@article{BasavaiahWiesnerAnoopetal.2014, author = {Basavaiah, Nathani and Wiesner, M. G. and Anoop, Ambili and Menzel, P. and Nowaczyk, Norbert R. and Deenadayalan, K. and Brauer, Achim and Gaye, Birgit and Naumann, R. and Riedel, N. and Stebich, M. and Prasad, Sushma}, title = {Physicochemical analyses of surface sediments from the Lonar Lake, central India - implications for palaeoenvironmental reconstruction}, series = {Fundamental and applied limnology : official journal of the International Association of Theoretical and Applied Limnology}, volume = {184}, journal = {Fundamental and applied limnology : official journal of the International Association of Theoretical and Applied Limnology}, number = {1}, publisher = {Schweizerbart}, address = {Stuttgart}, issn = {1863-9135}, doi = {10.1127/1863-9135/2014/0515}, pages = {51 -- 68}, year = {2014}, abstract = {We report the results of our investigations on the catchment area, surface sediments, and hydrology of the monsoonal Lonar Lake, central India. Our results indicate that the lake is currently stratified with an anoxic bottom layer, and there is a spatial heterogeneity in the sensitivity of sediment parameters to different environmental processes. In the shallow (0-5 m) near shore oxic-suboxic environments the lithogenic and terrestrial organic content is high and spatially variable, and the organics show degradation in the oxic part. Due to aerial exposure resulting from lake level changes of at least 3m, the evaporitic carbonates are not completely preserved. In the deep water (>5 m) anoxic environment the lithogenics are uniformly distributed and the delta C-13 is an indicator not only for aquatic vs. terrestrial plants but also of lake pH and salinity. The isotopic composition of the evaporites is dependent not only on the isotopic composition of source water (monsoon rainfall and stream inflow) and evaporation, but is also influenced by proximity to the isotopically depleted stream inflow. We conclude that in the deep water environment lithogenic content, and isotopic composition of organic matter can be used for palaeoenvironmental reconstruction.}, language = {en} } @article{PrasadAnoopRiedeletal.2014, author = {Prasad, Sushma and Anoop, A. and Riedel, N. and Sarkar, Saswati and Menzel, P. and Basavaiah, Nathani and Krishnan, R. and Fuller, D. and Plessen, Birgit and Gaye, B. and Roehl, U. and Wilkes, H. and Sachse, Dirk and Sawant, R. and Wiesner, M. G. and Stebich, M.}, title = {Prolonged monsoon droughts and links to Indo-Pacific warm pool: A Holocene record from Lonar Lake, central India}, series = {Earth \& planetary science letters}, volume = {391}, journal = {Earth \& planetary science letters}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0012-821X}, doi = {10.1016/j.epsl.2014.01.043}, pages = {171 -- 182}, year = {2014}, abstract = {Concerns about the regional impact of global climate change in a warming scenario have highlighted the gaps in our understanding of the Indian Summer Monsoon (ISM, also referred to as the Indian Ocean summer monsoon) and the absence of long term palaeoclimate data from the central Indian core monsoon zone (CMZ). Here we present the first high resolution, well-dated, multiproxy reconstruction of Holocene palaeoclimate from a 10 m long sediment core raised from the Lonar Lake in central India. We show that while the early Holocene onset of-intensified monsoon in the CMZ is similar to that reported from other ISM records, the Lonar data shows two prolonged droughts (PD, multidecadal to centennial periods of weaker monsoon) between 4.6-3.9 and 2-0.6 cal ka. A comparison of our record with available data from other ISM influenced sites shows that the impact of these PD was observed in varying degrees throughout the ISM realm and coincides with intervals of higher solar irradiance. We demonstrate that (i) the regional warming in the Indo-Pacific Warm Pool (IPWP) plays an important role in causing ISM PD through changes in meridional overturning circulation and position of the anomalous Walker cell; (ii) the long term influence of conditions like El Nino-Southern Oscillation (ENSO) on the ISM began only ca. 2 cal ka BP and is coincident with the warming of the southern IPWP; (iii) the first settlements in central India coincided with the onset of the first PD and agricultural populations flourished between the two PD, highlighting the significance of natural climate variability and PD as major environmental factors affecting human settlements.}, language = {en} }