Posted on 03/21/2022 7:34:30 AM PDT by Red Badger
Scientists studying ice cores packing in some 60,000 years of history have found signs of thousands of volcanic eruptions across that time, stretching back to the last Ice Age – with 25 of the eruptions larger than anything Earth has seen in the last 2,500 years.
Researchers excavated the cores near both poles: in Antarctica (where 737 eruptions were logged) and Greenland (where 1,113 eruptions were found). A total of 85 eruptions were large enough to leave evidence behind at both poles.
That evidence takes the form of sulfuric acid deposits left behind by the eruptions. It gives researchers clues as to just how large and impactful particular volcanoes have been.
"" Anders Svensson examining ice cores. (NEEM)
"To reconstruct ancient volcanic eruptions, ice cores offer a few advantages over other methods," says physicist Anders Svensson from the University of Copenhagen in Denmark.
"Whenever a really large eruption occurs, sulfuric acid is ejected into the upper atmosphere, which is then distributed globally – including onto Greenland and Antarctica. We can estimate the size of an eruption by looking at the amount of sulfuric acid that has fallen."
Using the Volcanic Explosivity Index (VEI), which ranges from a low of 1 to a high of 8, the team found 69 volcanic eruptions that exceeded the 1815 Tambora eruption (VEI 7) – an event that was enough to block out sunlight and initiate a period of global cooling.
Those 69 eruptions include one in Lake Taupo, New Zealand, some 26,500 years ago (VEI 8), and one in Toba, Indonesia, around 74,000 years ago (VEI 8). In comparison, the 2010 Eyjafjallajökull eruption in Iceland scored 4 on the VEI scale, while the 2011-2012 Puyehue-Cordón Caulle eruption in Chile reached VEI 5.
VEI 7 eruptions happen around once or twice every thousand years, so we might not have much of a wait until the next one. As for the next VEI 8 eruption, it could be in a hundred years or a few thousand years, according to the researchers.
The eruptions logged in the ice cores would have been much bigger in every sense than the ones in living memory and more catastrophic in terms of their impact on the planet. The research fills in some of the blanks in Earth's volcanic record, a record that before now has been a bit fuzzy beyond 2,500 years ago.
"The new 60,000-year timeline of volcanic eruptions supplies us with better statistics than ever before," says Svensson.
"Now, we can see that many more of these great eruptions occurred during the prehistoric Ice Age than in modern times. Because large eruptions are relatively rare, a long timeline is needed to know when they occur. That is what we now have."
The researchers built on previous work synchronizing timescales across ice cores taken from different poles – enabling them to more accurately identify the eruptions that had significant effects in both Antarctica and Greenland.
The research is more than just a history lesson. Ice cores also capture temperatures before and after eruptions, giving us a window into their effect on the global climate. The biggest events can cause cooling for 5-10 years after the actual eruption.
Knowing how sensitive Earth's climate is to major events like those documented in the ice cores can inform future climate models – whether those models are looking at the next volcanic eruption or the ongoing impact of rising carbon dioxide levels in the atmosphere.
"Ice cores contain information about temperatures before and after the eruptions, which allows us to calculate the effect on climate," says Svensson. "As large eruptions tell us a lot about how sensitive our planet is to changes in the climate system, they can be useful for climate predictions."
The research has been published in Climate of the Past.
535-537 AD are thought to be pretty bad for much of the world
As good ol' Rahm Emanuel observed, "You never want a serious crisis to go to waste." Left unsaid was the part about creating your own crisis, if there wasn't a real one around when you needed it...
;>)
https://roman-empire.net/places/mount-krakatoa-eruption/
The Krakatoa eruption of 535 ushered in several years of cold “dark age” when grain crops in the Holy Roman Empire failed. It ushered in the first of the plagues which persisted for centuries in Europe. The kill off of Roman grain eaters in the middle east ushered in the migration and takeover by beef-eating Turks from the Steppes. The population void gave us Muhamed’s goat-eating armies and Islam.
Modern CO2 is a non-existent blip.
You do?
How was it?
Most important. Was there beer?
Mead..................
Hot. Very HOT!...................
YUK..well its better’n nothing.
Spend a lot of time in the water?
Mead is good.............
Only on Saturday nights.....................
Yellowstone will eventually go off, and that will be the last of the global warming talk.
Does Catastrophism explain the mistaken idea that the earth is significantly older than 6,000 years?
/s
If the entirety of Earth’s history was a bar graph, with the height of the Empire State Building as the representation, the entirety of human history would be the thickness of a postage stamp on the top of it.........
Thanks Red Badger.
If there is a massive eruption that causes global cooling with a year or two without a summer, we can totally fix it if we raise the price of fossil fuels
There were ‘people’ around, so what did they do?................
[snip] In the last glacial period, many Greenland tephra deposits have been associated with Icelandic eruptions, while around a dozen of identified tephra layers originate in North America and eastern Asia (Abbott and Davies, 2012; Bourne et al., 2015; Davies et al., 2014). In Antarctica, tephra layers have been identified and associated with eruptions occurring within Antarctica and in the Southern Hemisphere (Narcisi et al., 2005, 2010, 2012). Recently, Mcconnell et al. (2017) identified tephra from the long-lasting and halogen-rich Antarctic Mount Takahe eruption that occurred around 17.80 ka. Tephra of the Oruanui eruption from the Taupo volcano in present-day New Zealand has been identified and dated to 25.32 ka before 1950 CE (BP) in the West Antarctic Ice Sheet Divide ice core (WDC) (Dunbar et al., 2017). [/snip]
https://cp.copernicus.org/articles/18/485/2022/
https://cp.copernicus.org/articles/18/485/2022/cp-18-485-2022-f06-web.png
74,000 years ago was the human population bottle neck. Our genome tells the story. We went down to a single tribe of 2,000 individuals. The volcanoes almost destroyed us. Once past this we contended with Neanderthal and other sub species.
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