Predicting the eruption at Mount Pinatubo: successful? (CS)

Question 1

Successful because of Timing

Answer 1

• 3rd June: 20,000 people living less than 10km away are evacuated, and 15,000 staff at Clarke Airbase are put on red alert
• 7th June: 120,000 people living less than 18km away are evacuated and a level 4 eruption likelihood is announced.
• 9th June: a danger zone of 60km is announced (300,000 people live there) and a level 5 is declared.

48 HOURS LATER, AN ERUPTION OCCURS

Question 2

Successful because of nature and scale

Answer 2

• The National Disaster Organisation distributed aa hazard map to all authorities; this map undoubtedly helped; pyroclastic flow and lahars were largely confined to this zone
• Final death toll was 847, with 300 actually killed in the eruption. This means the deaths caused by the eruption was minimised

Question 3

Limitations: timing

Answer 3

• The timing was not exact; a level 4 was announced on the 7th of June, implying an eruption would occur in 24 hours. It was not until the 12th however an eruption actually occurred.
• There was no written record of previous eruptions; the team had to start from scratch!

Question 4

Limitations: nature and scale

Answer 4

• Ashfall 10cm in depth was scattered in all directions well beyond the exclusion zone.
• Despite the radio-telemetered rain gauges in lahar source regions, predictions for all lahars were not successful. lahars continued to flow sporadically for 4 years after.
• The eruption coincided with a typhoon; the mixture of rainfall and ash mud killed over 1,000,000 livestock and buried thousands of hectares of arable land.

Question 5

Conclusion

Answer 5

• Yes there are limitations
• But the volcanologist were ultimately responsible for saving hundreds of thousands of lives with mostly accurate predictions
• The real reason for success was the excellent communication that existed between scientists, officials and locals.