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Roger Weller, geology instructor

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Mt. Pinatubo
by Sarah Biron
Physical Geology
Spring 2011
  
  
 

Mount Pinatubo
The eruption that rocked a nation.

 

Imagine, if one day you are sitting home, watching tv, and playing with your family, and the next you are being asked to move out of your house and flee your home, because it was possibly in the way of volcanic ash, debris and lava. This is what happened to many residents of the island of Luzon in the Philippines in 1991.

Description: http://www.camperspoint.com/IMG/jpg/luzon_map_2-2.jpg

 

I have been to the Philippines twice now, and each time when driving to Clark Air Force Base, the pastor on the church I visit, would tell us what it was like to be living in the Philippines when this devastation occurred. When driving on the highway, you can look out the window and still see ash and debris as it has coated the ground even 20 years later.
 

Description: http://c.photoshelter.com/img-get/I0000l0qjgachNVs/s/850/850/philippines005a.jpg
 

How does a volcano just erupt? On July 16, 1990, an earth quake struck the island of Luzon, creating multiple landslides, and damage to the surrounding area. This caused the earth to shirt underneath the lying volcano, and random eruptions of gas and ash would occasionally spew forth from different cracks. Small earthquakes frequently rocked Luzon.
 

Description: https://www.geology.ucdavis.edu/iype/june/pinatubo.jpg

 

On April 2nd 1991, the first magma eruption occurred out of the composite volcano. Since the magma had been seeping gasses on its push upwards towards the surface, it was not explosive but more like a seeping of magma and fluid.  This continued to happen on and off for the next couple of months. On June 3rd though, life of the people living on Luzon changed. The first eruption occurred out of the cone. It created a column of ash 4.5 miles skyward.
 

Description: http://pubs.usgs.gov/fs/1997/fs113-97/resources/AshCloud.jpg
 

People had to be evacuated from a radius of upwards of 27 miles around the volcano, many Aeta’s (the national inhabitants of the Philippines) who lived on the volcano fled. 
 

          Graphs and instruments began to show that the volcano was actually changing in size. It was filling with magma, which was creating the cone to grow outward and to become larger. On June 12th, the beginning of the worst of the eruptions started to occur. Fifteen minute eruptions sent ash into the air, and created eruptions clouds almost 15 miles high in the air. Eruptions continued to occur over the next 24 hours, continually getting worse as time wore on. Another 15 mile high eruption rocked Luzon, with earthquakes and ash and magma being shot everywhere.
 

Description: http://mail.colonial.net/~hkaiter/earth_science_images/Pinatubo1b2.jpg

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Description: http://www.nasa.gov/centers/goddard/images/content/161629main_Pinatubo_Volcano.jpg
 

On June 15th, a typhoon hit the Philippines and made any observation of the eruptions impossible, but graphs showed that eruptions hit as high as 21 miles skyward. Much of Luzon was covered in Ash, and put into darkness. 50,000 square miles were covered and taken over by the ash the volcano had spewed out.
 

Description: http://1.bp.blogspot.com/_MUFH06CiQjg/R9fQfgtxa3I/AAAAAAAAABw/we-xBz6Xbhw/S1600-R/Pinatubo-eruption.jpg

Description: http://3.bp.blogspot.com/_femhrxbNtS0/S8sacx2mZpI/AAAAAAAAFUA/j_PHEppUtNg/s1600/Ashfall_from_Pinatubo,_1991.jpg
 

This volcano was the 2nd largest volcano in the century; it was ten times stronger than the volcano eruption of Mount St. Helens. Over 800 people died from the eruption, and too many houses and places of business were destroyed because of this.
 

Since the eruption the volcano has remained fairly inactive with random occasions of spurts and emissions. The caldera on top has now been formed into a lake, where waters can sometimes reach boiling levels and become acidy.
 

Description: http://www.metrolic.com/wp-content/uploads/2010/10/MtPinatubo1.jpg

Description: http://t3.gstatic.com/images?q=tbn:ANd9GcR_qpVK-8zx3RRUV0409FYBy4vaXn_6nY7vO12zU8l1hv4RAlTz&t=1
 

Works Cited

http://www.coolgeography.co.uk/GCSE/Year11/Managing%20Hazards/Volcanoes/mount_pinatubo.htm

http://vulcan.wr.usgs.gov/Volcanoes/Philippines/Pinatubo/description_pinatubo.html

http://pubs.usgs.gov/fs/1997/fs113-97/