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.

The seismicity at Mount Merapi is reaching new peak values.

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The seismic activity at Mount Merapi in Indonesia has reached new peak levels. On September 2nd, there were 407 hybrid earthquakes recorded, followed by approximately 348 of these tremors detected the following day. These are record values that are rarely reached and indicate fluid movements beneath the volcano. It is expected that the growth of the volcanic dome will continue in the coming days and could potentially intensify.

In addition to the numerous hybrid earthquakes, other volcano-tectonic tremors have also been detected. Yesterday, 129 seismic signals indicated rockfall avalanches, increasing the risk of pyroclastic flows.

In their latest weekly report, researchers from BPPTKG explain that there have been morphological changes in both domes growing inside the volcano’s crater. The most significant changes were observed in the southwestern dome. The volume of this dome was 2,858,600 cubic meters, compared to 2,764,300 cubic meters measured the previous week. Despite some reductions, the dome has slightly increased in size. The central dome, on the other hand, experienced a decrease in volume. It had a volume of 2,355,100 cubic meters, indicating potential collapses or shrinkage processes due to the cooling of the magma inside the dome.

Earthquakes in the Northwest of Mount Etna

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Date: August 30, 2023 | Time: 16:28:00 UTC | Coordinates: 37.765, 14.939 | Depth: 21 km | Magnitude: Md 2.9

Today, on the INGV earthquake map, we can see an earthquake swarm that already occurred on August 30th. The earthquake sequence consisted of 13 tremors with magnitudes greater than 1. The strongest earthquake occurred at 16:28 UTC and reached a magnitude of Md 2.9. The hypocenter was located at a depth of 21 km, and the epicenter was identified as 1.4 km southwest of Monte Scavo, a wooded scoria cone in the northwest of Mount Etna. The nearest major town is Bronte. The weakest earthquake had a magnitude of 1.4 and had a similarly deep hypocenter as the strong earthquake. It is suspected that the earthquake swarm was triggered by magma rising in the upper part of the asthenosphere, on its way to penetrate the Earth’s crust. Earthquakes at this depth are more the exception than the rule, but it cannot be ruled out that they could have been purely tectonic in origin.

Ebeko erupts ash clouds up to 4000 meters in height

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The volcano Ebeko on Paramushir has been active in the past two days, emitting ash clouds up to 4000 meters above sea level. These ash clouds have been drifting southeastward due to the wind. The KVERT observatory has confirmed the volcanic activity and reported weak thermal anomalies detected at the crater. It was noted that eruptions could occur at any time, causing ash clouds to rise to 3500 meters in height, posing a danger to low-flying aircraft. The aviation alert status is currently set to “orange.”

Earthquake Magnitude 7.0 near Bali

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Date: 28.08.23 | Time: 19:55:32 UTC | Location: -6.810, 116.563 | Depth: 516 km | Magnitude: 7.0

The Indonesian Bali Sea was shaken by a strong earthquake with a magnitude of 7.0 yesterday evening. Initially, the magnitude was reported as 7.1, but it was later slightly downgraded. The seismic event occurred at 19:55:32 UTC (03:55:32 local time) and had an epicenter located 188 km north-northwest of Labuan on Lombok Island. The vacation island of Bali is approximately 220 km away from the epicenter. Closer was the coast of the small island of Soemoerboengkar, which is only about 30 km from the epicenter. Nevertheless, the strong tremor had no catastrophic consequences, and no significant damage was reported. A tsunami was also not generated. However, the island residents clearly felt the strong tremor.

Popocatépetl: Ash Cloud and Tremor

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At the Mexican volcano Popocatépetl, the tremor remains elevated. Yesterday, CENAPRED reported a tremor lasting a total of 349 minutes. However, only 9 instances of ash and steam exhalations were observed. In exchange, today an ash cloud was reported, which according to VAAC reached a height of 7600 meters and was carried in a northwesterly direction. On nocturnal live webcam images, an illuminated steam cloud is visible, indicating the presence of glowing lava within the vent or even the growth of a lava dome.

Lahar occurred on Santiaguito volcano

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Heavy rains at the Santa Maria-Santiaguito volcanic complex triggered a lahar yesterday. The moderate mudflow initially followed the Cabello de Ángel stream and then merged into the Nimá I and Samalá rivers. Along with mud, volcanic rocks as large as one meter in diameter were carried by the water. Additionally, branches and tree trunks were swept away. The lahar generated a significant seismic signal that exceeded the scale and masked any volcanically-induced earthquake signals.

