Posted on 12/24/2012 9:37:21 AM PST by Errant
In 1991, it was a disaster for the villages nearby the erupting Philippine volcano Pinatubo. But the effects were felt even as far away as Europe. The volcano threw up many tons of ash and other particles into the atmosphere causing less sunlight than usual to reach the Earth's surface. For the first few years after the eruption, global temperatures dropped by half a degree. In general, volcanic eruptions can have a strong short-term impact on climate.
Conversely, the idea that climate may also affect volcanic eruptions on a global scale and over long periods of time is completely new. Researchers at GEOMAR Helmholtz Centre for Ocean Research Kiel (Germany) and Harvard University in Massachusetts (USA) have now found strong evidence for this relationship from major volcanic eruptions around the Pacific Ocean over the past 1 million years. They have presented their results in the latest issue of the international journal "Geology".
The basic evidence for the discovery came from the work of the Collaborative Research Centre "Fluids and Volatiles in Subduction Zones (SFB 574). For more than ten years the project has been extensively exploring volcanoes of Central America.
"Among others pieces of evidence, we have observations of ash layers in the seabed and have reconstructed the history of volcanic eruptions for the past 460,000 years," says GEOMAR volcanologist Dr Steffen Kutterolf, who has been with SFB 574 since its founding. Particular patterns started to appear.
"There were periods when we found significantly more large eruptions than in others" says Kutterolf, the lead author of the Geology article.After comparing these patterns with the climate history, there was an amazing match. The periods of high volcanic activity followed fast, global temperature increases and associated rapid ice melting.
To expand the scope of the discoveries, Dr Kutterolf and his colleagues studied other cores from the entire Pacific region. These cores had been collected as part of the International Integrated Ocean Drilling Program (IODP) and its predecessor programmes. They record more than a million years of the Earth's history.
"In fact, we found the same pattern from these cores as in Central America" says geophysicist Dr Marion Jegen from GEOMAR, who also participated in the recent study.
Together with colleagues at Harvard University, the geologists and geophysicists searched for a possible explanation. They found it with the help of geological computer models. "In times of global warming, the glaciers are melting on the continents relatively quickly.
At the same time the sea level rises. The weight on the continents decreases, while the weight on the oceanic tectonic plates increases. Thus, the stress changes within in the earth to open more routes for ascending magma" says Dr Jegen.
The rate of global cooling at the end of the warm phases is much slower, so there are less dramatic stress changes during these times. "If you follow the natural climate cycles, we are currently at the end of a really warm phase.
Therefore, things are volcanically quieter now. The impact from man-made warming is still unclear based on our current understanding" says Dr Kutterolf. The next step is to investigate shorter-term historical variations to better understand implications for the present day.
Plastic Man was my favorite comic book character when I was a kid! Even modeled my stage name after his nickname of “Plas.”
Google "Isostatic Equalibrium." The Great Lakes region where you live is still slowly rising to achieve equalibrium after being relieved the weight of huge glaciers from the last ice age. Meanwhile the weight of the meltwater has been transferred to the Atlantic. That disequalibirum will, over time, affect tectonic plate boundaries.
Volcanic activity is caused by subduction of oceanic plates under continental plates. There are many forces affecting plate subduction, important among them the rate at which mid-oceanic ridges supply new plate material. But I think it's reasonable to investigate the relationship of isostatic movement at plate boundaries to volcanic activity.
On the other end, I've seen numerous reports saying the the Antarctic cap is seeing a record increase in ice buildup.
Looks to me like the start of a major ice-age cycle is past due and if you look at historic CO2 spikes from ice-core samples, we're seeing a similar drawn out spike now that also occurred 400K years ago.
Just sayin'...
:)
Merry Christmas my friend and keep an eye to the sky tomorrow and not for Santa either!....lol
LOL! Thanks partner! Been hearing some ominous reports for sure... Hope you and yours have a great Christmas too!!
It has long been known that volcanic activity can cause short-term variations in climate. Now, researchers at the GEOMAR Helmholtz Centre for Ocean Research Kiel (Germany), together with colleagues from Harvard University (Cambridge, Massachusetts, USA) have found evidence that the reverse process also occurs: Climate affects volcanic activity.Global warming shills alert.
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Well, that’s clearly a broccoli cloud, so maybe they were talking about something different.
“There were periods when we found significantly more large eruptions than in others” says Kutterolf, the lead author of the Geology article.After comparing these patterns with the climate history, there was an amazing match. The periods of high volcanic activity followed fast, global temperature increases and associated rapid ice melting.
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so this would explain why temperature rises cause carbon dioxide rise in the past. the extra carbon dioxide comes from volcanos
not a bad match. too bad most climatologists won’t notice that the arrow of causality is heat causes carbon dioxide rise rather than carbon dioxide causes heat rise.
Nope quakes have a cycle too.
Makes sense to me. That and that underwater volcanoes, which occur in much greater numbers
than above sea level, also contribute to the heating of the oceans, causing even more CO2 to be released into the atmosphere.
Your initial question concerned volcanic cycles. It's obvious, however, the two are certainly related. The question is which one drives the other; or, what is the amount of synergy taking place?
#36...?
awesome graph....interesting!
Spend your weekend combining them...lol
First of all this is not a brand new theory, I recently read a whole book on the volcanic activity in Europe as the Eurasian ice sheet melted at the end of the last ice age. Incidentally, the Pinatubo eruption had nothing to do with ice. However, it is very clear that the increased vulcanism in Europe at the end of the last ice age was probably triggered by the uplift of the land as the ice melted, rather than being connected to the beginning of an ice age. The Lacher Zee (sp?, can’t find my book) volcano in Germany, and volcanic activity in France occurred at that time, and there were also some very massive eruptions of Vesuvius, far larger than in historic times. These areas are on the north side of the plate for the movement of Africa.
There are no recent volcanic areas in the center of continental North America, however, there are some really old volcanic deposits (north and east?) near Yellowknife in Canada with Kimberlite deposits where diamonds have been discovered and I believe are being exploited now.
While there may be some effect from isostatic rebound, there is a chicken/egg question. Volcanic activity will be preceded by higher heat flow at the surface. Once started, ash deposits will decrease the albedo of existing ice/snow fields and accelerate melting, provided atmospherically suspended ash is not significant enough to retard insolation. Certainly, melting will accompany volcanic activity. To say melting owuld cause volcanic activity is a far stretch when there is the entire Canadian Shield in isostatic rebound from the last Ice Age and recent non-margin volcanic activity is pretty small.
The kimberlites in AB, for example, are 45 to 75 million years old, whereas the Caldera activity in Yellowstone is a few hundred thousand years old, and the Long Valley Caldera only a few hundred.
If melting ice caused volcanoes, (instead of the other way around) Saskatchewan, Manitoba, North Dakota, and Minnesota should be prime for eruptions--the ice sheets here were well over a kilometer thick, and in many places three times that.
Where melting ice and volcanoes are associated at all, my money is on heat flow from the magma melting the ice, not the melting ice causing volcanism.
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