Late Holocene monsoonal-climate change inferred from Lakes Ni-no-Megata and San-no-Megata, northeastern Japan

Abstract

Micro-sedimentological, geochemical data from Lakes Ni-no-Megata and San-no-Megata in northeastern Japan are used to reconstruct environmental and climate changes over the last 2000 years. Comparing these records in two neighboring maar lakes allows reconstruction of centennial scale climate change concerned the East Asian monsoon activities without the influence of human activities. S content and coarse mineral grains records show that long-term climate changes, with one warm/humid interval from AD 1200 to 750, and two cold/dry intervals from AD 1 to 750, AD 1200 to the present. These climate changes have similar trends to Asian monsoon records in China, and could correspond to the Dark Age Cold Period (DACP), the Medieval Warm Period (MWP) and the Little Ice Age (LIA) climate changes in Europe. Moreover, short-term climatic deterioration events occurred in the 6th, 10th and 18th centuries. Particularly the event around the 10th century is well correlated with other paleoclimate proxies in China, Europe and Mesoamerica, suggesting tele-connection by atmospheric circulation through the Northern Hemisphere. However, the record is asynchronous with solar activity. This might suggest the solar forcing has indirectly influenced lake sedimentation associated with Asian monsoon activities in Japan.