Volcanos

Roundup of Global Volcanic Activity – Ongoing Activity for the Week 11 November 2020 – 17 November 2020

Aira – Kyushu (Japan) : MA reported that during 9-16 November incandescence from Minamidake Crater (at Aira Caldera’s Sakurajima volcano) was visible nightly. Two explosions on 10 November produced ash plumes that rose as high as 1.6 km above the crater rim and ejected bombs 600-900 m away from the crater. An eruptive event at 0708 on 16 November generated a plume that rose 1.3 km. The Alert Level remained at 3 (on a 5-level scale).

Dukono – Halmahera (Indonesia) : Based on satellite and wind model data, the Darwin VAAC reported that during 11-17 November ash plumes from Dukono rose to 1.8-2.1 km (6,000-7,000 ft) a.s.l. and drifted NW, SW, and S. 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.

Ebeko – Paramushir Island (Russia) : Volcanologists in Severo-Kurilsk (Paramushir Island), about 7 km E of Ebeko, observed explosions during 6-13 November that sent ash plumes up to 3 km (10,000 ft) a.s.l. and drifted NE and SE. A thermal anomaly was identified in satellite images during 7-8 November. The Aviation Color Code remained at Orange (the second highest level on a four-color scale).

Helgrindur – Iceland : IMO reported that the Alert Level for Helgrindur was raised from Gray (insufficient monitoring) to Green (normal, non-eruptive) on 12 November, reflecting the recent installation of three seismic stations along the peninsula. The new instruments will allow for better coverage and sensitivity for the detection of seismic unrest. The Alert Level scale consists of five colors.

Ibu – Halmahera (Indonesia) : PVMBG reported that on most days during 10-16 November ash plumes were visible rising 200-800 m above Ibu’s summit and drifting in multiple directions. 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.

Pacaya – Guatemala : INSIVUMEH reported that Strombolian activity and lava effusion continued at Pacaya during 10-17 November. Explosions from the cone in Mackenney Crater ejected material as high as 300 m above the vent. Lava flows on the SW flank varied in length between 800 and 1,200 m during 11-13 November. Visual observations overnight during 13-14 November revealed a new lava flow from a vent higher up on the SW flank. In a special report issued on 15 November CONRED and INSIVUMEH stated that lava effusion had increased on the SW flank. Avalanches of material traveled as far as 500 m and generated plumes of ash; a white-and-blue gas plume rose 450 m above the summit. Strong explosions at the summit crater ejected material 300 m high. The two parallel flows, 300-1,000 m long, were active through 17 November.

Sabancaya – Peru : Instituto Geofísico del Perú (IGP) reported a daily average of 54 explosions at Sabancaya during 9-15 November. Gas-and-ash plumes rose as high as 3.3 km above the summit and drifted NE, N, and NW. Eleven thermal anomalies over the crater were identified in satellite data. Minor inflation continued to be detected in areas N of Hualca Hualca (4 km N) and on the SE flank. The Alert Level remained at Orange (the second highest level on a four-color scale) and the public were warned to stay outside of a 12-km radius.

Santa Maria – Guatemala : INSIVUMEH reported that a moderate explosion at Santa María’s Santiaguito lava-dome complex was recorded at 0715 on 16 November and produced an ash plume that rose 1.1 km above the complex. Pyroclastic flows descended multiple directions; the longest one reached the upper part of the San Isidro drainage. Ash plumes drifted SW.

Semeru – Eastern Java (Indonesia) : PVMBG that at 0921 on 11 November an ash plume from Semeru rose 300 m above the summit and drifted S. Weather conditions prevented views of the volcano during most of 10-17 November. The Alert Level remained at 2 (on a scale of 1-4).

Sheveluch – Central Kamchatka (Russia) : KVERT reported that a thermal anomaly over Sheveluch was identified in satellite images during 6-13 November. The Aviation Color Code remained at Orange (the second highest level on a four-color scale).

Sinabung – Indonesia : PVMBG reported that during 10-12 November activity at Sinabung was characterized by ash plumes that rose as high as 2 km above the summit, pyroclastic flows that traveled 1.5-2.5 km E and SE, and block avalanches that traveled 200-1,000 m E and SE. Sometimes dense white plumes rose 200-500 m above the summit during 14-16 November. Block avalanches descended the E and SE flanks as far as 1 km during 14-15 November. 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.

Snaefellsjokull – Iceland : IMO reported that the Alert Level for Snaefellsjokull was raised from Gray (insufficient monitoring) to Green (normal, non-eruptive) on 12 November, reflecting the recent installation of three seismic stations along the peninsula. The new instruments will allow for better coverage and sensitivity for the detection of seismic unrest. The Alert Level scale consists of five colors.

Stromboli – Aeolian Islands (Italy) : INGV reported that during 9-15 November activity at Stromboli was characterized by ongoing explosive activity from Area N (North Crater area) and in Area C-S (South-Central Crater area). Explosions from the N1 vent (Area N) ejected lapilli and bombs 80-250 m high, and produced ash emissions. Explosions at three N2 vents (Area N) ejected a mix of coarse and fine material at a rate of 6-10 events per hour. Explosions from vents in Area C-S also ejected fine material 150 m high at a rate of 1-2 events per hour. A series of at least four explosions began at 2104 on 10 November with a major, six-minute-long explosion in the southern part of Area C-S. The event ejected pyroclastic material which fell radially and along the Sciara del Fuoco, and produced a vertical ash plume. Within 30 seconds a second pulse of activity from the central crater area ejected coarse material 300 m above the vent and then produced in tense lava fountaining. A small explosion from vent N2 concluded the series. During an overflight the next day, scientists identified thermal anomalies from lava at the bottom of the S1 and C craters (central part of crater terrace) and craters N1 and N2. A small lava flow from S1 was also visible, and a small hornito (h1) had formed just outside the crater. A second hornito (h2) had formed on the south flank of N2. A series of major explosive and landslide events began at 1017 on 16 November and lasted for four minutes (based on the seismic signals). Explosions produced a dense ash cloud that rose 1 km, and within minutes caused ash and lapilli to fall in the town of Stromboli, about 2 km away on the NE coast of the island. A pyroclastic flow rapidly descended the Sciara del Fuoco to the NW coastline and expanded 200 m over the sea surface.

Suwanosejima – Ryukyu Islands (Japan) : JMA reported nighttime incandescence and intermittent eruptive activity at Suwanosejima’s Ontake Crater during 6-13 November. A total of 35 explosions were recorded, ejecting bombs up to 700 m from the crater and producing gray-and-white plumes that rose 1.8 km above the crater rim. Ashfall was periodically reported in Toshima village (4 km SSW). The Alert Level remained at 2 (on a 5-level scale).

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