What causes widespread earthquakes in some areas?

fiji-earthquake
Image Courtesy: USGS

(WWLP) – Ever wonder why earthquakes happen frequently in some areas, but not in others?

Large quakes have been in the news a lot lately, including a major 6.9 magnitude quake that happened on Tuesday. Why do earthquakes happen where they do? It all has to do with tectonic plates, which are oddly-shaped plates that cover the Earth. As these plates rub or bump into each other, they can cause earthquakes.

The Pacific Plate is a huge tectonic plate that covers most of the Pacific Ocean. Right along the edges of that plate, we see frequent earthquakes- in places like California, Alaska, Japan, and most recently in Fiji.

In western Massachusetts, on the other hand, we are not on the boundary of any major tectonic plates, so large earthquakes are not common here.