Plate Tectonics - Case Studies

Question 1

What is the earthquake case study?

Answer 1

Kobe, Japan

Question 2

What is the volcano case study?

Answer 2

Chaiten, Chile

Question 3

What were the causes of the Kobe earthquake?

Answer 3

• On a minor fault - Nojima Fault
• Destructive margin
• Philippines plate (oceanic) subducted under Eurasian plate (continental)

Question 4

When was the Kobe earthquake?

Answer 4

• 5:46 on 17th January 1995

Question 5

What were the details of the Kobe earthquake?

Answer 5

• 7.2 on the Richter scale
• Ground moved 18cm horizontally and 12cm vertically
• Focus near to surface and Kobe

Question 6

What were the effects of the Kobe earthquake?

Answer 6

• 180,000 buildings collapsed
• 1km stretch of Hanshin Expressway and many bridges destroyed
• Several trains derailed
• 120 quays in the port destroyed
• Electricity, gas and water supplies disrupted
• Fires -> Destroyed 7500 houses
• Roads were at gridlock -> Delaying ambulances
• 230,000 people made homeless
• Shortage of blankets, clean water and food
• 716 aftershocks
• Industries forced to close -> Mitsubishi + Panasonic
• 5500 people killed

Question 7

What was the response to the Kobe earthquake?

Answer 7

• The infrastructure (water, electricity, gas, telephone) was operational by July
• Rubble cleared but little rebuilding
• Rail service working by August
• A year later the port of Kobe was 80% functional
• Replacement buildings had to meet stronger earthquake-resistant standards.
• Increase in the number of seismic instruments

Question 8

What are the causes of the Chaiten volcano eruption?

Answer 8

• Nazca plate (oceanic) is subducted under South American plate (continental)
• The plate melts, rises and forms an explosive volcano

Question 9

When was the Chaiten eruption?

Answer 9

• 2nd May, 2008

Question 10

What were the effects of the Chaiten eruption?

Answer 10

• Volcanic ash and steam rose nearly 17 kilometers high
• Chaitén was blanketed with ash.
• Ash falls up to 15cm deep had blocked rivers and contaminated water supplies
• 4,000 people evacuated
• Schools, highways and airports were forced to close.
• Lahars cut communications in areas and made access difficult
• 1 death

Question 11

What was the response to the Chaiten eruption?

Answer 11

IMMEDIATE
• 5000 people had to be evacuated from nearby towns
• Residents were told not to drink the water
• Chilean officials distributed face masks and fresh water
• 50km exclusion around the town
• The government issued a monthly disaster fund of $1200 and $2200 per month per family

LONG TERM
• Financial aid to small businesses was granted
• Real-time seismic monitoring began