Evacuaties bij de Mayon - Actiefste vulkanen Filipijnen rommelen

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Thousands Flee a Volcano in the Philippines Fearing a Possible Violent Eruption

Hot, ground-hugging flows of volcanic ash and debris began cascading down the slopes of Mayon Volcano, a 1.5 mile-high volcano—the most active one in the Philippines—in a peninsular region around 202 miles southeast of the Manila capital, last week. Volcanic activity increased in the following days, with Mayon spewing incandescent lava at night and causing tremors to neighboring villages. By Wednesday, June 14, some 17,000 people were evacuated, including those within its six-kilometer dangerous perimeter. National volcanologists have predicted that hazardous, eruptive activity could be imminent in weeks or days.

The Philippines is no stranger to volcanic activity in the seismologically-active Pacific “Ring of Fire.” In 1991, the violent eruption of Mount Pinatubo in Zambales killed some 700 people—outnumbering casualties from Mount St. Helens’ eruption in Washington State in 1985. And in 2020, just as most of the world scrambled to find masks for COVID-19, Taal Volcano ejected tall columns of volcanic ash that reached as far as the country’s capital, forcing its airports to close and exposing residents to harmful particulates.

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But compared to these precedents, Mayon recently has shown some peculiar activity that may signal a gentler eruption, says Ma. Antonia Bornas, the chief of the volcanology institute’s monitoring and eruption prediction division: Levels of sulfur dioxide, which is typically released when magma is near the surface, is currently in the hundreds of tons, and volcanoes usually release at least thousands of tons of the gas before an explosive eruption. “We’re not seeing any volcanic activity,” Bornas tells TIME. “If you look at the seismic energy of the volcano—the way it charts—since a few months ago until now, it’s practically the same.”

Still, that’s no reason to be complacent. “For today, the chances of an explosive eruption are quite low,” she says. “But tomorrow might be a different story.”

Has Mayon erupted violently in the past?
Mayon, located in the Albay province, is a stratovolcano—steep volcanoes built up by eruptions of volcanic material over the course of thousands of years.

Data from the Philippines’ volcanology institute show the earliest recorded eruption of Mayon in 1616. Its eruptions range from phreatic (steam-driven) to Plinian—extremely explosive eruptions that can send volcanic debris tens of miles into the Earth’s atmosphere.

The last Plinian eruption of Mayon was in February 1814, which reportedly killed at least 1,200 people. Five foreign climbers were killed by falling rocks from a smaller eruption in 2013. From January 13 to March 18, 2018, volcanic activity in Mayon increased, spewing ash columns and lava and forcing thousands to evacuate, but there were no direct casualties.

What’s the current alert level for Mayon?
In a five-tier scale, Mayon’s activity as of Thursday was classified under Alert Level 3, which Bornas says indicates an effusive eruption from the crater.

The latest alert level can be found on the volcanology institute’s daily bulletin.

Despite the unrest, some volcano-watchers have flocked to see Mayon, which has become a popular tourist sight thanks to its majestic cone shape, prompting government officials to designate safe viewing zones, reports Philippine news site Rappler.

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The elevated activity at the volcano continues.

The viscous lava flow on the southern and southeastern slopes continues to be active, currently about 1000 meters long from the summit crater. Due to its high viscosity, glowing lava blocks frequently detach from the lava flow, turning into pyroclastic flows over the Mi-si and Bonga ravines, where collapsed debris deposits reach a distance of about 2 km from the summit.

A moderate ash fall has been reported in Sitio Buga, Brgy, Nabonton, City of Ligao and Purok 7, Brgy, San Francisco, Municipality of Guinobatan.

According to the Volcanic Ash Advisory Center Tokyo (VAAC), eruptions continue to take place from the summit vent, generating W-NW oriented ash plumes that reach 2,8 km altitude.
Sulfur dioxide (SO2) emissions (degassing) reached to a 826 tonnes yesterday.

The short-term electronic tilt monitoring continues to detect the middle and upper southeastern slopes inflated since February this year. However, the long-term ground deformation suggests the ongoing uplifting of the edifice, on the northwestern and southeastern slopes in particular, since 2020.

In order to mitigate the risk, people are forbidden to enter an area of 6 km distance from the summit crater due to impacts of rockfalls, pyroclastic falls and/or phreatic eruptions.

The alert level for the volcano remains at Level 3.

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The activity of the volcano continues at elevated levels.
The viscous lava on the southern Mi-si and southeastern Bonga gorges continues to keep the flow active by emerging from the summit lava dome. The main lava flow front has already reached approx. 1500 meters distance from the main vent.

Five incandescent dome-block avalanches reached considerable distance of about 3,3 km from the crater by emanating from the lava dome reported today.

Sulfur dioxide (SO2) emissions (degassing) reached to a 889 tonnes yesterday.

The short-term electronic tilt monitoring continues to detect the middle and upper southeastern slopes inflated since February this year. However, the long-term ground deformation suggests the ongoing uplifting of the edifice, on the northwestern and southeastern slopes in particular, since 2020.

In order to mitigate the risk, people are forbidden to enter an area of 6 km distance from the summit crater due to impacts of rockfalls, pyroclastic falls and/or phreatic eruptions.
The alert level for the volcano remains at Level 3.

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Alert Level 3 over Mayon volcano, hazardous eruption within weeks or even days still possible, Philippines

PHIVOLCS maintains Alert Level 3 over the Mayon volcano, which means that it is currently in a relatively high level of unrest, and hazardous eruption within weeks or even days could still be possible.

In 24 hours to 00:00 UTC on October 3, 2023, the Mayon Volcano Network recorded 6 volcanic earthquakes and 111 rockfall events. The lava flows have maintained their advances to approximately 3.4 km (2.1 miles) in Bonga (southeastern), 2.8 km (1.7 miles) in Mi-isi (south), and 1.1 km (0.7 miles) in Basud (eastern) Gullies.

Rockfalls and pyroclastic flows (PDCs) generated by collapses of the lava flow margins as well as of the summit dome deposited debris still within four 4 km (2.5 miles) of the crater.

Volcanic sulfur dioxide (SO2) emission averaged 1 390 tonnes/day on October 2.

Short-term observations from electronic tilt and GPS monitoring indicate continued inflation of the northwestern upper slopes since the fourth week of July 2023. Meanwhile, electronic tilt measurements show slight deflation on the northwestern middle slope starting in the third week of September.

Longer-term ground deformation parameters from EDM, precise leveling, continuous GPS, and electronic tilt monitoring indicate that Mayon is still generally inflated relative to baseline levels.

PIVOLCS recommends that the 6 km (3.7 miles) radius Permanent Danger Zone (PDZ) remain evacuated due to the danger of PDCs, lava flows, rockfalls, and other volcanic hazards.

Increased vigilance against PDCs, lahars, and sediment-laden streamflows along channels draining the edifice is also advised.

Heavy rainfall could generate channel-confined lahars and sediment-laden streamflows in channels where PDC deposits were emplaced. Civil aviation authorities must also advise pilots to avoid flying close to the volcano’s summit as ash from any sudden eruption can be hazardous to aircraft. Based on the current prevailing wind pattern, ash fall events may most likely occur on the south side of the volcano.

A total of 9 876 families or 38 396 persons are affected in 26 barangays in Albay.