Tag Archives: Tohoku quakes

Risk of Cancer after Japan Tsunami, Not Going to be Noticeable According to WHO

A group of experts convened by the agency assessed the risk of various cancers based on estimates of how much radiation people at the epicenter of the nuclear disaster received, namely those directly under the plumes of radiation in the most affected communities in Fukushima, a rural agricultural area about 150 miles north of Tokyo.

Some 110,000 people living around the Fukushima Dai-ichi nuclear plant were evacuated after the big March 11, 2011, earthquake and tsunami knocked out the plant’s power and cooling systems, causing meltdowns in three reactors and spewing radiation into the surrounding air, soil and water.

Experts calculated that people in the most affected regions had an additional 4 to 7 percent overall risk of developing cancers, including leukemia and breast cancer. In Japan, men have about a 41 percent lifetime risk of developing cancer of an organ, while a woman’s lifetime risk is about 29 percent. For those most hit by the radiation after Fukushima, their chances of cancer would rise by about 1 percent.

Read the rest of the story: Only slight risk of cancer after Japan tsunami, WHO says.



Japan Earthquake Unleashed Surprising Amount of Energy

The devastating earthquake that struck Japan in 2011 may have unexpectedly released nearly all of the energy that had built up near the source of the resulting tsunami, new research suggests.

These findings, detailed in tomorrow’s (Feb. 8) issue of the journal Science,may help lead to a better understanding of how earthquakes and fault zones work, “and with a better understanding, we may be able to anticipate extreme events or find out where super-large earthquakes might be possible in the world,” researcher Fred Chester, a geophysicist at Texas A&M University, told OurAmazingPlanet.

The magnitude 9.0 Tohoku-Oki quakewas the most powerful earthquake to hit Japan and the fifth-most powerful quake ever recorded, generating a tsunami that killed thousands and triggered a nuclear crisis. Research revealed the seafloor moved nearly 165 feet (50 meters) during the temblor.

Earthquakes are caused by stress that builds up on faults in the Earth’s surface. Usually, earthquakes are thought to release only a portion of this stress on the fault, but thecatastrophic level of activity seen with the 2011 temblor suggested that this quake may have relieved significantly more energy in that area — a boundary region where the tectonic plates that make up Earth’s surface meet.

Read the rest of the story: Japan Earthquake Unleashed Surprising Torrent of Energy.

The Big One: New Sea Sediment Samples to tell of past ‘Tohoku quakes’

Previous earthquakes that rivalled the March 2011 Tohoku tremor in size may be recorded in sediment samples just recovered from the seafloor off Japan.

A German-led scientific cruise obtained the cores from 16 different locations, some of them at a water depth of 7.5km.

The sediments hint at three major disturbances on the ocean bed that could be the result of the submarine landslides often seen with big quakes.

The researchers are currently trying to identify and date the events.

Read the rest of the story: Japan sea sediments tell of past ‘Tohoku quakes’.