English: Internal waves are waves that travel within the interior of a fluid. The waves propagate at the interface or boundary between two layers with sharp density differences, such as temperature. They occur wherever strong tides or currents and stratification occur in the neighborhood of irregular topography. They can propagate for several hundred kilometers. The ASTER false-color VNIR image off the island of Tsushima in the Korea Strait shows the signatures of several internal wave packets, indicating a northern propagation direction. The image covers an area of 60 x 120 km, was acquired July 4, 2000, and is located near 34.6 degrees north latitude, 129.5 degrees east longitude. The resolution has been reduced to 90 m.