Developing a comprehensive understanding of the drivers of global climatic change and, importantly, the patterns of differential geographical responses to these drivers represents one of the main scientific endeavours of our generation. To this end, the study of long, high-resolution palaeoenvironmental records has become an international scientific priority since historical data lack the length of records or range of climatic extremes necessary to achieve this fundamental understanding.
Among other highly sensitive regions to climatic change, the Tibetan Plateau is of critical societal importance, providing freshwater from the so-called “Water Tower of Asia” to a large proportion of the Asian population via multiple major river systems, as well as supplying sediment to mega-deltas that are home to tens of millions of people (Haberzettl et al., 2019). Gaining a better understanding of the hydrological effects of past climatic change is therefore key to predicting the regional environmental impacts of future climate scenarios.
Existing palaeoenvironmental records from the Tibetan Plateau are short (<32,000 years) and often discontinuous due to the complex tectonic setting. However, a newly retrieved, 150m long lacustrine core from Nam Co, central Tibetan Plateau, offers the opportunity to reconstruct past hydroclimatic change from the region over the last ~125,000 years – i.e. covering the last full glacial-interglacial cycle.
The present PhD project will contribute to a major international collaboration to extract high-resolution, multi-proxy palaeoenvironmental data from these Nam Co sediments. Crucial to the interpretation of these data though is robust chronological control – knowing when and how rapidly environmental changes took place – and obtaining this precise and accurate chronology is the primary aim of the proposed studentship.
The project will involve the development of approaches to chronology building in this exciting, yet challenging high altitude lake system, combining complementary geochronological methods (including radiocarbon dating and Optically Stimulated Luminescence, OSL) for Nam Co specifically, but that will also be transferable to other sites across the region and more broadly. This chronological understanding, and therefore the student themself, will be embedded centrally within the broader palaeoenvironmental interpretation at the site.
This is a rare opportunity to work on a palaeoenvironmental archive of truly global significance, with the broader Nam Co Drilling Project having recently been awarded financial support from the International Continental scientific Drilling Program (ICDP) for a further deep drilling campaign of the basin, provisionally scheduled for summer 2023, which the successful PhD applicant will be welcome to participate in (Haberzettl et al., 2019).
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Location of Nam Co (yellow dot), central Tibetan Plateau (orange area) with respect to the major climate systems influencing the region (the Westerly Jet Stream; Indian Summer Monsoon, ISM; and East Asian Monsoon, EAM). Existing ICDP (blue dots) and IODP (green dots) drilling sites are also shown. (Source: Haberzettl et al., 2019)