6.4 Earthquake Strikes Off Coast of Japan

A powerful 6.4-magnitude earthquake struck off the coast of Japan Monday, reportedly causing no major damage or injuries.

The earthquake struck at 5:32 a.m. around 72 miles southeast of Morioka on Japan's Pacific coast, according to the U.S. Geological Survey. A tsunami warning was not issued and the quake was rated at a level 4 on the Japanese seismic scale, indicating that no major damage is expected.

Japan is still recovering from the devastating undersea earthquake that triggered a massive tsunami last March. The tsunami left over 19,000 people dead or missing and crippled Japan's Fukushima Dai-ichi nuclear plant, resulting in what was the worst nuclear disaster the world had seen since Chernobyl.

Both the Chernobyl disaster and the Fukushima Daiichi nuclear disaster are classified as number 7 events on the International Nuclear Event Scale. Level 7 on the scale is interpreted as a major accident and indicates a major release of radioactive material with widespread health and environmental effects.

Following the Fukushima disaster, the Japanese government and power company responsible for the plant, Tokyo Electric Power Co., admitted that they had not been prepared for such an incident. They have since been working to upgrade and strengthen security systems to ensure that another disaster of similar magnitude does not occur again.

Sunday's earthquake came a day after Japanese officials approved to bring the country's first nuclear reactors back online since last year's disaster. All of Japan's 50 reactors have been offline for security and maintenance checks.

The decision has sparked some controversy and protesters gathered outside the Japanese prime minister's office on Saturday as the decision was announced. Many Japanese remain fearful of the use of nuclear reactors after last year's Fukushima disaster, but Japanese officials maintain that safety is of the utmost concern.

"Safety is our main concern. We have approved the beginning of the restarting process. It will take some time for the reactors to begin generating electricity," trade and industry minister Yukio Edano said on Saturday.