Facts & Figures

Earthquake

The Great East Japan Earthquake was the most powerful earthquake ever measured in Japan, unleashing far more devastation than many had thought possible.

It occurred near the portion of the Japan Trench where the Pacific plate is subducting under the North American plate. A number of focal regions, including hypocenters beneath the seabed off Miyagi, Fukushima and Ibaraki prefectures, were linked. The source fault appears to have been 500km long and 200km wide.

Tsunami

The Great East Japan Earthquake kicked up waves that reached higher than 10 meters. They destroyed homes, railways -- just about any structure in their path -- and left more than 15,000 people dead in the Tohoku and Kanto regions. According to research by the Geospatial Information Authority of Japan, the liquid locomotive inundated an area of more than 500 sq. kilometers, roughly eight times the size of the area encircled by Tokyo's Yamanote Line.

Nuclear crisis

The emergency at the Fukushima Daiichi nuclear power plant, in Okuma, Fukushima Prefecture, 220km north of Tokyo, started immediately in the wake of the earthquake. The quake produced a towering tsunami that knocked out most of the plant's emergency backup generators -- which are crucial for pumping the water needed to keep the reactor cores and spent fuel from overheating. As a result, meltdowns have occurred in the cores of the Nos. 1, 2 and 3 reactors. The accident has been given a severity rating of 7, the maximum level on the international scale and matching that of the 1986 Chernobyl catastrophe.

The plant was releasing up to 10,000 terabecquerels of radioactive materials per hour at one point after the quake. The government ordered residents within a 20km radius to evacuate, while those in the 20-30km range were ordered to remain indoors or evacuate voluntarily due to radiation concerns.

It may take several more months to cool down the crippled reactors, according to the plant's operator, Tokyo Electric Power Co.