Everything Science Forum

About 74,000 years ago a supervolcano erupted in Sumatra.

It would have been the loudest noise ever heard by man. It would have blasted vast clouds of ash across the world.

The resultant caldera formed Lake Toba, 100 kilometres long, 60 kilometres wide. it was, in short, colossal. Scientists are only now beginning to understand the effects of so much ash on the planet's climate. This is the ocean core repository at Columbia University in America. It contains thousands of drill samples from seabeds round the world, a historical keyhole through which scientists, like Michael Rampino can view volcanic history.

MICHAEL RAMPINO: The size of the Toba eruption was enormous. We're talking about, about 3,000 cubic kilometres of material coming out of that volcano. That's about 10,000 times the size of the 1980 Mount St. Helens eruption which people think of as a large eruption, a truly super eruption.

This is an ocean drilling core from the central Indian Ocean. It's about 2,500 kilometres from the Toba volcano and here are 35 centimetres of ash deposited after the Toba eruption. It shows that this Toba eruption was a supervolcanic event, it was much, much bigger than any other volcanic eruption we see in the geological record. Chemical analysis of the ash tells us that this eruption was rich in sulphur, would have released a tremendous amount of sulphur dioxide and other gases into the stratosphere which would have turned into sulphuric acid aerosols and affected the climate of the Earth for years.

from BBC2 - Horizon - "Supervolcanoes" - http://exodus2006.com/transcript.htm

How did it affect our ancestors - and us?

 :koala

Early signs of mega volcano in Sumatra very close to where the Tsunami happened - it can be devastating to the human civilization

http://www.indiadaily.com/editorial/2350.asp

Volcanic ashes have made thousands of people in Sumatra flea the active volcanic regions that are experiencing harmonic tremor and some solid signs of an eminent mega volcano in that region soon. The recent volcanic activities with the accompanying harmonic tremor since last week is alarming and is making many geologists run towards their computer model for finding clues and validation of facts.

Toba in Sumatra experienced the massive volcano of VEI 8.0 – super volcano 74,000 years back. The deep Java trench marks the line where the Indo-Australian plate subducts, i.e. slips under, the section of the Eurasian plate on which Indonesia sits. While sinking, the Indo-Australian plate heats up and its water content turns to superheated steam under enormous pressure. Prodigious energies are generated and the volcanoes on the fault line release a part of these energies. The speed of that push is 70 mm (2.75 in.) per year, adding up to more than 5 km (3.1 miles) in the 73,000 years since the last major Toba eruption.

According to computer models, somewhere near Toba, along the fault line there may be another super volcano getting ready for eruption. 3.1 mile sinking of Indo-Australian plate under the Eurasian Plate in the last 74,000 years has created enough magma for a super volcano.

The recent series of volcanoes in that area have increased the level of alarm. Some of the quakes mistaken as aftershocks were harmonic tremors signifying lava movements. If Toba or along Toba the volcanic eruption take place, it can bring the human civilization to its knees. This has the potential 3000 cubic Kilometer of eruption. That can be so devastating that earth may experience a drop in temperature of 30degrees Fahrenheit for many years. It can actually larger than the one Toba experienced 74,000 years back.

The volcanic activities in the regions in the past week may be signaling an eminent mega volcano a sort of repeat of what happened 74,000 years back. One interesting fact is that this area is just on the opposite side in the globe from the “Yellow Stone Hot Spot” in America.

If a mega volcano happens in Sumatra of VEI 8.0. it can be catastrophic to our civilization. The ashes will engulf the whole world with serious reparation on livelihood, agriculture and weather. Last time it wiped out almost 75% of all living beings on the land surface on the earth.

More info on Sumatran supervolcano - http://en.wikipedia.org/wiki/Supervolcano