Summary
Highlights
Mount Pinatubo, a volcano in the Philippines, lay dormant for five centuries, ignored by the hundreds of thousands of people living in its shadow. However, an ancient people called the Aetas, who lived on its slopes, considered the mountain sacred and believed Apomolari, the god of all things, resided within it. In April 1991, a series of small explosions and plumes of steam rocked Pinatubo's remote summit, a warning initially only seen by the Aetas.
A local nun, Sister Emma Fontavillia, and Flor de la Cruz, an Aeta, reported the explosions to Dr. Ray Punenbayan, a volcanologist at the Philippine Institute of Volcanology and Seismology. Despite initial skepticism from his poorly equipped department and the general public, Punenbayan sent a team to the summit. They detected over 200 earthquakes in 24 hours, confirming Pinatubo was coming to life. Punenbayan understood the immense stakes, as over a million lives, including those at the U.S. Clark Air Base, depended on his predictions.
Punenbayan sought aid from his friend Chris Newhall of the United States Geological Survey. On April 23rd, Newhall and his team arrived with high-tech instruments, setting up at Clark Air Base. They discovered that Pinatubo was an explosive volcano, capable of 'pyroclastic flows' – superheated tidal waves of rock and ash. Analysis of past eruptions revealed Pinatubo had a history of Krakatoa-sized events, capable of causing widespread devastation, such as the 1883 Krakatoa eruption that killed 36,000 people.
Worry about Pinatubo's past and continued seismic activity led Ray to order an evacuation of the immediate summit area, displacing thousands of Aetas. However, some Aeta tribes resisted, seeking shelter in caves, believing in their god Apomolari. The quakes then diminished, raising doubts about the volcano's activity. Recalling the avoidable tragedy of Nevado del Ruiz in Colombia in 1985, which killed 23,000, Punenbayan was determined not to lose lives. Chris Newhall's risky helicopter flight confirmed the presence of large quantities of sulfur dioxide, indicating magma rising, although initially the levels plummeted, suggesting a blockage and immense pressurization.
Ray Punenbayan ordered a general evacuation of nearby provinces, affecting almost a million people. Many, like Ben Mendoza, were reluctant to leave their homes, and the U.S. military at Clark Air Base also delayed, demanding precise predictions. In early June, mysterious earthquakes revealed a massive sea of magma. On June 7, Pinatubo launched its first significant eruption, a 28,000-foot plume of steam and ash, signifying the beginning of the attack. Despite this, some, including scientists and a Aeta tribe, remained on the mountain.
On June 12th, the military at Clark Air Base finally issued its evacuation order, with 15,000 personnel and their families leaving amid constant earthquakes. At 8:50 a.m., Pinatubo launched an enormous ash column 12 miles straight up, rising 60,000 feet in one minute, a silent, powerful event. This was not the main eruption but merely a prelude. For 48 hours, earthquakes intensified, and dense ash clouds blasted from the summit. On June 15, 1991, at 1:42 p.m., Pinatubo unleashed one of the most cataclysmic natural events of the 20th century. The eruption had a force 200,000 times greater than the Hiroshima atomic blast, ejecting five cubic kilometers of magma into the stratosphere, causing day to turn to night. Pyroclastic flows, 1500°F and traveling at 100 mph, thundered across the landscape, threatening those who remained, including the Aeta tribe in their cave.