Lake Tiefer See is located in the north-eastern part of the Natural Park Nossentiner-Schwinzer Heide. With a maximum depth of 62.5 metres, it is the deepest lake in the Klocksiner lake chain, which was created as a subglacial channel during the last glaciation. The lake is located near the Pomeranian ice margin (W2 moraine), which was deposited by the Scandinavian inland ice during the last ice age. The catchment area of the Lake Tiefer See was formed by glacial processes and the glacial deposits are characterised by boulders. After the glaciers melted, the lake basin was filled with dead ice for several thousand years until the formation of Lake Tiefer See in late Allerød, around 13,000 years ago. The initial lake deposits that we find in sediment cores are meltwater sands. The deposition of organic sediments began abruptly with the warming at the beginning of the Holocene 11,600 years ago.

(1) The weather station is mounted on a floating platform that is permanently anchored at the deepest point of the lake basin. We measure air temperature, air pressure, precipitation amount, global radiation, photosynthetically active radiation (PAR), wind direction and wind speed every 10 minutes. Precipitation water collectors and dust collectors are also installed on the platform. δD and δ¹⁸O isotope analyses of the precipitation water are carried out from the Stable Isotope Laboratory for Sediments and Water at monthly intervals.

(2) Lake water monitoring: two parallel automatic water probes measure water temperature, pH value, conductivity, turbidity, oxygen content, redox potential and chlorophyll every 12 hours at 1 metre intervals up to a water depth of 55 metres. In addition, permanent loggers are installed for temperature measurements every 6 hours at 1 metre intervals up to a water depth of 15 metres and at 5 metre intervals up to a water depth of 55 metres. The Secchi depth is measured manually at monthly intervals, water samples are taken for δD and δ¹⁸O analyses at depths of 1, 3, 5, 7, 10, 20, 40, 45, 50 and 55 m and solid particles are filtered from water samples taken at depths of 1, 3, 5, 7, 10, 20, 50 and 55 m. Lake level loggers are installed at the edge of the reed belt to the open lake for daily measurement of the lake level.

(3) Sediment traps: two different types of sediment traps are installed at different water depths. The traps collect the particles sinking in the water column at different temporal resolutions. A sequential trap at a water depth of 50 metres collects sediments at 15-day intervals. Two 4-cylinder traps at a water depth of 12 and 50 metres collect sediments at monthly intervals. From the sediment samples from all traps we determine in the laboratory total carbon (TC), total nitrogen (TN), calcium carbonate content (CaCO₃) and the isotope ratios δ¹³C_org, δ¹⁵N, δ¹³C_carb and δ¹⁸O_carb.

(4) Short cores: every year, short surface lake sediment cores are taken from different parts of the lake basin and then analysed geochemically in the laboratory, in order to link the high-resolution monitoring data currently obtained with the long lake sediment climate archives of the past and to gain insights for a better understanding of the sedimentation processes and the factors controlling them.