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Fraser
2004-May-25, 10:07 PM
SUMMARY: It seems that when an asteroid struck the Earth 65 million years ago, the resulting heat pulse incinerated every dinosaur on the planet in just a few hours; only those that were in burrows or underwater likely survived. When the 10 km (6 mile) asteroid hit Chicxulub in the Yucatan, it struck with the force of 100 million megatons of TNT. A new paper published by several US university researchers calculates how ejected material would have heated the atmosphere to the equivalent of a global oven set on broil.

What do you think about this story? Post your comments below.

StarLab
2004-May-25, 10:43 PM
Exactly how big was this asteroid, in comparison with the largest asteroids today?

antoniseb
2004-May-25, 10:45 PM
Whether these calculations are correct or not, this makes a fascinating story. I'm glad I wasn't standing around watching these events unfold, but it is a lot of fun to try and visualize them. I often wonder about what happened to the seismic energy of the impact. It must have triggered some serious vulcanism and earthquakes world wide, especially on the opposite side of the Earth where the Seismic waves must have converged.

antoniseb
2004-May-25, 10:47 PM
Originally posted by T-rouser@May 25 2004, 10:43 PM
Exactly how big was this asteroid, in comparison with the largest asteroids today?
Of the known asteroids that are on Earth-crossing orbits none are as large as this one. A few have more than 10% the mass of that one.

Greg
2004-May-26, 01:30 AM
The scary part of this story was that the impactor was probably a comet. If so, there might be another comet in the oort cloud with our name on it, and all the asteroid tracking in the world still won't give us much more warning than about 6 months or maybe a year of warning.

Cygnus X-1
2004-May-26, 04:55 AM
I think that it was most likely a rocky asteroid, as opposed to a comet, that did in the dinos', however, you make a good point Greg. I agree that an incomming object from the Kuiper or Oort regions would leave less time to take action. Calculation........"line drive,earth bound", uh oh
:o

Smutny Pavel
2004-May-26, 09:22 AM
{I warned you about doing this Pavel. This forum and this topic specifically are not the place to expound your personal theories.}

Smutny Pavel or Senmut or Resenmut or Han Dai

Eric Vaxxine
2004-May-26, 09:41 AM
Dzien Dobry ! Pavel....duza writing. :)

Eric Vaxxine
2004-May-26, 09:52 AM
Wasn't there some talk that it was an impact near Australia that hurt the dinosaurs? Is that unresolved?

GOURDHEAD
2004-May-26, 01:34 PM
It seems that when an asteroid struck the Earth 65 million years ago, the resulting heat pulse incinerated every dinosaur on the planet in just a few hours; only those that were in burrows or underwater likely survived.

I think this extrapolation to be extremely overdone as would be the dinosaurs if it were true. Turtles, frogs, crocidilians, and the progenitors of birds and us survived. The progenitors of none of us would have been in deep enough burrows to survive the described scenario. Life on land would have been reduced to the microbial level. It's difficult to imagine any lunged species surviving whether sea or land dwelling. My guess is their model is flawed.

GyuriO
2004-May-26, 05:18 PM
All would be OK if it is corelated with the extintion of all vegetal species at the surface of the Earth except seqoia, some mushroom and some other plants who spread through their roots, as it seems to me the majority of thevegetation was not in burrows.

Duane
2004-May-26, 08:49 PM
No Eric the impact near Australia is thought to be from the Permian extinction. It is the object that cleared the earth of most other creatures, thus giving rise to the dinosaurs.

Gourdhead, I would think that it would depend partly on the time of year the impact occurred. There is evidence that dinosaurs migrated, and frogs, crocs, birds etc have survived many extinction level events over the Earths history. Maybe it was winter and the eggs survived by being buried? Its not like crocs, turtles or frogs need a parent around.

Mammels were small furry burrow living animals at the time of the impact. Dirt is a great insulator, so if the temperture peaked within a fairly short period, they may have been protected. Furthermore, if some of them hibernated and it was winter, maybe they were protected that way.

Many plants can survive major firestorms of the kind that would have arisen during the impact. In fact, some plants don't even release seed unless there is a fire. That may account for the survival of some vegetation.

Also, again, if it was winter in the northern hemisphere, maybe the plants were in hibernation. There is evidence that northern species shed their leaves in the Cretaceous period, so maybe that is how some survived.

