Tropical climate instability: The last glacial cycle from a Qinghai-Tibetan ice core

An ice core record from the Guliya ice cap on the Qinghai-Tibetan Plateau provides evidence of regional climatic conditions over the last glacial cycle. Cl-36 data suggest that the deepest 20 meters of the core may be more than 500,000 years old. The delta(18)O change across Termination I is similar to 5.4 per mil, similar to that in the Huascaran (Peru) and polar ice cores. Three Guliya interstadials (Stages 3, 5a, and 5c) are marked by increases in delta(18)O values similar to that of the Holocene and Eemian (similar to 124,000 years ago). The similarity of this pattern to that of CH4 records from polar ice cores indicates that global CH4 levels and the tropical hydrological cycle are linked. The Late Glacial Stage record contains numerous 200-year oscillations in delta(18)O values and in dust, NH4+, and NO3- levels.