[Rockhounds] The death of dinosaurs was all about the asteroid

[Dora Smith]

I so far found this.

I found a lot on the impact, not much on the Deccan traps, outside of 
scholarly journals.

In addition to online documentaries and one reenactment of people trying 
to survive a repeat of the events of 65 million years ago, I found these 
two talks, by the same professor presenting his work.

https://www.youtube.com/watch?v=LiFF04rOq3Y
https://www.youtube.com/watch?v=oDiZRonhoa8

He and his fellow researchers at UC Berkeley found good evidence that 
the comet struck right in the middle of the Deccan traps, and 
immediately before they became truly massive.   They have a theory that 
the giant earthquakes that accompanied the impact could have conveyed 
enough kinetic energy across the planet to joggle something loose in the 
deccan traps or else liquefy something, resulting in a sudden flood from 
the mantle through channels that didn't previously exist.  This then 
went on for a very long time, I think.

Their efforts to pin down the two events have them extremely close 
together in time.

The later presentation then does some mushy idea about maybe one event 
setting up the dinosaurs for extinction by the other.

I honestly cannot see the logic of debating what effect an event that 
came later in time on the impact had on the dinosaurs if they were 
already dead.  It's hard to see how any land animal that couldn't burrow 
into the earth or find shelter could have survived.  The immediate 
fireball/ explosion would have impacted only part of the planet.  Ditto 
the tsunami.   But, the dust and gas blasted into space condensed and 
fell, they believe heating up and catching fire on reentry, all over the 
planet, starting massive fires everywhere, and heating the air at 
groundlevel worldwide to 700 degrees fahrenheit.   Then the ground 
dropped to 50 degrees below zero everywhere except on ocean coasts, and 
stayed there for months or years..    They think that at ground level 
for four months dust blocked out the sun to the degree that it was pitch 
dark, and plant life would have found it very hard to survive, and this 
was followed by a very long period of bitter cold.  Some versions have 
the long cold spell followed by a long hot spell that lasted months, 
years, or centuries.  The temperature would have increased by something 
like a hundred degrees.   Allegedly.

The wonder is any life survived this.

All that appears to be what they think WOULD happen, not necessarily 
what DID.   But, all versions of that are very similar.  Large slow 
stupid animals like dinosaurs weren't alive by the end of the first 
week, let alone four months later.   So they weren't still around for 
the increase in activity of the Deccan traps to kill.

It is hard to say if the asteroid and the traps would have opposed or 
reinforced each other as far as the climate.

But, if the two things occurred together or close together in time, the 
impact from the asteroid should have lasted maybe 15 years, I would have 
thought, though life could have been thousands or millions of years 
recovering.   But the Deccan traps went on for a million years.  If 
their long worst phase was after the eruption, that would have 
dramatically affected the climate for a long time, as well as the 
ecosystem trying to recover.

This becomes very important, because any nation planning for such a 
catastrophe is likely to tend to believe that what happened in the past 
is what will happen again, but that probably is not the case.   Humans 
could survive catastrophic climate events that went on for 15 years, 
centuries or thousands of years would be another story.

Yours,

Dora


On 1/30/20 8:17 PM, Paul wrote:
> Yale University. "In death of dinosaurs, it was all about the asteroid
> -- not volcanoes." ScienceDaily. ScienceDaily, 16 January 2020.
> www.sciencedaily.com/releases/2020/01/200116141708.htm
>
> Meteorite or Volcano? New Clues to the Dinosaurs’ Demise
> Twin calamities marked the end of the Cretaceous period, and
> scientists are presenting new evidence of which drove one of
> Earth’s great extinctions. New York Times, January 16, 2020
> https://www.nytimes.com/2020/01/16/science/dinosaurs-extinction-meteorite-volcano.html 
>
>
> The paper is:
>
> Hull, P.M., Bornemann, A., Penman, D.E., Henehan, M.J., Norris, R.D.,
> Wilson, P.A., Blum, P., Alegret, L., Batenburg, S.J., Bown, P.R. and
> Bralower, T.J., 2020. On impact and volcanism across the Cretaceous-
> Paleogene boundary. Science, 367(6475), pp.266-272.
> https://science.sciencemag.org/content/367/6475/266.abstract
>
> Yours,
>
> Paul H.
>
>
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