CALM LAKE. Taal Lake surrounds Taal Volcano Island. The impact of the volcano’s eruption last year on lake conditions and its aquatic life has yet to be fully studied by researchers due to Taal’s unrest and restrictions prompted by the pandemic. —GRIG C. MONTEGRANDE
MANILA, Philippines — The number of earthquakes being recorded in Taal Volcano has decreased to just 29 in the last 24 hours, the Philippine Institute of Volcanology and Seismology (Phivolcs) said.
Of the 29 volcanic quakes, 23 were tremors that lasted one to 12 minutes, and six were low frequency volcanic earthquakes and low-level background tremors that started at 9:05 a.m. on April 8.
Phivolcs also observed “very weak” emission of ten-meter steam-laden plumes from the volcano’s vents.
As of April 24, sulfur dioxide (SO2) emission averaged 1,051 tons per day.
Phivolcs also said ground deformation parameters recorded a “very slow and steady inflation and expansion of the Taal region that began after the January 2020 eruption.”
“These parameters indicate persistent magmatic activity at shallow depths beneath the edifice,” Phivolcs said in its latest volcano bulletin.
Alert Level 2 is maintained over Taal, meaning sudden steam-driven or phreatic explosions, volcanic earthquakes, minor ashfall, and lethal accumulations or expulsions of volcanic gas are possible.
Phivolcs strongly recommends that entry must be strictly prohibited on Taal Volcano Island, Taal’s permanent danger zone, especially the vicinity of the main crater, the Daang Kastila fissure, and occupancy and boating on Taal Lake.
Last March 25, Phivolcs warned about the increased possibility of a magmatic eruption after it observed a heightened level of seismic activity at Taal Volcano, registering 2,015 volcanic tremors, 734 low-frequency volcanic earthquakes and 18 hybrid earthquake events.
This went further down last April 18 with just 51 quakes in the last 24 hours, indicating continued unrest in the volcano. Of the 51 volcanic earthquakes, 43 were volcanic tremors that lasted one to 17 minutes and eight were low frequency volcanic earthquakes and low-level background tremors that started at 9:05 a.m. on April 8.
Other volcanoes
Meanwhile, Alert Level 1 is also maintained in Mayon Volcano, Kanlaon Volcano, and Pinatubo.
One volcanic earthquake was recorded in Mayon and Kanlaon, while four earthquakes were recorded in Pinatubo.
S02 emission was measured at an average of 80 tons per day in Mayon as of March 8, and 998 tons per day in Kanlaon as of April 23.
Ground deformation has also been recorded in both volcanoes, with a slight inflation since June 2020 in Kanlaon and a slight inflation of the edifice in Mayon since March 11.
While no magmatic eruption is expected in the three volcanoes, Phivolcs still prohibits entry in each of its permanent danger zones.
Phivolcs said it is closely monitoring all the volcanoes’ activity and any new significant development will be immediately communicated to the public.