Uncover Up

摘要

During the previous interglacial period, approximately 127,000 to about 116,000 years ago, Earth's climate was warmer than it is currently. Global average sea level was also 4 to 6 meters higher, but it is unclear how much additional ocean volume resulted from the melting of the Greenland Ice Sheet versus the Antarctic Ice Sheet. Colville et al. (p. 620) examined the Sr-Nd-Pb isotope ratios of silt-size sediment discharged from southern Greenland over the penultimate warm period in order to infer what terrane in Greenland was covered in ice. The results were compared with model outputs of the Greenland Ice Sheet in order to estimate the volume of ice and to calculate how much the ice sheet contributed to sea level. The findings indicate that the Greenland Ice Sheet supplied between 1.6 and 2.2 meters of the excess sea-level rise, which suggests that the Antarctic Ice Sheet also made a major contribution to the sea level.