Unless they break the planet to smithereens

Feb 18, 2009 12:01 GMT  ·  By
Long-term volcanic eruptions have the potential to wipe out life as we know it over thousands of years
   Long-term volcanic eruptions have the potential to wipe out life as we know it over thousands of years

Over the years, we've heard numerous theories and hypotheses as to how the dinosaurs went extinct, and what caused the global event responsible for it. We've been thought to believe a comet or an asteroid is more than capable of wiping out all life on Earth, but a new research seems to contradict that. That's not to say that an asteroid wouldn't have the ability to destroy us altogether, but it would also have to do away with the entire planet in the process. For any other cases, the original impact has to be doubled by a secondary extinction event, to ensure that life is completely annihilated.

And, according to the latest studies, it would appear that the “honor” belongs to volcanoes, which are the ones stirred up immediately after a comet impacts the crust. Because of the large amount of vibrations and the immense shock, most craters near the impact site, and later others, explode, and the magma trapped underground finally finds its way out. But the true extinction comes from the plumes of these volcanoes, from the ashes and the dust that set around their cones for hundreds of miles.

Scientists at the Hobart and William Smith Colleges, led by Nan Arens, argue in a paper published recently in the journal Paleobiology that there are two types of extinction events – “pulls” and “presses.” A “pull” is a sudden event, such as a comet or an asteroid impact, while “presses” are more Earthly phenomena, such as volcanic eruptions that last for millions of years. Their research shows that a “pull” alone is not enough to destroy 90 percent of life on the planet, as it happened during the Permian-Triassic extinction period.

Rather, that particular destruction was caused by a volcano in Siberia, which erupted non-stop for well over 200,000 years. This means that it wasn't shock or flying stones that killed all animals, but climate change, as nature became unable to support life, due to all the carbon dioxide in the atmosphere. The global warming process that was triggered by the eruption allowed only for a very short range of creatures to survive, along with trees, which multiplied in order to get more carbon out of the air.

Naturally, when both “pulls” and “presses” are combined, the results are devastating. 65 million years ago, when a comet struck the Earth, near the Yucatan Peninsula, the Deccan Traps, a supermassive volcano over what is today India was already erupting. This meant that the dinosaurs never stood a chance of surviving in the shape that they had at the time. As a result, their only living relatives are now some turtles, crocodiles, and a few birds.