Massive asteroid impact crater in Falklands linked with Great Dying mass extinction

Posted: May 7, 2017 by oldbrew in Geology, History, research, solar system dynamics

Credit: worldatlas.com


Something new for geologists to get their teeth into.

The Falkland Islands may be home to one of the world’s largest craters, reports the IB Times. A new analysis has revealed it has many characteristics of an asteroid impact and may date back to the ‘Great Dying’ extinction event.

About 200 similar large craters have been discovered so far on Earth but there are many other examples of them on other planets including on Venus, Mercury and Mars.

The Falkland Islands structure, which is described in detail in the journal Terra Nova, has a diameter measuring approximately 250 kilometres (150 miles). If it turns out to be an impact crater, this size would make it one of Earth’s largest – comparable to the famous Chicxulub crater discovered in the Yucatan Peninsula in Mexico nearly four decades ago.


Gravity and magnetism

In this research, the scientists have documented the geophysical features of a large basin situated on the Falkland (Malvinas) Plateau, to the northwest of West Falkland Island.

They have analysed marine seismic-reflection profiles of the area, and conducted gravity and magnetic surveys. Their investigations suggest that they are confronted with a large basin with traits consistent with those of impact craters caused by collisions with asteroids.

In particular, the researchers note a gravity anomaly, characterised by a decrease in the strength of Earth’s gravity over the site. This negative anomaly is surrounded by a ring-shaped positive gravity anomaly. These features are very similar to the one seen at the Chicxulub impact structure.

In contrast, there is an important increase in the strength of Earth’s magnetism in the basin’s vicinity – another characteristic of other large impact craters.

Continued here.

Comments
  1. Bloke down the pub says:

    Recent exploration for oil in the region has probably provided much of the new data for them to play with.

  2. craigm350 says:

    Reblogged this on CraigM350.

  3. tom0mason says:

    I wonder if the researcher could look south and consider the Drake Passage as a glancing blow from an asteroid (going from left to right) see http://topex.ucsd.edu/marine_topo/jpg_images/topo16.jpg

  4. ivan says:

    If I was wearing my SF authors hat I could make a good story that someone out there didn’t like what they saw in the Americas and opened up on them with a few well placed asteroids. Come to think of it maybe I will.

    Wearing my engineers hat I can’t help wondering where these asteroids came from. Was the earth in the path of a group of rocks displaced from the asteroid belt? It also begs the question, when was the asteroid belt formed?

  5. Adam Gallon says:

    The Asteroid Belt was formed around 4.6 Billion years ago. A planet’s formation was disrupted by perturbations from Jupiter’s gravitational field. Impact craters on Earth, are fairly well spread. http://www.lpi.usra.edu/publications/slidesets/craters/images/02_DISTRIBUTION_MAP.JPG

  6. oldbrew says:

    Jupiter created the Kirkwood Gaps.
    http://ssd.jpl.nasa.gov/?histo_a_ast

  7. Tim says:

    If we’re talking extinction scenarios what better than a cluster of asteroids – grape shot!

  8. ivan says:

    Adam, is there a way of dating those impact sites? I’m wondering if there is anything like clusters with X years between them.

  9. ralfellis says:

    Another interesting topographic anomaly there, is the semi-circular ridge that forms the South Sandwich islamds.

    https://www.google.co.uk/maps/place/South+Georgia+and+the+South+Sandwich+Islands/@-56.9799415,-30.7947959,5z/data=!3m1!1e3!4m2!3m1!1s0xb93db6e252a87925:0x7ee37cda884db0bd?hl=en-gb

    It looks like the S American plate (and Antarctic plate) have pushed past an old sea-floor plate, leaving a finger of sea-bed that looks like a massive crater. (Or a massive neolithic henge, with a circle of stones.). But I don’t think it is a crater.

    Ralph

  10. oldbrew says:

    Yes, interesting Ralph.

    The supposed crater is shown here [impact basin: red, Falklands: yellow]

    http://www.iflscience.com/environment/a-massive-impact-crater-may-be-hiding-near-the-falklands/

  11. ralfellis says:

    And this is the South Sandwich topographic anomaly, with the islands of the South Sandwich seemingly emulating the stones of some great southern henge.

    R

  12. ralfellis says:

    Or perhaps the Pacific Phallus penetrating the Atlantic Vagina.
    The circle of life on a sphere… 😉

    R

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