On Tuesday, January 17th 1995, at 5.46 a.m. (local time), an earthquake of magnitude 7.2 on the Richter Scale struck the Kobe region of south-central Japan. This region is the second most populated and industrialized area after Tokyo, with a total population of about 10 million people. The ground shook for only about 20 seconds but in that short time, over 5,000 people died, over 300,000 people became homeless and damage worth an estimated £100 billion was caused to roads, houses, factories and infrastructure (gas, electric, water, sewerage, phone cables, etc).
Why did the earthquake happen here?
Three crustal plates meet near to the coast of Japan. Close to Kobe, the denser oceanic Philippines Plate is being subducted beneath the lighter continental Eurasian Plate at a rate of about 10 centimetres per year. The Japanese island arc has been formed from the molten magma released by the melting Philippines Plate. Earthquakes are very common here and happen because of the friction resulting from the two plates colliding along this destructive margin. [In 1923, the Great Kanto Earthquake killed 140,000 people in this area.] The great destruction which resulted from the 1995 Kobe Earthquake was due to the shallow depth of the focus which was only about 16 kms. below the surface and the fact that the epicentre occurred close to a very heavily populated area. Seismic shockwaves travelled from Awaji Island (the epicentre) along the Nojima Fault to the cities of Kobe and Osaka.
The Effects of the Earthquake:
The immediate effects of the earthquake are known as primary effects. They include the collapse of buildings, bridges and roads resulting from the seismic waves shaking the crust. During the 20 second earthquake, the ground moved up to 50 centimetres horizontally and up to 1 metre vertically. Some of the deaths were caused by these primary effects.
The secondary effects include the fires that broke out all over the city of Kobe, the congestion and chaos on the roads, the closure of businesses and the problem of homelessness. Many more people died in the fires that followed the earthquake. Problems were made worse by the large number of aftershocks (over 1,300).
Many of the older, wooden houses completely collapsed. Fire, triggered by broken gas pipes and sparks from severed electrical cables, caused a huge amount of damage, destroying at least 7,500 wooden homes. Office blocks built in the 1960's of steel and concrete frequently collapsed in the middle so that a whole floor was crushed but the rooms above and below remained intact. Modern buildings, designed to be earthquake proof, did quite well on the whole and suffered little damage, although some were left standing at an angle when the ground beneath them liquefied. An additional problem for rebuilding was that most people were not covered by insurance due to the difficulties of insuring such an earthquake prone area.
Almost 300,000 people were made homeless by the earthquake and had to be given emergency shelter. The severe winter weather (-2°C.) made this a serious problem. People were put into schools, town halls, open parks, etc. and were forced to live, in some cases for long periods, in overcrowded, unsanitary conditions. Food, blankets, medical supplies and clean water were, for the first few days, in short supply. The scale of the problem made it difficult for the authorities to cope.
Kobe is an important route centre. It has motorway (Hanshin Expressway) and intercity ('bullet train') railway lines passing through it and a large modern port which handles millions of tonnes of trade each year. The earthquake caused massive damage to all the transport facilities. Several sections of motorway, many of which were built above the ground on tall concrete stilts, collapsed or toppled sideways. This resulted in the Hanshin Expressway being completely closed. Railway lines were buckled and many stations damaged. A 130 kilometre section of the 'bullet train' rail network had to be closed. At the port, cranes tilted or fell and 120 (out of 150) quays where ships were moored were destroyed. Port buildings and their contents were badly damaged in many places.
Between 3% and 5% of Japan’s industry is located in and around Kobe. This includes most types of industry - from light manufacturing to high-technology and heavy industry. Due to the shortage of suitable flat land, as elsewhere in Japan, much of the industry is concentrated near the port on reclaimed land. Strong ground movements led to settlement and liquefaction in these areas and so damage to industry was severe. The difficulties of transporting raw materials and finished goods to, from, and within the region also caused great problems for well-known industries such as Panasonic and Mitsubishi. Industries affected include shipbuilding, steelworks, breweries, pharmaceutical, computer hardware and consumer goods firms.
How did the authorities cope with the earthquake?
Japan prides itself on being well prepared for earthquakes. Most new buildings and roads have, in the last 20 years, been designed to be earthquake proof, schools and factories have regular earthquake drills, etc. As it turned out, however, things did not go according to plan. Many older buildings still collapsed or caught fire. This led to many blocked roads and massive problems of homelessness. Telephones and other communication services were put out of action making communication slow and difficult. Electricity and water supplies were badly damaged over large areas. This meant no power for heating, lights, cooking, etc. Clean, fresh water was in short supply until April 1995. The government and city authorities were criticised for being slow to rescue people and for refusing offers of help from other countries. Many people had to sleep in cars or tents in cold winter conditions. A large number of the people affected were elderly and many of the effects are unquantifiable - disrupted schooling, increased unemployment, worry, stress and mental fatigue. Putting things right after the earthquake
• 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.
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