Ancient Volcano's Devastating Effects Confirmed (Toba eruption and the following Ice Age)

A massive volcanic eruption that occurred in the distant past killed off much of central India's forests and may have pushed humans to the brink of extinction, according to a new study that adds evidence to a controversial topic.

The Toba eruption, which took place on the island of Sumatra in Indonesia about 73,000 years ago, released an estimated 800 cubic kilometers of ash into the atmosphere that blanketed the skies and blocked out sunlight for six years. In the aftermath, global temperatures dropped by as much as 16 degrees centigrade (28 degrees Fahrenheit) and life on Earth plunged deeper into an ice age that lasted around 1,800 years.

In 1998, Stanley Ambrose, an anthropology professor at the University of Illinois, proposed in the Journal of Human Evolution that the effects of the Toba eruption and the Ice Age that followed could explain the apparent bottleneck in human populations that geneticists believe occurred between 50,000 and 100,000 years ago. The lack of genetic diversity among humans alive today suggests that during this time period humans came very close to becoming extinct.

To test his theory, Ambrose and his research team analyzed pollen from a marine core in the Bay of Bengal that had a layer of ash from the Toba eruption. The researchers also compared carbon isotope ratios in fossil soil taken from directly above and below the Toba ash in three locations in central India — some 3,000 miles from the volcano — to pinpoint the type of vegetation that existed at various locations and time periods.

Heavily forested regions leave carbon isotope fingerprints that are distinct from those of grasses or grassy woodlands.

The tests revealed a distinct change in the type of vegetation in India immediately after the Toba eruption...

>> That is ash pain to the Nth
Homo Sapiens or perhaps Neanderthals must have done this... Gaia would never allow such a thing without Algore knowing via his internet.

Beware Denmark or it will all make sense to you. <<

Them Damned Neanderthals and their mining operations in Toba nearly doomed us all.....

Actually they are being very concervative in their estimates. It was the largest volcanic eruption in 450 million years.

This is a Super Volcano not your garden variety Mt St. Helens (explosive index=5) or (explosive index=6) or 1991 Mt Pinatubo eruption (explosive index=6 - 5 cubic kilometres of rock and 15-30 million tons of sulfur dioxide gas.

The Toba eruption was the largest disturbance of the stratosphere since the eruption of Krakatau in 1883. The average temperature in the Northern Hemisphere was reduced 0.5 to 0.6C (degrees) and the entire planet was cooled 0.4 to 0.5C (degrees). The maximum reduction in global temperature occurred in August 1992 with a reduction of 0.73 (degrees).

Toba was a 10 or better on the index. The crater is 60 X 100 km. The ash total is part of the larger 3,000 cu/km of ejected material.

1815 Tambora (explosive index=7 - "the year without a summer") 150 cu/km of rock, 200 million tons of aerosols.

1983 Mt St Helens eruption (.02 cu/km ).

Toba's plume is estimated to have reached 34 km high and 1 trillion tons of aerosols (including 200,000,000 tons of sulfur dioxide - SO2). The ash covered India between 1 and 6 meters deep. 6 year period during which the largest amount of volcanic sulphur was deposited in the past 110,000 years. Sea level was 160 feet below current.

There was also a 1000 year ice age right after - temps fell 12 degrees C. world wide.

If you are young enough, maybe you will have the misfortune to hear the overdue Yellowstone Super Volcano go off - won't matter where in the world you are - you will hear it. And that will make Toba look like a firecracker. And once again the human genome will be reduced - if any survive at all...

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Thanks colorado tanker. Note: this topic is from 12/04/2009. Blast from the Past. Just adding to the catalog, not sending a general distribution. To all -- please ping me to other topics which are appropriate for the GGG list.