Why Was the Virginia Earthquake Felt So Widely?

On August 23, just before 2 P.M. Eastern time, the entire eastern half of the North American continent rocked back and forth for a few moments. From northern Ontario down south to Georgia and inland as far as western Ohio and Tennessee, the 5.8-magnitude quake centered in Mineral, Va., had some broad reach.

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Why Was the Virginia Earthquake Felt So Widely?