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Roger Weller, geology instructor

by Emmanuel Padilla
Physical Geology
Spring 2012

Mount Pinatubo


Pinatubo is one of the most important volcanoes during the 1990s. Its eruption on June 15, 1991 greatly overwhelmed the planet and was considered to be the second-largest volcanic eruption on Earth in that century.


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 Volcanic ash clouds were released prior to the June 15 explosion.


Mount Pinatubo is located in the island of Luzon along the Manila trench, with the height of 4,872 ft. It has a 2.5 km wide caldera, which today is now called Pinatubo Lake.


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Pinatubo Lake (Today)


This volcano is said to be lying on the old relics of Ancestral Pinatubo. Though active, the volcano has no recorded history of eruptions before the June 1991 eruption, and it has been lying dormant before and after the eruption.


The preeruption of Mount Pinatubo was not as much devastating as its eruption. On June 7, 1991, the volcano released its first magma, flowing on the surface of the mountain. Shallow earthquakes were also being produced by the volcano. And as the days go by, there were noticeable increase in seismic energy. Light ash plumes and volcanic gases were also released on the early June 1991. The initial magma flows were not devastating, but on June 12 Pinatubo released a high vast of gas-charged magma that covered millions of cubic yards.  


Description: fig2.jpg


It was on June 15, 1991 that Mount Pinatubo exploded. The explosion destroyed the summit of the volcano, and the release of large quantities of materials caused the summit to collapse forming a large caldera. Almost 5.50.5 cubic kilometers of pyroclastic flow deposits were released and ash clouds rose as high as 22 miles into the air. Surrounding villages were greatly destroyed after the explosion. Though the local government and the military managed to save more the 50,000 lives, the number of casualties was still severe.

The monsoon rains also contributed to the destruction of homes and facilities. Raging lahars flashed through the valleys and villages. Heavy ash falls covered cities and destroying the facilities due to the weight. The explosion also affected the world by cooling down its temperature by 1 Fahrenheit. 


Today, Mount Pinatubo is still in its slumber. The effects of the eruption have been lifted, by the event never seems to be forgotten by the people. From a great destruction tool, Mount Pinatubo is now a paradise. With the formation of Pinatubo Lake, hiking is greatly endorsed by the local citizens. It is now a place where you can see the volcano’s beauty, rather than its former face of destruction.




Works Cited