Pinatubo 1991

• The eruption started on the 2nd of April 1991 and ended on the 2nd of September 1991.
• There were 874 killed, with 300 dying from collapsing roofs, 100 from mud flows as lahars.
• 10,000 were made homeless due to the destruction caused by the eruption.
• 58,000 were evacuated from the area.
• the cost of damages totalled to USD$700 million.
• the VEI of the explosion was 6.
• A preliminary earthquake on the 15th of March 1991 had a magnitude of 7.7
• It was the 2nd largest volcanic eruption of the 20th century.
• the HDI in 1991 was 0.599.
• the GDP per capita in 1991 was USD$821
• Pinatubo was formed due to the Eurasian plate sliding under the Philippines mobile belt along the Manila Trench.
• Hazards generated


  Large volumes of gas (18 million tons of Sulfur Dioxide) leading to short term global coolant (reduced by 0.5 degrees for two years);

  bombs;

  ash;

  tephra (lumps of volcanic rock);

  pyroclastic density currents (hot mixtures of gas and rock) (200m thick);

  5 km cubed of material.
• Increased by USD$69 million by 1992 (economic short term)
• 4,979 houses were totally destroyed and 70,257 houses were partially damaged (economic short term)
• damage to crops, infrastructure, and personal property at USD$ 374 million (economic short term)
• commercial aircraft were warned about the hazard of the ash cloud, but a number of jets piling far to the west of the Philippines encountered ash and sustained about USD$100 million in damages (economic short-term)
• U.S. Geological Survey had forecast Pinatubo’s 1991 climatic, resulting in the saving of at least 5,000 lives and USD$250 million in property (economic long term)
• Thousands of roofs were collapsed under the weight of ash made wet by heavy rain (social long term)
• most displaced still wait in resettlement camps for the day when they can return home (social long term)
• 20,000 people who evacuated from the lowlands surrounding Pinatubo before and during the eruptions have returned home but face continuing threats from lahars that have already buried numerous towns and villages (social short term)
• the home of 3 million people in Luzon was dramatically changed 20,000 Indigenous Aeta highlanders, who had lived on the slopes of the volcano, where completely displaced (social short term)
• ash cloud rose 22 miles (35km) in the air, and ash cloud blanketed the countryside (environmental short term)
• 20 million tons of sulphur dioxide dispersed globally to drop temperatures by 0.5 degrees (environmental short term)
• ash deposits were demobilised by monsoon and typhoon rains to form giant mudflows of volcanic materials (lahars). Some pyroclastic flows deposits have been insulated and kept their heat of 500 degrees (environmental long term)
• Department of health led to the provision of medical care and public health services at evacuation centres, including disease surveillance (modify the event, short term)
• dams were built to control destructive lahars that followed the eruption, and recovery costs totalled billions of Philippine pesos (modify the event short term)
• department of social welfare and development was in the forefront of providing emergency relief assistance to displaced families and victims in evacuation centres (modify the vulnerability short term)
• U.S. Geological Survey had forecast Pinatubo’s 1991 climactic eruption , resulting in the saving of at least 5,000 lives and USD$250 million in property.
• Many countries such as Sweden (USD$ 97087) , the UK (USD$ 89108), and Spain (40 tents, 100 kits of kitchen utensils) extended humanitarian assistance to the Philippine government and its support NGOs (modify the event, long term)
• 7 telemetered seismic sites were installed, with 2 telemetered tilt meters to measure ground deformation, and use correlation spectrometry (COSPEC) instrument to measure sulfur dioxide gases that would presage arrive of new magma deep in the volcano (Modify the vulnerability, long term)
• Philippine Institute of Volcanology and Seismology (PHIVOLCS) and the U.S Geological Surveu (USGS) were able to accurately predict the timing of the eruption and its effects. As a result, the Filipino government and the American military were able to carry out a timely evacuation of the population, saving thousands of lives and millions of dollar in property damage (modify the loss, long term)