REMEMBERING THE HISTORIC ERUPTION OF MOUNT PINATUBO, THE

PHILIPPINES JUNE 12, 1991

THE SECOND LARGEST ERUPTION OF THE 20TH CENTURY

Walter Hays, Global Alliance for Disaster Reduction, University of

North Carolina, USA

MOUNT PINATUBO: QUIET FOR 450-500 YEARS BEFORE ERUPTING

VOLCANO HAZARDS (AKA POTENTIAL DISASTER AGENTS)

• VERTICAL PLUME

• LAVA FLOWS

• LATERAL BLASTS

• LAHARS

• EARTHQUAKES (related to movement of lava)

NATURAL HAZARDS FOR WHICH NATURAL HAZARDS FOR WHICH EVACUATION IS TYPICALEVACUATION IS TYPICAL

NATURAL HAZARDS FOR WHICH NATURAL HAZARDS FOR WHICH EVACUATION IS TYPICALEVACUATION IS TYPICAL

FLOODS

HURRICANES

TYPHOONS

TSUNAMIS

VOLCANIC ERUPTIONS

WILDFIRES

HIGH BENEFIT/COST FOR SAVING LIVES, BUT LOW BEMEFIT/COST FOR PROTECTING PROPERTY

HIGH BENEFIT/COST FOR SAVING LIVES, BUT LOW BEMEFIT/COST FOR PROTECTING PROPERTY

GOAL: MOVE PEOPLE OUT GOAL: MOVE PEOPLE OUT OF HARM’S WAYOF HARM’S WAY

GOAL: MOVE PEOPLE OUT GOAL: MOVE PEOPLE OUT OF HARM’S WAYOF HARM’S WAY

SOURCE OF PHOTOGRAPHS

USGS

US AIR FORCE

PHILVOS

MOUNT PINATUBO’S FIRST PRECURSORS OF THE ERUPTION

PHILVOS: MONITORING GROUND SWELLING (ANOTHER PRECURSOR)

MOUNT PINATUBO: VERTICAL PLUME REACHES 19 KM: JUNE 12

LOURDES DESTROYED BY LAHARS WITHIN HOURS AFTER THE ERUPTION

MOUNT PINATUBO BLOWS ITS TOP: JUNE 15, 1991

MOUNT PINATUBO BLOWS ITS TOP: JUNE 15, 1991

THE JUNE 15TH CALDERA COLLAPSE LOWERED PINATUBO’S ELEVATION 1,000 FT

LATERAL BLAST: 5:55 AM, JUNE 15

CARS COVERED WITH VOLCANIC ASH: JUNE 16

DC-10 AT CLARK AIR FORCE BASE COVERED WITH ASH: JUNE 17

CLARK AIR FORCE COVERED WITH ASH: JUNE 24

RIVER WIDENED BY LOCAL FLOODING AND LAHARS

The eruption ejected roughly 10 billion metric

tons (10 cubic km) of magma, and 20 million tons

of sulfur dioxide.

The eruption injected large amounts of aerosols into the stratosphere – more

than any eruption since that of krakatoa in 1883.

Lahars that occurred immediately after the

eruption, and rejuvenated during subsequent rainy seasons, have destroyed

over 100,000 homes.

Global temperatures dropped by about 0.5

degree C.