Tsunami
The word "tsunami" means "harbor wave" in Japanese. Unlike typical sea tides, tsunamis are usually caused by geological hazards, such as earthquakes, volcanic eruptions, undersea landslides, and, rarely, meteor impacts. Tsunami waves can sometimes exceed 100 miles in length, and travel at more than 500 miles per hour. Tsunamis come ashore as a quickly rising swell and flood low-lying areas.