Overall, 48 volcanoes were in continuing eruption status as of 15 October 2021. An eruption marked as "continuing" does not always mean persistent daily activity, but indicates at least intermittent eruptive events without a break of 3 months or more. Detailed statistics are not kept on daily activity, but generally there are around 20 volcanoes actively erupting on any particular day; this is a subset of the normal 40-50 with continuing eruptions. Additional eruption data is available for recent years.
The Smithsonian / USGS Weekly Volcanic Activity Report (WVAR) for the week ending on 12 October 2021 includes the 14 volcanoes shown below marked "Yes" in the WVAR column (rollover for report). The most recently started eruption is at the top, continuing as of the Stop Date given. An eruption listed here might have ended since the last data update, or at the update time a firm end date had not yet been determined due to potential renewed activity. Complete updates are done about every 6-8 weeks, but information about newer eruptions can be found in the Weekly Report.
Report for Stromboli INGV reported that during 4-10 October activity at Stromboli was characterized by ongoing explosive activity from three vents in Area N (North Crater area) and six vents in Area C-S (South-Central Crater area). Explosions from two vents in the N1 vent (Area N) ejected lapilli and bombs 80 m high, and produced minor ash emissions. Explosions at two N2 vents (Area N) averaged 3-8 events per hour and ejected material less than 80 m high. Explosions from the S1 and S2 vents in Area C-S were sporadic and occurred at a rate of 4-8 per hour; coarse material was ejected 150 m high. Gas emissions rose from the C vent.
A short explosive event at the N2 vents began at 1617 on 6 October. Notably, a large explosion ejected tephra radially beyond the crater terrace as far as the upper part of the Sciara del Fuoco, and incandescent material rolled down to the coast. An ash cloud was produced, though it quickly dissipated. A small lava overflow from the vents followed but it did not travel past the upper part of the Sciara del Fuoco
Report for Kadovar Based on satellite and wind model data, the Darwin VAAC reported that during 8-9 October ash plumes from Kadovar rose to an altitude of 1.5 km (5,000 ft) a.s.l. and drifted W and NW.
Report for Merapi BPPTKG reported minor morphological changes to Merapi’s SW lava dome, located just below the SW rim and in the summit crater, and no changes to the summit crater dome during 1-7 October. The SW dome grew about 3 m taller had an estimated volume of 1.679 million cubic meters, and the summit lava dome had an estimated volume of 2.854 million cubic meters. As many as 76 lava avalanches traveled a maximum of 2 km SW. The Alert Level remained at 3 (on a scale of 1-4), and the public was warned to stay 3-5 km away from the summit based on location.
Report for Lewotolok PVMBG reported that the eruption at Lewotolok continued during 6-12 October. White-and-gray plumes generally rose as high as 800 m above the summit and drifted in multiple directions. A VONA stated that on 7 October and ash plume rose 1.9 km above the summit and drifted W. Rumbling and banging sounds were reported daily. Incandescent material was ejected daily as far as 300 m away from the vent in multiple directions, though during 5-6 October incandescent material was ejected as far as 1 km SE. BNPB noted that 25-26 eruptive events per day were sometimes recorded before activity increased in October. The Alert Level remained at 3 (on a scale of 1-4) and the public was warned to stay 3 km away from the summit crater.
Report for Suwanosejima JMA reported that 52 explosions at Suwanosejima's Ontake Crater produced eruption plumes that rose as high as 2.4 km above the crater rim during 4-11 October. Large volcanic bombs were ejected as far as 1.1 km from the crater. Crater incandescence was visible nightly. The Alert Level remained at 3 and the public was warned to stay 2 km away from the crater.
Report for Aira JMA reported that incandescence from Minamidake Crater (at Aira Caldera’s Sakurajima volcano) was visible at night during 4-11 October. The sulfur dioxide emission rate was 400 tons per day on 5 October. An explosion at 0517 on 8 October ejected material 600-900 m away from the crater and produced an eruption plume that was obscured by weather clouds. The Alert Level remained at 3 (on a 5-level scale), and residents were warned to stay 2 km away from the crater.
Report for Karymsky KVERT reported that a thermal anomaly over Karymsky was identified in satellite images on 7 October. 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 was identified in satellite images during 1, 4, and 6-7 October. Plumes of resuspended ash drifted 200 km SE during 6-7 October. The Aviation Color Code remained at Orange (the second highest level on a four-color scale).
Report for Semisopochnoi AVO reported that eruptive activity at Semisopochnoi's North Cerberus crater continued during 6-12 October. Seismicity remained elevated and a few explosions per day were detected in infrasound data. Although weather clouds often prevented webcam and satellite views, discontinuous, low-level ash emissions were visible rising to altitudes up to 3 km (10,000 ft a.s.l.) and drifting E during 8-9 October. Low-level ash emissions were also visible in webcam images during 9-12 October. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.
Report for Pavlof AVO reported that seismicity at Pavlof remained elevated during 6-12 October. Two explosions were recorded by infrasound network during 6-7 October. Mostly cloudy conditions obscured satellite and webcam images most days. The Volcano Alert Level and Aviation Color Code remained at Watch and Orange, respectively.
