India, Nov. 3 -- Afghanistan lies in one of the world's most earthquake-prone regions

At least 20 people were killed and about 320 injured after a powerful 6.3-magnitude earthquake struck Afghanistan early Monday morning, shaking the city of Mazar-e Sharif. The disaster hit just months after another series of quakes and aftershocks claimed more than 2,200 lives across the country.

Afghanistan lies in one of the world's most earthquake-prone regions because it sits near the collision zone of the Indian and Eurasian tectonic plates. The Indian plate continuously pushes northward into the Eurasian plate, building up immense pressure underground. When this stress is suddenly released, it causes strong and often deadly earthquakes.

Since 19...