Originally posted by JrDavis
So what we are seeing is the earth shaking due to the 7.3 in Japan today?
Why do we not feel this vibration?
The vibration exists, and is rather small, but can be calculated.
is such a calculator.
As a test, I plugged in the coordinates of London, and this is the result obtained for that big earthquake near Japan...
DATE-(UTC)-TIME LAT LON DEPTH MAG Q COMMENTS 2012/12/07 08:18:24 37.89N 144.09E 36.1 7.3 US: OFF EAST COAST OF HONSHU
Expected 20s period surface wave amplitude [ 1.38E+02 µm] [ 4.33E+01 µm/s]
Expected 1s period body wave amplitude [ 3.50E+00 µm] [ 2.20E+01 µm/s]
As you see, the amount of "shaking" felt in London would be in the micrometer scale, and the speed of the earth movement in micrometers per second.
Extremely tiny, measureable by sensitive equipment, but humans wont notice.
edit on 7-12-2012 by alfa1 because: (no reason given)