Earthquake - Is This What They Mean When They Describe a Book as “Shaken”?

Around 8:00 p.m. tonight (Tuesday, October 30), we had a moderate earthquake. I’ve lived in the San Francisco Bay Area all my life, and there are two different kinds of earthquake I’ve experienced. There are gentle, wavelike, rolling earthquakes and there are very fast, banging earthquakes, as if someone is lifting the building up and down and pounding it on the ground. This one was a gentle, rolling earthquake (think of an ocean wave cresting under your feet), measuring about 5.6 on the Richter Scale. It only lasted about 15 seconds, and we were happy it was not the other type of sharp, jolting earthquake, which, even when small, are much more jarring and much more scary. Although windows rattled and the chandelier swayed, not much else happened. Not one book fell off the shelves (thankfully).