Ocean Facts: What are Kelvin waves? Kelvin waves are difficult to see with the naked eye as they are large in scale, slow moving, and don't break onshore like typical ocean waves. In this graphic, satellite radar altimetry measurements reveal the sea surface signature of Kelvin waves where the ocean surface is higher or lower than its long-term average. The yellow color represents elevated sea surface heights at ranges of 0 to 0.25 meters (0 to 10 inches). The red/orange color represents elevated sea surface heights at ranges of 0.25 to at least 1 meter (10 inches to at least 40 inches). (Image credit: NOAA Satellites) Download Image October 14, 2026 Ocean & Coasts ocean facts El Nino, La Nina, ENSO 0 Off