Why do some earthquakes happen deep inside continents far from plate boundaries?
Quick Answer
Old faults can be reactivated when stress builds up inside a plate. A few regions also have ancient weak zones that make intraplate earthquakes possible.
The Full Story
Not all earthquakes happen at the edges of tectonic plates. Continental interiors contain ancient faults and zones of weakness left over from past tectonic events, and these can be squeezed by stresses transmitted across the plate. When the stress exceeds the strength of the rocks, they slip and produce an intraplate earthquake. The 1811–1812 New Madrid earthquakes in the central United States are a famous example. These quakes show that even plate interiors are not completely rigid.
Key Facts
YouTube Angle
Suggested video title for this topic:
"Earthquakes in the middle of a continent? Here’s why they happen"
Was this answer helpful?
Tap a reaction — it helps us pick what to cover next.