Where do most earthquakes occur in the world?
The surface of the earth is divided like a jigsaw puzzle into giant pieces called tectonic or crustal plates. These giant pieces move slowly over partially melted rock known as the mantle. As they move, they slide along each other, move into each other, move away from each other, or one slips under another. On these active plate boundaries about 95% of all the world’s earthquakes occur. California, Alaska, Japan, South America, and the Philippines are all on plate boundaries. Only 5% are in areas of the plates far away from the boundaries. These are called mid-plate or intra-plate earthquakes and are, as yet, poorly understood.