Volcanos

Record Blast

The explosive force of the massive volcanic blast off Tonga earlier this month appears to have far exceeded that of the biggest nuclear detonation ever conducted. The global network of 53 seismic, underwater acoustic and surface infrasound detectors used by the Comprehensive Nuclear-Test Ban Treaty Organization measured the low-frequency boom, which was heard as far away as Alaska, 6,200 miles to the north. Those measurements show it was more powerful than the Soviet Union’s 1961 Tsar Bomba.

Roundup of Global Volcanic Activity – Ongoing Activity for the week 19 January – 25 January 2022

Aira – Kyushu (Japan) : JMA reported that incandescence from Minamidake Crater (at Aira Caldera’s Sakurajima volcano) was visible at night during 17-24 January. Sulfur dioxide emissions were somewhat high on 17 January at 1,000 tons per day. Two explosions on 18 January produced ash plumes that rose as high as 2 km above the crater rim and ejected ballistics 1-1.3 km away from the crater.

Great Sitkin – Andreanof Islands (USA) : AVO reported that slow lava effusion at Great Sitkin likely continued during 18-25 January, and seismicity remained at very low levels. Elevated surface temperatures were identified in satellite data during 19-22 January.

Kanlaon – Philippines : PHIVOLCS issued a special notice for Kanlaon on 21 January, noting that a total of 18 volcanic earthquakes were recorded in the past day. Four of those events were classified as shallow “tornillo” signals indicating gas movement along shallow fractures in the upper part of the volcano. Ground deformation data from continuous GPS and tilt measurements indicated slight inflation of the volcano since mid-October 2021. The seismic activity and ground deformation was likely caused by shallow hydrothermal processes and could generate phreatic events.

Karymsky – Eastern Kamchatka (Russia) : KVERT reported that on 15 and 17 January explosions at Karymsky produced ash plumes that rose as high as 7 km (23,000 ft) a.s.l. and drifted 172 km W. A thermal anomaly was visible in satellite images on 16 January.

Kilauea – Hawaiian Islands (USA) : HVO reported that lava effusion resumed at the vent in the lower W wall of Kilauea’s Halema`uma`u Crater at around 1045 on 18 January. By 1630 the level of the lava lake had risen 12 m, slightly surpassing the high recorded on 12 January, but then slightly dropped within 30 minutes. The W part of the lake was active. The sulfur dioxide emission rate was about 2,100 tonnes per day the next day. During 19-20 January lava oozed out along the SE and NW margins of the lake, though by the afternoon of the 20th the active portion of the lake was small and located N of the cone. Just after 0400 on 21 January the effusion rate increased and the W half of the lake was again active. Notable overflows of lava later that evening sent flows NW, SW, and SE. The lake level dropped 9 m during the morning of 22 January, and again only a small portion of the lake was active. Lava oozed out from the E and NW lake margins. Lava input into the small lake became intermittent starting at around 1500 on 23 January, though lava oozed out along the NW and S margins. The effusion rate increased at 0552 on 25 January and lava flowed W and N along the crater margins. By 0820 the lava lake had risen 11 m.

Merapi – Central Java (Indonesia) : BPPTKG reported no significant morphological changes at Merapi’s lava domes, located just below the SW rim and in the summit crater, during 14-20 January. Seismicity remained at high levels. As many as 91 lava avalanches traveled a maximum of 2 km SW down the Bebeng drainage, and one pyroclastic flow traveled 2 km SW.

Pavlof – United States : AVO reported that the eruption at Pavlof was ongoing during 18-25 January, with periods of elevated tremor. Small daily explosions were recorded on local and regional infrasound sensors during 18-22 January. A satellite image from 19 January showed that the lava flow on the E flank was 1.3 km long, and a lahar on the same flank was 4.4 km long. Elevated surface temperatures consistent with the active lava flow persisted through 25 January.

Reventador – Ecuador : IG reported that a high level of activity continued at Reventador during 18-25 January. Gas-and-ash plumes, often observed multiple times a day with the webcam or reported by the Washington VAAC, sometimes rose higher than 1 km above the summit crater and drifted mainly NW, W, and SW. Crater incandescence was visible at night during 19-20 January. Cloudy weather sometimes prevented visual observation during 21-23 January. Lava flows on the E and NE flanks were visible during 23-25 January and continued to advance.

Rincon de la Vieja – Costa Rica : OVSICORI-UNA reported that two eruptions were recorded at Rincón de la Vieja, at 2227 on 20 January and 0225 on 23 January, though weather conditions prevented visual confirmation of plumes. Each event was 1-2 minutes long. At 1139 on 25 January an eruption produced a plume that rose 500-1,000 m.

