Late-Pleistocene to Holocene tephrostratigraphy over continental China
This research focuses on the identification of tephra (volcanic ash) layers from continental China and neighbouring regions. Tephra layers from explosive eruptions can serve as important event horizons for Quaternary studies, enabling the dating and correlation of sedimentary records of past environmental change.
Understanding climate change relies on long records of past climate behaviour, which can be interpreted from sedimentary archives such as peat bogs, lake sediments or ice cores. Establishing the timing and extent of past climate change requires robust dating evidence.
Explosive volcanic eruptions eject large quantities of ash into the atmosphere. The ash is dispersed by atmospheric winds over thousands of kilometres, until it falls out of the atmosphere and becomes incorporated in sediments within days, weeks or months of the eruption. As such, ash layers form instantaneous time-markers, even when the ash particles are too sparse to be seen with the naked eye. These invisible layers are called cryptotephras. The chemistry of the particles can indicate from which volcano the ash was erupted, and therefore it is possible to link cryptotephras across very large regions. Where the dates of the eruptions or cryptotephras are known, the ash layers also provide a means of dating the sediment in which they occur.
We aim to search for cryptotephra layers (tephra in concentrations too small to be visible to the naked eye) in peat and lacustrine sediments across a wide expanse of continental China (from north to south, and from the southeast to southwest) to investigate the potential of using this method for dating and correlating past environmental records. The presence of tephras could greatly improve the understanding of different climate systems in the region which will in turn help the interpretation of the main natural causes of climate change, and the impacts they have in different regions.
Impact of Research
The research will establish the potential to correlate palaeoenvironmental records across east and southeast Asia, including the first examination of volcanic ash dispersal across southern and central China. The findings will furthermore elucidate the extent of past ash clouds, therefore furthering the understanding of the spatial extent of volcanic ash cloud hazards.
Major grants and funding
The research is supported by a Newton International Fellowship to Dr Sun (Grant Number: NIF\R1\181359).
Recent papers :
Sun, C., Wang, L., Plunkett, G., Zhang, E. & Liu, J. 2021 An integrated Late Pleistocene to Holocene tephrostratigraphic framework for South‐east and East Asia. Geophysical Research Letters 48, 2020GL090582.
The research has evolved to include international collaborators:
Dr Luo Wang, Chinese Academy of Sciences, Beijing, China
Prof. Jiaqi Liu, Chinese Academy of Sciences, Beijing, China
Dr Jungjae Park, Seoul National University, South Korea
Dr Larissa Schneider, Australian National University, Australia
Dr Nguyen-Van Huong, Vietnam National University, Vietnam
Dr Christopher Newhall, University of Washington, USA