By Chris Hogg
BBC News, Tokyo
The number of people who would be killed if a major earthquake hit Japan is far greater than was previously thought, according to a report.
Earthquakes are common in Japan
The research by the Central Disaster Management Council estimates that a strong earthquake in central Japan could kill up to 42,000 people.
The study will be used to create a plan for earthquake prevention, emergency response and post-quake reconstruction.
A major earthquake in the city of Kobe killed more than 6,400 people in 1995.
On average, there are three tremors each day in Japan strong enough for people to feel.
The experts looked at the likely impact 13 different strong earthquakes would have if they hit central Japan - a densely populated area of more than 44 million people.
The report's authors analysed the chances of buildings collapsing and power lines coming down, the risk of fires spreading and landslides. Their conclusions make grim reading.
A strong quake near Japan's second city of Osaka could kill up to 42,000 people, the report says.
It estimates that 34,000 people would be killed as buildings collapsed and a further 7,500 would perish in fires.
The worst time of day for an earthquake to occur would be at 0500 in the winter, when most people would be at home.
But if it hit at noon, there would be more fires as more people would be cooking, the report says.
The report points out that in that in central Japan many people live in wooden houses that were built before 1981, when the current earthquake resistance standards were established.