Black Sea deluge hypothesis

Black Sea today (light blue) and in 7550 cal BP (dark blue) according to the hypothesis by Ryan and Pitman

In 1997, William Ryan, Walter Pitman and their colleagues first published the Black Sea deluge hypothesis. They proposed that a catastrophic inflow of Mediterranean seawater into the Black Sea freshwater lake occurred at 7150 ¹⁴C years BP (possibly around 7550 calendar years BP).[3] Before that date, glacial meltwater had turned the Black and Caspian Seas into vast freshwater lakes draining into the Aegean Sea. As glaciers retreated, some of the rivers emptying into the Black Sea declined in volume and changed course to drain into the North Sea. The levels of the lakes dropped through evaporation, while changes in worldwide hydrology caused overall sea level to rise.

The rising Mediterranean finally spilled over a rocky sill at the Bosporus. The event flooded 100,000 km² (39,000 sq mi) of land and significantly expanded the Black Sea shoreline to the north and west. According to these researchers, 50 km³ (10 cu mi) of water poured through each day, two hundred times the flow of Niagara Falls. The Bosporus valley roared and surged at full spate for at least three hundred days. They argued that the catastrophic inflow of seawater resulted from an abrupt sea-level jump that accompanied the Laurentide Ice Sheet collapse and the ensuing breach of a bedrock barrier in the Bosporus strait.

As proposed, the Early Holocene Black Sea flood scenario describes events that would have profoundly affected prehistoric settlement in eastern Europe and adjacent parts of Asia and possibly was the basis of oral history concerning Noah's flood.[3] Some archaeologists support this theory as an explanation for the lack of Neolithic sites in northern Turkey.[4][5][6] In 2003, Ryan and coauthors revised the dating of the early Holocene Noah's flood to 8400 ¹⁴C years BP (possibly around 8800 calendar years BP).[7]

Popular discussion of this Early Holocene Black Sea flood scenario was headlined in The New York Times in December 1996[8] and later published as a book.[9]

In addition to the early Holocene Noah’s Flood scenario proposed by William Ryan, Walter Pitman and their colleagues[3][7] and the Caspian Sea overflow scenario of Chepalyga,[10][11] the non-catastrophic progressive flood model (or gradual inflow model) has been proposed to explain the Late Quaternary sea level history of the Black Sea.[2][12] For the progressive flood model, it is argued that as early as 11,000 or 10,000 BP, the level of the Black Sea rose above the shallowest sill depth of about 30 m (98 ft) in the Bosporus Strait and spilled into the Marmara Sea. At least for the first 1,000 years, this connection was a one-way outflow of the Black Sea into a very shallow Marmara Sea. At about 8,000 BP, the level of the Marmara Sea rose high enough such that a two-way flow started. The evidence used to support this scenario includes the disparate ages of sapropel deposition in the eastern Mediterranean Sea and Black Sea; buried backstepping barrier islands observed on the Black Sea shelf; and a sub-aqueous delta composed of Black Sea sediments in the Marmara Sea near the Bosporus Strait.[13][14][15]

In 2003 and 2007, a more ancient catastrophic flood scenario was proposed by Andrei L. Chepalyga for the Late Quaternary sea level rise of the Black Sea.[1][2][10] The hypothesis for a Late Pleistocene Great Flood argues that brackish Neoeuxinian Lake, which occupied the Black Sea basin, was rapidly inundated by glacial meltwater overflow from the Caspian Sea via the Manych-Kerch Spillway shortly after the Late Glacial Maximum, about 17,000–14,000 BP. These extensive meltwater flooding events linked several lacustrine and marine water bodies, starting with the southern edge of the Scandinavian and southward, through spillways to the Manych-Kerch and Bosphorus, ultimately forming what has been referred to as the Cascade of Eurasian Basins.[11] This event is argued to have caused a rapid, if not catastrophic rise in the level of the Black Sea. It might have imposed substantial stresses upon contemporary human populations and remained in cultural memory as the Great Flood. The authors also suggested that the event might have stimulated the beginning of shipping and horse domestication.[1][11]

The Post-Glacial Sea Level.

