How did geography protect the united states and canada during world war i and world war ii?

Welp they both had two great oceans between them, a land invasion is near Impossible, and a sea  attack would not be smart for the Central Powers/Axis

An Air attack needs refueling and no enemy had a close airbase plus we had anti air any attack on North America or any of the Americas is useless.

true. earthquakes are felt whenever there is a slip around a fault in the rocks below the earth. this reorientation of faults create sesmic waves and is known as earthquake, the severity of which is measured in richter scale. these are more prominent in hilly regions as the rocks usually form faults to balance the pressures on it.