Time of earthquake: 14:46 local time (0546 GMT). A tsunami warning was issued three minutes later.
Epicentre: At 38.1 degrees north latitude, 142.9 east longitude in the Pacific Ocean, at the depth of 24 kilometres (14.9 miles) underwater.
Height of waves: Waves higher than 15 metres (49.5 feet) were observed in various places -- Ishinomaki, Soma, Ofunato, among others.
Confirmed deaths: 15,846
People still missing: 3,317
(No deaths have so far been attributed to exposure to radiation in the accident at the Fukushima Daiichi nuclear power plant)
Refugees across the country: 341,411
Temporary houses constructed or under construction: 52,882
Buildings totally destroyed: 128,558
Buildings damaged: 916,883
Rubble generated in the three worst-affected prefectures (Miyagi, Iwate, Fukushima): 22 million tonnes.
The government has approved four reconstruction budgets for the fiscal year from April 2011 to March 2012, totalling 20.5 billion yen ($253 million).