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 email@example.com
Dr. Mike Branney | EurekAlert!
World’s oldest known oxygen oasis discovered
18.01.2018 | Eberhard Karls Universität Tübingen
A close-up look at an uncommon underwater eruption
11.01.2018 | Woods Hole Oceanographic Institution
On the way to an intelligent laboratory, physicists from Innsbruck and Vienna present an artificial agent that autonomously designs quantum experiments. In initial experiments, the system has independently (re)discovered experimental techniques that are nowadays standard in modern quantum optical laboratories. This shows how machines could play a more creative role in research in the future.
We carry smartphones in our pockets, the streets are dotted with semi-autonomous cars, but in the research laboratory experiments are still being designed by...
What enables electrons to be transferred swiftly, for example during photosynthesis? An interdisciplinary team of researchers has worked out the details of how...
For the first time, scientists have precisely measured the effective electrical charge of a single molecule in solution. This fundamental insight of an SNSF Professor could also pave the way for future medical diagnostics.
Electrical charge is one of the key properties that allows molecules to interact. Life itself depends on this phenomenon: many biological processes involve...
At the JEC World Composite Show in Paris in March 2018, the Fraunhofer Institute for Laser Technology ILT will be focusing on the latest trends and innovations in laser machining of composites. Among other things, researchers at the booth shared with the Aachen Center for Integrative Lightweight Production (AZL) will demonstrate how lasers can be used for joining, structuring, cutting and drilling composite materials.
No other industry has attracted as much public attention to composite materials as the automotive industry, which along with the aerospace industry is a driver...
Scientists at Tokyo Institute of Technology (Tokyo Tech) and Tohoku University have developed high-quality GFO epitaxial films and systematically investigated their ferroelectric and ferromagnetic properties. They also demonstrated the room-temperature magnetocapacitance effects of these GFO thin films.
Multiferroic materials show magnetically driven ferroelectricity. They are attracting increasing attention because of their fascinating properties such as...
08.01.2018 | Event News
11.12.2017 | Event News
08.12.2017 | Event News
19.01.2018 | Materials Sciences
19.01.2018 | Health and Medicine
19.01.2018 | Physics and Astronomy