A powerful earthquake struck Saturday morning (local time) off Japan’s east coast, according to the U.S. Geological Survey (USGS). The USGS is now placing the magnitude of the quake at 7.1, down from an earlier estimate of 7.3. No Pacific-wide tsunami warning was issued, but a 3-foot (3-meter) tsunami warning from Japan’s Meteorological Agency included a stretch of Japan’s northeastern coast, including the crippled Fukushima nuclear site. Later, Japanese television reported that the tsunami height was smaller, reaching only 1 foot (30 centimeters) at the plant.
The Fukushima nuclear plant became crippled during a similar situation, although the offshore quake of March 11, 2011 was much stronger at magnitude 9.
Reuters is reporting that there have been no immediate reports of damage to the Fukushima plant:
The operator of Japan’s wrecked Fukushima nuclear plant said on Saturday there was no damage or spike in radiation levels at the station after a large earthquake struck in the ocean east of Japan, triggering a small tsunami.
There were no immediate reports of damage on land from the quake, classified as magnitude 7.1 by the Japan Meteorological Agency, which struck about 370 km (230 miles) out to sea.
Details of the quake from USGS are as follows:
2013-10-25 17:10:16 UTC
2013-10-26 03:10:16 UTC+10:00 at epicenter
325km (202mi) ESE of Ishinomaki, Japan
326km (203mi) E of Namie, Japan
331km (206mi) SE of Ofunato, Japan
333km (207mi) ESE of Yamoto, Japan
475km (295mi) ENE of Tokyo, Japan
The quake hit at 2:10 a.m. local time Saturday morning. Japanese broadcaster NHK reported that Tokyo Electric Power Co., the operator of the Fukushima plant, ordered workers near the cost to move to higher ground.
The tremor was felt in Tokyo, some 300 miles away.
Japan and the surrounding islands straddle four major tectonic plates: Pacific plate; North America plate; Eurasia plate; and Philippine Sea plate. This region is extremely vulnerable to earthquakes.
Bottom line: A very strong earthquake has occurred offshore in Japan. A local tsunami warning included the Fukushima nuclear plant, but plant managers are saying at this time there was no damage.
Deborah Byrd created the EarthSky radio series in 1991 and 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.