China quake rattles well in Virginia
The magnitude 7.9 earthquake that rocked much of China today, killing thousands, also sent tremors through the earth that caused water levels in a USGS monitoring well in Christiansburg, Va. to slosh more than a foot.
Here's the trace on the water level. (The smaller, wave-like variations before and after the big spike are caused by tidal forces in the ground - the action of lunar gravity on the Earth's crust as the planet spins.)
