Hazards (seismic) - Tohoku, Japan 2011 Flashcards
(22 cards)
What was the magnitude of the earrthquake?
9
Was it in the top 10 recorded on the Richter Scale?
Yes
When did it happen?
2.46pm, Friday 11th March, 2011
How many km east of Sendai was it?
100km
Which ocean did it occur under?
Pacific
Immediate global impacts:
- Honshu Island moved 2.4km closer to NA
- shifted Earth’s axis 10cm
- made Earth’s day shorter by 1.8 microseconds
- carved 125km squared of icebergs from Antarctic coastline
- caused visible waves in Norwegian fjords
What caused it?
400-500km segment of NA plate suddenly slipped upwards by 5-10m
What led to the tsunami?
sea water displacement from the quake
What plates is Japan on?
NA plate, Phillapine plate, South Pacific plate
When did the 1st wave hit?
30 minutes after the earthquake on the north-east coast
How long after were waves seen in Hawaii?
8 hours after
How long after were waves seen in California?
9-10 hours after
How long until waves were in the whole of the Pacific basin?
22 hours after
Did the tsunami travel in all directions?
Yes - circular
How high were the waves?
10m
How many waves were there?
10
How long between each wave?
1km
How far did the waves surge inland?
10km inland
Why did the waves surge inland?
overwhelmed the tsunami defence walls
What are the primary effects?
- buildings collapsed
- destroyed everything in its path
- flooded 500km squared
- trains vanished
- 18,000 killed and missing
What are some secondary effects?
- 1/2 million homeless
- 150,00 lived in temporary shelters for weeks
- 6 million homes lost electricity
- 1 million with no running water
- shortages of food, water and petrol
- nucleur power plant explosion
How many after shocks were there and how long did they last?
700 aftershocks for 2 weeks
