Holocene Monsoon Variability
Climate changes over northwest India inferred from climate proxies indicate warm and humid climate with frequent floods between 10,000 and 4500 years ago (Pant and Maliekal 1987). Results from more precisely dated lake sediments (Enzel et al. 1999) from Lunkaransar, Rajasthan, however, showed that the monsoon fluctuated often in the early Holocene (the last * 10,000 years) and then intensified abruptly around 6300 years ago. The lake completely desiccated around 4800 years ago. The major Harappan-Indus civilization began and flourished in this region 1000 years after desiccation of the lake during arid climate. Globally, six major climate events are recorded in the Holocene 9000-8000 ,6000-5000, 4200-3800, 3500-2500, 1200-1000, and 600-150 a (Mayewski et al. 2004).
Fig. 1 Locations of marine and terrestrial proxies. Stars are sediment cores, Core SK-17 (Singh et al. 2006), Core AAS9/21 (Govil and Naidu 2010), Core 3268G5 (Sarkar et al. 2000), Core AAS62/1 (Kessarkar et al. 2013), Core SK237-GC4 (Saraswat et al. 2013), and Core SK148/4 (Rao et al. 2010). Terrestrial proxies are (1) Akalagavi cave stalagmite (Yadava et al. 2004), (2) Parambikulam tree cellulose (Managave et al. 2011), and (3) and (4) Dandak and Kotumsar caves (Yadava and Ramesh 2005)