Thursday 27 October 2022

Volcanos

Roundup of Global Volcanic Activity - New Activity for the week 19 October - 25 October 2022

Alaid - Kuril Islands (Russia) : KVERT reported that the eruption at Alaid was ongoing during 14-20 October. An intense thermal anomaly was identified in satellite images during 13-16 and 20 October; weather clouds obscured views on the other days. Explosive activity during 13-16 October generated ash plumes that rose as high as 6.5 km (21,300 ft) a.s.l. and drifted 360 km E and SE.

Bezymianny - Central Kamchatka (Russia) : Activity at Bezymianny increased during 22-23 October characterized by incandescence at the summit, sometimes strong fumarolic activity, and an increasing temperature of a thermal anomaly identified in satellite images. A strong explosive phase commenced and by 2340 local time on 23 October satellite images showed ash plumes rising to 10 km (32,800 ft) a.s.l. and drifting 10 km ENE. The Aviation Color Code was raised to Red. By 1005 local time on 24 October the phase was over, and the Aviation Color Code was lowered to Orange. Satellite images showed gas-and-steam plumes drifting NE and an intense thermal anomaly. The ash plumes from the day before had drifted as far as 1,915 km NE.

Cotopaxi - Ecuador : IG reported minor eruptive activity at Cotopaxi. A low-amplitude tremor signal recorded by the seismic network from 1950 on 21 October to 0040 on 22 October was associated with gas-and-ash emissions. The emissions were not visible due to darkness and weather conditions, but minor ashfall and a sulfur odor was reported by mountaineers in the Refugio José Rivas, 2 km N of the summit crater; the mountaineers evacuated. The Washington VAAC reported that during 2150-2200 on 21 October ash plumes rose to 7.6-8.5 (25,000-28,000 ft) a.s.l. and drifted NE based on information from IG and the Guayaquil MWO, satellite images, and webcam views. The ash had dissipated by 0410 on 22 October. A second ash plume was identified in webcam and satellite images rising to 7 km (23,000 ft) a.s.l. and drifting W at 0700 on 22 October. Ash was no longer visible by 1250. IG noted that following the end of the tremor signal seismicity declined and plumes of gas-and-steam rose as high as 1 km above the summit and drifted W. Weather conditions at the volcano improved on 23 October and a layer of dark gray ash on the volcano, deposited the previous two days, became visible. Based on seismic data and media reports, small secondary lahars generated from the melted glacier beneath the ash deposit, were recorded during 1115-1300 and traveled short distances down the flanks. Weather clouds frequently prevented views of the volcano during 24-25 October, though steam emissions rising 200 m above the summit and drifting W were visible during a break in the cloud cover the morning of 25 October.

Kerinci - Central Sumatra : PVMBG reported that white-and-brown or gray plumes from Kerinci rose as high as 750 m above the summit and drifted NE and NW during 18-24 October.

Langila - New Britain (Papua New Guinea) : The Darwin VAAC reported that on 20 October an ash plume from Langila rose 2.7 km (9,000 ft) a.s.l. and drifted NW. The plume had dissipated within 5 hours.

Mauna Loa - Hawaiian Islands (USA) : HVO reported continuing unrest at Mauna Loa during 19-25 October. The seismic network detected 10-46 daily small-magnitude (below M 3) earthquakes 3-5 km beneath Mokua’weoweo caldera and 6-8 km beneath the upper NW flank of Mauna Loa. Data from Global Positioning System (GPS) instruments at the summit and flanks showed continuing inflation, though data from tiltmeters at the summit did not show significant surface deformation over the past week. A M 3.1 earthquake was recorded at 2035 on 23 October at a depth of 4 km beneath Mokua’weoweo caldera.

Popocatepetl - Mexico : CENAPRED reported that there were 27-62 steam-and-gas emissions, sometimes containing minor amounts of ash, rising from Popocatépetl each day during 19-25 October. Weather clouds often prevented visual observations of activity. The seismic network recorded daily periods of tremor lasting from 16 minutes to 10 hours and 35 minutes. One or two daily volcano-tectonic earthquakes were recorded. During 20-23 October daily periods of low-amplitude, high-frequency events varied between two hours and 19 minutes to five hours, and periods of harmonic tremor lasted from 11 minutes to five hours and 35 minutes. A small explosion was recorded at 0039 on 25 October. According to a news article a small new lava dome, about 60 m in diameter, had been growing on the crater floor since 7 October.

Taal - Luzon (Philippines) : PHIVOLCS reported continuing unrest at Taal during 18-25 October. Daily white steam emissions rose as high as 3 km above the lake and drifted NE, NW, and SW. Upwelling gasses and hot fluids in the lake were periodically visible. Sulfur dioxide emissions averaged 6,702 tonnes per day on 20 October. The seismic network recorded 0-6 daily volcanic earthquakes and a few periods of volcanic tremor during 20-23 October. Webcam images showed increased activity during 21-22 October with 29 small phreatomagmatic bursts from a vent on the NE part of the lake, each lasting 1-5 minutes long. Some of the events produced 200-m-tall steam-rich plumes and very, short, dark ash plumes that immediately collapsed back into the water. Not all events generated detectable signals in the seismic and infrasound records. Ash plumes rose to 600 m (2,000 ft) a.s.l. on 21 October and drifted W according to the Tokyo VAAC. Two small phreatomagmatic bursts, each lasting 6-7 minutes long were recorded during 22-23 October. Sulfur dioxide emissions averaged 1,403 tonnes per day on 24 October. Ground deformation measurements continued to show slight inflation in the western half of the caldera and deflation in the eastern half.

Villarrica - Central Chile : On 25 October SERNAGEOMIN reported that activity at Villarrica had been gradually increasing. Both the number and amplitude of long-period earthquakes increased during the month, and further increased the last week. Continuous tremor increased slightly. Webcams showed persistent gas emissions rising 460 m above the crater rim, and ash plumes drifting downwind on 2 and 23 October. Sulfur dioxide emissions averaged 535 (plus or minus 115) tonnes per day, peaking at 1,273 tonnes per day on 13 October. These values were within normal levels and were lower than in September. Crater incandescence increased in both frequency and intensity, consistent with reports from POVI and other collaborators, and likely indicated periodic Strombolian activity. On 14 October satellite images showed the active lava lake covering an area of 36 square meters in the E part of the crater floor. A partial collapse (less than 300 square meters) of the inner SSW crater rim was also evident. POVI reported that lava fountaining and Strombolian explosions were visible in webcam images at 1917 on 18 October. The most intense thermal anomaly over the crater since September 2019 was detected in satellite images on 23 October, and crater incandescence was visible in webcam images. That same day tourists described seeing splashes of lava ejected from a depth of 80 m and hearing loud degassing sounds. Deposits of ejected tephra were visible around the crater rim and on the upper flanks on 24 October, and intense crater incandescence was visible in images on 25 October.

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