A Channel Carved by Tides
The S-shaped channel of Suncheon Bay results from powerful tidal dynamics acting on a vast coastal wetland. The bay's formation began after the Last Glacial Maximum, around 8,500 years ago, as rising sea levels flooded ancient river valleys. Today, the bay contains a 28-square-kilometer tidal flat, a type of coastal wetland where land and sea merge. This landscape is constantly reshaped by a macrotidal regime, where the difference between high and low tide can exceed six meters.
Unlike a river meander formed by a constant, one-way flow, the S-curve is sculpted by the bidirectional ebb and flow of the ocean. Twice a day, tidal currents rush into the bay and then recede, carrying fine sediments of sand and mud. The water's velocity carves out the channel, eroding the outer banks of the curves while depositing sediment on the slower-moving inner banks. This process, repeated over millennia, has exaggerated the serpentine shape of the waterway. The sediment layers in this region, known as the Getbol, are among the thickest in the world, reaching depths of up to 40 meters. The entire wetland is part of a UNESCO World Natural Heritage Site designated in 2021.