Taal Volcano Eruption: Ashfall Coverage Reaches Cities 300kms Away, Volcanic Tsunami Feared

Taal Volcano in the Philippines -- one of the country's most dangerous volcanoes and ranked by some as one of the 10 most dangerous volcanoes in the world -- erupted without warning Sunday afternoon triggering widespread panic and portents of doom.

The violent eruption sent tens of thousands of terrified residents fleeing their homes well into midnight and onto traffic-clogged roads where they were hit by "mud rain" in which raindrops and black ash from the eruption mixed to form a cloying mud that stuck to everything. Ashfall from the eruption was hurled as far north as the province of Pangasinan over 300 kilometers away by prevailing winds. Taal is located some 50 km south of the capital Manila.

Philippine media is now repeatedly warning Filipinos in provinces bordering this once picturesque volcano in a lake to brace for a monstrous "magmatic eruption" threatening to ignite a "volcanic tsunami." Taal Volcano last erupted in 1977 but a 1965 eruption took more than 200 lives.

Since 1572, Taal has erupted on 33 occasions. This volcano, whose 30 or more volcanic craters are located beneath a placid 19 mile-wide caldera in Taal Lake, is ranked a VEI 6, or Level Six (or “colossal”), eruption threat in the Volcanic Explosivity Index (VEI). The maximum level this open scale has reached is seven. Taal has produced four VEI 4 eruptions over the last 200 years and one VEI 6 eruption 5,500 years ago.

Sunday's phreatic eruption, or an eruption mainly of superheated steam, ash and pumice, propelled a monstrous ash cloud, or a "tephra column," to a height of 15 kilometers into the atmosphere and ignited an unending series of volcanic lightning strikes amid the tumbling cloud of ash visible for miles.

Taal was ranked the ninth most dangerous volcano in the world by Wired magazine in 2017. Most dangerous refers to a volcano's ability to inflict mass casualties. Some 2.5 million people live within a 30 km distance from the volcano.

Filipino fears over a monstrous eruption is being fanned by a warning early Sunday evening by the Philippine Institute of Volcanology and Seismology (Phivolcs) that raised Taal's eruption threat to a Level 4 on a scale of 5. Level 4 means a “hazardous explosive eruption is possible within hours to days.”

Phivolcs urges the immediate evacution of Taal Volcano island due to high risk of pyroclastic density currents, or a fast-moving current of hot gas and volcanic matter. There's also the danger from a deadly "volcanic tsunami" within a 14 km radius from the main crater or caldera.

Phivolcs said a volcanic tsunami might occur in a caldera lake like Taal when water is displaced by a deformation of the lake floor due to rising magma. A volcanic tsunami might also be caused by pyroclastic materials flowing down from the volcano into the lake, or landslides caused by volcanic activity.

"Taal is a very small volcano but a dangerous volcano," said Renato Solidum, Phivolcs director. "It is unique because it is a volcano within a volcano."

Phivolcs has recorded continuous volcanic tremors since 11:00 a.m. Sunday with magnitudes measuring 2.5 and 2.9. It said eruptive activity at Taal Volcano intensified at 5:30 p.m. Sunday.

"Eruptive activity at Taal Volcano Main Crater intensified as continuous eruption generated a tall 10-15 kilometer steam-laden tephra column with frequent volcanic lightning that rained wet ashfall on the general north as far as Quezon City," said Phivolcs in a bulletin.

Some government sources claim as many as 200,000 persons have been evacuated from danger zones around the volcano. Of this total, 8,000 are residents of the volcano island and other high-risk towns while 6,000 were out of the danger zone by Sunday evening, said the National Disaster Risk Reduction and Management Council.