Dino extinction event may have been caused by magnetic chaosDecember 13th, 2008 - 2:20 pm ICT by ANI
Washington, Dec 13 (ANI): A new theory has suggested that the mass extinction event that killed the dinosaurs 250 million years ago, was caused by the Earths magnetic field going into complete disarray, exposing the planet to a shower of cosmic radiation.
According to a report in Discovery News, the theory has been put forward by Yukio Isozaki of the University of Tokyo.
The Permian-Triassic mass extinction event happened 250 million years ago, snuffing out 90 percent of life on the planet.
Now, the new theory by Isozaki suggests that the catastrophe was set in motion 15 million years earlier, deep in the Earth.
On the edge of the molten outer core, a plume of super-hot material began rising through the mantle, upsetting convection in the core and throwing the planets magnetic field into disarray.
The weakening of Earths magnetic field exposed the surface to a shower of cosmic radiation, according to Isozaki. He believes that the radiation broke nitrogen in the atmosphere into ions that acted as seeds for clouds enshrouding the planet.
This wouldve caused severe cooling and a drop in sea level as the cool temperatures allowed massive ice sheets to accumulate on the continents, Isozaki said.
If you check the rock record at that time, tropical coral reefs die first. Then, you start to see fauna from mid latitudes move into the tropics. It all points to cooling, he added.
The superplume disrupted the magnetic field and put a strain on creatures living on the surface, but it was only the beginning.
According to Isozaki, five million years later it reached the surface, and the hot material punched through the crust, erupting as three successive supervolcanoes.
Today, the remnants of those volcanoes are scattered through India, China and Norway.
On their own they were too small to do much harm, but together, they cooled the climate even further, launching an extinction as bad as the one that would kill the dinosaurs 185 million years later.
Then, 10 million years later, the Permian-Triassic extinction struck.
The effects of the superplume were just the first punch of extinction, Isozaki said. Then came the knockout punch, the Permian-Triassic extinction, he added.
Isozaki said that both punches were caused by the same superplume.
Ten million years after the smaller volcanoes blew their tops, a much larger volcano, the Siberian Traps, erupted, launching the worst killing in the planets history. (ANI)
- Global extinction was not a sudden event - Feb 05, 2012
- Ancient global warming turned earth an inferno - Nov 18, 2011
- Massive volcanic eruption 'caused world's largest extinction' - Jan 24, 2011
- Corals, big mammals to go extinct in future catastrophic event? - Sep 03, 2010
- Did birds' ancestors breathe their way to dominance? - Jan 15, 2010
- Fossil site in China offers clues to mass extinction recovery - Dec 23, 2010
- 250mn-year-old footprints discovered push back dino evolution by 9mn yrs - Oct 06, 2010
- Fossil haul shows life's recovery after near-extinction - Dec 23, 2010
- World's forests were wiped out in global catastrophe 250 mln yrs ago - Oct 02, 2009
- Mystery over Sun's missing sunspots over 11-year cycle solved - Mar 03, 2011
- Massive volcanic eruptions wiped out life on sea, land - Jan 24, 2011
- Telescope captures galactic super volcanic explosion - Aug 23, 2010
- Global mass extinction 250 million years ago triggered fungus explosion - Oct 05, 2009
- Alligators' breathing method may explain how dinos ruled the Earth - Jan 15, 2010
- Volcanic eruptions affect rainfall over Asian region - Nov 05, 2010
Tags: cosmic radiation, deep in the earth, dinos, disarray, discovery news, earths magnetic field, five million years, india china, isozaki, living on the surface, mass extinction event, massive ice, mid latitudes, nitrogen in the atmosphere, outer core, permian triassic, triassic mass extinction, tropical coral reefs, university of tokyo, yukio