More Evidence Supports Massive Asteroid Strike 84
InnerPeace Volunteers writes "From a BBC Sci/Tech article: The idea is that a giant asteroid about 10 kilometres wide, travelling at 90,000 km/hour slammed into the Earth at the southern margin of North America. This was a case of global devastation rather than North American catastrophe. The asteroid devastated pretty much everything."
gulf of mexico (Score:2, Insightful)
Everything but the frogs (Score:3, Insightful)
Now I'm not saying that this theory isn't very convincing, but its going to be a long time before we truly understand the nature of what happened during this massive impact. I'm not doubting that a massive metor / asteroid hit the earth and caused catastrophic environmental fallout, but the facts are far from convincing.
Frogs and salamanders and other small amphibians like these are very delicate fragile creatures which are very easily affected by even small changes in their habitats. They breathe and drink through their skin, and so absorb pretty much anything thats in the air and water. They are also very sensitive to light & heat conditions. If a massive environmental disaster occured that was so devastating that it wiped out thousands of species, including very large robust reptiles like dinosaurs, why did it not wipe out the many frog & reptile populations that have continued pretty much unchanged since that time.
Understanding the consequences of a massive explosion / impact of this sort is very important to us. We should understand thoroughly the consequences and the survival strategies that are important in a post-nuclear / post-asteroid fallout situation. The dillemma of the frogs is just one of the massively understated holes in our knowledge about such disasters, and the verdict on what really did kill the dinosaurs is far from conclusive at this point - despite what the popular media likes to portray.
Giant space rocks hitting the earth and causing massive fallout is a great story, and the media loves to play it up. It satisfies our thirst for biblical-type plague stories and apocalyptic premonitions, but as far as the science goes, its anything but conclusive. Certainly this meteor impact did happen at the same time as the beginning of the end of the dinosaurs, but we must remember that despite what you may remember seeing in Disney's Fantasia, they didn't all just drop dead in a matter of one symphony movement. Their extinction happened over a long period ( although geologically it might look quick ), and we are very far from understanding the ecological and environmental changes that came out of it.
Re:Yellow journalism (Score:5, Insightful)
Nowadays, if the face of so much consistent evidence, you'd have to have some really spectacular counter-evidence to be taken seriously. There are still scientists out there trying to debunk the idea, of course, but mostly they just keep turning up more evidence in favor of the impact. That's what this story was. One more of a chain of hundreds of findings that support the general idea of a major impact 65 million years ago.
Has anyone found strata anywhere that is well-dated and continuous across the 65-million-year age that doesn't show a thin anomalous layer and a radical change of fossils?
(Yes, there are continuous strata of around that age that can't be firmly dated. There are also strata that straddle the date but can't be shown to be continuous. None of these is evidence pro or con the impact.)
What does it have to do with nerd news? Well one thing that a few people have been pushing is funding for equipment and people to do a thorough study and census of small objects in the solar system. There could be such an object aimed to hit us Real Soon Now. We don't know. The sooner we can spot such things, the sooner we can do something to deflect them. If we don't, well, one of them will hit the Earth eventually. Maybe it'll hit next week; maybe it'll hit 30 million years from now.
There are roughly a thousand objects now known of km-size or greater that cross the Earth's orbit. None of the known objects will hit the Earth within a century or so. But we have no idea how many more may be out there.
We nerds are just the ones to find them. And knowledge of earlier disasters is one of the best ways to pry funding out of governments agencies.
Re:Everything but the frogs (Score:4, Insightful)
Re:Everything but the frogs (Score:4, Insightful)
You cant take amphibians alone as counter evidence. There are for example several species of toads and frogs that live in the desert, and lie buried under ground, sometimes for many years, waiting for the conditions to become just right to come to the surface and reproduce.
When food is suddenly very scarce, a huge dinosaur suddenly loses its robustness and starves, while small creatures, or species that can lie dormant for some time (seed bearing plants for instance) gain in robustness...
Old news! (Score:2, Insightful)
Seriously, this has been accepted widely already in geology. I as a geology student was pleasantly surprised about 4 years ago when my teacher Dr. Jan Smit from the Free University of Amsterdam (a sedimentologist) gave us an introduction in the extinction of the dinosaurs. And even then this was already not *the latest*.
For the non-geologists: J. Smit discovered after some fieldwork and years of research all around the world measuring the K-T boundary (the boundary of strata of where the creteaucious rocks and the tertiary rocks have contact, which is, of course at 65 million years age), that at the Yucatan peninsula there has been an impact crater with a huge diameter (~240km). From this crater ejecta had travelled as far as the great plains...
The story posted here is just one of *many* researches going on right now to verify this theory.
The major point being discussed now is not why did the dinosaurs die, but how did they die when the asteroid hit. The most discussion goes about nuclear winters and climate changes, or even thermal heating due to infall of debris (think 'big eruption'), because it has not really been identified how long the period of extinction was. (at least, as far as I know, comment, anyone?)
I guess the world has some time to accept this story as true, funny how a sometimes dusty science area as geology can already be ahead of the media by far.
Re:Everything but the frogs (Score:2, Insightful)
When it starts getting cold and/or dry, they hibernate. They bury themselves and basically shut down completely until warmth/water returns. They can survive for years in that state. Ditto for salamanders.
If anything, the prevalence of hibernating reptilians and amphibians today is good evidence for mass extinction via asteroid strike.
Re:human ingenuity (Score:1, Insightful)
Re:gulf of mexico (Score:2, Insightful)
"Determined" is much too strong a word. The nature of the magnetic grains has been disputed from the start, and the question is still very much open.
Re:"Suddenly disappeared..." (Score:3, Insightful)
Fossils are rare. Damn rare to create, even harder to find. Up until Jurassic Park came out, there were all of THREE T-Rex fossils found. They've since found more.
This means that you may find only four or five fossils of a given species. The last one you -happen- to find may be a million years before the K-T boundary, but that's only because you haven't found any newer ones yet.
What is significant, though, is that there is a time when 99.99% of the fossils stop appearing past. There's also evidence of massive dieoffs in the area of the crater of much more common things - I think ammonites were the significant ones, but I don't have the book handy.
Now, this is all thirdhand data (studies, paraphrased by the book, [mis]remembered by me). But it does help explain why you may seem to see species slowly drifting off, when they really all stuck around until that fateful year.