Burckle Crater
Encyclopedia
Holocene Impact Working Group
The Holocene Impact Working Group is a group of scientists from Australia, France, Ireland, Russia and the USA who hypothesize that meteorite impacts on Earth are more common than previously supposed....
. They considered that it likely was formed by a very large scale and relatively recent (c. 2800-3000 BC) comet
Comet
A comet is an icy small Solar System body that, when close enough to the Sun, displays a visible coma and sometimes also a tail. These phenomena are both due to the effects of solar radiation and the solar wind upon the nucleus of the comet...
or meteorite
Meteorite
A meteorite is a natural object originating in outer space that survives impact with the Earth's surface. Meteorites can be big or small. Most meteorites derive from small astronomical objects called meteoroids, but they are also sometimes produced by impacts of asteroids...
impact event
Impact event
An impact event is the collision of a large meteorite, asteroid, comet, or other celestial object with the Earth or another planet. Throughout recorded history, hundreds of minor impact events have been reported, with some occurrences causing deaths, injuries, property damage or other significant...
. It is estimated to be about 30 km (18 mi) in diameter , hence about 25 times larger than Meteor Crater
Meteor Crater
Meteor Crater is a meteorite impact crater located approximately east of Flagstaff, near Winslow in the northern Arizona desert of the United States. Because the US Department of the Interior Division of Names commonly recognizes names of natural features derived from the nearest post office, the...
.
Its proposed location is to the east of Madagascar
Madagascar
The Republic of Madagascar is an island country located in the Indian Ocean off the southeastern coast of Africa...
and west of Western Australia
Western Australia
Western Australia is a state of Australia, occupying the entire western third of the Australian continent. It is bounded by the Indian Ocean to the north and west, the Great Australian Bight and Indian Ocean to the south, the Northern Territory to the north-east and South Australia to the south-east...
in the southern Indian ocean
Indian Ocean
The Indian Ocean is the third largest of the world's oceanic divisions, covering approximately 20% of the water on the Earth's surface. It is bounded on the north by the Indian Subcontinent and Arabian Peninsula ; on the west by eastern Africa; on the east by Indochina, the Sunda Islands, and...
. Its position was determined in 2006 by the same group using evidence of its existence from prehistoric chevron
Chevron (land form)
A chevron is a wedge-shaped sediment deposit observed on coastlines and continental interiors around the world. The term chevron was originally used independently by Maxwell and Haynes and Hearty and others for large, v-shaped, sub-linear to parabolic landforms in southwestern Egypt and on islands...
dune
Dune
In physical geography, a dune is a hill of sand built by wind. Dunes occur in different forms and sizes, formed by interaction with the wind. Most kinds of dunes are longer on the windward side where the sand is pushed up the dune and have a shorter "slip face" in the lee of the wind...
formations in Australia and Madagascar that allowed them to triangulate
Triangulation
In trigonometry and geometry, triangulation is the process of determining the location of a point by measuring angles to it from known points at either end of a fixed baseline, rather than measuring distances to the point directly...
its location. But the theory that these chevron dunes are due to tsunamis has been challenged by geologist Jody Bourgeois; using a computer model to simulate a tsunami, she believes the structures are more consistent with aeolian processes.
Burckle Crater lies at 30.865°S 61.365°E in the Indian Ocean and is 12,500 feet (3,800 m) below the surface.
Formation
Burckle Crater has not yet been dated by radiometric analysis of its sediments. The Holocene Impact Working Group think that it was created about 5,000 years ago (c. 2800–3000 BC) during the HoloceneHolocene
The Holocene is a geological epoch which began at the end of the Pleistocene and continues to the present. The Holocene is part of the Quaternary period. Its name comes from the Greek words and , meaning "entirely recent"...
epoch
Epoch (geology)
An epoch is a subdivision of the geologic timescale based on rock layering. In order, the higher subdivisions are periods, eras and eons. We are currently living in the Holocene epoch...
when a comet impacted in the ocean, and that enormous megatsunami
Megatsunami
Megatsunami is an informal term to describe a tsunami that has initial wave heights that are much larger than normal tsunamis...
s created the dune formations which later allowed the crater to be pin-pointed.
- Unusual carbonate (CaCO3) crystals, translucent carbon spherules, fragments of mineral glass and native metals are reported in near the crater and associated with impact ejecta or hot water precipitates form crater ridges and vents.
See also
- SpaceguardSpaceguardThe term Spaceguard loosely refers to a number of efforts to discover and study near-Earth objects . Asteroids are discovered by telescopes which repeatedly survey large areas of sky. Efforts which concentrate on discovering NEOs are considered part of the "Spaceguard Survey," regardless of which...
- B612 FoundationB612 FoundationThe B612 Foundation is a private foundation dedicated to protecting the Earth from asteroid strikes. Their immediate goal is to "significantly alter the orbit of an asteroid in a controlled manner by 2015"....
- Torino scaleTorino ScaleThe Torino Scale is a method for categorizing the impact hazard associated with near-Earth objects such as asteroids and comets.It is intended as a communication tool for astronomers and the public to assess the seriousness of collision predictions, by combining probability statistics and known...
- Fenambosy ChevronFenambosy ChevronThe Fenambosy Chevron is one of four chevron-shaped land features on the southwest coast of Madagascar, near the tip of Madagascar, 180 metres high and 5 km inland. It is composed mainly of material found on the ocean. Chevrons such as Fenambosy have been hypothesized as providing evidence of...
- Impact eventImpact eventAn impact event is the collision of a large meteorite, asteroid, comet, or other celestial object with the Earth or another planet. Throughout recorded history, hundreds of minor impact events have been reported, with some occurrences causing deaths, injuries, property damage or other significant...
External links
- Meteor 'misfits' find proof in sea Impacts more recent and often, researchers say
- Impact Craters as Sources of Megatsunami Generated Chevron Dunes
- Transcript of ABC interview with Ted Bryant
- Chevron-shaped Accumulations Along the Coastlines of Australia as Potential Tsunami Evidences? Science of Tsunami Hazards (2003), Vol. 21, #3, p 174.