In case you were wondering what happened to the earthquake to which some of you might have been alerted this morning: it was an erroneous call after all.
The physical principles on which the warning system are based make it prone to errors but it's the best we've got at the moment,
so there's not really point in blaming anyone for false alarms.
Earthquakes are an ever-present danger in Japan so it is important to be thoroughly prepared in the eventuality that one strikes. Although many areas in Japan publish comprehensive guides in English and other languages — see 'Tokyo Bousai' ('Disaster Preparedness Tokyo') published by the Tokyo...
Seismologically, Japan is one of the most active countries in the world: almost ten per cent of all active volcanoes are located there, and ten per cent of all major earthquakes ranging in the magnitude of 7 on the Richter scale (nowadays...