Japan is positioned on the margin of the Eurasian Plate.
The Philippine Sea Plate subducted below the Eurasian Plate --> results in high levels of seismic + volcanic activity in Japan.
Immediatley south of Osaka Bay is a fault called the Median Tectonic Plate (MTL), and it was the sudden movement along this fault that triggered the Kobe earthquake.
At 5:46am on January 17th 1995, Kobe was hit by the largest earthquake in Japan since 1923.
The Hyogo-ken Nanbu earthquake hit with a magnitude of 6.9 - the epicentre was only 20km southwest of the city --> resulted in massive damage to property + loss of life (6432 deaths).
The area is built on soft + easily moved rocks, and so the ground is liquefied (acts like thick soup) - buildings topple sideways (Huge cranes in the harbour toppled over into the sea).
Because the earthquake struck in Kobe, with such a high population (10million people), the damage levels were significant:
- Over 102,000 buildings were destroyed in Kobe, leaving 300,000 people homeless.
- The government's estimate of the cost to restore the basic infrastrucutre of the city was about $150 billion dollars.
- All expenses taken into account, the Hyogo-ken Nanbu earthquake was probably the most expensive disaster in modern history.
Transport & Communications
Kobe is situated on a strip of flat land between hgih mountains and sea. This narrow strip of land carries all communication routes between northeastern Japan + Western Japan - Emergency aid for the city needed to use these routes, but many of them were destroyed during the quake.
The railway link from Tokyo, and the whole of western Japan was cut in half when the bridges in Kobe fell down. The remaining two rail links were also cut during the quake.
As the shockwaves passed under the supports holding up Kobe's raised motorway, the ground gave way + large sections of the road collapsed in 3 parts of the city. One section was 1/2km long!!
The only way to travel around the city was to use the smaller roads at ground level, but many were closed due to fallen debris/cracks and bumps.
Utilities + Services
Gas, electricity + sewerage were provided throgh a network of underground pipes + cables. When the ground began to move, the more rigid pipes fractred. 3/4 of the water supply was out of action, gas pipes leaked, and sewers discharged onto the street.
Electricity supplies were not all routed underground - most of the supply transmitted around the city by cables on poles. As buildings collapsed + the ground shook, the poles collapsed, cutting off the electricity supply.
The earthquake struck early in the morning - most people were still asleep. But those people who were not still in bed were making breakfast - people were cooking meals at the very moment their homes began to shake + collapse ---> FIRE!!!
Collapse of electricity + telephone systems --> impossible for people to let the fire teams know where they were needed. Broken water pipes + blocked roads made it tough for the fire teams to work.
Within a day, teams of fire fighters arrived from all over Japan, but despite this there were 12+ major fires that burned for up to 2 whole days before being brought under control.
Research suggests that 500 deaths were due to fires, and 7000 buildings were destroyed by fire alone.