With earthquakes dominating the headlines from coast to coast this week, some Americans are becoming anxious -- particularly those on the East Coast. But earthquakes in the U.S. are far more common than most people are aware.

Although most now know about three earthquakes this week -- first in Colorado, then Virginia and finally last night in northern California -- not everyone realizes they are among a whopping but not unusual 728 earthquakes in various parts of the country this week, the Los Angeles Times reported Wednesday.

At around 11:30 p.m. Tuesday, a 3.6-magnitude earthquake rattled the East Bay region outside of San Francisco, with an epicenter near San Leandro, Calif. A second, lesser quake with a magnitude of 2.3 hit about five minutes later.

Some West Coast-based headlines Tuesday gently mocked the panicked reaction of East Coast residents who are unaccustomed to seismic activity. A Los Angeles Times article titled What?! An earthquake? East Coast reacts with shock highlighted the opposing coastal sensibilities when it comes to earthquakes:

...an earthquake is the kind of thing that's supposed to happen in Los Angeles. But not New York City. Or Boston. Or Washington, D.C. Or North Carolina ...Yet, up and down the East Coast on Tuesday people reacted with outright shock and disbelief as the news was confirmed by the U.S. Geological Service.

The Washington Post published a tweet from West Coast writer Matt Honan, responding to the California quake: That's what we get for making fun of the East Coast today.

For some New Yorkers, particularly those working in tall buidlings, Tuesday's earthquake triggered recall of the 9/11 terror attacks.

My desk started to shake, so then everybody on the floor decided to evacuate. We didn't know what it was, but we said let's not take any chances and just leave the building, one Manhattan worker told NY1.

Adrian Ollivierre, a 28-year-old accountant with an office on the 60th floor of the Empire State Building, raced down the stairs and out into the street after the quake rattled his office. I thought I was having maybe a heart attack, and I saw everybody running, he told The Associated Press. I think what it is, is the paranoia that happens from 9/11, and that's why I'm still out here -- because, I'm sorry, I'm not playing with my life.

Some fear the series of mini-disasters have apocalyptic implications. I sure hope this whole earthquake-thing hitting Massachusetts, Colorado, and every other place doesn't turn into 'The Day After Tomorrow, the Washington Post reported someone posting on Twitter.

By Wednesday, the East Coast had settled down in time to prepare for a more familiar weather event: Hurricane Irene is now classified as a Category 3 storm, and North Carolina homes are currently being evacuated in anticipation of its arrival.

Federal and state authorities said the hurricane would probably affect nearly every state along the East Coast, The New York Times reported.