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Chapter 01
Introduction to Research
This may be related to the advent of agriculture and the period of Rushabhdev discussed above. The climate is reflected in lake levels and record of agricultural activity may be preserved in pollens in the lake sediments. We discuss these aspects next. a. Climatic record based on Lake levels and Glaciation Three types of climatic data of Tibet are available for the past 40,000 years. Temperature (determined by oxygen isotopes in ice cores), thickness of ice sheets and inferred lake levels. For western Tibet such data are available for only 13000 years but may be related to overall Tibetan climate over longer periods of time. During glaciations the lake levels decreased significantly. The work of Daut et al (2010) suggest several epochs of low lake levels going down by as much as 95 meters (compared to the present lake levels) in Lake Nam Co in Central Tibet. Except for a 10-15 meter decrease recently during the Little Ice Age, other low lake level epochs occurred prior to 10000 years. Some data suggest that higher lake levels existed between 40,000 and 30,000 years. It is likely that the first appearance of prehistoric man coincided with this period. S. K. Gupta (1992) studied the ice cap on the Tibetan plateau using oxygen isotopic data, which is a temperature index. They find a temperature decrease of 5 to 7 °C during the Last Glacial Maximum (LGM) lowering the ice line by 700 to 1200 meters, covering much of the Tibetan Plateau. There is evidence of three periods of relatively high temperature during (i) 32-38,000 years, (ii) 24-28,000 years and (iii) 12000 years to present, resulting in higher lake levels, suitable for habitation and agricultural activity. The intervening period was very cold and ice thickness of the Tibetan Plateau was large. There is also evidence based on moraines that glaciers in Kailash region were more extensive in the past. Juyal et al (2011) based on their studies of geomorphological observations around inner Kora of Mount Kailash suggest three distinct events of glaciation dating to pre LGM, LGM and mid Holocene era. Since then the ice volumes have been decreasing due to rise in summer temperatures and reduction of monsoon precipitation. 6. Future prospects We have given an overview of various aspects, related to the problem of identifying Ashtapad, which includes, besides the references found in scriptures, archaeological, cultural and climatic data. All these patterns seem to be inter-related. Integrating all these data provides a broader perspective which underlines the complexity of the problem. These approaches may enable us first to define the period of Rushabhdev and then possibly help in locating the Ashtapad site. Further studies are important not only for the limited objective of locating Ashtapad but from global perspective related to cultural and climatic evolution in Tibet and their global context. The pioneering work and field expeditions carried out under ARIF has provided a basis on which we can design the future line of action. Although further field exploration and excavation is required which should include study of archaeological Sites en-route from Ayodhya to Kailash, Gompa and monasteries in the area, caves etc. which might have been inhabited by Jain monks for their penance and meditation. In addition, it may be useful to have a multi-thematic, multinational research study which may include (1) A multi pronged study of sediment cores taken from Lake Mansarovar, (2) Space based studies using high resolution remote sensing and (3) Ground based and space borne exploration using ground penetrating radar. We discuss the rationale of these studies here.
15
The Quest for Ashtapad
