Textural and stable isotopic records from the absolute-dated stalagmite of the Daeya Cave (DY-1) provide new insights into the climatic evolution of the Korean Peninsula during the Holocene and Eemian climatic optima. The stalagmite yielded ages of 8572 ± 227 to 5907 ± 158 and 1,23,456 ± 535 to 1,19,837 ± 1089 years, which coincide with the Holocene and Eemian climatic optima, respectively. The stalagmite's δ13C record closely resembles previously reported Chinese speleothem δ18O data. Thus it can be suggested that textural and geochemical results of the DY-1 reflect East Asian monsoon intensity, which is forced by summer insolation patterns in the northern hemisphere. Lighter carbon isotopic compositions, well-developed fibrous calcite crystals, and their relatively faster growth rate in the stalagmite sample are interpreted to reflect the warmest and wettest climate conditions of the Holocene and Eemian interglacials. Both climatic optima took place when insolation was decreasing from its maximum level, temperature in Greenland was highest, and sea level approached its maximum level. These climatic optima also coincide with decreasing Antarctic temperatures. Compared the DY-1 data to other proxies, it is suggested that the Holocene and Eemian climatic optima developed through a balance among boreal insolation, monsoon intensity, and sea level (also continental ice volume), which are the main climatic forcing factors in the northern hemisphere. These trends also follow the bi-polar seesaw mechanism as previously described.
Bibliographical noteFunding Information:
This work was supported by the K-Polar Program (PP11010) of the Korea Polar Research Institute and the Korea Meteorological Administration Research and Development Program ( RACS 2010-3007, PN10040 ). This research was also supported in part by the project of the research on the abrupt climate change for the prediction of extreme geo-hazards and sea level change around the Korean Peninsula (GP2009-005) funded by the Korea Institute of Geoscience and Mineral Resources (KIGAM). We thank the person in charge of natural heritages in Yeongweol-gun, Gangwon-do, South Korea for authorizing cave sample collection and KNUCIC (Kangwon National University Cave Investigation Club) members for supporting field work. First author thanks for financial support from the post-doctoral research program of Kangwon National University . The authors are grateful to the Dr. Hillaire-Marcel, Dr. Huang, and two anonymous reviewers for helpful reviews and suggestions.
- Climatic optimum
- East Asian monsoon
- Stable isotopes