7.8 Magnitude Quake Strikes Japan Saturday, No Tsunami Risk Due To Quake's Depth
(CBS SF)-- A strong 7.8 magnitude quake struck the open ocean, 543 miles south of Tokyo early Saturday morning.
The initial report from seismographs pegged its magnitude at 8.5 but it was later significantly downgraded to a 7.8 quake.
Despite the intense shaking with the quake, no tsunami was expected for the Pacific Ocean.
The quake struck very deep in the earth's crust, at over 400 miles beneath the surface, so its power was dissipated before it was able to create significant tsunami wave energy in the ocean above.