Calculating odds. An 8.9-magnitude earthquake struck off the northeast coast of Japan on Friday, shaking office buildings in Tokyo and setting off a devastating tsunami that swept away cars and boats in northeastern Japan. The quake struck at 2.46 p.m. local time. The ensuing tsunami is affecting the United States, with waves reaching the coasts of California and Oregon. The Federal Emergency Management Agency (FEMA) is prepared to respond to the tsunami effects, should they reach disaster levels.The odds that a federally declared disaster is an earthquake are 1 in 115 in the United States.