The brief sensation caused by Ryan and Pitman has turned into an ongoing controversy. Critiques of the deluge hypothesis focus on the magnitude and pace of the water level rise. With enough moderation of these features, the catastrophe hypothesis is voided. However, a few key points should be noted:

• Since the ending of the last glacial period the global sea level has risen some 120 m (390 ft). The process took approximately 10,000 years and abated about 7,600 years ago.
• The flood hypothesis hinges on the geomorphology of the Bosphorus since the end of the glacial age.[16] The Black Sea area has been sealed off and reconnected numerous times during the last 500,000 years.[17]
• Various methods have been used to study and date (e.g., sea floor drillings, radiocarbon dating, biological markers) the recent evolution of the Black Sea. The heterogeneous data do not fit into a neat frame, which precludes the confirmation for a sharply defined event.

Opponents of the deluge hypothesis point to clues that water has been flowing out of the Black Sea basin as late as 15,000 years ago.[18] The local level must have been higher than the current-then-global level which had already risen from the last glacial minimum. In order to produce a Black Sea flooding such as the one described by Ryan and Pitman a solid obstruction of the Turkish Straits should have occurred. It must have had a significant height to allow for a rise on the south side, while to the north the water level should have been dropping. A notable point here is that the low lands in the Black Sea's basin would have already been flooded.

In this alternative scenario, much depends on the evolution of the Bosphorus. According to a study from 2001, the modern sill is 32–34 m (105–112 ft) below sea level and consists of Quaternary sand over-lying Paleozoic bedrock in which three sills are found at 80–85 m (260–280 ft) below sea level. Sedimentation on these sills started before 10,000 years ago and continued until 5,300 years ago.[19]

A large part of the academic geological community also continues to reject the idea that there could have been enough sustained long-term pressure by water from the Aegean to dig through a supposed isthmus at the present Bosphorus or enough of a difference in water levels (if at all) between the two water basins.[20]

In 2007, a research anthology on the topic was published which makes much of the earlier Russian research available in English for the first time and combines it with more recent scientific findings.[21]

According to a 2009 study by Liviu Giosan, Florin Filip, and Stefan Constatinescu,[22] the level in the Black Sea before the marine reconnection was 30 m (100 ft) below present sea level, rather than the 80 m (260 ft), or lower, of the catastrophe theories. If the flood occurred at all, the sea level increase and the flooded area during the reconnection were significantly smaller than previously proposed. Since the depth of the Bosphorus, in its middle furrow, at present varies from 36 to 124 m (118 to 407 ft), with an average depth of 65 m (213 ft), a calculated Stone Age shoreline in the Black Sea lying 30 m (100 ft) lower than in the present day would imply that the contact with the Mediterranean might never have been broken during the Holocene, and hence there could have been no sudden waterfall-style transgression.[22] An August 2009 article, based on this same study, reported that the flooding could have been "not so big".[23]

In 2011, a nice summary of this controversy was presented by Valentina Yanko-Hombah,[24] concluding that "there is no underwater archaeological evidence to support any catastrophic submergence of prehistoric Black Sea settlements during the Late Pleistocene or Early Holocene intervals".

A 2012 study based on process length variation of the dinoflagellate cyst Lingulodinium machaerophorum shows no evidence for catastrophic flooding.[25]

A 2015 study reviewed the evidence accumulated and acknowledged a "fast transgression" lasting between 10 and 200 years.[26]

• Black Sea undersea river – A current of particularly saline water flowing through the Bosphorus Strait and along the seabed of the Black Sea
• Altai flood – Prehistoric event in Central Asia
• Flood myth – Myth in which a great flood destroys civilization
• Noah's Ark – The vessel in the Genesis flood narrative
• 4.2 kiloyear event
• 5.9 kiloyear event
• 8.2 kiloyear event
• West Siberian Glacial Lake – A periglacial lake of the Weichselian Glaciation
• Zanclean flood – Theoretical refilling of the Mediterranean Sea between the Miocene and Pliocene Epochs, flooding of the Mediterranean

