By Chito Chavez

The Philippine Institute of Volcanology and Seismology (Phivolcs) said that 24 instances of rockfall activity and one volcanic earthquake were recorded at Mayon Volcano in the past 24 hours.

Clouds partially cover Mayon volcano's crater as it spews a column of ash.
(REUTERS/Stringer / MANILA BULLETIN)

Phivolcs added that it had also recorded lava flow, tremors, ground deformation and monitored gas in the volcano as alert level 3 remains hoisted in the area.

State volcanologists said Mayon's current activity may be categorized as a “non-explosive eruption” with a few eruptions similar to that in 2006 and 2009.

Phivolcs explained that a major eruption can only happen if there is an excessive pressure that would cause gas volume inside the volcano.

Earlier, an aerial inspection by Phivolcs revealed the absence of explosive deposits like pyroclastic flows on some areas of the volcano.  But the agency still cautioned residents to stay alert as mudflow and lahar flow may still occur, adding they should steer clear of the danger zone of the volcano.

Phivolcs Director Renato Solidum also noted that Mayon Volcano’s iconic near-perfect cone--damaged by past eruptions--has been restored by the lava flow in the succeeding years.  However, he warned that the “face-lifted” crater, where a new lava dome has emerged due to recent volcanic activity, could be damaged anew in the event ‘an explosive “more dangerous eruption” occurs in the future.

Solidum said the volcano maintains its perfectly symmetrical conical shape because of the distribution of volcanic deposits on all its sides.

The Phivolcs chief warned of loose deposits and lahar, which could be triggered by heavy rainfall.