The government called for an electronic mapping system Thursday as part of measures to respond to the feared Nankai Trough earthquake, which threatens to spawn 30-meter tsunami that could wipe out populous areas of the Pacific coast from central to western Japan in a matter of minutes.

The measures in the interim report, which the Land, Infrastructure, Transport and Tourism Ministry adopted the same day and aims to finalize by March, include a four-step timeline for countering the feared quake.

The e-map would contain detailed geographical data that would be updated with floods, mudslides and other changes as observed from satellites and helicopters, it said. Analysis of "big data" from people's cellphones and Internet postings will also be used to grasp the movement of evacuees and traffic.