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Large animal extinctions - part 1
Timo Niroma (timo.niroma@tilmari.pp.fi)
3 Jul 1996 15:31:48 GMT
P3voices and Karen have commented my letter concerning the large animal
extinctions in the end of the ice age. I choose to answer question by
question and comment by comment, because the traditional style would
lead to great confusion. I have originally cited two scientists,
indirectly one and the main thesis is my own, then p3voices made great
snips and added his/her own comments and based on that Karen made her
own ones. If I now add my answers and comments between, nobody knows
who said what.
First I must apologize and correct an error I made in my letter. Ice
age ended 11600 years ago (11600+-50 to be accurate) or, if you prefer,
9600 (+-50) BC. I used the right value in the debate in sci.archaeology
newsgroup in January-February, as did the other debators. I realized
the error immediately when I read Karen's letter, I don't know why my
mind did this trick to me. One thing of the accuracy of the end of the
ice age. The ice age ended in less than three years and we know this
date for a +-50 year's accuracy. What is defined as the end of the ice
age, as the end of its last cold spell, the Younger Dryas, is the time,
when the temperature of the Earth rose suddenly, heavily and permanent
ly and the great ice sheets of Laurentide (America), Fennoscandia
(Europe) and around Antarctis began to melt. The melting approximately
to today's ice sheets lasted in average about 2000 years, but that's
not the concern here. I talk about the time when the process began,
11600 BP(2000) or 9600 BC.
According to First in - First out or FIFO -principle I first answer to
P3voices. Because P3voices uses at the end block letters, which
according to netiquette mean a scream, I begin with these. Although
P3voices calls my theory "so absurd that it hardly deserves rebuttal",
he/she gives still a rebuttal to it. I have heard that phrase being
used in the case of Copernicus (the Earth does not revolve around the
Sun), by the French Academy of Science in 1790 (meteorites can't come
from outer space, heaven is eternal and unchanging), in 1890-1910
repeatedly (the Barringer crater in Arizona cannot be extraterrestrial,
no such things exist), in 1935-1960 quite commonly against Wegener (the
continents can't move), in 1980-1989 especially among geologists
against Alwarez (how could an asteroid kill the dinosaurs in the middle
of the day), to mention only a few. So I feel to be in good company.
1. "Where is the impact crater?"
A: There are three possibilities: a. in the bottom of the Atlantic
ocean, b. originally a, but distorted as to having been become
unrecognizable during these intervening 11600 years and c. there never
was any crater.
a. Of the 150 or so meteorite craters known on Earth (the amount is
increasing in average by 2-3 craters per year) only 1 or possibly 2 are
found in sea despite the fact that 70% should be found in oceans. The
bottom of the oceans, at least in the depth of kilometers, outside the
continent shelves, are very difficult to investigate. So one possibili
ty is that the crater is deep in the North Atlantic out of the reach
of detectability.
b. The bottom of the Atlantic Ocean is moving about 3 cm per year,
which makes almost 400 m since the end of the ice age and the supposed
catastrophe. If we take the most likely figure for the crater, it would
be at most 2 to 4 km in diameter, so it would now be greatly distorted,
and difficult to find even if it exists in the shallower parts of the
western North Atlantic. This supposition is based on the assumption
that the extraterrestrial was an iron one. If it was stony, it should
have been very big (say half a kilometer in diameter).
c. If the extraterrestrial was a stony one and of middle size (100-300
m in size), it could have caused no permanent crater in the bottom of
the ocean, only a temporary crater in the water. The water would boil
and the tremendous explosion would have heated the water plus the
extraterrestrial into the atmosphere as water vapour and small debris
sand. That would cause torrential and long lasting rains and world-wide
floods wherever there were rivers and lowlands with large gathering
areas for the pouring rain. A darkness should have reigned for weeks
partly because of the thick clouds and partly because of the debris.
Tsunami there sure was but how high is difficult to estimate, because
the explosion that boiled away cubic kilometers of water would cause
an implosion that would fill the water crater within some hours.
Remember that the stony Tunguskan asteroid had a diameter only of some
60-70 meters and it exploded already in the height of 8 or 7 kilome
ters. No crater has ever been found, although the ground zero is known.
I think this answers the other bold letter questions also, such as the
shock-damaged rocks. The ashfall may need a comment. In the youngest
ice of the ice age there has been found more iridium and nickel than
from the old ice age ice or today's ice. Iridium and nickel are sure
signs of extraterrestrial, the surface of the Earth contains them only
because of extraterrestrials. Earth contains iridium and nickel of its
own, but they are deep below the surface, nickel right in the core.
2. "Where's the corollary extinction events among smaller animal &
plant fauna?"
The dinosaur-killer 65 million years ago left after it no animals whose
weight exceeded 23 kg. The smaller the animals the more shelter they
could get 65 million and 11600 years ago and the smaller the animal the
less food in average they needed. The dinosaur-killer killed also the
tiny trilobites which hade thrived hundred of millions of years since
Cambrian, but that was most probably the result of breakup of the chain
of flood, boiling and poisonous oceans made a great havoc amongst
plankton. But to compare these two events is unfair: the dinosaur-
killer was a giant of the class once-in-a-100-million-years, the
supposed ice age ender was by its TNT power less than a percent of its
big brother.
Plant fauna near the epicenter is of course burnt by the tremendous
heat, but the seeds in the ground survive, as can be seen after forest
fires.
3. "Your (and Brian Fagan's) hypothesis is UTTERLY ABSURD."
As I already implied, all new hypothesis that contain odd features to
the recipients, may sound absurd to them. But I take this, because poor
Fagan has been accused of an utterly absurd idea. I can here confirm
that all Fagan part was strict in quotes. And he doesn't talk anything
extraterrestrial. Not of comets, not of asteroids. The short quotation
of dinosaurs and the anti-Clovis statement are from a very thorough
study made by Gary Haynes. But the catastrophe theory of 11600 years
ago is mine, already reconstructed in 1982-83. I have in the early
1990s got some support from one of the leading astronomers, prof.
Duncan Steel, both personally and by his book about comets and
asteroids. But still I take the full responsibility of this "utterly
absurd" theory. To save Fagan, I quote his end conclusion: "Complex
variables must have affected the steps that led to extinction, with
intricate feedback among the effects of intensive big-game hunting,
changing ecology, and the intolerance of some mammalian species to
seasonal contrasts in weather conditions." And to my own rescue I note,
that Fagan published his words in 1986, before we knew how sudden and
great the climate change at the end of the Pleistocene 11600 years ago
really was.
4. "Maybe man's role in these extinction events was insignificant;
maybe not; new data will have to be uncovered to prove this point one
way or the other."
My theory of a comet or an asteroid does not exclude the possibility
that Clovis hunting may have caused some ravages. But a wholesale
extinction is out of question and that is also the opinion of both
Fagan and Haynes and a lot of other investigators. I developed my
catastrophe theory in the first place because these kind of catast
rophes caused by extraterrestrial debris are inevitable from time to
time. The fact that it neatly explains the sudden and catastrophic end
of the ice age plus great megafauna extinctions is an addendum. They
give more credibility to my theory, unless someone finds more plausible
explanations for these events. And then we would be leaved with the
question, why hasn't there been any impacts in recent times (during the
last tens of thousands of years).
These are the answers and comments specifically to P3voices and
generally to others. The specific answers and comments to Karen are in
the making and due to be published tomorrow.
Friendly,
Timo
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