Echo of the Younger Dryas in Holocene Lake Sediments on the Tibetan Plateau

Abstract

Reading the sediment record in terms of past climates is challenging since linking climate change to the associated responses of sedimentary systems is not always straightforward. Here we analyze the erosional response of landscapes on the Tibetan Plateau to interglacial climate forcing. Using the theory of dynamical systems on Holocene time series of geochemical proxies, we derive a sedimentary response model that accurately simulates observed proxy variation in three lake records. The model suggests that millennial variations in sediment composition reflect a self-organization of landscapes in response to abrupt climate change between 11.6 and 11.9 ka BP. The self-organization is characterized by oscillations in sediment supply emerging from a feedback between physical and chemical erosion processes, with estimated response times between 3,000 to 18,000 years depending on catchment topography. The implications of our findings emphasize the need for landscape response models to decipher the paleoclimatic code in continental sediment records.Plain Language Summary Lake sediments are an important source of information on past climates. Reading the information is not always straightforward. Complex interactions in landscapes can affect the transmission of climatic signals to the sediment record. However, the exact nature of such complex interactions remains unknown. This study compares sediment deposits of three lakes on the Tibetan Plateau. The deposits are continuous records of landscape responses to climate change during the last 12,000 years. We identified a mathematical model that accurately simulates changes in sediment composition at all sites. The model simulations suggest that an abrupt warming at the end of the last glacial period destabilized the landscapes. This caused fluctuations in the transport of sediments, which persisted for several thousand years. Our findings present evidence for a long-lasting impact of abrupt climate change on fundamental Earth surface processes.

Reconstruction of palaeoenvironmental variability based on an inter-comparison of four lacustrine archives on the Peloponnese (Greece) for the last 5000 years

“…While other studies indicate an overall drying trend for ca. 3000-2000 cal BP, with a short break of one wetter phase or two separate dry phases, as observed for example at Agios Floros or Thassos Cave, Skala Marion, NE Greek island (Norström et al, 2018;Psomiadis et al, 2018).…”

“…(h) Mavri Trypa δ 18 O (reversed; Finné et al, 2017). (i) Thassos Cave δ 18 O, Skala Marion (reversed, Psomiadis et al, 2018). (j) Closani Cave, Romania, autumnwinter precipitation (Warken et al, 2018).…”

Current perspectives on the capabilities of high resolution XRF core scanners

“…In the case of XRF data, the direction and length of the elements displayed in a bi-plot reveal the correlation and strength of the correlations, which helps to link the elements measured with the observed sediment fractions (e.g. Bloemsma, 2015;Martin-Puertas et al, 2017;Ramisch et al, 2018). For instance, the bi-plot visualization of the Early-Holocene varved sediments from Meerfelder Maar (Figure 3a NEAR HERE) reveal that these sediments mainly consist of detrital siliciclastics (inferred from K, Ti), redox-sensitive components (inferred from Mn, Fe) and carbonates (inferred from Ca, Sr).…”

VARDA (VARved sediments DAtabase) – providing and connecting proxy data from annually laminated lake sediments

“…Networks of varved lake sediments also provide means to test contrasted proxy responses to climate change (e.g. Ott et al, 2017;Ramisch et al, 2018;Roberts et al, 2016), further enhancing the robustness of palaeoclimatic reconstructions. However, despite their usefulness for the generation of highly resolved multisite networks, a global synthesis of varve-related palaeoclimatic data is still not available.…”