High seismic activity, tearing Africa in two parts

In northeastern Africa, in the deserts of Ethiopia's erupting volcano Erta Ale. In the crater of the volcano was always bubbling mass of silver-black lava. But in November 2010, the volcano began erupting again, waking up after decades of inaction. (University of Bristol / Lorraine Field)

Cracks began to appear a few years ago. But in recent months, seismic activity in the north-eastern Africa has intensified, reflected in a slow and gradual break of the continent. Researchers say that lava in this area as a result of magma streamed, usually seen on the sea floor, and that eventually the water will cover the land.

Cynthia Ebindzher — a geologist from the University of Rochester in New York — she could hardly believe what the man was saying, who returned from the deserts of Ethiopia. It was an employee of the company for the extraction of minerals, and it is reported that known in the north-eastern Ethiopia Erta Ale volcano erupted. Ebindzher, who has studied the volcano for years, was puzzled. The crater of the volcano was always filled with bubbling "soup" silver-black lava, but similar was observed in the last decade since its last eruption.

The announcement of this came in November last year. And Ebindzher immediately flew to Ethiopia with some same as she did the researchers. "The volcano is literally seething, bubbling, red-hot lava shot into the sky" — Spiegel Online reported Ebindzher (Spegel Online — an online version of the famous German newspaper "Der Spiegel" — annotated. Interpreter).

Earth as it is raised, is biased towards the north-east Africa and the region is changing quickly. Desert tremble, crack, cracks, volcanoes "boil", and sea water gradually invade the land. The researchers are confident that Africa split at rarely observed in geology.

The first fracture appeared millions of years ago, which led to the emergence of the Red Sea and Gulf of Aden. The second fault, which extends from the south of Ethiopia to Mozambique, is known as the East African Rift Valley, along the lines of which there are several volcanoes. Reach millions of years, and this area will also be filled with sea water.

This can happen quickly

But in the Danakil Depreshn (Danakil Depression), the northern region of Ethiopia, the ocean can appear much earlier (in comparison to the sea). There are 25-foot hills — the only thing that somehow inhibits the onset of the Red Sea. Ground level to the rear of them, have already dropped by a few meters (from previous levels), and the available white, salty deposits indicate past incursions of the sea, the occurrence of which still prevented the lava.

While no one can say with certainty when the sea capture the desert. But when it comes to that, it will happen very quickly. "Immersion hills — it's a matter of days," — said Tim Wright — researcher at the University of Leeds School at a recent conference organized by the American Geophysical Union in San Francisco.

"Over the past 5 years the geological transformation of northeastern Africa has accelerated sharply," — says Wright. Indeed, these processes are much faster than many expected. In recent years, geologists fixed only a few millimeters movement every year. "But now, these values increased up to a meter," — says Lorraine Field, a scientist from the University of Bristol, who also attended the conference.

Tremors cause deep cracks formed at the base of the desert and is the base in East Africa collapses like broken glass. Researchers in the Gulf of Tadjourah, which acts in Djibouti (A state in north-eastern Africa) Gulf of Aden, the newly registered a large group of seismic events. "Earthquakes occur along the mid-ocean ridge," — said Ebindzher.

The shift of tectonic plates

In these underwater mountain ranges outpouring of lava cracks constantly contributes to the creation of a new layer of the earth's crust, when lava cools, it becomes a part of the seabed. As the magma rises to the surface of the cortex, it is spread on both sides of the ocean, thus shifting tectonic plates and causing tremors.

In recent months, tremors in the Gulf of Tadjourah are getting closer and closer to the shore. As explained Ebindzher, split the ocean floor will gradually approach the land. What is now the place to be along the fault lines in the Ethiopian desert is nothing but an example of the geological phenomenon that occurs deep below the ocean surface.

Even the model of earthquakes supports the findings that the desert landscape is gradually transformed into the seabed, according to a recent article in the journal Geophysical Research, published by Zhaohui Yang and Wang-Ping Chen — two geologists from the University. Illinois. These researchers have recorded several strong earthquakes at shallow depth in the north-eastern Africa, which was similar to the record of earthquakes occurring in the mid-ocean ridges far out at sea.

In recent months, researchers have documented the growth of volcanic activity. Indeed, geologists have discovered volcanic eruptions close to the ground for 22 sites in the Afar Triangle in northeastern Africa. Magma has led to an increase in cracked up to 8 meters, according to Derek Keir from the University of Leeds. While most of the magma remains beneath the surface, in other places, such as Erta Ale volcano, it has cut its way through the land in the form of lava.

Ocean without water

They also noted that that the magma, which is observed in the area under discussion, is a kind of a kind of magma erupting at mid-ocean ridge in deep water. One of its features — low in silica. In magma coming out of Erty Ale, the same chemical compound that is deep and volcanoes. This whole area is becoming more and more like the bottom of the ocean … but without water.

A new round of activity began in 2005, when the crack length is 60 km suddenly formed in the Afar Depreshn (Remote region of Ethiopia). Since going on the expiry of the magma volume of 3.5 cubic kilometers, according to Tim Wright, it is enough that cover the whole territory of London and the coating thickness corresponded approximately to the average growth of a person.

From a geological point of view, the speed with which the magma is moving, is impressive. Its speed of navigating its way through the rock below the earth's surface is about 30 meters per minute, reports Eric Jacques from the Paris Institute of Earth Physics. Satellite measurements have documented the presence of the Earth's land surface, raised by magma, an area of about 200 km, similar to the asphalt on a hot summer day. Magma has also spread under the volcano Dabbah (North of Ethiopia, this volcano is considered to be the hottest place on the earth's surface — annotated. Interpreter), distribution area is comparable to the size of Lorraine (France) as reported at a conference in San Francisco.

