The tectonic plates in china have a lot of hotspots and there are more than one. When these plates have immense amounts of pressure on them, it causes earthquakes.
In, say, the eastern united states the tectonic plate (there is only one) completely surrounds it, causing little to no earthquakes.
In, say, the eastern united states the tectonic plate (there is only one) completely surrounds it, causing little to no earthquakes.
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The how and the why are the same as with earthquakes everywhere else in the world. Why should China be any different?
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