Phivolcs: No permanent danger zone on Pinatubo

ADVENTURE Mt. Pinatubo has been attracting outdoor enthusiasts seeking an adventure in the volcano’s lahar canyons. —INQUIRER PHOTO

CITY OF SAN FERNANDO—Unlike five other active volcanoes in the county, Mt. Pinatubo has no permanent danger zone (PDZ) where human settlement is prohibited, the chief of the Philippine Institute of Volcanology and Seismology (Phivolcs) said on Wednesday.

Phivolcs instead identified a hazard zone where its settlers could be evacuated should Alert Level 3 be hoisted over the volcano, according to Renato Solidum, the agency’s director.

He said this would mean that local governments needed to conduct an information drive up to the summit or go up farther to bring people down to the lower flanks.

“Our wording [for the hazard zone] was up to 10-kilometer distance from the crater,” Solidum told the Inquirer in a telephone interview on Thursday.

The defunct Mt. Pinatubo Commission built 10 upland resettlements outside the 10-km radius of the volcano in Zambales, Pampanga and Tarlac provinces.

Mt. Pinatubo has drawn attention since March 4 when Phivolcs placed it on Alert Level 1 after exhibiting low-level unrest almost 30 years after its June 15, 1991 eruption.

“Phivolcs has not designated a PDZ as Mt. Pinatubo has not erupted in historical time before 1991 [and so the extent of hazards was not known],” Solidum said.

He said there was no mention of a PDZ in the 1996 “Fire and Mud” paper by Dr. Raymundo Punongbayan and other scientists, which he was also a coauthor. Punongbayan was then the director of Phivolcs.

Precautionary evacuation

According to Solidum, Phivolcs initially recommended a precautionary evacuation of villages within 10 km from the summit before the 1991 eruption.

“Evacuations were essentially based on the alert level in combination with hazard maps,” Solidum said.

He said Taal, Mayon, Bulusan, Kanlaon and Hibok-Hibok volcanoes have PDZs because these were “in constant danger from various hazards, such as phreatic (steam-driven) eruptions, rockfalls, gas emissions and affected by small eruptions.”

“What is important to remember is that hazards assessment of an area is critical in determining if an area is suitable for settlement,” Solidum said.

Renewed interest

The matter of PDZ cropped up in the March 9 meeting of the response cluster of the Regional Disaster Risk Reduction and Management Council in Central Luzon, the Inquirer learned.

Representatives of the Department of the Interior and Local Government and the Department of Social Welfare and Development inquired about the 10-km PDZ in relation to their responses.