AQA Geography A2 Plate Tectonics Case Studies listening notes

Plate Tectonics Case Studies

Volcanic case studies

Mount Pinatubo

This caused the most atmosphere disturbance since Krakatau due to the vast amount of ash released.

Where: Philippines, East Asia

Plate boundary: Philippine plate sub-ducts beneath the Eurasian plate

When: 19,91, 7^th to 15^th June

Type of volcano:  Composite or stratovolcano due to Andesitic lava present.

Last eruption: 13,80

Volcanic Explosivity Index: 6

Timeline:

April 2^nd: Volcano started having small eruptions along a 1.5 kilometre fissure, these continued for a couple months with the surrounding areas being dusted with volcanic ash and there being hundreds of small earthquakes every day. First evacuation of 5000 people happened

May 13^th to 28^th:  Rapid increase in the amount of Sulphur Dioxide so there is rising magma in the volcano, by the 28^th May this has decreased a lot which would mean that the magma had been blocked.

June 5^th: The First eruptions with magma happened, there was also a high alert sent out that there could be a major eruption within the next two weeks.

June 7^th: There had been a large lava dome form which caused a evacuation area of 20km from the volcano and 20 thousand people evacuated

June 15^th: The big eruption lasted for nine hours, which caused an ash plume which was 7km high. A tropical storm called Yunkya caused the ash to mix with the water vapour which caused lahars down river valleys. There was a 10 up to 30 inches of ash covering a 2 thousand kilometres radius from the mountain.

After June 15^th: A large amount of sulphur dioxide to be released (15 to 30 million tons), this mixed with water and oxygen to become sulphuric acid to fall as rain which is harmful to people. The gas and ash reached 34km into the atmosphere which was then transported around the world

Effects:

Short term

·         Jets flying over the Philippines sustained damage and cost about 100 thousand dollars in repairs

·         About 20 million tons of sulphur dioxide were released into the atmosphere

·         Over 800 people were killed

·         The volcano itself was decrease in height by 2.5 kilometres

·         58 thousand in total evacuated

·         $700 million in total damages

·         4 thousand homes were destroyed and 70 thousand were damaged

·         Roads were damaged

Long term

·         There were 200 thousand people affected in the area.

·         The local American air base was shut down

·         Global temperatures dropped by 1° around the world for a year

·         Over 1 million animals died

·         Respiratory disease

Management

·         Some 58 thousand people were evacuated

·         Massive rebuild effort was put into place to help the local communities recover from the disaster

·         Thanks to early warning system there were 5,000 people saved and a $250 million in property…