Outstanding Geoheritage Values of the Island-Type Tidal Flats in Korea

Island-type tidal flats are located along the west and south coast of the Korean Peninsula on the east of the Yellow Sea. Due to the highly dynamic and complex combination of geological, oceanographic, and climatic conditions, the area is characterized by extremely dynamic past and ongoing sedimentary processes, thus representing one of the most intricate and diverse sedimentary and ecological systems in the world. Thousands of islands are scattered around a vast area adjacent to the land. Rapid macrotidal currents flow between these islands through tidal channels that are narrow or wide, short or long, and shallow or deep, changing their direction every 6 h. This creates one of nature's most spectacular phenomena along the coast with coastal landform. Tidal sedimentation is also greatly influenced by the seasonal changes of the Asian monsoon climate regime, resulting in high geodiversity exposed to constant changes in hydrology and sediment supply. At the same time, the system has maintained a sustained sedimentation equilibrium, resulting in one of the world's thickest Holocene intertidal mud deposits and most productive coastal ecosystems. The study area comprises four serial sites, each with different geological and geomorphic features. It also forms a single sedimentary circulation system between the source and one of the final sinks. The Korean tidal flat system therefore demonstrates unique and outstanding coastal landforms with ongoing dynamic and sustainable coastal processes, making it a potential inscription on the UNESCO World Heritage List.