more scary stuff

[Roanon]

Originally posted by rextorres:
Anyway ozone depletion by Volcanos is not a fact as you keep stating it's a theory.

It's not even a theory. It's most certainly plain wrong. One link has been provided. Doesn't make sense to list more. This is probably another area where you will not be able to counter myths, believes, and/or ideology with something as dull as facts.

[narf poit chez BOOM]

so, all that massive smoke billowing out of a volcanic eruption has no effect on the ozone? provide more than your opinion, please. Fyron did provide links.

[Roanon]

Rextorres provided a link with specific information and explanation about why volcano eruptions do not interact with the ozon layer in a significant way. Fyron's links contained "informations" like "it is a well known fact that volcanic eruptions interact with the ozone layer..:" - I stopped reading there. A myth repeated by a lot of people does not become a "well known fact". Scientific essays on a similar level have begun with "it is a well known fact that the earth is flat and the center of the universe..."
But, as I said, someone clinging to his myth or believe will take this sentence as 100% scientific proof and will ignore anything else. This happens very often: people first make up their minds about what they want to believe, and then search for facts (or "facts") supporting it and ignore anything else. Unfortunately, some of them even publish a book (or an internet article) and claim knowing it all because they have done "extensive research"...
The scientific approach is to first collect as much facts as possible, check for possible faults and errors, and then make a theory. And if some facts do not fit into the theory, it is probably the theory and not the facts that are wrong. Therefore, I'm not saying "this and that causes the ozone hole and it will develop like this" - I'm just sure that a few volcanic eruptions within the Last years didn't cause anything like that. Volcanoes have erupted since the formation of the earth, more and heavier when earth was younger, and I'm too missing an explanation why they should cause significant ozone holes only in our century.

[solops]

The “Volcano Question” is a good one. Much of the information floating about seems heavily influenced by personal bias or by who happens to be funding the study. I suggest two documents as helpful:

http://plaza.ufl.edu/airwess/
http://climate.envsci.rutgers.edu/pd...ThePlanet2.pdf

They have a spin, but are informative. The gist of these and other sources, plus my geology classes and industry experience, seems to be that we live on a planet that is dynamically changing and totally indifferent to our existence and mostly unaffected by our efforts. The biological component of the planet scrambles and reacts to the planet’s physical changes by either adapting or dying. It would seem that volcanism is responsible for creating our atmosphere and has changed the atmosphere’s composition over time. That change is ongoing and is still underway. Our admittedly shallow database of measurements seem to indicate that climatic changes induced by a single eruption from carbon dioxide and ash are significant but relatively short termed (2-6 years, depending on the source). The emissions of sulphur compounds and other materials are less well understood. Apparently the gross emissions of sulphur dioxide from eruptions are only 15% of man-made emissions. That number is shaky and there are natural sources other than explosive eruptions. Perhaps more important is where the injection of the SO2 occurs. Much of the volcanically generated SO2 occurs at high enough altitudes to have an impact out of proportion to its volume. Also, I know that in drilling for oil and gas we use layers of ash at different depths as markers to aid in telling where we are relative to certain target zones. Some of these as layers are local, covering only a few states. At least one is found world-wide. In the end, our climate and weather are driven by that overwhelming engine of heat, the sun. That is as true on Venus, with a sulphurous atmosphere, as it is on Earth or Jupiter. The composition of that atmosphere is a product of the planet itself.

Anyway, I think that our activities have some impact but that over time they are overwhelmed by natural processes (unless we do something really silly; nuclear war, anyone? Even that will disappear over geologic time). Perhaps even more interesting is the clustering of major volcanic and meteor activity at the great extinction events in history, particularly the Paleozoic-Mesozoic and Mesozoic-Cenozoic boundaries. Most people don’t realize that 60% of all known species became extinct at the Paleozoic-Mesozoic boundary. A company called Pan Terra produces a fabulous wall chart titled “A Correlated History of the Earth” detailing the evolution of animal and plant life, plate tectonics, and volcanic and meteor activity.

Another comforting thought: the Galactic Drift theory has us due for a meteor/comet strike and another massive die-off….

Edit for grammar.

[ February 13, 2004, 18:45: Message edited by: solops ]

[narf poit chez BOOM]

Volcanoes have erupted since the formation of the earth, more and heavier when earth was younger, and I'm too missing an explanation why they should cause significant ozone holes only in our century.

i'm undecided on this, but i don't see how we'd have instruments to measure holes in the ozone more than a century ago. unless they leave a mark somewhere; tree rings, geology...

[solops]

Originally posted by narf poit chez BOOM:

quote:

---

Volcanoes have erupted since the formation of the earth, more and heavier when earth was younger, and I'm too missing an explanation why they should cause significant ozone holes only in our century.

i'm undecided on this, but i don't see how we'd have instruments to measure holes in the ozone more than a century ago. unless they leave a mark somewhere; tree rings, geology...

---

I'm not sure either, though I have read work on paleo-atmospheres. I recall the evidence as coming from rock and water samples from cores. We also learn of paleo-environments from things like crude oil:

"Crude Oils Provide Molecular and Isotopic Clues about OAEs
John Zumberge, GeoMark Research, Ltd, and Roger Summons, MIT"

http://aapg.confex.com/aapg/da2004/t...aper_86525.htm

[ February 13, 2004, 20:17: Message edited by: solops ]

[rextorres]

Core samples from glaciers in Greenland and Antartica. The gases caught in the ice enable researchers to measure the ratio of gases in the atmosphere.

Anyway - You are right natural effects will eventually overwhelm anything humans can do but that wasn't the issue.

The issue was that Fyron wrote - as it if were self-evident - that:

we just did not cause the hole in the ozone layer over Antarctica. That was caused by massive volcanic eruptions.

Even your two links refute that myth.

[ February 13, 2004, 20:34: Message edited by: rextorres ]