A NATURAL DISASTER: "Mount Pinatubo Eruption"

In June 1991, the volcano Mount Pinatubo in Philippines had been dormant for more 500 years and in that year came back to life. The eruption forced evacuation of more than 50,000 people, including the “Clark Air Base”, a U.S. military installation near the volcano. However 800 people dead and 100.000 became homeless after the episode. Indications of a possible eruption had started a year ago but the size and impact of it were completely unexpected.

The events of the 1991 Mount Pinatubo eruption began in July 1990, when a magnitude 7.8 earthquake occurred 100 kilometers northeast of the Pinatubo region, determined to be a result of the reawakening of Mount Pinatubo. After that, small explosions began and earthquakes continued. On June 5, a Level 3 alert was issued for two weeks due to the possibility of a major eruption. On June 15, the eruption of Mount Pinatubo began.

During the eruption, the upper slopes of the mountain suffered immediate destruction. Unfortunately, at the time of the eruption, Tropical Storm Yunya was passing 75 km to the northeast of Mount Pinatubo, causing a large amount of rainfall in the region. The ash that was ejected from the volcano mixed with the water vapor in the air to cause a rainfall of tephra that goes across almost the entire island of Luzon. In addition to the ash, Mount Pinatubo ejected between 15 and 30 million tons of sulfur dioxide gas. Sulfur dioxide in the atmosphere mixes with water and oxygen in the atmosphere to become sulfuric acid, which damages the ozone layer.

A week later after the major eruption, heavy rains from Typhoon Brenden sent thousands of tonnes of ash, silt and volcanic debris surging down the mountain. Enormous mud flows killed many people and forced thousands to flee from their homes.

Its consequences were the following:

Mt Pinatubo’s massive eruption produced the largest cloud of climate-modifying gases. The cloud over the earth reduced global temperatures. In 1992 and 1993, the average temperature in the Northern Hemisphere was reduced 0.5 to 0.6°C and the entire planet was cooled 0.4 to 0.5°C.

The human impacts of the disaster were devastating. In addition to the up to 800 people who lost their lives, there was almost one half of a billion dollars in property and economic damage. The volcano eruption destroyed 4,979 homes and damaged another 70,257. The following years, 3.281 homes were destroyed and 3,137 were damaged.

The Pinatubo volcano never became a dormant mount, because another eruption in August 1992 killed 72 people.