2dimes wrote:That's pretty interesting. 5.0 and there's a lot of people that didn't notice that were near it. I wonder if it depends on the density of the ground you're on or something as to how much it shakes.
Yes. It definitely depends on the substrate.
Also, remember that the scale is logarythmic. So, a 5.1 is ten times as strong as a 5.0. For most people, a 5.0 would not do much more than a big truck going by. If you live in a poorly constructed building, like a cheap apartment over a carport or live in filled land (like much of the marina district in San Francisco -- the part that was so heavily damaged), then you might notice a good deal more.
We were roughly 150 miles from the center of the Petrolia Quake in California, back in 1991 or 92. I felt my apartment sway(cheap, over a carport) and later we found some cracks in the wall and around the light fixtures. On the other hand, I lived far closer to some quakes on the San Andreas fault (our house was almost on top of the fault line), in an old, but well-built farmhouse and did not feel as much swaying.
If you want a cute trick to show kids, for example, how a quake "liquifies" filled-in soil, try taking a good part of a box of corn starch and add some water. Go slow, you don't want soup! Food color makes it more fun (at least for kids). Anyway, when you have it just right, it will look and feel solid, until you shake it, when it will "liquify".