Compound Specific D/H Records of Marine and Terrestrial Biomarkers From Core MD972151 in the Southern South China Sea During the Last Glacial-Interglacial Cycle

Hydrological changes in the Western Pacific Warm Pool are a recent central issue of the paleoclimate study for the tropical Pacific. Here we present 150-kyr records of deuterium/hydrogen ratios of short- and long-chain n-fatty acids, which derived from aquatic organisms and terrestrial higher plants, respectively, in the IMAGES MD972151 core. The delta D of short-chain fatty acids (C16 and C18) ranged from ~-220 to ~-150 permil vs SMOW. A strong negative shift of delta D occurred at ~17 ka, which is attributed to the decrease of salinity in the southern South China Sea, suggesting an enhanced riverine discharge. The delta D of long-chain fatty acids (C24 to C28) ranged from ~-160 to ~-120 permil. The delta D showed a minimum at ~17 ka. This phenomenon is attributed to changes in either moisture or precipitation D/H ratio. These findings suggest a drastic change of hydrological dynamics in the Western Pacific Warm Pool in the early stage of the last deglaciation.