1. Bridget House ESS 315/POE 313 1/27/17
Mount Pinatubo
Bridget House
ESS 315/POE 313
1/27/17

2. Location: Subduction Zone Volcanism

3. Pre-Eruption of 1991 Began with small earthquakes
Northeast-Southwest fissure opened
Pre-eruptions of lower scale June 12th-14th
Phreatic eruptions dispelled old hydrothermally altered rock
Degassed Andesite erupted as lava dome
Followed by increase in shallow, low frequency Earthquakes
Real eruption June 15th

4. Eruption Continued VEI= 6 10 km^3 of volume erupted
Majority of the Summit of volcano was removed
Pyroclastic material dispersed over the landscape
Dispelled a very large SO^2 cloud of 17 MT
Largest release of SO^2 on record
Lowered global temperature by 0.5 degrees Celsius for 2 years
Warnings started April 5th, increased urgency of warnings June 5th-9th
Evacuated 85,000 peopled before eruption

5. Pyroclastic Flow

6. Lahar Effects
Approximately 400 deaths and 200,000 semi-permanently displaced from homes
Long-term disruption of transportation and agriculture
Lahars kept coming long after the eruption, as late as 1994
Lahars reached as far as 35 km from the summit of the volcano
Over 200 meters of erosion in the Marella Valley
60% of the pyroclastic material deposited on the slopes of the volcano in 1991 eruption were taken by lahar flows by 2001

7. Lost and Saved: Success Story
The 400 lives lost were mainly due to roof collapse
500 more people died in the evacuation camps due to measles
Hundreds of millions of dollars lost in local damage
$100 million lost in commercial aircraft damage
Saved 10,000-20,000 lives
Saved $2 billion dollars

8. References
"The Cataclysmic 1991 Eruption of Mount Pinatubo, Philippines, Fact Sheet " The Cataclysmic Eruption of Mount Pinatubo, Philippines, Fact Sheet N.p., n.d. Web. 31 Jan <
"Mount Pinatubo." Mount Pinatubo. N.p., n.d. Web. 31 Jan <
"Lahars of Mount Pinatubo, Philippines, Fact Sheet " Lahars of Mount Pinatubo, Philippines, Fact Sheet N.p., n.d. Web. 31 Jan <
"1991 Mt Pinatubo, Phillipines, Volcano by Hannah." Platetectonicproject [licensed for non- commercial use only] / 1991 Mt Pinatubo, Phillipines, Volcano by Hannah. N.p., n.d. Web. 31 Jan < bo,%20Phillipines,%20Volcano%20by%20Hannah>.