Abundant evidence indicates that such a new volcano exists at L'ihi, a seamount (or submarine peak) located about 20 miles off the south coast.
In 2011, a 9.0-magnitude earthquake -- one of the worst ever to hit Japan -- killed more than 20,000 people and caused tsunamis of up to 12 meters (40 feet) which swamped the Fukushima Daiichi nuclear power plant, triggering a nuclear meltdown. Fukushima resident: We live in fear.
Measuring Earthquakes. The recent earthquake that hit northeastern Japan was measured at 9.0 on the Moment Magnitude Scale (MMS). Scientists known as seismologists use the MMS to determine the magnitude (strength) of an earthquake. The MMS measures the total energy of an earthquake, called the seismic moment.