Thar Desert

The Thar Desert, also known as the Great Indian Desert, is an arid region in the north-western part of the Indian subcontinent that covers an area of in India and Pakistan. It is the world's 18th-largest desert, and the world's 9th-largest hot subtropical desert. About 85% of the Thar Desert is in India, and about 15% is in Pakistan. The Thar Desert is about 4.56% of the total geographical area of India. More than 60% of the desert lies in the Indian state of Rajasthan; the portion in India also extends into Gujarat, Punjab, and Haryana. The portion in Pakistan extends into the provinces of Sindh and Punjab (the portion in the latter province is referred to as the Cholistan Desert). The Indo-Gangetic Plain lies to the north, west and northeast of the Thar desert, the Rann of Kutch lies to its south, and the Aravali Range borders the desert to the east. During the Last Glacial Maximum 20,000 before present, an approximately ice sheet covered the Tibetan Plateau, causing excessive radiative forcing i.e. the ice in Tibet reflected at least four times more radiation energy per unit area into space than ice at higher latitudes, which further cooled overlying atmosphere at that time. This impacted the regional climate. Without the thermal low pressure caused by the heating, there was no monsoon over the Indian subcontinent. This lack of monsoon caused extensive rainfall over the Sahara, expansion of the Thar Desert, more dust deposited into the Arabian Sea, a lowering of the biotic life zones on the Indian subcontinent, and animals responded to this shift in climate with the Javan rusa deer migrating into India. 10,000-8,000 years ago a paleo channel of Ghaggar-Hakra River - identified with the paleo Sarasvati River, after confluence with Sutlej flowed into the Nara river - a delta channel of the Indus River, changed its course, leaving the Ghaggar-Hakra as a system of monsoon-fed rivers which did not reach the sea and now ends in the Thar desert.