Episodic coastal dune development in the Taean Peninsula and Anmyeon Island, Korea, during the mid to late Holocene

The episodic nature of coastal dune development has been widely identified in many dune areas over the world. What causes such episodicity is still hotly debated. Sea-level change, climatic change and human impact have widely been reported as the main forcings, though there is no agreement yet upon which factors are critical. This research provides some evidence that sea-level fluctuation and climatic factors controlled the episodic dune building together, based upon optically stimulated luminescence (OSL) dune ages on the west coast of Korea. The newly obtained and published OSL dune ages on the west coast of the Taean Peninsula and Anmyeon Island, Korea, indicate the six main periods of dune building: 5.5, 4.3, 1.5, 1.3, 1.1 and 0.7 ka. They correlate with evidence of colder climate in East Asia that imply stronger dune-forming winds during the winter under the influence of a more intense Siberian High. They also correlate with periods of higher sea level over the present one with fluctuations. Thus, episodic dune activity along the west coast of the Korean Peninsula during the mid to late Holocene appears to be linked to stronger winter winds capable of moving sand from the beach to the foredune ridges with short-term fluctuations during the high stands.