Piotr Smietana needed opportunities to extend his tennis career, and he found them at Iowa.

The day after Christmas in 2004, an undersea earthquake occurred near the Indonesian island of Sumatra, triggering 30-foot waves that roiled the Indian Ocean as far as East Africa and killed at least 225,000 people in a dozen countries. In 2011, an immense underwater earthquake shook Japan, triggering a tsunami that destroyed the Fukushima nuclear reactor and decimated a large swath of the country’s eastern coast. While earthquakes are common, some, like the megathrust quakes off Indonesia and Japan, are particularly devastating. “On a global scale, they produce the Earth’s largest earthquakes because they occur along the Earth’s largest faults,” says Bill Barnhart, an earthquake specialist at the University of Iowa.