Wikipedia

Umm al Binni lake

Umm al Binni lake is a mostly dry lake within the Central Marshes in Maysan Governorate in southern Iraq. The 3.4 km (2.1 mi) wide lake is approximately 45 km (28 mi) northwest of the Tigris–Euphrates confluence. Because of its shape, location, and other details, it was first conjectured by Sharad Master, a geoarchaeologist, to represent an impact crater.[1][2] However, these claims have been disputed, with other studies finding subsidence of the underlying rock a more plausible explanation.[3]

Umm al Binni Lake
Location of Umm al Binni lake in Iraq.
Location of Umm al Binni lake in Iraq.
Umm al Binni Lake
LocationMaysan Governorate
Coordinates31°14′29″N 47°06′21″E / 31.24139°N 47.10583°E / 31.24139; 47.10583
Lake typeformer lake
Basin countriesIraq
Max. length3.4 km (2.1 mi)
Max. depth3 m (9.8 ft)

Evidence as an impact crater edit

Based on the interpretation of satellite imagery, Sharad Master suggests[4][5] the 3.4 km (2.1 mi) in diameter dry lake may be an impact crater based on its nearly circular, slightly polygonal rim shape, and contrasting shape to other lakes in the region. However, the circularity of its shape has been disputed, with a 2018 study finding that the northeastern and southwestern sections of the lake rim were straight, corresponding to the directions of regional faulting.[3] As to its origin, Masters rejects karst topography, salt doming, tectonic deformation, and igneous intrusion as well as possible bombing or man-made origins. However, a 2018 study concluded that the formation of the lake could be better explained by the subsidence of the underlying basement fault blocks, and that the southern part of the rim had been anthropogenically shaped.[3]

Details and historical context edit

Master estimates the age of the crater to be less than 5000 years old, or between 2000 and 3000 BC,[2] due to the deposition of sediments of the Tigris-Euphrates plain as a result of the 130–150 km (81–93 mi) seaward progradation[6] of the Persian Gulf during that time period.[4][5] Some relate this apparent impact site to the 2350 BC Middle East Anomaly.[7] A lack of writings describing this event by well-known authors like Herodotus (484–425 BC) and Nearchus (360–300 BC) or later historians implies the impact may have occurred much earlier, between 2000 and 3000 BC.[5]

Climate change and impact effects edit

It has been proposed that sudden climate changes and catastrophic events around 2200 BCE (including the collapse of the Sumerian civilisation) could be linked to a comet or asteroid impact.[5][7][8][9][10][11] Master[4][5] has conjectured that the alleged Umm al Binni impact could be responsible for this catastrophe, producing the energy equivalent to thousands of Hiroshima-sized bombs.

Using equations describing impact effects based on work from Collins et al.,[12] Shoemaker,[13] Glasstone & Dolan[14] and others, Hamacher[15] determined that an impacting bolide would have produced energy in the range of 190 to 750 megatons of TNT (for an asteroid and comet impact, respectively). For comparison, the Tunguska event was estimated to have an explosive force of about 10-15 megatons.

See also edit

References edit

  1. ^ Master, S. (2001) A Possible Holocene Impact Structure in the Al Amarah Marshes, Near the Tigris-Euphrates Confluence, Southern Iraq, Meteoritics & Planetary Science 36: A124
  2. ^ a b Master, S. (2002) Umm al Binni lake, a possible Holocene impact structure in the marshes of southern Iraq: Geological evidence for its age, and implications for Bronze-age Mesopotamia. In: Leroy, S. and Stewart, I.S. (Eds.), Environmental Catastrophes and Recovery in the Holocene, Abstracts Volume, Department of Geography, Brunel University, Uxbridge, West London, UK, 29 August - 2 September 2002, pp. 56–57
  3. ^ a b c Sissakian, Varoujan K.; Al-Bahadily, Hayder A. (November 2018). "The geological origin of the Umm Al-Binni Lake within the Ahwar of Southern Mesopotamia, Iraq". Arabian Journal of Geosciences. 11 (21): 669. doi:10.1007/s12517-018-4004-6. ISSN 1866-7511. S2CID 135022453.
  4. ^ a b c Master, S. and Woldai, T., (2004) The Umm al Binni structure in the Mesopotamian marshlands of southern Iraq, as a postulated late Holocene meteorite impact crater, Economic Geology Research Institute Information Circular, October 2004, University of Witwatersrand - Johannesburg
  5. ^ a b c d e Master, S. and Woldai, T., (2007) Umm al Binni structure, southern, as a postulated late Holocene meteorite impact crater: new satellite imagery, and proposals for future research. In: Bobrowsky, P. and Rickmann, H. (Eds.), Comet/Asteroid Impacts and Human Society, Springer-Verlag, Heidelberg
  6. ^ Larsen, C.E. and Evans, G. (Brice W.C. Ed.), (1978) The Holocene Geological History of the Tigris-Euphrates-Karun Delta in The Environmental History of the Near and Middle East Since the Last Ice Age. Academic Press, London. pp. 227–244
  7. ^ a b Courty M-A (1998) Causes and effects of the 2350 BC Middle East Anomaly evidenced by micro-debris fallout, surface combustion and soil explosion. In: Peiser BJ, Palmer T, Bailey ME (eds) Natural catastrophes during Bronze Age civilisations: archaeological, geological, astronomical and cultural Perspectives. British Archaeol Reports S728, Archaeopress, Oxford
  8. ^ Bjorkman, J.K., (1973) Meteors and Meteorites in the Ancient Near East, Meteoritics 8(2): 91
  9. ^ Weiss, H., Courty, M.-A., Wetterstrom, W., Guichard, F., Senior, L., Meadow, R. and Curnow, A. (1993) The genesis and collapse of Third Millennium North Mesopotamian civilization, Science 261, pp. 995–1004
  10. ^ Peiser, B. (1997) Comets and Disaster in the Bronze Age, British Archaeology 30: 6-7
  11. ^ Napier, W., (1997) Cometary Catastrophes, Cosmic Dust and Ecological Disasters in Historical Times: The Astronomical Framework, Society for Interdisciplinary Studies Conference: Natural Catastrophes during Bronze Age Civilizations, July 11–13, 1997 in Cambridge, UK
  12. ^ Collins, G. S.; Melosh, H. J.; Marcus, R. A. (2005) Earth Impact Effects Program: A Web-based computer program for calculating the regional environmental consequences of a meteoroid impact on Earth, Meteoritics & Planetary Science 40: 817
  13. ^ Shoemaker, E.M. (1983) Asteroid and comet bombardment of the Earth, Annual Review of Earth and Planetary Sciences 1(1): 461-494
  14. ^ Glasstone, S. and Dolan, P. J., (1977) Effects of Nuclear Weapons 3rd Edition, Washington D.C.: United States, Department of Defense and Department of Energy
  15. ^ Hamacher, D.W. (2005), The Umm Al Binni Structure and Bronze Age Catastrophes, The Artifact: Publications of the El Paso Archaeological Society, vol 43, pp 115–138

External links edit

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