Answers

2015-06-17T06:52:03+08:00
It seems to me that the question is about locating areas which are prone to earthquakes. If that is the question, I believe it is determined by identifying seismic history of particular locations, fault lines, and tectonic plates under a particular area. 

The question can also be interpreted by the area that an earthquakes would affect. If this is the interpretation of your question, it's determined through a seismograph. Hope it helps!
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