The 8.9-magnitude earthquake that struck coastal Japan on Friday, devastating large swaths of the coast and spawning a powerful tsunami, was caused by the Pacific tectonic plate thrusting underneath the country, and forcing the seabed and ocean water upward.

In other news Tuesday, demonstrations calling for leaders' resignations continued in Bahrain and Yemen. In New Zealand, the hunt for survivors began after a magnitude 6.3 earthquake devastated Christchurch, the country's second-largest city, and killed at least 65 people.