(Eagle News)– The Philippine Institute of Volcanology and Seismology on Friday, Feb. 14, lowered Taal volcano’s status to alert level 2 following a decrease in volcanic unrest.
In its latest bulletin, the Philippine Institute of Volcanology and Seismology said since an alert level 3 was hoisted over the volcano on Jan. 26, volcanic earthquakes recorded by the Taal Volcano Network averaged 141 events per day while the number of significant events recorded by the Philippine Seismic Network across the Taal region declined to 127 events of magnitudes 1.4 to 4.3.
“The number and energy of tremor and low frequency events associated with activity in the shallow magma and hydrothermal region beneath the (Taal Volcano Island) edifice have also diminished,” PHIVOLCS said.
PHIVOLCS added sulfur dioxide flux averaged 62 tons per day since then, “consistent with a weakly degassing shallow magma source, diminished plume activity or absorption of volcanic gas by a recovering lake at the main crater and by TVI’s recovering hydrothermal system.”
“The overall ground deformation behavior of Taal Volcano for the above periods indicates post-eruptive subsidence and relaxation of the edifice after the cessation of magma transport, signaled by hybrid earthquake activity, on 18 January,” PHIVOLCS added, noting that activity in the main crater has been characterized by the generation of “weak steam-laden plumes, consistent with decreased magmatic unrest.”
According to PHIVOLCS, the lowering of the alert level “should not be interpreted that unrest has ceased or that the threat of an eruption has disappeared.”
PHIVOLCS reminded the public that at alert level 2, “sudden steam-driven or phreatic explosions, volcanic earthquakes, ashfall and lethal accumulations or expulsions of volcanic gas can occur and threaten areas within TVI and along its coast.”
PHIVOLCS recommened that entry into Taal’s Permanent Danger Zone be strictly prohibited.
Local government units were also advised to “additionally assess previously evacuated areas within the seven-kilometer radius for damages and road accessibilities and to strengthen preparedness, contingency and communication measures in case of renewed unrest.”
People were also advised to “observe precautions due to ground displacement across fissures, frequent ashfall and minor earthquakes.”
Civil aviation authorities must advise pilots to avoid flying close to the volcano, PHIVOLCS said.