Smutny Pavel
2004-May-27, 05:51 AM
We had thought that there is not censorship in USA in topics like Astronomy, Geology, but there is!!!
You have realy similar sistem how was Marxism Leninism in CCCP.

emerald
2004-May-27, 09:59 AM
[Pavel, once again you are posting your personal platform in breach of the rules. In the event you haven't taken the time to read them:

6. No Advertising

Don't use the Universe Today forums as a way to promote your own website, product, or forum. And don't use the forum as a platform for your ideas or theories. We'll give you a little leeway if you're an active contributor to the forum. And don't think we won't notice. **Emphasis added**

I have warned you and left a thread open for you to make whatever comments you like on the subject of a possible unseen planet. If you continue to promote your platform in other threads, the next step will be to have you banned.

This is the last time I am going to warn you about this.]

antoniseb
2004-May-27, 11:24 AM
Originally posted by Smutny Pavel@May 27 2004, 05:51 AM
We had thought that there is not censorship in USA in topics like Astronomy, Geology, but there is!!!
You have realy similar sistem how was Marxism Leninism in CCCP.
Hi Paval,

There are a few things I should point out.
First, this web-site is based in Canada, not the USA.
Second, though there is free speach in Canada, this is a privately funded website, not a government sponsored chat room.
Third [and most importantly] we monitor this list and keep it on topic. We believe that your postings about Planet X are off topic, because they have no scientific merit.

As an example, please imagine that you have a website about your Planet X theory, including a discussion forum, and I and dozens of others started to post a lot of stuff on the forum about how to buy perscription drugs cheaply, or sad details of my first wedding, or some diatribe about the harsh treatment of laboratory rats, or links to pay-sites of images of underdressed people. These issues would be totally off topic and would damage the focus of the forum. You'd need a mechanism to expunge them.

It is a stretch to call the Planet X theory Astronomy or Geology. There is no real research on it. No observational evidence. There is plenty of observational proof against it. I will grant you that your topic is near the boundary of what we'd call acceptable for this forum, but the owner and moderators all agree that it is outside the bounds. That is our decision to make.

So, I encourage you now. Start your own website. You can do it for as little as $15/year for a domain name and a little effort. Exercise your right to free speach and uncensored ranting. You won't be able to promote that site here, but if you become a member, you can include a link to it in your user profile. I've had hundreds of hits on my website through a similar link in my user profile.

Good luck with your future endeavors.

GOURDHEAD
2004-May-27, 01:35 PM
Gourdhead, I would think that it would depend partly on the time of year the impact occurred. There is evidence that dinosaurs migrated, and frogs, crocs, birds etc have survived many extinction level events over the Earths history. Maybe it was winter and the eggs survived by being buried? Its not like crocs, turtles or frogs need a parent around.

Even if it were winter prior to the event, the article claims the heat pulse was strong enough to kill every dinosaur within a few hours at a temperature equivalent to an oven set to broil. This implies a temperature of the atmosphere hot enough to last long enough to kill all plants except for seeds buried 6 or more inches in soil or immersed in water. That much heat will take quite a while to dissipate especially since the heat would have greatly increased the water content of the atmosphere further prolonging the dissipation. Some plants might survive from seeds or spores near the top of the atmosphere, but I doubt that enough would survive to feed the first emerging hatchlings, if any. I can accept that something similar to what the article proposes may have happened but not to the extremes it suggests--there were too many survivorsof too many genotypes.

Duane
2004-May-27, 04:50 PM
Yea Gourdhead, you could be right. I was just naming a couple of ways that some survival might have occurred, as there was obviously some survival.

I still think that there had to have been plants that could survive a heat pulse like that, even considering a temperature of about 500 or so degrees (assuming the analogy to an oven set on broil is accurate). There are lots of examples of trees in old growth forests that have been burned several times in their lifetimes, yet they lived through it and continued to thrive.

Same same with crocadilians and amphibians. I mean, assuming that some areas were protected from the worst of the heat pulse, and vegetable matter continued to be available, you would have the start of a food chain. Insects eat plants, frogs eat insects, croccs eat frogs, small bird like creatures eat frogs and small crocs, etc. You know what I mean?

I wonder how long the heat pulse would have lasted?

