MANILA – There has been a marked weakening of slow lava effusion from the summit crater of Mayon Volcano in the past 24 hours but it remains under Alert Level 3 at a “relatively high level of unrest.”

“Mayon Volcano is on Alert Level 3 since June 8 and its effusive eruption is still ongoing. So when we say effusive eruption, this is the release of magma on the slope of the volcano,” Dr. Teresito Bacolcol, officer in charge of the Philippine Institute of Volcanology and Seismology Geology (Phivolcs) – Geophysics Research and Development Division, said at the Saturday News Forum in Quezon City.

Level 3 also means nobody is allowed within the 6-km. permanent danger zone, he added.

As of Friday, he said, the volcano has released about 19 million cubic meters of volcanic materials.

“For us to have an idea of how big those 19 million cubic meters of volcanic materials are, a dump truck’s capacity would be around 14 cubic meters. So, these 19 million cubic meters will be equivalent to around 1.4 million dump trucks,” he said.

Bacolcol said at best, they were hoping that no explosive eruption would happen.

“Effusive eruption is the slow release of magma on the edifice. So, we are constantly monitoring the parameters and hopefully there will be no explosive eruption,” he said.

“The downside is, it would probably take (a) few more weeks whereas. If it’s an explosive eruption like what happened in 2000, it only took two weeks. But for an effusive eruption like what happened in 2014, it took three months.”

Still, a volcanic eruption has benefits.

“Volcanic ash is fertile. That’s why it’s hard for people to leave areas that have active volcanoes because the land around volcanoes is fertile,” he said.

In its 8 a.m. bulletin, Phivolcs said 40 volcanic earthquakes, including 39 low-frequency volcanic earthquakes, and 45 rockfall events were recorded by the Mayon Volcano Network.

Evacuation from the permanent danger zone is recommended due to lava flows, rockfalls and other volcanic hazards.

“The parameters are fluctuating and it’s really difficult to say if this probably would lead to an explosive eruption. We’re assessing the situation on a day-to-day basis,” Bacolcol said. (PNA)