Villarica - 07.08.2020 - fallout from the explosion on the SE flank - photo @AngaritaVPhotography / via volcanologia en Chile
On August 7 at 3:22 p.m. local time, an explosion occurred at the Villarrica volcano, associated with a long-lasting earthquake (movement of fluids) with a displacement reduced by 12 cm2. The activity was accompanied by an infrasound signal of 10 pascal, 1 km from the crater.
The plume of gas and ash rose to max. 370 meters above the emission point
Particulate matter from the column dispersed to the southeast, depositing a layer of ash on the snow.
The technical alert is Amarilla / change in behavior of volcanic activity.
Sources: Sernageomin and Volcanologia en Chile
The Copahue monitoring stations recorded on August 6 at 4:25 am local a change in activity, marked by the emission of more colored gas, due to the particle load, accompanied by a "subtle" increase in the tremor and a displacement. reduced.
The plume reached a height of max. 1,000 meters above the point of emission and dispersed in a northeastern direction.
The emission lasted until 6:50 am local, then decreased to return to a usual white degassing.
The volcanic technical alert remains in Amarilla.
Source: special report by Sernageomin
An orange VONA was issued for Sinabung, Sumatra, on August 7, following an eruption, accompanied by an ash plume, at 18:58 UTC / 01:58 WIB, observed from the ground at a height of 4,460 meters asl. (about 2,000 meters above the summit), moving in the ESE direction.
The seismicity of August 7 is characterized by:
- 15 blast earthquakes, with an amplitude of 1 to 8 mm and the earthquake lasted 6 to 20 seconds.
- 6 low frequency earthquakes, with an amplitude of 1 to 7 mm and the duration of the earthquake was 7 to 19 seconds.
- 1 hybrid / multiphase earthquake with an amplitude of 5 mm, S-P was not observed and the earthquake lasted 11 seconds.
- 21 deep volcanic earthquakes with an amplitude of 2-13 mm, S-P 1-3 seconds and a long earthquake of 6-11 seconds.
- 2 distant tectonic earthquakes.
On August 8, some ashes are reported from the surrounding area
The last activity dates back to June 9, 2019 (GVP)
The eruption was phreatic in nature, not preceded by a significant increase in volcanic earthquakes, indicating the lack of magma supply to the surface. The eruption that occurred on August 8, 2020 was more due to overpressure and surface activity.
The eruptions lasted only briefly, not followed by an increase in seismicity and visual changes leading to a larger series of eruptions. (PVMBG analysis / 11:24 WIB)
The activity level remains at 3 / Siaga, with a forbidden zone of 3 to 5 km depending on the flanks concerned.
Source: CVGHM, Magma Indonesia, Nachelle Homestay
In Merapi, Java, the BPPTKG reports a dome currently in stable condition.
The seismicity of August 7 is marked by
- 4 collapse earthquakes, with an amplitude of 2-9 mm and a long earthquake of 15.44-57.3 seconds. The sliding distance and the direction of the avalanche were not observed.
- 2 blast earthquakes, 1 low frequency earthquake, 6 multiphase hybrid earthquakes, a deep volcanic earthquake.
The Merapi deformation monitored by EDM shows a shortening of the distance of approximately 2 cm from the reflectors RB1 and RB2.
The alert activity level remains at 2 / waspada. Recommended danger distance of 3 km from the summit.
Potential hazards currently in the form of pyroclastic flows from the collapse of the lava dome and shards of volcanic material from explosive eruptions.
The activity of Nishinoshima continues, with ash emissions, reported by the VAAC Tokyo, partially obscured in its western part by clouds. A strong sulfur dioxide signal is noted by Tropomi.
The Taiwan News reports that volcanic dust from an eruption on the Japanese island of Nishinoshima was responsible for a sudden deterioration in air quality on Taiwan's sparsely populated East Coast on Thursday evening (August 6), according to Taiwan News. meteorological experts.
Yilan, Hualien and Taitung counties are known for their fresh air and natural beauty, but on Thursday evening their skies turned gray and the air quality went from excellent to average, CNA reported. On the WeatherRisk Facebook page, Central Weather Bureau chief executive Cheng Ming-dean (鄭明典) said the change was not the result of mere environmental pollution, but of eruptions on the volcano. Nishinoshima at 2000 km.
Sources: VAAC Tokyo, Tropomi and Taiwan news