Eruption Of Mt Pinatubo, Phillipines 1991

Question 1

Tectonic, geological location (6)

Answer 1

. South East Asia on the eastern rim in the Asiatic Mediterranean
. The Philippine mobile plate ( also know as Taiwan Luzon) the archipelago
. Philippine plate (oceanic) and Eurasian plate ( continental)
. Philippine plate subducts the Eurasian plate
. Destructive plate boundary
. A mature Island arc

Question 2

VEI ( volcanic explosivity index ) and Lava type (5)

Answer 2

6- Plinnian ( rhyolitic) violent eruptions of gases ash and pumice
. Rainstorms cause devastating laha’s
. Very high viscosity ( due to high silica content)
. High magnitude
. Low frequency

Question 3

Primary hazards (4)

Answer 3

. Pyroclastic flows ( fast moving avalanche of volcanic material- pumice and hot gases
. Ash falls and plumes
. Tephra falls- solid material/ volcanic bombs, ash)
. Volcanic gases, SO2 sulphur dioxide

Question 4

Duration

Answer 4

. Major eruption in 1991( June 15)
. Lasted more than 15 hours
.

Question 5

Secondary hazards

Answer 5

. Laha’s- volcanic mud flows caused by the ash erupting from a volcanos mixing with rain water - The large density of ash and gas ejected into the atmosphere can reduce global temperature by blocking out sunlight ( creating global diming)

Question 6

Economic development

Answer 6

. Volcanic eruption created agriculture production ( particularly in tropical areas )

Question 7

Management/ response
(4)

Answer 7

. The Air Force ( The US GS) helped protect the Americans
. Alert systems were put in place ( particularly in lowland areas) to warn for the eruption- preparedness
. 75,000 people where evacuated due to accurate prediction- mitigation
. Using a correlation speedometer (OSPEC) used to measure the amount of sulphur dioxide - first readings were 500 tonne per day to 5000 tonnes per day - preparedness

Question 8

Impacts (3)

Answer 8

. 847 deaths
. 1.2 million people lost their homes
. 650,000 people lost their jobs