River Ghaggar / Saraswati Did Not Have A Glacial Source In Historical Times[Update : New geochemical and geomorphological studies strongly suggest that Yamuna and Sutlej stopped flowing in to the Ghaggar /Saraswati thousands of years before the Harappan civilization. See these posts for more on this topic -
1) Geological Update On the River Ghaggar
2) New Geochemical and Sedimentological Work On Ghaggar
3) New Geomorphological Work on Ghaggar
4) K.S Valdiya On The Glacial Saraswati Published in Current Science
A number of recent studies have bolstered the case that the River Ghaggar - which has been equated with the River Saraswati described in the Rigveda - did not have a glacial source in historical times and was likely always fed from the sub Himalayas (Siwaliks).
Why is this of any interest?
The background is the controversial question of the origin of the Aryans.
The more widely accepted theory is that proto-Sanskrit speakers entered the northwestern parts of India after or during the latter stages of the demise of the Harappan city states beginning around 1800 -1500 B.C. The ancestors of these proto-Sanskrit speakers can be traced according to this theory to the central Asia steppes. In terms of the local ecology, geological evidence shows that by this time the River Ghaggar which was once a river with substantial water flow and was perhaps perennial had transformed into a smaller ephemeral stream.
The competing theory is that the Aryans are indigenous to India - indigenous in the sense that they were present on the northwestern plains at least since the advent of agriculture. In this scenario the Harappan city states was an Aryan civilization. To support this more ancient presence of the Aryans on the plains of Haryana, Punjab and Rajasthan, one line of argument is to point to the Rigveda which mentions a mighty Saraswati river located between the rivers Sutlej and the Yamuna. The argument is that the composers of the Rigveda must have been living on the plains of Haryana when the Ghaggar = Saraswati was perennial which means before 1800 B.C which in one way supports the theory that they and the Harappan people were one and the same.
The Rigveda describes the Saraswati as originating high in the Himalayas. It is described as a mighty river and so has been thought to have been perennial and having a glacial source. But today the Ghaggar / Saraswati is no doubt fed from only the Siwaliks, nowhere near the high glaciers. To account for this, supporters say that earlier the glacially fed Sutlej and /or Yamuna flowed into the Saraswati. Later around 1800 B.C or so the channels shifted and the Ghaggar was stranded as a small ephemeral Siwalik fed river. Image below shows the Ghaggar basin flanked by the Sutlej and Yamuna.
A virtual industry dedicated to creating geological scenarios as to how this must have happened and to collecting "evidence" has proliferated on the internet, in various articles and in popular books.
A review of the peer reviewed geological literature shows that these scenarios are wrong and are based on exaggerations of the size of the Ghaggar and misunderstandings of geological processes. I have written an explanation of much of the list below in an article for the magazine Pragati. A short list is given here.
1) Use of isotopes in search of Lost River - Journal of Radioanalytical and Nuclear Chemistry: Data on stable isotopes of water in buried channels of ancient Ghaggar in Rajasthan shows a composition compatible with water from Siwaliks and not glacial high Himalayas.
2) Is River Ghaggar, Saraswati? Geochemical constraints - Current Science: Shows based on sediment geochemistry and composition and geomorphologic and paleo-climatic constraints that the River Ghaggar was likely always Siwalik fed.
3) Late quaternary geomorphic evolution of Yamuna-Sutlej interfluve: Significance of terminal fan - Journal of the Indian Society of Remote Sensing : Studies the stratigraphy and geomorphology of Yamuna channels and concludes that the Yamuna has been flowing within its channel and has not been part of the Indus system i.e. could not have flowed into the Saraswati.
4) Saraswati Nadi in Haryana and its Linkage with the Vedic Saraswati River – Integrated Study Based on Satellite Images and Ground Based Information - Journal Geological Society of India: Collected data shows that metamorphic pebbles in the upper reaches of the River Ghaggar can be derived from Siwalik source rocks and does not indicate a high glacial Himalayan source. Also shows based on geomorphology that the Yamuna did not flow into the Saraswati.
5) Reconstruction of buried channel-floodplain systems of the northwestern Haryana Plains and their relation to the ‘Vedic’ Saraswati - Current Science: Demonstrates based on stratigraphic, sedimentologic and geomorphologic data that the River Ghaggar in historical times had a smaller flow regime than in the earlier Quaternary period and derived its sediments likely from the Siwaliks.
I say it is time to abandon the theory that Ghaggar/Saraswati had a glacial source in historical times.
That does not mean abandoning the broader theory that the Aryan /Vedic people were present on the Haryana plains before the collapse of the Harappan civilization. Archaeology and linguistics and perhaps genetics are a more powerful tool to address that question. Let me add here that most archaeologists and linguists support the theory that the Aryans were late arrivals to the northwestern part of India.
The funny thing is, in my opinion the theory of a glacial source of Saraswati is not necessary in this debate. The Ghaggar was a wetter river before 1800 B.C. because of a generally more wetter climate. Strong summer monsoons over the Siwaliks and then spring flow would have made human settlements along its banks sustainable. A life sustaining river would have been holy to the people depending on it, regardless of whether it had a glacial origin or not.
The insistence that there was a past glacial source derives from a belief that the Rigveda is accurate in every aspect of its recording of geography and physical events. Descriptions of Saraswati in Rigvedic hymns as originating from Heaven...High Mountains..boundless....impetuous...fast flowing.. arising from a slowly moving serpent Ahi (source here) has led to a conviction that the Saraswati arose from glaciers. This reading of the Rigveda has led to the theory being proposed initially and for sustaining it.
Unhappily for science and for those who are looking for a scientifically accurate account, this has frustratingly meant a popularization and easy availability through the internet of an increasingly untenable and unsupported geological narrative which is creeping into the public consciousness as the correct story. People who are supporting the glacial origin theory assert that they are approaching the problem as a scientific question and with a scientific temperament. I would like to take them at face value.
However, that does come with a condition and this is the willingness to give up on your pet theory if the evidence piles up against it. This is one of the critical tests of the scientific temperament. There is plenty to show now that the Ghaggar / Saraswati was always a Siwalik fed river. Persisting with the glacial theory in light of this gathering evidence and pointing to scripture as a back-up will diminish the scientific credibility of the "early Aryan presence" supporters and perpetuate misinformation about the subject. I hope one of them stands up and admits that geological data does not support this particular theory.