Umm al Binni lake is a mostly dry

lake A lake is an area filled with water, localized in a basin, surrounded by land, and distinct from any river or other outlet that serves to feed or drain the lake. Lakes lie on land and are not part of the ocean, although, like the much large ...

within the Central Marshes in

Maysan Governorate , image_map = Maysan in Iraq.svg , mapsize = 200px , settlement_type = Governorate , subdivision_type = Country , subdivision_name = , subdivision_t ...

in southern

Iraq Iraq,; ku, عێراق, translit=Êraq officially the Republic of Iraq, '; ku, کۆماری عێراق, translit=Komarî Êraq is a country in Western Asia. It is bordered by Turkey to Iraq–Turkey border, the north, Iran to Iran–Iraq ...

. The wide lake is approximately northwest of the

Tigris The Tigris () is the easternmost of the two great rivers that define Mesopotamia, the other being the Euphrates. The river flows south from the mountains of the Armenian Highlands through the Syrian and Arabian Deserts, and empties into the ...

–

Euphrates The Euphrates () is the longest and one of the most historically important rivers of Western Asia. Tigris–Euphrates river system, Together with the Tigris, it is one of the two defining rivers of Mesopotamia ( ''the land between the rivers'') ...

confluence. Because of its shape, location, and other details, it was first conjectured by Sharad Master, a

geoarchaeologist Geoarchaeology is a multi-disciplinary approach which uses the techniques and subject matter of geography, geology, geophysics and other Earth sciences to examine topics which inform archaeological knowledge and thought. Geoarchaeologists study ...

, to represent an

impact crater An impact crater is a circular depression in the surface of a solid astronomical object formed by the hypervelocity impact of a smaller object. In contrast to volcanic craters, which result from explosion or internal collapse, impact craters ...

. However, these claims have been disputed, with other studies finding

subsidence Subsidence is a general term for downward vertical movement of the Earth's surface, which can be caused by both natural processes and human activities. Subsidence involves little or no horizontal movement, which distinguishes it from slope move ...

of the underlying rock a more plausible explanation.

Evidence as an impact crater

Based on the interpretation of

satellite imagery Satellite images (also Earth observation imagery, spaceborne photography, or simply satellite photo) are images of Earth collected by imaging satellites operated by governments and businesses around the world. Satellite imaging companies sell ima ...

, Sharad Master suggests the in diameter dry lake may be an

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 In geology, a fault is a planar fracture or discontinuity in a volume of rock across which there has been significant displacement as a result of rock-mass movements. Large faults within Earth's crust result from the action of plate tectonic ...

. As to its origin, Masters rejects

karst topography Karst is a topography formed from the dissolution of soluble rocks such as limestone, dolomite, and gypsum. It is characterized by underground drainage systems with sinkholes and caves. It has also been documented for more weathering-resistant ro ...

, 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

of the underlying

basement A basement or cellar is one or more floors of a building that are completely or partly below the ground floor. It generally is used as a utility space for a building, where such items as the furnace, water heater, breaker panel or fuse box, ...

fault block Fault blocks are very large blocks of rock, sometimes hundreds of kilometres in extent, created by tectonic and localized stresses in Earth's crust. Large areas of bedrock are broken up into blocks by faults. Blocks are characterized by rela ...

s, and that the southern part of the rim had been anthropogenically shaped.

Details and historical context

Master estimates the age of the crater to be less than 5000 years old, or between 2000 and 3000 BC, due to the deposition of sediments of the Tigris-Euphrates plain as a result of the seaward

progradation In sedimentary geology and geomorphology, the term progradation refers to the growth of a river delta farther out into the sea over time. This occurs when the volume of incoming sediment is greater than the volume of the delta that is lost through ...

of the

Persian Gulf The Persian Gulf ( fa, خلیج فارس, translit=xalij-e fârs, lit=Gulf of Persis, Fars, ), sometimes called the ( ar, اَلْخَلِيْجُ ٱلْعَرَبِيُّ, Al-Khalīj al-ˁArabī), is a Mediterranean sea (oceanography), me ...

during that time period. Some relate this apparent impact site to the 2350 BC Middle East Anomaly.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 A lack of writings describing this event by well-known authors like

Herodotus Herodotus ( ; grc, , }; BC) was an ancient Greek historian and geographer from the Greek city of Halicarnassus, part of the Persian Empire (now Bodrum, Turkey) and a later citizen of Thurii in modern Calabria ( Italy). He is known f ...

(484–425 BC) and

Nearchus Nearchus or Nearchos ( el, Νέαρχος; – 300 BC) was one of the Greek officers, a navarch, in the army of Alexander the Great. He is known for his celebrated expeditionary voyage starting from the Indus River, through the Persian Gulf and e ...

(360–300 BC) or later historians implies the impact may have occurred much earlier, between 2000 and 3000 BC.

Climate change and impact effects

It has been proposed that sudden climate changes and catastrophic events around 2200 BCE (including the collapse of the

Sumer Sumer () is the earliest known civilization in the historical region of southern Mesopotamia (south-central Iraq), emerging during the Chalcolithic and early Bronze Ages between the sixth and fifth millennium BC. It is one of the cradles of c ...

ian civilisation) could be linked to a

comet A comet is an icy, small Solar System body that, when passing close to the Sun, warms and begins to release gases, a process that is called outgassing. This produces a visible atmosphere or coma, and sometimes also a tail. These phenomena ar ...

asteroid An asteroid is a minor planet of the inner Solar System. Sizes and shapes of asteroids vary significantly, ranging from 1-meter rocks to a dwarf planet almost 1000 km in diameter; they are rocky, metallic or icy bodies with no atmosphere. ...

impact. Master 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., Shoemaker, Glasstone & Dolan and others, Hamacher determined that an impacting bolide would have produced energy in the range of 190 to 750

megatons TNT equivalent is a convention for expressing energy, typically used to describe the energy released in an explosion. The is a unit of energy defined by that convention to be , which is the approximate energy released in the detonation of a m ...

of TNT (for an

and

impact, respectively). For comparison, the

Tunguska event The Tunguska event (occasionally also called the Tunguska incident) was an approximately 12-megaton explosion that occurred near the Podkamennaya Tunguska River in Yeniseysk Governorate (now Krasnoyarsk Krai), Russia, on the morning of June 30, ...

was estimated to have an explosive force of about 10-15 megatons.

References

{{reflist, 30em, refs= Bjorkman, J.K., (1973) Meteors and Meteorites in the Ancient Near East, Meteoritics 8(2): 91 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 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 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 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 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 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 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 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 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 Peiser, B. (1997) Comets and Disaster in the Bronze Age, British Archaeology 30: 6-7 {{Cite journal, last=Sissakian, first=Varoujan K., last2=Al-Bahadily, first2=Hayder A., date=November 2018, title=The geological origin of the Umm Al-Binni Lake within the Ahwar of Southern Mesopotamia, Iraq, url=http://link.springer.com/10.1007/s12517-018-4004-6, journal=Arabian Journal of Geosciences, language=en, volume=11, issue=21, pages=669, doi=10.1007/s12517-018-4004-6, issn=1866-7511 Shoemaker, E.M. (1983) Asteroid and comet bombardment of the Earth, Annual Review of Earth and Planetary Sciences 1(1): 461-494 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

External links

Google Earth view (taken when the lake was completely dry)
Lakes of Iraq Holocene impact craters Possible impact craters on Earth

Evidence as an impact crater

Details and historical context

Climate change and impact effects

See also

References

External links