Dinosaurs Died Within Hours of Asteroid Impact, says New Study

colonist writes "SPACE.com reports that most dinosaurs were incinerated within hours by the 'heat pulse' of an asteroid impact 65 million years ago. The study 'Survival in the first hours of the Cenozoic' presents a scenario where the only survivors were underground or were underwater in swamps or oceans. All unprotected creatures were 'baked by the equivalent of a global oven set on broil.'"

Comments

Re:Correct me if I'm wrong.

[another_henry]

Actually it's well accepted as by far the most likely candidate for what happened. By the way, other theories include the theory of gravity, relativity theory etc... all pretty much proven, ask Hiroshima about E=mc^2 if you don't believe that one :P

kill all the plants too

[slothman32]

Of course I didn't read the article, as I don't subscribe and am lazy, but wouldn't the heat kill all the plants too? And I thought there were "many" survivors. Mostly small animals, besides plants and lower life forms. And how could 1 impact effect the entire planet with such a high amount of heat? Wouldn't that metemorph rocks as well? Or even react the atmosphere?

Re:kill all the plants too

[ultramk]

Plus, if it were that powerful to bake animals, would not the water temperature rise, and the air bake the animals which did survive, and destroy the birds as they're not too good about going underwater, and melt the ice at the caps, and...

To kill most large animals, the air doesn't need to be hot enough to bake the whole animal, just ruin its lungs.

Plants are easy. Many (most?) plants have evolved mechanisms to allow them to survive forest fires, brush fires and the like. The root stock would survive, and the seeds are mixed with soil/blown into protected places etc. Remember, they don't all have to survive, just enough to repopulate the species. There would be myriad places where plants or animals would be sheltered by the shape of a canyon/cave or whatever.

There are quite a few bird species that live in burrows/caves/hollow logs etc which would have survived. There are a lot of bird species that respond to any danger by diving into the water, and diving deep. Grebes, cormorants, and the like. There are lots of diving birds.

As far as raising the temperature of the water, you're vastly underestimating the amount of energy it would take to raise the temperature of all of the earth's oceans. It takes a lot more energy to raise the temperature of a volume of water than it takes to raise the same volume of air the same amount. (any physicists/chemists/engineers want to run the numbers?) The surface temperature of the oceans would probably rise a bit, then most of that energy would be shed back into the atmosphere by evaporation. The overall temp of the oceans would remain pretty constant, certainly not enough to melt the ice caps. For the superheated air directly above the glaciers, there would probably be a little bit of surface melting, which would immediately refreeze, leaving a glazed surface.

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