Monday, March 29, 2010
Kobe earthquake
Occurred on January 17, 1995.
Magnitude: 7.2 on Richter scale
Hit South-Central Japan
Caused by liquefaction that led to ground shaking and thus, collapsing of buildings.
Effects:
· 4000 over deaths
· One in five of the buildings in the worst-hit area were completely destroyed (or rendered uninhabitable).
· About 22% of the offices in the central business district were rendered unusable and over half of the houses in that area were deemed unfit to live in.
· damage to highways and subways
· Most railways in the region were also damaged
· Port damaged therefore, business lost. Impact on economy.
Mitigation:
· water, electricity, gas, telephone services were fully working by July 1995
· The railways were back in service by August 1995
· A year after the earthquake, 80% of the port was working but the Hanshin Expressway was still closed.
· By January 1999, 134,000 housing units had been constructed but some people were still having to live in temporary accommodation.
- New laws were passed to make buildings and transport structures even more earthquake proof.
-More instruments were installed in the area to monitor earthquake movements.
Sunday, March 28, 2010
Introduction to Earthquake
The speed of an earthquake wave is not constant but varies with many factors.
Speed changes mostly with depth and rock type. P waves travel between 6 and 13 km/sec. S waves are slower and travel between 3.5 and 7.5 km/sec.