herpguy Posted June 5, 2006 Posted June 5, 2006 What caused the largest extinction ever on Earth, and what created the continent of Australia? Scientists say Australia may be the result of a large meteor that crashed into Antarctica. Gravity measures show that the crater, which is 483 kilometers wide and hidden 1.6 kilometers below the East Antarctic Ice Sheet, dates back to about 250 million years ago. That's also around the time of one of Earth's several mass extinctions. "Its size and location -- in the Wilkes Land region of East Antarctica, south of Australia -- also suggest that it could have begun the breakup of the Gondwana supercontinent by creating the tectonic rift that pushed Australia northward," the scientists say. http://news.yahoo.com/s/afp/20060602/sc_afp/ussciencemeteor;_ylt=AgJ_ZVBMSx_plllx3o5uMj0PLBIF;_ylu=X3oDMTA0cDJlYmhvBHNlYwM-
herpguy Posted June 5, 2006 Author Posted June 5, 2006 See also (provided by Martin): http://www.newscientistspace.com/article.ns?id=dn9268&feedId=space_rss20 http://researchnews.osu.edu/archive/erthboompix.htm http://researchnews.osu.edu/archive/erthboom.htm
ecoli Posted June 5, 2006 Posted June 5, 2006 I don't really understand how a meteor could have caused a tectonic rift... aren't those crustal plates lying on the mantle? How could a meteor break up a plate?
Dr. Dalek Posted June 5, 2006 Posted June 5, 2006 I don't really understand how a meteor could have caused a tectonic rift... aren't those crustal plates lying on the mantle? How could a meteor break up a plate? Hit with the right force in the right place, Krack!!!!!!!!!!!! sempre ubi sub ubi: Always wear under wear! I learned that in Latin I
Martin Posted June 6, 2006 Posted June 6, 2006 Hit with the right force in the right place' date=' Krack!!!!!!!!!!!! sempre ubi sub ubi: Always wear under wear! I learned that in Latin I[/quote'] SEMPER dammit sempre is not a Latin word, you should know that Dalek!
Martin Posted June 6, 2006 Posted June 6, 2006 Great story herpguy. check out what Wikipedia says about the extinction at the end of the Permian http://en.wikipedia.org/wiki/Permian-Triassic_extinction they have a bar graph showing all the major known extinction events in Earth history=====the P-T event is way biggest also you remember the controversy about the 65 million BP dinosaur extinction? Vincent Courtillot a French geophysicist said it was due to the volcanic eruption at the DECCAN TRAPS in India which happened about the same time and is on the opposite side of the earth from the gulf of mexico where the bolide hit. An even bigger volcanic province is the SIBERIAN TRAPS. It is the biggest lava-flow provence anywhere. it is bigger than the Deccan Traps. Apparently "traps" in geology means a huge region of basalt made by outpouring lava. So there were already people discussing the possibility that a bolide impact might TRIGGER a massive antipodal volcanic action on the OPPOSITE SIDE OF THE BALL. there was already some speculation about this for several years. You could almost have known to look in Antarctica for somewhere opposite the Siberian Traps. Except of course continents move around. So anyway there is some speculation that the volcanic activity triggered by the impact 250 million BP amplified the bad conditions that led to extinction.
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