Indian monsoon variability at different time scales: Marine and terrestrial proxy records

Abstract

Here, we present a review of the work done in India during 2007-2011 on various proxy records of monsoon variability preserved in the marine (Central Indian Basin, western, northern and eastern Arabian Sea and the Bay of Bengal) and terrestrial (Northeast, Gujarat, Himalayan Lakes, Siwaliks, Thar Desert, Ganga Valley, etc.) realms, in order to understand how Indian monsoon has evolved through the Tertiary and Quaternary periods. Though, there are clear indications of heavy rainfall occurrence throughout the Palaeogene and early Neogene, seasonality in rainfall pattern becomes apparent only in the Late Miocene record. Northern Hemisphere Glaciation played a major role in the evolution of Pliocene monsoon, whereas, glacial-interglacial cycles influenced the Pleistocene monsoonal variability. The Holocene, which is characterized by millennial-scale climatic fluctuations, started with a strong monsoonal phase, often known as "Holocene Climatic Optimum", lasted till the mid Holocene. This strong phase was followed by weak phases causing drier conditions mostly around 2,500-1,500, 1000, 650-450 yrs BP and the little Ice Age (AD. 1450-1850).