References

Sources

• Aksu, Ali E.; et al. (2002). "Persistent Holocene Outflow from the Black Sea to the Eastern Mediterranean Contradicts Noah's Flood Hypothesis". GSA Today. 12 (5): 4–10. doi:10.1130/1052-5173(2002)012<0004:PHOFTB>2.0.CO;2.
• Sperling, M.; Schmiedl, G.; Hemleben, C.; Emeis, K. C.; Erlenkeuser, H.; Grootes, P. M. (2003). "Black Sea impact on the formation of eastern Mediterranean sapropel S1? Evidence from the Marmara Sea". Palaeogeography, Palaeoclimatology, Palaeoecology. 190: 9–21. Bibcode:2003PPP...190....9S. doi:10.1016/s0031-0182(02)00596-5.
• Gökaşan, E.; Algan, O.; Tur, H.; Meriç, E.; Türker, A.; Şimşek, M. (2005). "Delta formation at the southern entrance of Istanbul Strait (Marmara sea, Turkey): a new interpretation based on high-resolution seismic stratigraphy". Geo-Marine Letters. 25 (6): 370–377. Bibcode:2005GML....25..370G. doi:10.1007/s00367-005-0215-4. S2CID 130792746.
• Eris, K.; Ryan, W. B. F.; Cagatay, N.; Sancar, Ü.; Lericolais, G.; Menot, G.; Bard, E. (2008). "The timing and evolution of the post-glacial transgression across the Sea of Marmara shelf south of İstanbul" (PDF). Marine Geology. 243 (1–4): 57–76. doi:10.1016/j.margeo.2007.04.010.
• Dimitrov, Petko.; Dimitrov, Dimitar. 2004. The Black Sea, the flood, and the ancient myths. Varna (Bulgaria): Slavena.
• Keith, M.L.; Anderson, G.M. (1963). "Radiocarbon Dating: Fictitious Results with Mollusk Shells". Science. 141 (3581): 634–637. Bibcode:1963Sci...141..634K. doi:10.1126/science.141.3581.634. PMID 17781758. S2CID 24213036.
• National Geographic News. 2009-02-06. "Noah's Flood" Not Rooted in Reality, After All?
• Nature. 2004 August 12. Noah's Flood. 430: 718–19
• Ryan, W.B.F.; Pitman III, W.C.; et al. (1997). "An abrupt drowning of the Black Sea shelf" (PDF). Marine Geology. 138 (1–2): 119–126. Bibcode:1997MGeol.138..119R. CiteSeerX 10.1.1.598.2866. doi:10.1016/s0025-3227(97)00007-8. Archived from the original (PDF) on 2016-03-04. Retrieved 2014-12-23.
• Yanko-Hombach, Valentina. 2007. The Black Sea Flood Question: Changes in Coastline, Climate and Human Settlement. Springer ISBN 1-4020-4774-6.
• Chepalyga A.L. The late glacial Great Flood in the Ponto-Caspian basin. In: The Black Sea Flood question: changes in coastline, climate and human settlement. Springer. 2006. pp. 119–148

• Giosan, Liviu; et al. (2009). "Was the Black Sea catastrophically flooded in the early Holocene?". Quaternary Science Reviews. 28 (12–2): 1–6. Bibcode:2009QSRv...28....1G. doi:10.1016/j.quascirev.2008.10.012.
  This article (possibly not identical to the preceding citation) is available online with unrestricted access here at the sponsoring institution's website.
• Noah's Not-so-big Flood
• Lericolais, G.; et al. (2009). "High frequency sea level fluctuations recorded in the Black Sea since the LGM". Global and Planetary Change. 66 (1–2): 65–75. Bibcode:2009GPC....66...65L. doi:10.1016/j.gloplacha.2008.03.010.
• "Ballard and the Black Sea"
• Ryan, William B.; Pitman, Walter C. (2000), Noah's Flood: The new scientific discoveries about the event that changed history, Simon & Schuster, ISBN 978-0-684-85920-0

• Dimitrov, D. 2010. Geology and Non-traditional resources of the Black Sea. LAP Lambert Academic Publishing. ISBN 978-3-8383-8639-3. 244p.
• The late glacial Great Flood in the Ponto-Caspian basin
• Yanko-Hombach, Valentina (December 8, 2006), Allan S. Gilbert, Nicolae Panin and Pavel M. Dolukhanov (ed.), The Black Sea Flood Question, Springer, p. 999, ISBN 978-1-4020-4774-9
• Shopov Y. Y., Т. Yalamov, P. Dimitrov, D. Dimitrov and B. Shkodrov (2009b) Initiation of the Migration of Vedic Aryans to India by a Catastrophic Flooding of the Black Sea by Mediterranean Sea during the Holocene." Extended Abstracts of LIMPACS-3 International Conference of IGBP, PAGES, 5–8 March 2009, Chandigarh, India, pp.126–127.