Tsunami waves can travel across the open ocean at 500 mph, matching the speed of a commercial jet.

Tsunamis are shallow-water waves because their wavelengths are extremely long, often exceeding 60 miles. In the deep ocean, the speed of a tsunami is determined by the square root of the product of gravity and the water depth. At an average ocean depth of 13,000 feet, this calculation results in speeds of approximately 500 mph, which is comparable to a Boeing 747 cruising speed.According to the National Oceanic and Atmospheric Administration (NOAA), these waves lose very little energy as they travel because the entire water column is in motion. Unlike wind-driven waves that only affect the surface, tsunamis involve the movement of water from the seafloor to the surface. This massive volume of water allows the energy to propagate across entire ocean basins with minimal dissipation.The 2004 Indian Ocean tsunami serves as a primary example of this speed and power. Triggered by a 9.1 magnitude earthquake off Sumatra, the waves traveled 3,700 miles to reach Africa in just under seven hours. As the waves enter shallower water, a process called shoaling occurs where the wave speed decreases while the wave height increases dramatically.This transition happens because the trailing part of the wave catches up to the front as it slows down due to friction with the rising seabed. This compression of energy transforms a wave that was only a few feet high in the deep ocean into a wall of water dozens of feet tall. The Pacific Tsunami Warning Center uses deep-ocean pressure sensors called DART buoys to detect these rapid energy shifts and provide early warnings to coastal regions.