1. The Eruption of Mount Pinatubo 1991

2. The second-largest volcanic eruption of the last century, and by far the largest eruption to affect a densely populated area, occurred at Mount Pinatubo in the Philippines on June 15, 1991. The impacts of the eruption continue to this day. The eruption produced high-speed avalanches of hot ash and gas, giant mudflows, and a cloud of volcanic ash hundreds of miles across.

3. The Location of Pinatubo

4. April 2 nd 1991 First rumblings after 450 years. Small amount of ash thrown up to 800 metres in the air For next 2 months small tremors were recorded in the volcano. Events leading up to the eruption

5. June 3 rd 1991 Pinatubo ejects ash which lasts for 30 minutes. Up to 2,000 quakes a day, some suggesting that the magma was getting near the surface.

6. Sunday June 9 th 1991 Ash and steam ejected from the volcano for 8 hours. Pyroclastic flows reached 5km from the crater.

7. Wednesday June 12 th 1991 At 8.51 a.m. three major explosions sent a mushroom shaped cloud over 20km into the air. Ash, pumice and other fragments were ejected. Rivers overflowed due to pyroclastic flows. Around midnight more explosions sent ash 25 km into the atmosphere.

8. Thursday June 13 th 1991 Another violent eruption created further ash falls covering three settlements. Winds carried the ash hundreds of kilometres in all directions.

9. Friday June 14 th 1991 The fourth major eruption happened at 1.09 p.m. Ash went 25 km above the vent. At 3.30 p.m. a much bigger eruption sent a cauliflower-shaped cloud of volcanic debris 30 km into the air. Major pyroclastic flows reached 15km from the volcano. Smaller eruptions at 6.35 pm, 10.18 pm and 11.21 pm.

10. Saturday June 15 th 1991 Two eruptions occurred at dawn which caused a pyroclastic flow travelling at 80 kph. Seven more eruptions caused an ash cloud 18 km wide and 25 km high. Pyroclastic flows reach 16 km from the volcano. At 10.27 a.m. a violent eruption forced debris up 40 km into the air. Five similar eruptions quickly followed. Over 19 eruptions during the day!

11. The Effects of the Eruption

12. Up to 12km 3 of rock and ash were blasted into he atmosphere Before the Eruption After the Eruption

13. A large area around the volcano was affected by ash deposits, pyroclastic flows and mudflows (lahars)

14. The Effects of the Ash

27. Pyroclastic flows

28. The effects of lahars

29. Before the eruption After the eruption

30. Before the eruption After the eruption

31. Before the eruption After the eruption

32. The Global Effects of the Eruption

33. The Global Effects of the Eruption

34. 847 people killed. 184 injured. 23 missing presumed dead. 1.18 million people affected Houses and public buildings collapsed from weight of ash deposits. 650,000 workers forced out of work due to destruction of farms, shops and factories. America had to evacuate their Air Force Base. Volcanic dust blanketed towns. Public buildings had to be used for evacuation centres to accommodate refugees from devastated area.