LEGAZPI CITY, Philippines—Mount Mayon’s volcanic activities were slowing down, indicating that an eruption was no longer imminent, government volcanologists said on Thursday.
In an advisory, the Philippine Institute of Volcanology and Seismology (Phivolcs) lowered Mayon’s alert status from Level 2 to Level 1 after noting the continued decline in volcanic quakes, magma buildup, gas emission, crater glows, lava flows and ground deformation.
But Eduardo Laguerta, Phivolcs resident volcanologist based in this city, urged the public to remain vigilant because the active volcano could again get restive. Entering the 6-kilometer-radius permanent danger zone is still prohibited due to perennial hazards of rockfall, avalanche, ashfall and sudden steam-driven eruption at the summit.
Gov. Joey Salceda said crater climbing up to Camps 1 and 2, and the Mayon Skyline, ziplines and ATV (all-terrain vehicle) activities would resume but should be coordinated with local tourism and disaster risk reduction and management offices.
Harry Esquivel, 28, one of the ATV operators based at Cagsawa Ruins in Daraga town, said the lowering of the alert status was timely, as the last quarter is usually the peak season for Mayon-related tour activities.
Since Level 2 was raised in September last year and ATV activities were stopped, business was badly affected, Esquivel said. Operators used to earn an average of P50,000 a day, he said.
Joven Ruly, 22, a tour guide from Barangay Binitayan here, said the Phivolcs announcement was an early Christmas gift to him and his colleagues.
Alert Level 3 was hoisted over Mayon on Sept. 15 last year after it showed heightened restiveness, prompting the evacuation of about 50,000 people living within the danger zones.
Some 41,000 were allowed to return home during the first week of November after the volcano began to quiet down, but those living within the 6-km danger zone, or about 15,000, remained in evacuation centers until the alert status was lowered to Level 2 on Dec. 19, 2014.
Since then, Mayon’s volcanic earthquakes have been decreasing to an average of just once a day, triggered by rock fracturing beneath the edifice and occasional rockfalls, the Phivolcs said.
“There is currently no active transport of eruptible magma to the shallow level of the volcano,” Laguerta said, citing the absence of low-frequency quakes associated with magma or volcanic gas movement.
He said the swelling of the crater that began in May last year—an indication of magma movement beneath the northern flank of the crater—had also stopped, along with lava buildup similar to what was recorded in October last year.
Gas emission has also considerably dropped, from a high of 6,253 tons per day in September 2014 to the lowest measurement in January at 32 tons. Shallow magma degassing has generally declined due to the progressive loss of volcanic gas, Phivolcs said.
There has also been no crater glow since the last recorded incident on Nov. 28, 2014, it added.