Legazpi city: Effusive eruption at Mayon Volcano continues for the 63rd consecutive day on Monday but there is nothing unusual with this, the head of the Philippine Institute of Volcanology and Seismology (Phivolcs) said. An effusive eruption can last for weeks or even months as long as magma continues to reach the surface, Phivolcs Director Teresito Bacolcol told the Philippine News Agency in an interview.

According to Philippines News Agency, Bacolcol noted that in 2023, an effusive eruption at Mayon Volcano lasted for six months, from June to December. He clarified, however, that while continuous effusive eruption is normal, this doesn't mean that it is not dangerous. "It still generates lava flows, rockfalls, PDCs (pyroclastic density currents) and volcanic hazard," he said.

Bacolcol explained that compared to explosive eruptions, effusive eruptions are more predictable since they move slowly. "That is why we don't raise the volcano's alert level despite the continuous effusive eruption, because the observed activity is within the expected behavior and confined within the permanent danger zone," he said. An effusive eruption involves the gentle release of lava, whereas an explosive eruption involves sudden and forceful ejection of ash, gas, and rocks.

Meanwhile, Phivolcs also reported on Monday a minor strombolian activity at Mayon Volcano. Strombolian activity, according to Bacolcol, is a short explosive burst caused by gas escaping from magma. It can throw lava fragments and may produce small ash plumes. "This activity usually lasts for seconds to minutes, and its effects may include falling lava fragments near the summit, short ash plumes, and minor ashfall," he said. The Phivolcs chief added that not all active volcanoes show strombolian activity, as this depends on the type of magma and how the gas escapes.