Pinatubo Volcano’s monitoring network recorded nine (9) volcanic earthquakes during the 24-hour observation period, PHIVOLCS reported Friday, March 5.
Alert Level 1 is hoisted over Pinatubo Volcano, which means that there is low-level unrest that may be related to tectonic processes beneath the volcano and that no imminent eruption is foreseen.
Entry into the Pinatubo Crater area must be conducted with extreme caution and should be avoided if possible. Communities and local government units surrounding Pinatubo are reminded to be always prepared for both earthquake and volcanic hazards and to review, prepare and strengthen their contingency, emergency and other disaster preparedness plans.
DOST-PHIVOLCS continues to strengthen its monitoring of the volcano with ongoing upgrades to the PVN and periodic geochemical surveys of the Pinatubo crater lake and satellite analysis of ground deformation. DOST-PHIVOLCS is closely monitoring the volcano’s condition and any new development will be relayed to all concerned.
On Thursday, DOST-PHIVOLCS raised the status of Pinatubo Volcano from Alert Level 0 to Alert Level 1 due to persistence of seismic activity.
Pinatubo Volcano records 9 volcanic earthquakes in last 24 hours
Since 20 January 2021, the Pinatubo Volcano Network (PVN) has detected a total of 1,722 imperceptible earthquakes beneath the Pinatubo edifice. The first cluster of earthquakes on 20-26 January 2021 occurred along the Sacobia Lineament at depths of 15-28 kilometers and ranged between ML1.0 and ML2.5 in magnitudes.
This has been succeeded by a more persistent cluster of earthquakes occurring along a north-northwest-south-southeast-trending structure 10 to 35 kilometers beneath the center of the edifice itself, with a few shallower earthquakes occurring on both ends of the cluster.
The earthquakes ranged between ML0.5 and ML2.8 in magnitude; all earthquakes recorded are associated with rock-fracturing processes. Measurements at its Crater lake in February 2021 yielded a total CO2 flux of 378 tonnes/day which is still within the background range of 1,000 tonnes/day recorded in the past decade.
Slight increases in the temperatures of monitored fumaroles or gas vents were recorded but other characteristics such as acidity (pH) remain unchanged.
Pinatubo Volcano has had at least 6 periods of activity with large explosive eruptions in its past 35,000 years prior to the 1991 eruption.