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Seminar Detail
The Great Mass Extinction - a Sudden Event or a Slow Moving Train-Wreck?
Presenter: Roger Summons (Department of Earth, Atmospheric and Planetary Sciences, MIT)
November 24, 2008 11:00 AM Pacific
A great mass extinction took place 252 million years ago when approximately 90% of the existing marine taxa were lost. Both the magnitude of the extinction and the slowness of the subsequent faunal radiation are enigmatic. The event is also known for the number and diversity of theories about its cause(s) including catastrophic volcanism, sudden climate change, overturn of stagnant oceans and bolide impact. Studies of molecular fossils confirm that the oceans were stagnant (euxinic) for some considerable period of time before and after the main biological turnover. Accordingly this event appears to be the culmination of particular paleo-oceanographic circumstances that happened on a geological timescale.
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The Director’s Seminar series features talks from scientists who are invited by the NAI Director to present their research results to the community. A primary goal of the seminars is to encourage interdisciplinary collaboration across NAI teams and within the astrobiology community at large.
Team Overview Seminars describe the work of the fourteen NAI teams and NAI Central. They offer an opportunity to find out more about the science, E/PO and other activities being performed by the NAI teams and the NAI Central office.
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