Orange. Within the next hour the ash plume drifted 82 km E.