A powerful 7.7 magnitude earthquake has struck deep in the Sea of Okhotsk off the east coast of Russia, north of Jpan’s northern island of Hokkaido. The tremor was felt as far away as Tokyo, some over 1,000 miles (1,600 kilometers) away. No tsunami warning has been issued, and there have been no reports of injuries or casualities.

Here are the details of the quakes, according to the U.S. Geological Survey.

Event Time

2012-08-14 02:59:42 UTC

2012-08-14 12:59:42 UTC+10:00 at epicenter

2012-08-13 21:59:42 UTC-05:00 system time

Nearby Cities

158km (98mi) ENE of Poronaysk, Russia

227km (141mi) ENE of Shakhtersk, Russia

237km (147mi) ENE of Uglegorsk, Russia

244km (152mi) ESE of Aleksandrovsk-Sakhalinskiy, Russia

1626km (1010mi) NNE of Tokyo, Japan

The quake’s epicentre was deep – over 380 miles (625 km) down – according to the US Geological Survey in an initial report.

Japan is situated along the so-called Ring of Fire in the Pacific – a place where tectonic plates come together. As a result, it undergoes earthquakes regularly. In this region, relative to a fixed North America plate, the Pacific plate is moving northwest between 83 mm and 75 mm per year. The Pacific tectonic plate subducts – or goes below – down into Earth’s mantle below the larger North America tectonic plate. This natural movement of Earth causes earthquakes and volcanoes.

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According to Japan’s Meteorological agency, those in Japan’s northern island of Hokkaido felt the August 14 quake. AFP journalists said it was felt as far away as Tokyo.

Last year – on March 11, 2011 – the 9.0-magnitude Tohoku earthquake of the coast of northeastern Japan – and subsequent tsunami – caused devastation and left some 18,000 people dead or missing. Most who died did so by drowning. The March 11, 2011 quake was the most powerful known earthquake ever to have hit Japan, and one of the five most powerful earthquakes in the world since modern record-keeping began in 1900.

Bottom Line: A very strong 7.7-magnitude earthquake struck deep in the ocean east of Russia and north of Japan’s northern island of Hokkaido. No injuries or casualties have been reported, and no tsunami warning was issued. This region of the world is prone to earthquakes. A 9.0-magnitude earthquake – the most powerful ever known to have struck Japan – took place a little over a year ago on March 11, 2011.