Bulusan Volcano

Phivolcs downgrades Bulusan Volcano to Alert Level 0

Acor Arceo
Phivolcs downgrades Bulusan Volcano to Alert Level 0

BULUSAN VOLCANO. The volcano in the province of Sorsogon.


People are still advised not to enter the 4-kilometer permanent danger zone surrounding Bulusan Volcano

Bulusan Volcano was downgraded back to Alert Level 0 on Wednesday, August 18, more than three months since Alert Level 1 was raised last May 11.

Alert Level 0 means the volcano in Sorsogon has returned to a normal state, coming from low-level unrest.

The Philippine Institute of Volcanology and Seismology (Phivolcs) said on Wednesday that there has been “a general decline in monitoring parameters.”

These parameters include:

  • Volcanic earthquakes: Two to three weak earthquakes were recorded per day between July 1 and August 17, for a total of only 109. “This indicates that rock fracturing within the volcanic system associated with shallow hydrothermal activity has diminished.”
  • Ground deformation: This has been “driven by tectonic processes rather than pressurization from subsurface magma.”
  • Gas emission: Sulfur dioxide emission has stayed “below detection levels” since May 6, while “ambient carbon dioxide concentrations in most monitored springs have weakened” since April.
  • Surface activity: Emission of steam plumes has been very weak to weak.

While Phivolcs said “no magmatic eruption is foreseen in the immediate future,” Alert Level 1 could be raised again for Bulusan Volcano if any of the parameters increase.

Phivolcs also reminded the public not to enter the 4-kilometer permanent danger zone surrounding Bulusan Volcano.

There could be rockfalls, avalanches, and steam-driven or phreatic eruptions “which may occur without warning.”

“Furthermore, people living in valleys and active river channels are cautioned to remain vigilant against sediment-laden streamflows and floods in the event of prolonged and heavy rainfall,” added Phivolcs. – Rappler.com

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Acor Arceo

Acor Arceo is the head of copy and editorial standards at Rappler. Trained in both online and TV newsrooms, Acor ensures consistency in editorial standards across all sections and also supervises Rappler’s coverage of disasters.