Burckle Crater
Burckle crater | |
---|---|
Location of Burckle Crater in the Indian Ocean | |
Impact crater/structure | |
Confidence | Probable[1] Hypothesized, contested |
Diameter | ~29 km (18 mi) |
Depth | 3,800 m (12,500 ft) |
Age | ~5000 years (Holocene) |
Exposed | No |
Drilled | No |
Bolide type | Unknown, possibly remains of a comet |
Location | |
Coordinates | 30°51′54″S 61°21′54″E / 30.865°S 61.365°E |
Burckle crater is an undersea feature about 29 kilometres (18 mi) in diameter,[2] in the southwestern Indian Ocean.
The Russian Academy of Sciences lists the feature as a potential impact crater.[1] The Holocene Impact Working Group (HIWG)[3] propose that it was formed by a very large-scale and relatively recent (c. 3000–2800 BCE) meteorite impact event, possibly resulting from a comet.
Description
The feature is located east of Madagascar and west of Western Australia in the southern Indian ocean, adjacent to the SW Indian Ocean Ridge.[4] Its position was determined in 2006 by the Holocene Impact Working Group using prehistoric chevron dune formations in Australia and Madagascar. Based on the hypothesis these dunes were formed by a megatsunami resulting from an impact, the researchers were able to triangulate the location of Burckle crater. The hypothesis that these chevron dunes were caused by a megatsunami has been challenged by geologists Jody Bourgeois and R. Weiss in 2009. Using a computer model to simulate a tsunami, they argue that the structures are more consistent with aeolian processes.[5] The tsunami origin of these chevrons is also disputed by other Earth scientists.[6]
Burckle crater is located at 30°51′54″S 61°21′54″E / 30.865°S 61.365°E in the Indian Ocean and is 3,800 metres (12,500 ft) below the surface.
Formation
Burckle crater has not yet been dated by radiometric analysis of its sediments. The Holocene Impact Working Group researchers think that it formed about 5,000 years ago (c. 3000–2800 BCE), during the Holocene epoch. They consider the possibility that a comet, or the remains of one, hit the ocean floor, with subsequent megatsunamis creating the dune formations which allowed the crater to be pin-pointed.
Unusual calcite (CaCO3) crystals, translucent carbon spherules, fragments of basaltic glass and native metals (native iron and nickel) are reported near the crater and associated with impact ejecta or hot water precipitates. Seawater at the depth of the crater is undersaturated with respect to calcite and rapid burial would have been needed to preserve those crystals.[4]
See also
- Fenambosy Chevron
- Flood myth
- List of possible impact structures on Earth
- Mahuika crater
- Umm al Binni structure
References
Bibliography
External links
- Anonymous (2009) Past Tsunamis? Contrary To Recent Hypothesis, 'Chevrons' Are Not Evidence Of Megatsunamis. ScienceDaily, April 30, 2009.
- Colvin, M. (2006) Researchers claim link between tsunamis and outer space." ABC News, Australia (Transcript of ABC interview with Ted Bryant) November 14, 2006.