Correlative 90 kyr northeast Asia–northwest Pacific climate records

Abstract

Specific regional and hemispheric responses to past variations in solar radiation demonstrate the complex interconnections that exist between components (land/sea/atmosphere) of the climate system^1,2. Few empirical palaeoclimatic studies are available from northeastern Asia, a region essential for the construction of composite models of global climate change and critical to analyses of northwestern North American climate. Among these, Quaternary climatic data from Japan are restricted largely to pollen sequences <30 kyr BP, as limited chronostratigraphic control constrains older data^3–6. Palaeoenvironmental studies of the northwest Pacific Ocean focus on comparing modern conditions with the last glacial maximum⁷. Continuous marine palaeoclimatic series are far from land and are not correlated directly with continental sequences^8,9. Here we present the first continuous records of vegetation and climate from northeastern Japan over the past 90 kyr, relating them directly to sea-surface temperature (SST) estimates from the same deep-sea core, RC14-103 located in the northwest Pacific Ocean east of Hokkaido (Fig. 1). Relative stable glacial (∼80–20 kyr BP) environments are cold (<4 °C) and wet (∼1,000 mm), with boreal forest and tundra on Hokkaido associated with cool (<16 °C) summer and cold (<1.0 °C) winter SSTs offshore; non-glacial (∼10–4 kyr BP) environments on land are warm (>8°C) and humid (>1,200 mm), whereas SSTs are cold (10.4–14.3 °C) in summer and warm (>1.5 °C) in winter.