Re: Why was Earth a fiery hell 55 million years ago?

[Dora Smith <villandra@austin.rr.com>]

On the other hand, this article, 
http://www.washingtonpost.com/wp-srv/national/horizon/sept98/sea.htm

states,

One day in the Caribbean Sea, at the end of the Paleocene epoch 55 million 
years ago, a volcano blew, spewing a climate-altering parasol of tiny 
particles high into the atmosphere. Such events are hardly rare. But this 
was no ordinary volcano: It was huge. And this was no ordinary time in the 
planet's history: The environment already was on the threshold of profound 
change.

According to a new theory proposed by marine geologist Timothy Bralower of 
the University of North Carolina at Chapel Hill, climatic fallout from the 
Caribbean eruption pushed Earth beyond that threshold, triggering what has 
been identified in the last 10 years as one of the most remarkable worldwide 
transformations known.

In the dry argot of earth scientists, this event is called the Late 
Paleocene Thermal Maximum, or LPTM. In the language the rest of us speak, it 
is simply unbelievable.

Its prelude, innocuously enough, was a long-term global warming trend that 
began about 60 million years ago and weakened the circulatory system of the 
world's oceans. Five million years of that warming seems to have left 
Earth's environment vulnerable to catastrophic change.




Then, at the very end of the Paleocene, the circulation system experienced 
the oceanic equivalent of a heart attack. The global network of ocean 
currents stopped doing its vital job of delivering cold, oxygen-rich water 
to the deep ocean. As a result, the abyss warmed and stagnated.

This shock caused a mass extinction of marine organisms, including as many 
as half of all species of deep-sea foraminifera. This family of ubiquitous 
one-celled sea animals forms one of the primary links in the oceanic food 
chain. The mass killings of forams and other species, Bralower says, 
represent "the biggest extinction event in the deep sea in the last 90 
million years. Nothing else even comes close."

When the oceanic heart attack struck, Earth was considerably warmer than 
today, thanks to the 5-million-year global warming trend. Global average air 
temperature was several degrees higher than now, chiefly because the poles 
were far warmer.



I guess I'll have to contact him and find out what he's talking about.


Yours,
Dora Smith
Austin, TX
tiggernut24@yahoo.com
----- Original Message ----- 
From: "Dora Smith" <villandra@austin.rr.com>
To: <villandra@austin.rr.com>
Sent: Saturday, January 26, 2008 2:27 PM
Subject: Re: Why was Earth a fiery hell 55 million years ago?


> Actually, closer reading of these articles betrays possible confusion.
>
> First of all, the Caribbean large igneous province isn't even in teh 
> Caribbean; it's in the Pacific.
>
> Second, that event ended 69 million years ago, and the articles in 
> question appear to link it to an ocean die-off 94 million years ago, which 
> is a different event.    This and a string of flood basalt volcanoes from 
> Greenland to Great Britain that did occur at 55 to 56 million years ago, 
> just happen to sometimes get discussed together.
>
> So I don't know if there is any evidence for a Caribbean eruption of that 
> magnitude at 55 mya, or not.
>
> Yours,
> Dora Smith
> Austin, TX
> tiggernut24@yahoo.com



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