Lahars form when water mobilizes deposited volcanic ash on the volcano’s slopes. These mudflows have a high destructive potential and typically flow along drainage channels and riverbeds, but they can exit these paths and cause flooding. Survival chances are low if caught in a mudflow. Lahars are nearly as dangerous as pyroclastic flows, which can also occur at Santiaguito. The dome volcano on the flank of Santa Maria is active, building its lava dome. A viscous lava flow extends from the dome, flowing southwestward. Debris avalanches occur, and explosions propel volcanic ash up to 900 meters above the crater’s rim.

Kilauea with increased seismic activity

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Seismic activity is still high south of Hawaii’s Kilauea summit caldera. Yesterday, there were 250 small tremors in just 24 hours. In Hawaii, it’s now 8:00 PM on August 24th, and more than 150 earthquakes have been recorded so far. Though it’s unlikely to reach the previous day’s high count, earthquake activity remains elevated. Ground deformation is also increasing significantly, rebounding from a slight dip 2 days ago. Since last September, the ground has risen by about 65 cm, despite previous lava activity. The volcano’s magma chamber couldn’t be emptied enough to reduce the uplift. The erupted lava filled Halema’uma’u crater by 400 meters. A new graph shows current measurements of the crater’s depth using a laser rangefinder. This depth is measured against the point after the 2018 Leilani eruption collapse when the crater was at 518 meters above sea level.

Mount Dempo Volcano in Sumatra with phreatic eruption

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Yesterday, the VSI reported that there was an eruption at Mount Dempo volcano on Sumatra. A seismic signal was recorded, with a strong shaking that lasted for about 3 minutes. This signal was detected at 9:05 AM local time. At first, there was no visual confirmation of the eruption. However, a video showing the eruption was shared on the social media platform ‘X’ this morning.

Last year, there were signs that the volcano might become active again when there was a sudden burst of steam and gas in May. In January 2022, the alert level was raised to ‘yellow’ due to some shaking underground. There were some smaller eruptions at the end of July this year, but I missed them because I was traveling in Kenya. An ash cloud was seen rising up to 2 km above the volcano’s opening on July 25, 2023. There were also more earthquakes than usual on that day. It’s possible that the volcano is slowly getting ready for bigger eruptions.

Lavadome on Mayon remain active

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On the Philippine island of Luzon, Mayon continues to remain active, erupting a lava dome. Three lava flows emanate from the dome, flowing through the channels of Bonga, Mi-isi, and Basud, measuring 3.4 km, 2.8 km, and 1.1 km in length, respectively. Both lava flows and the dome are generating rock avalanches that leave glowing traces in nighttime images. Yesterday, 127 of these rock avalanches were recorded by seismographs. Additionally, signals from 6 pyroclastic flows were detected, resulting from larger collapse events and traveling up to 4 km. Ash clouds reached altitudes of up to 3 km. Mayon also remains seismically active, with 35 volcano-related earthquakes detected. Among these events, 20 were characterized as tremor signals, lasting for up to 80 minutes. Tremors are caused by fluid movements underground, indicating the presence of more magma in transit. This is further indicated by a high concentration of gaseous sulfur dioxide. In the last 24 hours, 1467 tons of this gas were emitted. A steam plume rose up to 700 m above the dome. The volcanic structure of Mayon is swollen, and inflation is occurring.

Mount Etna unexpectedly produced a paroxysmal eruption

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Paroxysm Mount Etna @fabrizio_zuccarello & @etnative

Once again, the spectacular scene of a paroxysmal eruption from the new Southeast Crater could be admired on Mount Etna. The eruption began in the evening around 8:30 PM UTC (Central European Summer Time +2 hours) with Strombolian activity from the volcano. This activity rapidly intensified, and just an hour later, ash clouds started to rise, reaching up to 1000 meters above the crater’s elevation, as reported by the Toulouse VAAC. The main phase of the paroxysm then began around 12:00 AM UTC and reached its peak around 1:20 AM UTC. During this phase, ash was ejected to a height of 6100 meters, and a lava fountain several hundred meters high illuminated the night sky over Sicily. By 3:20 AM UTC, the lava fountain collapsed, but ash continued to rise. An hour later, the ash reached a height of 8200 meters and drifted southward. The ash emissions ended around 5:50 AM UTC. The lava fountain activity was accompanied by a lava overflow, with the lava flow not heading into Valle del Bove but rather towards the southwest. This corresponds to the path from the vent in the new Southeast Crater that previous lava flows had taken.