According to two recent studies from the Chinese Academy of Sciences published in Earth-Science Reviews and in the Chinese Science Bulletin, analyzing the chemical elements present in the shells of giant clams and coral samples, the temperatures of the southern sea of China during the 'Middle Ages' — between the 5th and 15th century under the Western dating system — would have been higher than the current ones.
In their research, the experts studied the ratio of strontium to calcium and to heavy oxygen isotopes in the shells of the molluscs, elements which can serve as a sensitive and reliable record of the temperatures of the sea surface. Through an elaborate technique of micro-perforation, the scientists could gain access to the different layers making up the shells, which allowed them to rebuild the history of the changes in temperature during the last 2,500 years .... http://en.institutomanquehue.org
