Short Sharp Science: Asteroid strike may have frozen Antarctica
A massive asteroid hit the Timor Sea around 35 million years ago - and the impact apparently contributed to the formation of the Antarctic ice sheets.
So says Andrew Glikson, a specialist in the study of extraterrestrial impacts, from the Planetary Science Institute at the Australian National University in Canberra, who analysed a dome found 2.5 kilometres below the Timor Sea, about 300 kilometres off Australia's north west coast.
Based on the structure of the dome, called Mount Ashmore, there were two obvious explanations for its formation: from a mud volcano or from the movement of tectonic plates.
But using a barrage of tests including scanning electron microscopy and seismic surveys, as well as chemical analysis of the rocks, Glikson concluded that the dome was the result of an asteroid crashing into the Earth at such speeds that it caused the Earth's crust to rebound (Australian Journal of Earth Sciences, DOI: 10.1080/08120099.2010.481327).
Images from scanning electron microscopy showed that the cracks and pulverised rocks throughout the dome were unlike those seen in tectonic plate movements.
A massive asteroid hit the Timor Sea around 35 million years ago - and the impact apparently contributed to the formation of the Antarctic ice sheets.
So says Andrew Glikson, a specialist in the study of extraterrestrial impacts, from the Planetary Science Institute at the Australian National University in Canberra, who analysed a dome found 2.5 kilometres below the Timor Sea, about 300 kilometres off Australia's north west coast.
Based on the structure of the dome, called Mount Ashmore, there were two obvious explanations for its formation: from a mud volcano or from the movement of tectonic plates.
But using a barrage of tests including scanning electron microscopy and seismic surveys, as well as chemical analysis of the rocks, Glikson concluded that the dome was the result of an asteroid crashing into the Earth at such speeds that it caused the Earth's crust to rebound (Australian Journal of Earth Sciences, DOI: 10.1080/08120099.2010.481327).
Images from scanning electron microscopy showed that the cracks and pulverised rocks throughout the dome were unlike those seen in tectonic plate movements.
Posts
No comments:
Post a Comment