Recently, Xu Hai, a researcher in the Institute of Earth Environment, at the Chinese Academy of Sciences, delivered a presentation on “The records of ancient lakes and marshes on the eastern margin of the Tibetan Plateau and their global connections in the late Holocene” at Tianjin University. His studies are mainly concerned with environmental geochemistry and geology in the Quaternary period, in particular focusing on records of limnetic environment processes and the ancient climate. In recent years, he began studying different time-scale climate records of ancient lakes and marshes on the eastern margin of the Qinghai-Tibet Plateau and exploring their dynamic origins. Attendees included teachers and students with an interest in the topic.
During the presentation, Xu demonstrated his research process and major findings. He began his lecture with an introduction of related scientific problems. His research is based on ancient climate and ancient hydrology, ancient lakes and ancient runoff. Choosing appropriate time-scales is a crucial part of his research, for climate change and its driving mechanisms vary over different time-scales. Why the eastern margin of the Tibetan Plateau? “The Tibetan Plateau plays an important role in large scale atmospheric circulation. The eastern margin of the Tibetan Plateau is influenced by the Eastern Asia Summer Monsoon (EASM), the India Summer Monsoon (ISM), and the Westerly and Siberian Cold. Therefore, it is the ideal place to study global climate change and its origins.” Xu explained. Moreover, many ancient climate carriers such as tree rings, ice cores, lake sediments in the region provide them with abundant study materials.
Xu also introduced his research methods. His research on lake sediments covers four steps: drilling, dating, discussion, and analysis. While research on lakeshores or terraces should follow another four steps. Pictures were also presented to illustrate their work environment and methods. They have collected data from many lakes, analyzed and drawn comparisons utilizing numerical modeling. After many years’ research, he has hypothesized that such large scale hydro-climatic differences between the southern and northern parts of the ETP may be related to the adjustment of the sea-surface temperature of the tropical Pacific at the location of the intertropical convergence zone and the strengthening of the Walker circulation.
After his lecture, teachers and students asked questions about his studies. The precision and data collection methods were students’ focal points. The lecture also aroused attendees’ discussion about an urgent topic facing humanity and linked to current changes in the Earth’s climate - global warming.
By: Zhao Han
Editors: Qin Mian and Christopher Peter Clarke
