Mulyeongari Oreum

About

Mulyeongari Oreum is an oreum (small extinct volcano, parasitic cone) on Jeju Island, South Korea. It has a lake and wetland. It is the only wetland in Korea which is located within a volcanic crater in an oreum. The oreum is one of the secondary volcanoes around the Hallasan volcano, which is the highest mountain in South Korea. Through continuing scientific research, it is thought that Mulyeongari Oreum was formed by volcanic activity continuing for 2,500 years at the end of the third Cenozoic Era on Jeju Island. On top of the oreum, there is a shallow crater lake which displays a unique example of a wetland. The level of water changes with the seasons due to rainfall and the particular geology. Some 370 parasitic cones are located around Hallasan. Only about 30% of them have mountain craters. The geology is mostly composed of water-permeable basalt, so it is unusual to have a lake on top of such volcanic cones. During the dry season, most of wetland becomes dries out, except the deepest part in the south (about 50m of water depth). During the rainy season, most of it is submerged.

Adapted from Wikipedia (CC BY-SA). Photography via Wikimedia Commons.