Eruptions

News about eruptions and volcanoes can be found in this category. It is updated frequently. Volcano expert and journalist Marc Szeglat reports live from his expeditions to volcanoes.

Semeru: pyroclastic flows were erupted

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The Indonesian volcano Semeru generated 2 pyroclastic flows tonight, which spread panic among the inhabitants. According to media reports, 550 people are on the escape without evacuation orders. While trekking tours on the volcano were prohibited the day before, the alarm status remained at “yellow”. However, the affected slope in the south of the volcano is already closed.According to media reports, 550 people are on the escape without evacuation orders. While trekking tours on the volcano were prohibited the day before, the alarm status remained at “yellow”. However, the affected slope in the south-south-west of the volcano is already closed. The pyroclastic flows went down over it. The longer one covered a distance of 3 km. The two glowing clouds generated seismic signals of 18 minutes duration and with maximum amplitudes of 25 and 15 mm. They reached the base of the volcano and apparently destroyed an excavator that was inserted in one of the volcano’s drainage channels.

The VAAC detected volcanic ash at an altitude of 6100 m. The “normal” explosive activity has strongly decreased since the viscous lava flow has been extracted. It emanates from a lava dome. Probably the pyroclastic flows were created when parts of the lava flow collapsed. It is also possible that larger explosions triggered the pyroclastic flows. Harmonic tremors have been recorded, suggesting that magma is rising and erupting in the conveyor system. The dome is growing and further events must be expected.

Erta Alé: New lava lake in November

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A new lava lake probably formed at the Ethiopian volcano Erta Alé. This at least suggests a thermal anomaly, which can be seen on a Sentinell satellite photo since yesterday. According to MIROVA, thermal radiation with a power of 103 MW is emitted. The anomaly was detected for the first time on 28.11.2020 at 10.45 am. At that time it had an output of 131 MW. In the days before it was cloudy from time to time, so the activity might have started earlier without noticing it. The last time a thermal anomaly was recorded was in September. However, it originated from the North Crater and not from the South Crater as now. Comparing satellite images from now and October, morphological changes in the North Crater can also be seen.

There are two reasons why traveling to the region is currently out of the question: Because of the Corona-related travel restrictions and the civil war in the Tigray region. The regional capital Mekele is not only the focus of the fighting, but also the gateway to the Danakil desert, where the volcano is located. But more about that soon in a special report.

Lewotolok started with eruption

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On the Indonesian island of Lembata the Lewotolok has erupted. The VAAC reported an ash cloud that rose to an altitude of 1800 m above sea level. The volcanologists of MAGMA/VSI recorded a corresponding seismic signal with a duration of 120 seconds and a maximum amplitude of 34 mm. In addition, 10 volcano-tectonic earthquakes were recorded in the first half of the day. Already in January 2019 first warnings were given and the alarm status was increased after the seismic activity increased. There is a 2 km exclusion zone around the crater.

The Levotolok can be passed by taking a boat to Komba Island, where the Batu Tara volcano is located. This volcano has been quiet for a few years, but thermal signals are always registered. More often this happened in the last month. To my knowledge the volcano is not systematically monitored and is one of the few white spots on earth.

Semeru erupts lava flow

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The Indonesian volcano Semeru is located on the island of Java and forms a volcanic massif together with Bromo. Since months Semeru is effusive and explosive active. It is busy building on its flat pancake dome and strombolian eruptions are occurring, and debris avalanches are taking place. What has not been communicated so far is the fact that a lava flow has been flowing for about 2 weeks. It comes through the breach in the southeastern crater wall and is moving along the upper part of the flank. It has a length of 800-900 m and should be quite viscous. Since when exactly it is on its way remains unclear. I discovered it on a satellite image from November 16. On a picture from November 11th it was not yet visible. In the reports of MAGMA/VSI it is mentioned that the southeast side is restricted area and that pyroclastic flows may be released. During earlier eruption phases these occurred especially in connection with the high viscous lava flows.

Etna: Another ash-eruption

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Etna celebrated the new day with another ash eruption. Place of the happening was again the New South East Crater. The ash rose a good 200 m and was carried by the strong wind in southwestern direction. The VAAC gave no warning. Previously, the tremor decreased significantly during the night and is now fluctuating in the middle of the yellow area. The earthquake activity was quite high on November 21 and 22. SismoWeb (INGV) shows 26 quakes for the two days. Many manifested themselves under the central crater area and in the Valle del Bove. The strongest quake reached M 2.5 and was located at 5 km depth near the village of Zafferana on the eastern flank. It continues to accumulate magma under the volcano.

Santiaguito: Update 24.11.20

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The volcanologists of INSIVUMEH (Guatemala) published a new report on the activity of the dome volcano Santiaguito: The seismic record allows the observation of weak and moderate explosions. These generate columns of gas and ash, and heights of up to 3100 meters (10170 feet). Avalanches of blocks and ashes are also registered mainly towards the southwest flank, however these can be generated towards the south, southeast and west flanks. The path of such material reaches the base of the dome and causes fine ash particles to fall on the volcanic perimeter. Due to the location of block lava flows in the dome of the hot dome in a west-southwest direction, the occurrence of block and ash flows in this same direction, as well as long range pyroclastic flows, is not ruled out. For short periods of time it is possible to hear aircraft turbine like sounds due to the prolonged degassing in the hot dome. MIROVA registered a thermal anomaly with 11 MW power.

Merapi: Dome growth continues

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The seismic activity at Merapi remains at a very high level. Yesterday about 510 tremors occurred in connection with the dome growth. This was the third highest value in this growth phase. First place was taken by November 20 with about 560 seismic signals. In the first 6 hours of today 83 hybrid earthquakes and 5 volcanic tectonic quakes were recorded. In addition there were 23 signals caused by strong degassing and 10 quakes caused by rockfall/debris avalanches. The dome continues to grow busily. The danger of pyroclastic flows is high.

Already on November 7, 133 people were evacuated. They were mostly elderly people who are not able to escape spontaneously. Prior to this, the alarm status was raised to “3”.

Stromboli: Third strong explosion

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The LGS reports a third strong eruption this month: On November 21, 2020, at 00:33:21 UTC, the geophysical monitoring network recorded a very strong explosive event above ordinary explosive activity. 3 minutes bevore the event ground deformation (0.41 µrad at the OHO reference tiltmeter in Rina Grande) was detected. The event falls within the lower limits of the field for major explosions.

Santiaguito generates pyrocalstic flows

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Another report from INSIVUMEH about the eruptions at Santiaguito volcano in Guatemala is available: Weak and moderate explosions were recorded. These can generate columns with large amounts of gas and with heights up to 3300 meters (10,826 feet). There are also avalanches of blocks and ash towards the southwest flank mainly, however, these can be generated towards the south, southeast and west flanks. The path of such material reaches the base of the dome and causes fine ash particles to fall on the volcanic perimeter. Due to the location of block lava flows in the dome of the hot dome in a west-southwest direction, the occurrence of block and ash flows in this same direction, as well as long range pyroclastic flows, is not ruled out. For short periods of time it is possible to hear aircraft turbine like sounds due to the prolonged degassing in the hot dome.

Pacaya: Lava flow still active

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INSIVUMEH reports today that the Pacaya is still active. Due to night and early morning weather conditions, visibility to the Mackenney cone and its crater was limited. The PCG and PCG5 seismic stations register tremors associated with the rise of magma and constant degassing. Lava flow in southwest direction one of 1,025 meters in length, approximately. The lava flow is clearly visible on sentinel satellite images.