Derwood Puckett
2004-May-27, 11:15 PM
I like the web page, but don't one second do I by the part about an
Asteroid wiped out the Dinosaurs. God is the creator of of all things
seen and unseen. I would think they were here the same time man
was made, but could not survive the World Flood. Also was a big
climit change after the Flood, Man life spain got shorted and shorted.
With the Dinosaurs, if were on the ark, could not survived life after
the Flood. And also man killed most of those that survived, with
the ice age that followed the flood.
Youall should study the Genesis Flood by John C. Whitcomb Jr. and
Henry M. Morris. For Biblical Records and its Scientific Implications.

Thanks Derwood, Salisbury, NC

Guest
2004-May-28, 03:24 AM
did anyone hear of this asterorid that is supposed to hit the earth in 2004? is this true?

charmquark
2004-May-28, 05:31 AM
The impact environment is ubiquitous in this solar system. Get use to it. If our genes carry memory it is as a pixel of the inevitable firestorm. (No wonder our pattern making brains invented gods.)

Gene Shoemaker was brilliant ... he knew that the story of life had everything to do with impacts.

The supernatural is not required to explain anything. Because impacts are ubiquitous, that fact explains lots.

Carl Sagan said it too .. we go to space or we go extinct.

I would like to know some seismic facts. Imagine a thin bit of lithosphere like Hawaii ... imagine a thick continental lithosphere like the Canadian Shield. I want to see models of how impacts impact each of them.

Seems to me the rock would go thud in Canada, but in Hawaii it would cause all kinds of crust cracking, causing major volcanic flooding. And what is an average crust thickness and what average size impact would be needed to crack that bit of crust?

Guest
2004-May-28, 06:36 AM
Tell me what is here outside of topic!!??

Hit of asteroid (comet) which happened before 65 millions years was part of one of periodic cataclysmas, which affected Earth in 26-30 millions years periodicity. Also for extinghuishing of animals, plants from time before 250 millions years was responsible similar, but probably little biger one object. What can bring here such objects in quite regular intervals?
Officialy according top scientiests idea was Moon created from Earth after bump of very big body (Marsoid) to our Earth, and we can see Pacific basin how result of it.
Moon rocks but are 3 billions years old!
Pacific basin rocks have not more than 200 millions years!
Where is the truth!
If you look on geological map of Pacific ocean, so you can see that there is actualy rest after big tidal bubble which was sucked from Earth surface layers and after departure of that big body (Planet X?) from Earths vicinity that bubble flatten. There are ripps, barrows which are clearly making circular pattern. Enough is to look on geological map of Pacific in high school school book...
but this topic is not recomanded to speak about...

You have only approved here, that plates tectonics finished aprox 200 millions years before.
There aren't (in pacific basin) older or younger rocks!!!
Why we don't have rocks from tectonic on oceanic basin which are younger than 200 millions years, for example 100, 50 millions years old??!!
Plates moved only till 200 millions years ago??!!
Something very catastrophic had happen before circa 200 million years!!!


Another my unpleasent idea is that shift of North magnetic pole during last 100 years what is circa 10 degrees is caused by Planet X, because that planet changed its angle toward us and toward ecliptic more than 10, till 20 degrees in last 100 years according my computations, according Senmut map!
This shift of North magnetic pole is now accelerating and also PX, because is much closer than before 100 years is changing its angle toward us much more quickly.

Official scientiests speak only about some special mechanism of these changes but they can't describe it, they have no good solution for it!!!

With global warming, with change of ocean water level it is the same!
According serious researches is for only 1/5 till 1/6 th of water add (2mm in average) responsible humans activities.

GOURDHEAD
2004-May-28, 03:37 PM
Why we don't have rocks from tectonic on oceanic basin which are younger than 200 millions years, for example 100, 50 millions years old??!!
Plates moved only till 200 millions years ago??!!
There aren't (in pacific basin) older or younger rocks!!!

I'm not sure you have the facts right. Plate tectonics is continually reshaping and relocating the pacific basin with rocks as young as a few hours ago upwelling. Consider the shapes, history, and locations of the gondwanaland and pangaea continents.


I wonder how long the heat pulse would have lasted?

That's the key question. I have assumed that in order to kill all dinosaurs within a few hours the premise of the article is that enough heat had to be generated to keep the entire atmosphere up to several miles high at or near 500 degrees F. Do we have reliable paleological data describing the prevailing climate of the era? In this scenario one would expect increased volcanic activity adding more heat during the ensuing hours/days/weeks which, coupled with the thicker blanket of dust and water vapor would have sustained the heat at intolerable levels for months. Again, I agree something real b-a-a-a-d happened. I'm quibbling over just how bad. I still wonder why the giant sea reptiles (mosasaurs, icthyosaurs, etc.,) perished; They seemed to have been very suited to the environment and were believed to be primarily fish eaters. Subsequent global cooling looks like a prime suspect. Then there are always those specie specific prions that accumulate oer time.


we go to space or we go extinct

I second the motion or is it an assertion!

