A strong undersea earthquake and several strong aftershocks struck near the northeast coast of Japan – east of Sendai, Japan – Friday (December 7, 2012), in the same region that was hit by a massive 9.0 magnitude earthquake in March, 2011. CBSNews is reporting that a small tsunami hit a small city in the region, but there were no reports of injuries or damage. The Pacific Tsunami Warning Center said there was no risk of a widespread tsunami and has now dropped all tsunami warnings for the Japanese coast. The Japan Meteorological Agency said the epicenter was 6.2 miles beneath the sea floor.
Here are the details of the quake, according to the U.S. Geological Survey (USGS):
2012-12-07 08:18:24 UTC
2012-12-07 18:18:24 UTC+10:00 at epicenter
2012-12-07 02:18:24 UTC-06:00 system time
37.889°N 144.090°E depth=36.1km (22.4mi)
245km (152mi) SE of Kamaishi, Japan
245km (152mi) ESE of Ofunato, Japan
251km (156mi) ESE of Ishinomaki, Japan
251km (156mi) SE of Otsuchi, Japan
462km (287mi) ENE of Tokyo, Japan
The December 7, 2012 7.3-magnitude earthquake, occurred due to movement within faults in the oceanic lithosphere – the crust and the uppermost mantle – of the Pacific plate. It happened approximately 20 km east of the plate boundary between the Pacific and North America plates, in a place where the Pacific plates subducts, or dives beneath, Japan. At the epicenter of this earthquake, the Pacific plate moves west-northwestard with respect to the North America plate at a velocity of approximately 83 millimeters (about 3.3 inches) per year.
Bottom line: The northeast coast of Japan – same area affected by a more powerful 9.0-magnitude earthquake in March, 2011 – underwent a strong undersea earthquake and several strong aftershocks on Friday (December 7, 2012). A small tsunami hit a small city in the region, but there were no reports of injuries or damage. The Pacific Tsunami Warning Center said there was no risk of a widespread tsunami and has now dropped all tsunami warnings for the Japanese coast.
Deborah Byrd created the EarthSky radio series in 1991 and founded EarthSky.org in 1994. Today, she serves as Editor-in-Chief of this website. She has won a galaxy of awards from the broadcasting and science communities, including having an asteroid named 3505 Byrd in her honor. A science communicator and educator since 1976, Byrd believes in science as a force for good in the world and a vital tool for the 21st century. "Being an EarthSky editor is like hosting a big global party for cool nature-lovers," she says.