Flying rocks and other dangers posed by erupting Taal

The continuous eruption of the Taal Volcano could lead to several scenarios, similar to some of the events that took place during the volcano’s strongest and longest eruption in 1754, state volcanologists have said.

Huge plume of ash and weak lava flow have sent over 40,000 residents in Batangas and Cavite seeking refuge in evacuation centers, according to the national disaster management council.

Base surges

The volcano’s eruption in 1754 lasted seven months and created base surges, which are mixtures of gas and smoldering rocks that may make their way toward the towns near the crater.

Hazard maps from the Philippine Institute of Volcanology and Seismology (PHIVOLCS) showed that several towns are at risk in the event that base surges are formed.

“Kakalat po palayo mula sa crater ang eruption deposit at gagapang at posibleng tumawid sa tubig at umabot doon sa lupa,” PHIVOLCS Director Renato Solidum said in a 24 Oras report by Bernadette Reyes.

The 1754 eruption completely changed the face of Batangas.

"Old Taal" is now known as San Nicolas, while the center of Tanauan was moved over 10 kilometers away from the Taal Lake.

“Nag-relocate lahat ng mga towns na ito away from the lake,” Ma. Antonia Bornas, chief of the PHIVOLCS Volcano Monitoring and Eruption Prediction Division, said.

Ballistic projectile

Another possible effect of the Taal Volcano’s magmatic eruption is a ballistic projectile or the spewing of gigantic rocks.

“In 1965, I think noon nag-evacuate ang mga tao, nagkaroon ng mga malalaking bitak ng bato na tumatama sa bangka, tinatamaan ‘yung mga tao,” Solidum recalled.

Volcanic tsunami

A magmatic eruption can also lead to volcanic tsunamis between one and three meters tall.

“Kung significant 'yung volume na mahuhulog sa tubig, madi-displace din niya ‘yung tubig sa lake at ‘pag ganyan po, merong wave na maitutulak pupunta sa dalampasigan,” Solidum explained.

Lahar or volcanic mudflows may also be formed if rains accompany the volcano’s spewing of ash.

PHIVOLCS added that they have recorded fissuring in some towns in Batangas that were caused by volcanic activities.

“May report tayo ngayon ng fissuring. Kung susunod siya sa 1911, parang gano’n ‘yung pwede nating i-expect although hindi natin sinasabing ganitong ganito ang mangyayari,” Bornas said, referring to the Taal Volcano’s 1911 eruption that claimed over 1,300 lives. —LDF, GMA News