For Mike W!! Volcanoes threaten to divide Africa.

[Rissask]

Volcanoes threaten to divide Africa


A plume of hot volcanic mantle rock is rising beneath Africa, trying to split the continent apart.


According to international researchers, it could eventually create a new ocean.

"The Ethiopian rift is one of the few places in the world where we can see the transition from continental rifting to something that looks more oceanic," Dr Cindy Ebinger told the BBC World Service's Discovery programme. "It's a unique area worldwide."

The crack in the Earth's surface runs for 2,000 kilometres from Malawi in the South, through Tanzania, Kenya and Ethiopia, to link-up with the Red Sea and the Gulf of Aden.

A look deep into the Earth's interior shows a huge plume of warm soft mantle rock rising diagonally from the core's boundary and running up beneath Southern Africa towards the Afar region of Ethiopia.

Volcano valley

The mantle super-plume, as it is called, may be responsible for the high elevation of much of Southern and Eastern Africa. It may also account for the line of volcanoes that runs up the Great Rift Valley, including Mount Nyiragongo, which recently sent red-hot lava pouring into the Congolese eastern town of Goma.

For most of its length the East African rift valley is just that: a rift running through a continent. But as it gets further north, its character changes.


By the time it joins up with the Red Sea it is more like a mid-ocean ridge, a line of cracks along which volcanic magma rises to create the floor of an ever widening sea.

In Ethiopia it is in transition between the two and this gives geologists their best chance of studying how a new ocean forms.

Earth tremors

Project Eagle (Ethiopian Afar Geophysical Lithospheric Experiment) draws together researchers from Royal Holloway College London, and the universities of Leicester, Leeds and Addis Ababa.

The project aims to see deep into the Earth by using many sensitive seismometers to record natural earth tremors and the vibrations from explosive charges detonated in boreholes.

<!-- inlineIMAGE --><TABLE cellSpacing=3 cellPadding=3 width=154 align=right border=0><TBODY><TR><TD> <SMALL>Project EAGLE researchers map out the terrain</SMALL>




</TD></TR></TBODY></TABLE>The seismic waves travel at different speeds through rocks of different temperatures and densities to bounce off distinct layers.

In this way, Dr Cindy Ebinger and her colleagues hope to discover any reservoirs of hot, molten magma within the crust that could feed future volcanoes as well as seeing how the crust is thinned as it is pulled apart.

"There are several dormant volcanoes but there has never been a study to monitor volcanoes in the rift," Dr Ebinger explained.

"These are dangerous because the lava has more silica in it and is resistant to flow, so these are explosive eruptions that can cause death and damage to a large region."

New ocean

So far, the indications are that a mantle plume alone is not enough to open an ocean.

There needs to be a sideways pull to rift the continent, allowing the hot magma to rise underneath to fill the gap and form the floor of the new ocean.

Opinions vary over whether that will actually happen along the East African rift.

With the Atlantic Ocean still opening and pushing on Africa from the west and India still colliding with Asia and the Indian Ocean opening to the east, there may be nowhere for the rift to expand.

Further north however, the picture may be different, said Professor Peter Maguire, of Leicester University.

"We do believe that we are on the transition from continental to oceanic rifting," he explained. "The continent in the northern part of Ethiopia is separating and there will be an ocean penetrating down into East Africa."

http://news.bbc.co.uk/1/hi/sci/tech/1823019.stm

Cool! Not that we will see the new 'island' or continent and new sea, in our lifetimes, but still neat- doesn't look like Pangaea is gonna be reunited anytime soon though Mike.

[BonnyW]

Yet another example of a 'doomsday' report...
Entropy doom... (Second law of thermodynamics).

[MikeW]

Damn, this goes against everything I believe in politically. I bet GW is involved. Cheney probably told him there was oil down there. It's time to get Cheney and his son out of office.

[rugger]

Originally Posted by BonnyW

Yet another example of a 'doomsday' report...
Entropy doom... (Second law of thermodynamics).

Entropy! bonnie your not your average, blonde, naughty chica are you?

[Rissask]

Yeah, Bonny is one smart cookie.

Damn, this goes against everything I believe in politically. I bet GW is involved. Cheney probably told him there was oil down there. It's time to get Cheney and his son out of office.

Funny. Always blaming everything on poor Georgie boy. You give him too much credit I think!

Although.....Bonny, I don't think it's a doomsday report really at all .....I read in a book that was written in the late nineties about how Africa is splitting in the region of the Rift Valley, they have known this for ages....it's not gloom and doom at all, just geographical fact- isn't it?

Divergent plate boundaries occur where two plates are moving apart from each other. When plates break apart, the lithosphere thins and ruptures to form a divergent plate boundary. In the oceanic crust, this process is called seafloor spreading, because the splitting plates are spreading apart from each other. On land, divergent plate boundaries create rift valleys—deep valley depressions formed as the land slowly splits apart.

When seafloor spreading occurs, magma, or molten rock material, rises to the sea floor surface along the rupture. As the magma cools, it forms new oceanic crust and lithosphere. The new lithosphere is less dense, so it rises, or floats, higher above older lithosphere, producing long submarine mountain chains known as mid-ocean ridges. The Mid-Atlantic Ridge is an underwater mountain range created at a divergent plate boundary in the middle of the Atlantic Ocean. It is part of a worldwide system of ridges made by seafloor spreading. The Mid-Atlantic Ridge is currently spreading at a rate of 2.5 cm per year (1 in per year). The mid-ocean ridges today are 60,000 km (about 40,000 mi) long, forming the largest continuous mountain chain on earth. Earthquakes, faults, underwater volcanic eruptions, and vents, or openings, along the mountain crests produce rugged seafloor features, or topography.

Divergent boundaries on land cause rifting, in which broad areas of land are uplifted, or moved upward. These uplifts and faulting along the rift result in rift valleys. Examples of rift valleys are found at the Krafla Volcano rift area in Iceland as well as at the East African Rift Zone—part of the Great Rift Valley that extends from Syria to Mozambique and out to the Red Sea. In these areas, volcanic eruptions and shallow earthquakes are common.

http://encarta.msn.com/text_76155462...Tectonics.html


Now if they were claiming it was going to happen in the next two weeks- now that would be a 'doomsday report'!

And re-reading my original post ....yeah, that's the media for you- the plain truth is too bland and boring I guess huh? It was worded fairly.....excitedly, wasn't it?



(not sure if you were being funny about being funny...or just being funny...damn internet, sorry! )

[BonnyW]

Originally Posted by Rissask

(not sure if you were being funny about being funny...or just being funny...damn internet, sorry! )

Yep.

[Donny]

Originally Posted by rugger

Entropy! bonnie your not your average, blonde, naughty chica are you?

We don't call her Doctor fer nuttin'!
I'm jest worried I'm gonna learn way too much on our Peepfest Fishin' Expedition. But I am lookin' forward to the honor!