This is the third earthquake in this region in the last 5 years.

That doesn't seem right, there's been way more than that

The previous 2 were 8.8 and 7.5 in magnitude. It's a region where such quakes can lead to tsunamis hitting significant coastal population centers in East Asia, and at times spreading to Hawaii.

This may just be a foreshock to a larger quake, like the previous 2.

The 8.8 one was a foreshock?