Volcanos

Roundup of Global Volcanic Activity – New Activity for the Week 24 February 2021 – 2 March 2021

Etna – Sicily (Italy) : INGV reported continuing episodes of lava fountaining at Etna’s Southeast Crater (SEC) and 24 and 28 February. Strombolian activity at two vents in SEC increased during the late afternoon of 24 February. Lava overflowed the crater at 1820 and headed ESE towards the Valle de Bove. During 1900-2122 lava fountains rose as high as 500 m above the summit. A second lava flow traveled SW, and at 2100 a pyroclastic flow descended 1 km into the Valle de Bove. An eruption plume rose as high as 11 km a.s.l. Weak Strombolian activity was visible at 0810 on 28 February. Lava fountaining began at 0839, feeding lava flows that traveled E, and abruptly intensified at 0902 with jets of lava rising 700 m above the crater rim. An eruption plume rose as high as 11 km a.s.l. and drifted ESE, causing ashfall in areas downwind. A small lava overflow at the S part of SEC began at 0909, followed by a pyroclastic flow at 0920. Lava fountaining ended at 0933, though the lava flow descending E remained active.

Klyuchevskoy – Central Kamchatka (Russia) : KVERT reported that the eruption at two vents on Klyuchevskoy’s lower NW flank continued during 24-26 February. Both vents produced lava flows and ejected lava 50 m high. A cinder cone had formed over the higher vent. A bright thermal anomaly over the vents was identified in satellite images. The Aviation Color Code remained at Orange (the second highest level on a four-color scale).

Krysuvik – Iceland : IMO reported that seismicity in the area between Krýsuvík and Reykjanes-Svartsengi volcanic systems remained elevated during 26 February-1 March. More than 6,000 earthquakes had been detected after a M 5.7 event was recorded at 1005 on 24 February; two of those events were above M 5. The earthquakes were distributed over a 25-km-long section of a N-S striking fault along the E-W striking plate boundary, primarily located between Keilir and Fagradalsfjall. GPS data showed 4 cm of horizontal displacement near the epicenter of the M 5.7 event. An InSAR interferogram showed left-lateral movement over a large section of the plate boundary. Tremor began to be recorded by several stations at 1425 on 3 March, in an area located 2 km SW of Keilir. The signals possibly indicated magma rising towards the surface and prompted IMO to raise the Aviation Color Code for Krýsuvík to Orange.

Kuchinoerabujima – Ryukyu Islands (Japan) : JMA reported that the number of volcanic earthquakes located at shallow depths beneath Kuchinoerabujima’s Shindake Crater increased on 21 February and remained elevated. The Alert Level was raised to 3 (the middle level on a scale of 1-5) on 28 February. No other monitoring data showed upward trends and no surficial changes were visible; sulfur dioxide emissions remained low at 60 tons per day on 24 February.

Pacaya – Guatemala : INSIVUMEH and CONRED reported that during 23-25 February explosions at Pacaya’s Mackenney Crater ejected incandescent material as high as 200 m. A lava flow, originating from a vent 300 m below the summit crater, was about 1.1 km long and produced incandescent blocks from the flow front that descended 300 m. more intense pulses of activity at the summit produced dense ash plumes that drifted more than 30 km S and SW. Ashfall was noted in areas downwind including Los Pocitos, Pacaya, El Rodeo, and El Patrocinio. Explosions continued during 26-29 February, although weather conditions sometime prevented visual confirmation. RSAM data values notably increased during the morning of 1 March, reflecting an increase in Strombolian activity. Moderate-to-strong explosions ejected ballistics as high as 500 m above the summit. Ash plumes rose 1 km above the summit and drifted W and SW, causing ashfall at least in El Patrocinio. Incandescent material was ejected 150 m high, and ash plumes drifted W; ashfall was reported in El Patrocinio. The lava flow on the SSW flank was about 700 m long. On 2 March gas and ash plumes rose 150 m and drifted 2 km S. A lava flow on the SSW flank was 150 m long.

Sinabung – Indonesia : PVMBG reported that the eruption at Sinabung continued during 24 February-2 March. White plumes rose as high as 500 m above the summit most days. On 25 February avalanches of material traveled 500-1,000 m down the E, SE, and S flanks. The Darwin VAAC noted that an ash plume rose to 4 km (13,000 ft) a.s.l., or 1.5 km above the summit, and drifted SE, based on satellite images and information from PVMBG. On 28 February avalanches of material traveled 1,000-1,250 m down the E, SE, and S flanks; the VAAC noted that ash plumes were visible in satellite images and rose to 3.4 km (11,000 ft) a.s.l. (about 1 km above the summit) and drifted SW. On 1 March avalanches of material descended the E, SE, and S flanks as far as 1.3 km. A series of lava-dome collapses began at 0642 on 2 March. A total of 13 pyroclastic flows, each lasting between about two and eight minutes, traveled 2-5 km SE and E. Ash plumes rose 4-5 km along the length of the pyroclastic flows and drifted W, SW, S, and E. The VAAC reported that ash plumes were visible in satellite images beginning at 0640 rising to 4.3 km (14,000 ft) a.s.l. and drifting SW. Ash plumes rose to 7.6 km (25,000 ft) a.s.l. and drifted W by 0758; within another 25 minutes the plumes had risen to 12.2 km (40,000 ft) a.s.l. According to BNPB ashfall was noted in 17 villages in the Tiganderket District, eight villages in the Kutabuluh District, and 15 villages in the Tigabinaga District. The Alert Level remained at 3 (on a scale of 1-4), with a general exclusion zone of 3 km and extensions to 5 km in the SE sector and 4 km in the NE sector.

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