Information has been received from the Indonesian Center for Volcanology and Geological Hazard Mitigation (CVGHM) suggesting that a significant eruption may be imminent at Merapi volcano, the Darwin VAAC said in a Volcanic Ash Advisory issued 06:40 UTC on November 8, 2020. The Aviation Color Code was raised to Red.
Authorities raised the alert level for the volcano from 2 to 3 (on a scale of 1 - 4) on November 5, after a significant increase in seismicity, advising residents and tourists to stop all activities in the vicinity of the volcano.
Hundreds of people living on the slopes of the volcano have since been evacuated.
Credit: DARWIN VAAC. Issued 06:40 UTC on November 8, 2020
The volcano-tectonic activity has remained elevated since the powerful eruption on June 21, when the volcano ejected ash up to 6 000 m (20 000 feet) above sea level.
The seismicity started intensifying again in October, with all monitored conditions above those recorded before the formation of the lava dome on April 26, 2006.
Credit: MAGMA Indonesia
As of November 3, there are no new lava domes observed, CVGHM noted on November 5.
However, both seismicity and deformation are still increasing.
"Based on this, it is possible the volcano could experience an explosive eruption or fast magma extrusion," CVGHM volcanologists said.
Potential hazards include lava flows, ejection of volcanic material and pyroclastic flows to a maximum distance of 5 km (3.1 miles).
Mount Merapi on September 18, 2020. Credits: Copernicus EU/Sentinel-2, TW
On Friday, November 7, the local disaster mitigation agency said about 500 people from four villages, mostly the elderly, pregnant women and children, were taken to emergency shelters in Central Java's Magelang district.
"Emergency measures to evacuate people living within 6 km (3.7 miles) of the crater’s mouth are being prepared as local administrations in Central Java and Yogyakarta provinces closely monitor the situation."
Merapi's eruption in 2010 killed 347 people and forced the evacuation of nearly 400 000 people.
Merapi, one of Indonesia's most active volcanoes, lies in one of the world's most densely populated areas and dominates the landscape immediately north of the major city of Yogyakarta. It is the youngest and southernmost of a volcanic chain extending NNW to the Ungaran volcano.
Growth of Old Merapi during the Pleistocene ended with major edifice collapse perhaps about 2 000 years ago, leaving a large arcuate scarp cutting the eroded older Batulawang volcano.
Subsequently, the growth of the steep-sided Young Merapi edifice, its upper part unvegetated due to frequent eruptive activity, began SW of the earlier collapse scarp.
Pyroclastic flows and lahars accompanying growth and collapse of the steep-sided active summit lava dome have devastated cultivated lands on the western-to-southern flanks and caused many fatalities during historical time. (GVP)
Featured image: Mount Merapi on October 15, 2020. Credits: Copernicus EU/Sentinel-2, TW