Report for Kilauea HVO reported that the summit eruption at Kilauea continued in Halema`uma`u Crater during 6-12 October. At the beginning of the eruption, on 29 September, lava erupted from vents along the floor and from the W wall of the crater, though by 8 October only the W vent was active. Sulfur dioxide emissions remained high and were 5,300 tonnes per day on 8 October. A 10-m-wide, horseshoe-shaped spatter rampart had formed around the W vent and was open to the E where lava was feeding the lake. Lava fountains from the W vent were generally 12-15 m high but decreased to 4 m during 10-11 October. The total erupted volume was an estimated 15.9 million cubic meters on 8 October and the lake was as deep as 40 m on 12 October. The lava lake was not level; the W end was 2-3 m higher than the N and S parts of the lake and 5 m higher than the E end. Cooled and crusted parts of the lake’s surface overturned, or “foundered,” in all parts of the lake, though by 11 October foundering was not observed in the E. HVO noted that the central island (or raft) of cooler material from the 2020 eruption remained above the surface as the lava lake rose, and other smaller rafts had reemerged in the E and N parts of the lake. The Aviation Color Code and the Volcano Alert Level remained at Orange and Watch, respectively.
Report for Sabancaya Instituto Geofísico del Perú (IGP) reported a daily average of 27 explosions at Sabancaya during 4-10 October. Gas-and-ash plumes rose as high as 2 km above the summit and drifted in multiple directions. One thermal anomaly originating from the lava dome in the summit crater was identified in satellite data. Minor inflation continued to be detected near Hualca Hualca (4 km N). 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.
Report for Nevados de Chillan SERNAGEOMIN reported continuing explosive and effusive activity at Nevados de Chillán’s Nicanor Crater during 16-30 September though weather conditions often prevented visual confirmation. Explosions generated plumes with low ash content that rose as high as 1.1 km above the crater rim. A new lava dome (Dome 3) in the crater was first identified on 15 September and was 27 x 40 m, elongated NW-SE, and 990 square meters in area. The dome formation was preceded by a decrease in the extrusion rates and temperatures of the L5 and L6 lava flows. By 24 September growth at Dome 3 reached 36 x 43 m and covered 2,137 square meters. Dome 4 was first visible on 29 September, adjacent to Dome 3 on the NE side, and produced a new lava flow (L7) that traveled 50 m down the flank between the L5 and L6 flows. The L5 lava flow also began to advance.
On 5 October the L5 and L7 lava flows advanced and nighttime incandescence from both flows increased. Incandescence from the crater was visible in webcam images at night during 8-9 October. On 9 October a long-period earthquake was recorded at 0706 on 9 October; an associated emission rose more than 240 m above the vent and drifted NW. The Alert Level remained at Yellow, the second lowest level on a four-color scale. ONEMI stated that Alert Level Yellow (the middle level on a three-color scale) remained in place for the communities of Pinto and Coihueco, noting that the public should stay at least 2 km away from the crater.
Report for La Palma The eruption at La Palma continued during 6-12 October, characterized by Strombolian explosions, lava fountaining from multiple vents, advancing and branching lava flows, and daily ash emissions. Eruption details are based on official sources including PEVOLCA (Plan de Emergencias Volcánicas de Canarias) steering committee summaries. Seismicity continued to be elevated with most earthquakes located 10-15 km deep (though some deeper than 35 km) in the same area where the swarm first began on 11 September; dozens of events were felt by local residents and some were felt across the entire island.
The largest earthquake, at 0816 on 12 October, was a M 4.1 at a depth of 37 km. Sulfur dioxide emissions fluctuated at high levels between 4,522 and 21,868 tons per day. Sulfur dioxide plumes drifted in multiple directions; on 8 October they reached the Caribbean and on 12 October plumes were over northern Africa, Spain, and Portugal. The main cone had at least three effusive vents and another vent to the N was also active. Multiple collapses of parts of the cone sometimes sent large blocks of cooler lava rafting down the flows. The lava delta was fed by numerous streams of lava during most of the week. Plumes of steam containing hydrochloric acid rose from the edge of the lava delta and were quickly dissipated by the wind; local resident were not affected.
On 6 October a breakout lava flow from the W end of the main flow field traveled S between Los Guirres and El Charcó (previously evacuated), destroying crops and buildings. The flow covered about 0.4 square kilometers and was about 350 m from the coast. Ash plumes rose 3-3.2 km (10,000-10,500 ft) a.s.l. during 6-7 October. On 8 October a new vent formed on the main cone and ash plumes rose as high as 3.5 km (11,500 ft) a.s.l. Ash accumulation at the La Palma and Tenerife North (on Tenerife Island) airports caused a temporary shutdown of operations until the ash was removed. On 9 October a collapse of the N part of the cone sent a wide, multi-lobed flow carrying larger blocks NW over older flows that quickly advanced W along the N margins of the flow field, covering crops and destroying buildings in both Todoque and an industrial area. Ash plumes continued to rise from the vents; lightning was visible in the plume at times.
By 10 October the flow field was 1,520 m wide, and covered 4.9-5.7 square kilometers, depending on the source of the estimates. Between 726 and 1,323 buildings had been engulfed by lava and more than 1.3 square kilometers of crops were lost. About 6,000 people had been evacuated. A partial collapse of the cone allowed the inner lava lake to spill out, sending flows and very large cooled blocks downslope. Ash plumes rose 3.5 km a.s.l. and caused ashfall to the S. Video showed lava fountains rising 500 m above the vent late that night. By 11 October the lava delta had grown mainly to the N and S, and was an estimated 0.34 square kilometers in size, though flows feeding it had slowed. Dense dark ash plumes were seen rising from the main vents. The most northern flow had continued to advance and was 300 m from the coast. The flows overtook a concrete plant, prompting authorities to instruct residents in El Paso and Los Llanos de Aridane to remain indoors and take measures to reduce exposure to toxic fumes. On 12 October the advancing northern flow caused the pre-emptive evacuation of the La Laguna area, totaling 700-800 people. The flow continued to cover crops and was 200 m from the coast, but had slowed. The lockdown for El Paso and Los Llanos de Aridane was lifted after air quality improved. Ash plumes from the main vent rose 3.5 km a.s.l. The Alert Level remained at Red (the highest level on a four-color scale) for affected communities.