Volcanologists from the Universities of Leicester and Durham have forensically reconstructed the impact of a meteorite on Earth and how debris was hurled from the crater to devastate the surrounding region.
New research by Mike Branney, of the University of Leicester's Department of Geology, and Richard Brown, University of Durham, shows that some aspects of giant meteorite impacts onto Earth may mimic the behaviour of large volcanic eruptions.
Meteorite impacts are more common than is popularly appreciated – but what happens when the meteorite hits? Direct observation is understandably difficult, but researchers pick through impact debris that has been spared the ravages of erosion, to forensically reconstruct the catastrophic events.
Mike Branney and Richard Brown analysed an ejecta layer derived from the impact of a huge meteorite and discovered that much of the ejected debris moved across the ground as rapid, dense, ground-hugging currents of gas and debris, remarkably similar to the awesome pyroclastic density currents that flow radially outwards from explosive volcanoes.
Dr Branney said: "In particular, the way that ash and dust stick together seems identical. Moist ash from explosive volcanoes sticks together in the atmosphere to fall out as mm-sized pellets. Where these drop back into a hot pyroclastic density current, they grow into larger layered structures, known as accretionary lapilli."
The researchers studied a finely preserved deposit in northwest Scotland from a huge impact that occurred a billion years ago. It shows both types of these 'volcanic' particles - pellets and lapilli - are produced.
Dr Brown added: "This reveals that that the 10 meter-thick layer, which has been traced for over 50 km along the Scottish coast, was almost entirely emplaced as a devastating density current that sped outwards from the point of impact - just like a density current from a volcano. Only the uppermost few centimetres actually fell out through the atmosphere. "
The Leicester and Durham scientists say that an improved understanding of what happens when large objects hits the Earth will help us understand how these catastrophic events may have affected life on the planet in the past ...and possibly in the future.
Note to editors
Publication: Branney, M.J. & Brown, R.J. 2011. Impactoclastic density current emplacement of terrestrial meteorite-impact ejecta and the formation of dust pellets and accretionary lapilli: evidence from Stac Fada, Scotland. Journal of Geology 119, 275-292.
Contact: Dr. Mike Branney, Department of Geology, University of Leicester. E-mail firstname.lastname@example.org
Dr. Mike Branney | EurekAlert!
Volcanoes and glaciers combine as powerful methane producers
20.11.2018 | Lancaster University
Massive impact crater from a kilometer-wide iron meteorite discovered in Greenland
15.11.2018 | Faculty of Science - University of Copenhagen
Innsbruck quantum physicists have constructed a diode for magnetic fields and then tested it in the laboratory. The device, developed by the research groups led by the theorist Oriol Romero-Isart and the experimental physicist Gerhard Kirchmair, could open up a number of new applications.
Electric diodes are essential electronic components that conduct electricity in one direction but prevent conduction in the opposite one. They are found at the...
Max Planck researchers revel the nano-structure of molecular trains and the reason for smooth transport in cellular antennas.
Moving around, sensing the extracellular environment, and signaling to other cells are important for a cell to function properly. Responsible for those tasks...
Researchers at the University of New Hampshire have captured a difficult-to-view singular event involving "magnetic reconnection"--the process by which sparse particles and energy around Earth collide producing a quick but mighty explosion--in the Earth's magnetotail, the magnetic environment that trails behind the planet.
Magnetic reconnection has remained a bit of a mystery to scientists. They know it exists and have documented the effects that the energy explosions can...
Biochips have been developed at TU Wien (Vienna), on which tissue can be produced and examined. This allows supplying the tissue with different substances in a very controlled way.
Cultivating human cells in the Petri dish is not a big challenge today. Producing artificial tissue, however, permeated by fine blood vessels, is a much more...
Faster and secure data communication: This is the goal of a new joint project involving physicists from the University of Würzburg. The German Federal Ministry of Education and Research funds the project with 14.8 million euro.
In our digital world data security and secure communication are becoming more and more important. Quantum communication is a promising approach to achieve...
19.11.2018 | Event News
09.11.2018 | Event News
06.11.2018 | Event News
21.11.2018 | Life Sciences
21.11.2018 | Power and Electrical Engineering
21.11.2018 | Life Sciences