The Eruption of

Mount Pinatubo

June 1991

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.

The Location of Pinatubo

April 2nd 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

June 3rd 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.

Sunday June 9th 1991

Ash and steam ejected from the volcano for 8 hours.

Pyroclastic flows reached 5km from the crater.

Wednesday June 12th 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.

Thursday June 13th 1991

Another violent eruption created further ash falls covering three settlements.

Winds carried the ash hundreds of kilometres in all directions.

Friday June 14th 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.

Saturday June 15th 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!

The Effects of the Eruption

Up to 12km3 of rock and ash were blasted into he atmosphere

Before the Eruption

After the Eruption

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

The

Effects

of the

Ash

                                                                      

          

The effects of lahars

Before the eruption After the eruption

Before the eruption After the eruption

Before the eruption After the eruption

                                                                       

          

The Global Effects of the

Eruption

The Global Effects of the Eruption

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.

Today’s ActivitiesAnswer the following questions:

WRITE QUESTIONS IN BOOK!

1.Where is Mount Pinatubo?

2.When did it erupt? (Dates)

3.What caused the eruption?

4.How many people died?

5.How many people were affected?

6.What were the impacts (effects) of the eruption?

•Using the worksheet, complete a DETAILED timeline of events leading up to Mount Pinatubo’s eruption – the statements are NOT in order – try to put into your own words!

35 mins