Is the U.S. ready for “the really big one”?

A natural disaster of titanic proportions is overdue to strike the U.S., physicist Michio Kaku warns.

Seismologists predict it will be the worst natural disaster in North American history, and the federal government estimates it could contribute to 13,000 deaths and 27,000 injuries.

“It’s not a question of if, it’s a question of when,” the City University of New York physics professor said Thursday on “CBS This Morning.”

A devastating earthquake and subsequent tsunami, dubbed “the really big one” in a New Yorker article of the same name, is destined to strike a fault line called the Cascadia subduction zone that runs for 700 miles off the Pacific Northwest coast from Vancouver through parts of California.

The Really Big One

An earthquake will destroy a sizable portion of the coastal Northwest. The question is when.

When the 2011 earthquake and tsunami struck Tohoku, Japan, Chris Goldfinger was two hundred miles away, in the city of Kashiwa, at an international meeting on seismology. As the shaking started, everyone in the room began to laugh. Earthquakes are common in Japan—that one was the third of the week—and the participants were, after all, at a seismology conference. Then everyone in the room checked the time.

Seismologists know that how long an earthquake lasts is a decent proxy for its magnitude. The 1989 earthquake in Loma Prieta, California, which killed sixty-three people and caused six billion dollars’ worth of damage, lasted about fifteen seconds and had a magnitude of 6.9. A thirty-second earthquake generally has a magnitude in the mid-sevens. A minute-long quake is in the high sevens, a two-minute quake has entered the eights, and a three-minute quake is in the high eights. By four minutes, an earthquake has hit magnitude 9.0.