A million years of climate history Drilling campaign on Tibetan plateau with Braunschweig researcher
Dr. Anja Schwarz from the Institute of Geosystems and Bioindication at Technische Universität Braunschweigwas was recently on a research trip at 4,718 metres above sea level. The biologist took part in an international drilling campaign at Nam Co, the world’s highest salt lake on the Tibetan plateau. In total, almost 1,400 metres of lake sediment were successfully retrieved from a water depth of around 94 metres. A maximum drilling depth of over 500 metres was achieved. These sediments can now be used to reconstruct the climate history of the last million years approximately.
Bay on the north bank of the Nam Co with field camp. Photo credit: Anja Schwarz/TU Braunschweig
Dr. Anja Schwarz spent four weeks on the Tibetan plateau collecting the valuable research material with scientists from China, Germany, the UK, Switzerland, the USA and France. Covering an area of more than 2,000 square kilometres, Lake Nam Co is the third largest lake on the Tibetan Plateau, almost four times the size of Lake Constance. Preliminary studies show that the lake, which is currently about 100 metres deep, has a sediment thickness of almost one kilometre. “This is an incredibly valuable archive for climate research, but also for research into the development of biodiversity in high-altitude ecosystems and changes in the Earth’s magnetic field,” says Dr. Anja Schwarz.
The project could only be organised and carried out thanks to years of preparation involving experts from all over the world, including the Institute of Geosystems and Bioindication at TU Braunschweig, led by Professor Antje Schwalb, and long-standing Chinese collaborators.
The drilling platform, where drilling was carried out around the clock in twelve-hour shifts. Photo credit: Anja Schwarz/TU Braunschweig
Drilling rig for the preservation of sediment cores. Photo credit: Anja Schwarz/TU Braunschweig
Handover from Team 1 to Team 2 during the ICDP drilling campaign in Nam Co. The night shift of Team 1 is missing. Photo credit: Anja Schwarz/TU Braunschweig
Dr. Anja Schwarz on the drilling platform. Photo credit: Claudia Wrozyna (University of Greifswald)
Hard work on the platform. It only works as a team. Photo credit: Junbo Wang (ITP)
Cleaning the drilling tool. Photo credit: Claudia Wrozyna (University of Greifswald)
Sunrise after a successful night shift. This can be seen from the number of sediment cores. Photo credit: Anja Schwarz/TU Braunschweig
Scientists and workers of the drilling company at the farewell photo. Photo credit: Junbo Wang (ITP)
Adapting to altitude in Lhasa at 3,600 metres above sea level. Photo credit: Anja Schwarz/TU Braunschweig
On the Damxung Pass at 5,190 metres above sea level with a view of the Nam Co. photo credit: Anja Schwarz/TU Braunschweig
The drilling depth of 500 metres has been reached! Photo credit: Junbo Wang (ITP)
Research in difficult conditions
“However, the field work on site was a great challenge,” says Anja Schwarz. The location of the lake at 4,718 metres above sea level requires a gradual adaptation with temporary headaches, nausea and insomnia. “Fortunately, I was already familiar with this from previous fieldwork at Nam Co and was able to adapt to it,” says the scientist. This was compounded by difficult weather conditions such as storms, heavy rain showers, thunderstorms, strong sunlight and extreme temperature fluctuations, which made the drilling campaign increasingly difficult as the monsoon season progressed. Work on the rig had to be interrupted for safety reasons, or one shift could not replace the next after twelve hours as planned because the transport boat could not sail due to high waves.
“Nevertheless, my time at Nam Co was a valuable experience for which I am very grateful,” says Dr. Anja Schwarz, looking back on the drilling campaign. “Being part of such an important project is overwhelming. Working on the platform and in the field laboratory was also great fun and provided the opportunity to get to know other scientists better, exchange ideas, establish new research collaborations and consolidate existing ones.”
Following initial measurements of the sediment cores at the Institute of Tibetan Plateau Research (ITP) in Lhasa, the material will be opened and sampled by scientists from a wide range of disciplines in Beijing over the next few months.