Pollen/event stratigraphy of the varved sediment of Lake Suigetsu, central Japan from 15,701 to 10,217 SG vyr BP (Suigetsu varve years before present): Description, interpretation, and correlation with other regions

Abstract

High-resolution pollen data (average interval between samples<15 years) are reported on part of a varved sediment core from Lake Suigetsu, Japan, spanning the interval 15,701 to 10,217 SG vyr BP (Suigetsu varve years Before Present). This new record is compared with a previously proposed event stratigraphy based on pollen-based reconstructed changes of mean annual temperature. The deglacial climate history reconstructed at Lake Suigetsu resembles that observed in the North Atlantic, although the major boundaries of pollen zones are asynchronous with those in the North Atlantic event stratigraphy by several centuries. The onset of the Late Glacial interstadial occurred earlier in Japan than in the North Atlantic. This demonstrates that the climate in Japan was closely linked to the low-latitude Pacific Sea Surface Temperatures that first reacted to orbital forcing. Conversely, the onset of the subsequent cold reversal phase in Japan lagged that of the North Atlantic (Younger Dryas) by several centuries. The duration of this cold phase was about the same as the Younger Dryas event, but the amplitude was much reduced (4±2 °C in Δmean annual temperature). These findings support the hypothesis that this pan-hemispheric cooling event was triggered by North Atlantic forcing, most probably by a meltwater pulse and an associated change in the North Atlantic thermohaline circulation. However, the mechanism which transmitted the change in the North Atlantic to the Far East is unknown.