Continued expansion

"These satellite observations also showed that the area of the territory, which went on a crack, much more than previously thought," — said Keir. Underground magma flows also cause an increase in temperature of the earth to the east of Egypt, as recently reported a group of geologists from the Egyptian National Research Institute of Astronomy and Geophysics in Seismological Research Letters (Seismological Research Letters is a bit of a common forum for informal communication among seismologists — annotated. Interpreter). At the Conference in San Francisco, James Geerti from Columbia University reported that as a result of the expiration of the magma in the desert in the north of Malawi emerged 17-kilometer deep ditch, and that has arisen due to the sides of the ditch of the land uplift pressure was 50 cm

The greatest increase growth of the magma in recent years, however, there is a place where it is not expected. In May 2009, has had an underground volcano in Saudi Arabia. A strong earthquake of magnitude 5.7 followed by tens of thousands more than the moderate tremors, causing about 30,000 people were forced to seek refuge. Area magma was roughly equivalent to the area together in Berlin and Hamburg, as reported at the conference which was the Sigerdzhon Jonsson from the King Abdullah University of Science and Technology. "The fact that the eruption was almost 200 km from the fault line in the north of Africa, surprised us all," — says Cynthia Ebindzher. And the biggest geological "building site" continues to expand. Lorraine Field confirms that magma is increasingly making its way to the surface of the earth, explaining that "the underground is the excessive accumulation of magma."

David Ferguson of Oxford University predicts a significant increase in volcanic eruptions and earthquakes in this area in the next decade. According to him, they will become more and more intense.

Also read:

> In Africa, the ocean is born — the Afar triangle. Photo
> In the west, the Gulf of Aden has happened more than a dozen earthquakes
> Whirlpool of the Gulf of Aden
> Earthquake in the Afar Triangle

All pictures are clickable.

Black lava rose and spilled out of the crater of the volcano November 22, 2010. (University of Bristol / Lorraine Field)

The picture of the volcano before the recent eruption. (D. Keir)

The eruption of the volcano signals the increasing geological activity in the East African Rift Valley. (University of Bristol / Lorraine Field)

North-east Africa is not the same as it was before. Began to shift the earth's crust. (University of Bristol / Lorraine Field)

The surface of the earth in the desert shakes and breaks, volcanoes erupt, the sea floods the surrounding land, gradually forming new shapes coast. (University of Bristol / Lorraine Field)

Undoubtedly, the African continent is beginning to crack. Last gap in the last million years has led to the emergence of the Red Sea and Gulf of Aden. Now the crust begins to move south from Ethiopia to Mozambique. (University of Bristol / Lorraine Field)

After a couple of million years that crack filled with sea water. (University of Bristol / Lorraine Field)

Scientists were also surprised by the quality and magma as it is the type that was discovered only during eruptions in oceanic ridges, deep under water. One of the distinguishing features of this magma is low levels of silicic acid. (University of Bristol / Lorraine Field)

Magma from the eruption of Erta Ale has the same composition as that of a deep-sea volcanic eruptions. Indeed, the entire region is beginning to show similarities with the ocean floor — in the absence of the fact that there is no water. (University of Bristol / Lorraine Field)

A large crack in the Ethiopian desert like the cracks that appear in the deep ridges far out at sea. (University of London / Elizabeth Baker / Royal Holloway)

Similar cracks in the Afar depression. Only low hills still prevent flooding of the area by the Red Sea. (University of Leeds / Tim Wright)

New flurry of activity began in 2005, when the 60-kilometer-long crack appeared in the Afar depression. (University of Rochester / Cindy Ebinger)

This entire region increasingly resembles the sea floor, just waiting for the water. (University of Rochester / Cindy Ebinger)

Radar imagery satellite recorded fault. In this picture you can see how volcanoes and Dabbahu Gabho away from each other. (University of Leeds / Tim Wright)

Excessive dust plot in the upper right hand corner of this image shows a fresh volcanic ash. In recent months, geologists have recorded 22 eruptions in the Afar depression. (University of London / Elizabeth Baker / Royal Holloway)

Cracks like this near the volcano Dabbahu depth is below sea level. (University of Auckland / Julie Rowland)

The information obtained from satellites, shows that in this region a much larger area was covered with cracks than previously assumed. (University of Auckland / Julie Rowland)

Since 2005, about 3.5 km? magma erupted onto the surface of the earth, scientists say — this amount is enough to cover the whole of London layer taller than a man. (University of Bristol / Lorraine Field)

Loraine Field, a scientist from the University of Bristol, said that more and more magma is ejected to the surface, adding that "magma pool becomes full." (University of Bristol / Lorraine Field)

According to Tim Wright, a current member of the Institute of Land and Environment of Leeds, in the last five years of the onset of the sea on the north-eastern Africa, "an incredibly accelerated", and everything happens much faster than expected. (University of Bristol / Lorraine Field)

The outlook on Erta Ale: David Ferguson of Oxford, predicts a substantial increase in volcanic activity and earthquakes in the region over the next few decades. (University of Bristol / Lorraine Field)

Translation: Anna Krasnov — article Antoshkina Anastasia — photos
Source: SPIEGEL ONLINE

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