Iridescent
2004-May-29, 05:56 PM
Originally posted by Greg@May 26 2004, 01:30 AM
The scary part of this story was that the impactor was probably a comet.
I don't think it was a comet.
on the boundary between cretaceous and tertiary ages, geologers found lots of iridium in the soil.
iridium is very rare on earth, but since it is a very heavy metal similar to platinum, i think it's much much rarer in comets. so i think it was an asteroid, most probably a very metallic (=dense, iron-rich) one.

pmf71
2004-May-29, 06:44 PM
Originally posted by antoniseb@May 25 2004, 10:45 PM
Whether these calculations are correct or not, this makes a fascinating story. I'm glad I wasn't standing around watching these events unfold, but it is a lot of fun to try and visualize them. I often wonder about what happened to the seismic energy of the impact. It must have triggered some serious vulcanism and earthquakes world wide, especially on the opposite side of the Earth where the Seismic waves must have converged.
In fact, the other side does contain a large site, the Deccan Traps in India. Although there is still a lot of debate about it, a good few people who examined the site agree that massive volcanism occurred there about 65 million years ago. If their assumptions are correct, one could conclude that the deccan traps are indeed the site of where the seismic waves converged and literally whipped the crust open. Imagine the amount of energy needed for that.

Duane
2004-Jun-01, 12:08 AM
Ok Pavel, I agree you have stayed close enough to the topic, so I will leave your post alone.

Allow me to point out a few flaws:


Hit of asteroid (comet) which happened before 65 millions years was part of one of periodic cataclysmas, which affected Earth in 26-30 millions years periodicity. Also for extinghuishing of animals, plants from time before 250 millions years was responsible similar, but probably little biger one object. What can bring here such objects in quite regular intervals?


Raup and Sepkoski's idea of periodicity has been quite controversial. Thier methods has been called into question with respect to the time scales they used because the cyclical pattern is not highly apparent, or even visible, in several of the other known time scales, such as climatic changes.

While there is a possibilty that some type of astronomical force has caused a regular pulse in the extinction record, such regularity would show up in more than just the fossil record of extinctions. It is just as possible, therefore, that the periocity is a statistical aberation.

But, lets assume for a minute that there is periocity. Besides a so-called planet X, there is Nemesis, the regular passing of the solar system through the plane of the milky way, coincedental close encounters with other stars, periodic passing through higher density galactic clouds, orbital induced climatic changes, solar induced climatic changes, and probably others I can't think of right now.


Officialy according top scientiests idea was Moon created from Earth after bump of very big body (Marsoid) to our Earth, and we can see Pacific basin how result of it.


No Pavel, the Pacific basin has nothing to do with a proto-earth impact with a Mars-sized planitoid. That collision arose some 4 billion years ago, and it would not have left a crater.

I will try to tell you this in a way that you might understand--the Pacific basin is the result of the accidental placement of continents today after billions of years of movement which arose through plate tectonics.


Pacific basin rocks have not more than 200 millions years!


Pavel, the oldest rocks in the Pacific basin are 200 million years old--they then become progressively younger until, like gourdhead says, they are only a few minutes old at the site of sea-floor spreading. For the Pacific basin, the only area of seafloor spreading left is in the southern ocean near the tip of South America, the rest of the basin is subducting. Please take 10 minutes and read up on plate tectonics.


You have only approved here, that plates tectonics finished aprox 200 millions years before.
There aren't (in pacific basin) older or younger rocks!!!


No, plate tectonics continue to this day. There is so younger rock in the Pacific basin.

Guest_T-rouser
2004-Jun-01, 04:10 AM
I live in LA. It's no fun, no joke: a hella lotta plate tectonic activity goin' on here! :o :ph34r:

DippyHippy
2004-Jun-01, 04:19 AM
StarLab, you've been asked to just use the one username... please stick to it.

GOURDHEAD
2004-Nov-17, 02:52 PM
Here (http://www.sciencedaily.com/releases/2004/11/041108020753.htm) is an article that supports my assertion that the K-T boundary extinction was not as severe as indicated by the article cited to initiate this thread.