Geology: Taal and Mayon
Mayon and Taal volcanoes have been visibly active lately. Let us therefore look at the geological history of these two volcanoes, to understand what we really are up against.
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Daily TribuneMayon and Taal volcanoes have been visibly active lately. Let us therefore look at the geological history of these two volcanoes, to understand what we really are up against.
Taal Volcano
Millions of years ago, Taal Volcano was as beautiful as the regal Mt. Fuji in Japan today, with a perfect symmetrical cone. Then, it exploded in a mega-blast. Eighty percent of the volcano disintegrated and its remnants reached the stratosphere and spread around the planet. It darkened the skies in many places across the northern hemisphere.
Today, like the Sword of Damocles, it is still one of the most active volcanoes in the archipelago, because the monstrous magma vent underneath that caused the mega-blast is still active. That blast, worse than the infamous mega-explosion of Krakatoa in Indonesia decades ago, affected weather conditions as far as the North and the South Polar regions.
The remnants of the blast today, the so-called caldera, is shown in the attached Phivolcs graph below. The “crown” of the caldera shows the Tagaytay ridge on the left and the town of Cuenca on the right. A huge crater lake was formed through the centuries by periodic rain. The new volcano, the son of the old monster, persists today as a tiny but super-active volcano within a volcano.
Mariton Bornas of Phivolcs explains it eloquently: “Ang maliit na bulkan na kilala natin bilang Taal ay ‘bangkay’ ng isang sinauaning dambuhalang bulkan. Bago pumutok ang Taal ilang milyong taong nakaraan, yon ay kasing ganda ng Mount Fuji sa Japan.” (The tiny Taal Volcano we know today is the “corpse” of an original monster volcano. Before that cosmic blast millions of years ago, Taal was as beautiful as Mount Fuji in Japan.)
The rare fish that evolved through the centuries.
Geologists report that, centuries ago, there existed a long underground river that connected the deep vertical crater to the ocean several hundred kilometers away, and that saltwater sardines migrated to the crater lake, evolving into freshwater sardines through the centuries, the only known species in the world today. This is called “tawilis” by Batangas fishermen.
The tawilis suddenly “disappear” momentarily, as reported by fishermen, diving deep to spawn, and then return to the surface. The tawilis is an endangered species due to overfishing. The succulent delicacy is tastier than its saltwater sardine predecessor. Fishermen predict they will become extinct soon. The entrance to the underground river has not been located by marine biologists and geologists.
Another saltwater fish, the “talakitok,” has evolved into a freshwater variety called “maliputo,” also sought after for its succulent taste. It is also an endangered species.
It is recommended that the Bureau of Fisheries and Aquatic Resources perhaps launch a project to protect and proliferate these two endangered ancient species. This project can be located on the crater lake itself.