Santa Maria – Guatemala : INSIVUMEH reported that the eruption at Santa María’s Santiaguito lava-dome complex continued during 19-25 January. Crater incandescence was visible at night. Avalanches generated by both lava effusion at the W and SW part of Caliente dome and collapsing material descended the W, SW, and SE flanks, often reaching the base of the dome. Periodically the avalanches produced curtains of ash along their paths that dissipated near the volcano. Almost daily explosions produced ash plumes that rose 700-900 m above the summit and drifted 10-15 km W and SW; ashfall was reported in areas downwind during 21-23 January including in San Marcos Palajunoj (8 km SW) and Loma Linda (6 km WSW). Lava flows on the W and SW flanks were 500 and 700 m long, respectively.

Semeru – Eastern Java (Indonesia) : PVMBG reported that an eruptive event at 0911 on 21 January produced an ash plume that rose 200 m above Semeru’s summit and drifted N. A second event, recorded at 0741 on 25 January, generated an ash plume that rose 200 m and drifted SE. The Alert Level remained at 3 (on a scale of 1-4). The public was warned to stay at least 500 m away from Kobokan drainages within 17 km of the summit, along with other drainages originating on Semeru, including the Bang, Kembar, and Sat, due to lahar, avalanche, and pyroclastic flow hazards.

Semisopochnoi – Aleutian Islands (USA) : AVO reported that low-level eruptive activity at Semisopochnoi’s North Cerberus cone continued during 18-25 January. Seismicity was elevated, characterized by periods of tremor and low-frequency earthquakes. Steam emissions were periodically visible in webcam images during 18-19 January and minor explosions were recorded by local seismic and infrasound sensors on 19 January. Steam and low-level ash emissions were visible in webcam and satellite images during 20-25 January. Daily explosions were recorded during 21-25 January, and elevated surface temperatures were identified in satellite data during 22-23 January.

Sheveluch – Central Kamchatka (Russia) : KVERT reported that a thermal anomaly over Sheveluch was identified in satellite images during 14-21 January. Intense steam-and-gas emissions with ash were visible during 15-16 January; plumes rose as high as 6.5 km (21,300 ft) a.s.l. and drifted 77 km W.

Stromboli – Aeolian Islands (Italy) : INGV reported that during 17-23 January activity at Stromboli was characterized by ongoing explosions from five vents in Area N (North Crater area) and two vents in Area C-S (South-Central Crater area). Explosions from Area N vents (N1 and N2) averaged 7-14 events per hour; explosions from two vents in the N1 vent ejected lapilli and bombs 80 m high and those at three N2 vents ejected material less than 80 m high. Spattering at N2 had been intense the week before, depositing material onto the upper part of the Sciara del Fuoco that then rolled down the flank to the coastline on 16 January; spattering was again intense on 22 January. No explosions occurred at the S1 and C vents in Area C-S; explosions at the two S2 vents occurred at a rate of 3-4 per hour and ejected coarse material mixed with fine ash higher than 80 m.

Suwanosejima – Ryukyu Islands (Japan) : JMA reported that incandescence at Suwanosejima’s Ontake Crater was visible nightly during 17-24 January. There were 46 explosions recorded, producing ash plumes that rose at least 1.8 km above the crater rim and ejected material up to 1 km away from the crater. Rumbling sounds and ashfall were reported in Toshima village (3.5 km SSW).

Taal – Luzon (Philippines) : PHIVOLCS reported that unrest at Taal continued during 18-25 January. Low-level background tremor persisted; one volcanic earthquake was recorded during 18-19 January. Hot volcanic fluids were upwelling in the crater lake, and daily gas-and-steam plumes rose 0.6-2.4 km above the lake and drifted SW. Sulfur dioxide emissions continued to be elevated, averaging 10,986 and 11,228 tonnes/day on 20 and 23 January, respectively.

Turrialba – Costa Rica : OVSICORI-UNA reported that periodic eruptive events, lasting 1-2 minutes each, were recorded at Turrialba’s West Crater during 19-24 January. At 0546 on 19 January an eruption produced an ash plume that rose 200 m above the summit and drifted W. A small eruption at 1052 generated a plume that rose 50 m and drifted NW. At 0706 on 24 January an event generated a plume that rose 100 m and drifted SW. Two points of incandescence on the internal SW crater wall were also visible.

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