In 2004 tsunamis in the Indian Ocean swept over entire islands, wiping some of them completely off the map and killing more than 230,000 people. Unfortunately, tsunamis like these cannot be stopped, but they can be better understood. What causes thes e huge waves to form? How can they be detected? And what can be done to alert people that these fast-moving waves are approaching? As author and illustrator Taylor Morrison explains, ever since a deadly tsunami hit Hawaii in 1946, scientists have be en hard at work, developing the first Seismic Sea Wave Warning System and studying these powerful waves in hopes of saving lives by decreasing false alarms and by reacting with greater speed and accuracy to real threats.