Recently, researchers of the Key Laboratory of Marginal Sea and Ocean geology (OMG) of the Key Laboratory of Marginal Sea and Oceanic Geology (OMG) of the Institute of Oceanography of the Chinese Academy of Sciences and experts from relevant units within the United Nations have made new progress in the study of coral oxygen stable isotopes (δ18O) to record sea level changes, and the relevant research results have been published in the international journals Palaeogeography, Palaeoclimatology, Palaeoecology (Paleogeography, Paleoclimatology, Paleoecology"). Dr. Shi Chen of OMG Laboratory researcher Shi Qi's team is the first author of the paper, and Researcher Yu Is the corresponding author.
As global warming intensifies, meltwater from the ice sheet and thermal expansion of the oceans, the resulting rapid rise in sea levels is increasingly affecting islands and reefs as well as coastal cities. The trend, magnitude and rate of future sea level changes have attracted the attention of international academics and the whole society. Reconstructing the delicate process of sea level change has always been a hot and difficult issue in global change research. Reef-building coastal corals are excellent natural recorders of changes in the marine environment due to their high growth rate, clear annual growth layer, high-precision uranium (U-Th) dating, and sensitivity to changes in the surrounding marine environment. Reef-building coastal corals are widely developed in the South China Sea, providing favorable conditions for reconstructing sea level changes.
Paracel Coast corals for quantitative reconstruction
The researchers comprehensively analyzed the relationship between coral δ18O and the measured sea level, sea temperature, salinity and rainfall of corals on the south coast, and determined the statistical relationship between sea level and coral δ18O in the South China Sea, as well as the control mechanism. The history of sea level change in the South China Sea since 1850 AD was reconstructed quantitatively using coral delta 18O. The results of the study showed that the average rate of sea level decline in the 1850-1900 period was 0.73 mm/year; with global warming, the rate of rise in the 1900–2015 period was 1.31 mm/year, so calculated that the sea level in the South China Sea rose by 150 mm since 1900, while the rate of rise since 1993 was 3.75 mm/year, and the sea level of the South China Sea showed an accelerated upward trend. The study suggests that sea level changes in the South China Sea from 1850–1950 may have been the result of a combination of solar activity and greenhouse gases, which may have dominated rapid sea level rise since the 1950s.
Quantitative reconstruction of the history of sea level change in the South China Sea over the years of 1850 and its comparison with related records
This study is the first to use coral δ18O to quantitatively reconstruct sea level changes at annual resolution, which provides a new method for future sea level change studies at different periods.
This research was funded by the National Natural Science Foundation of China, the National Key R&D Program, the Special Project of Science and Technology Basic Resources Survey of the Ministry of Science and Technology, and the Team Project of Guangdong Provincial Laboratory of Southern Marine Science and Engineering (Guangzhou).
Text, photo/Guangzhou Daily, Xinhua City Reporter: Long Kun Correspondent: Li Shu
Guangzhou Daily New Flower City Editor: Long Chengliu