Both quakes occurred in this horseshoe-shaped area the National Geographic Society defines as "a string of volcanoes and sites of seismic activity, or earthquakes, around the edges of the Pacific Ocean."
It may seem more than coincidental that the quakes occurred a few days apart. But it's also true that the large majority of the world's earthquakes -- about 90% -- occur in the Ring of Fire, per the National Geographic Society.
The Ecuador earthquake was almost 16 times stronger than the Saturday morning quake in Japan.
That figure comes courtesy of the "Try It Yourself" calculator on the USGS website. Ecuador was hit by a magnitude-7.8 quake, Japan by a magnitude-7.0 quake. Plug those numbers into the calculator, and you come up with 15.848. (The Thursday Japan quake was magnitude-6.2.)
How often do quakes of this power occur?
Quakes with a magnitude between 7.0 and 7.9 occur about 15 times a year, according to information collected by the USGS over the decades.
The bigger ones -- magnitude-8 and over -- happen about once a year.