BACOLOD City – Despite the uptick in its volcanic activity, Kanlaon volcano does not pose an immediate threat to its environs, according to the Philippine Institute of Volcanology and Seismology (Phivolcs).
Thirty-five 35 volcanic-tectonic tremors were recorded between 10 p.m. on July 20 until 9:06 a.m. yesterday.
But according to Dr. Raymund Patrick Maximo, Phivolcs’ Science Research Specialist II, these were still considered “normal activity” for Kanlaon.
Maximo was the guest speaker during yesterday’s Emergency Preparedness Forum in this city.
The earthquakes ranged between 0.9 and 2.3 magnitude, which occurred 12 to 15 kilometers below the volcano’s crater.
Tectonic earthquakes occur when rocks beneath the volcano move due to pressure from magma.
The volcano has also emitted a higher amount of sulfur dioxide gas emission averaging 786 tonnes on July 18, higher than the average emission of 566 tonnes per day in March.
Maximo said Negros Island has several “potentially active” volcanoes – Mt. Mandalagan, located right beside Kanlaon volcano; Mt. Silay; and Mt. Talinis or “Cuernos de Negros” located 20 kilometers from Dumaguete City, Negros Oriental.
He further said “potentially active” volcanoes usually look young, but have not erupted for the last 10,000 years.
Explaining the connection between earthquakes and volcanic activity, Maximo said Negros Island has several active fault lines – the west Negros fault system, central Negros fault system, east Negros fault system, and Negros trench.
The science research specialist said the fault systems are the cause of the tremors being felt in Negros and it has no connection to the tremors of the Kanlaon volcano, which is classified as volcanic, not tectonic.
As an example, Maximo pointed out the magnitude of 6.7 earthquake in Negros in 2012 with the epicenter located 72 kilometers north of Dumaguete City.
The earthquake was later blamed to the movement of east Negros fault system which was undiscovered at the time.
Maximo also pointed out that the Negros trench located at the southwest coast of Negros island is similarly dangerous as not only can it cause destruction but could also generate a tsunami if the tremor is strong.
As part of safety precautions, Maximo is again urging local government units (LGUs) not only in Negros but also in the neighboring islands to strictly abide with the National Building Code of the Philippines (Republic Act No. 6541).
Under the National Building Code, all buildings should be constructed with hollow blocks that are six-inches thick and vertical steel bars with a spaced diameter of 10 millimeters (40 centimeters) to each other. (Watchmen Daily Journal)
