Cracks began to appear a few years ago. But in recent months, seismic activity in the north-eastern Africa has intensified, as manifested in the slow and gradual breaking of the continent. Researchers say that lava in this area as a result of magma streamed usually visible on the seabed, 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 people say, who returned from the deserts of Ethiopia. It was an employee of the company for the extraction of minerals and it is reported that the famous north-eastern Ethiopia Erta Ale volcano erupted. Ebindzher, who has studied the volcano for years, was puzzled. Crater was always filled with bubbling "soup" of silver-black lava, but similar was observed in the last decade since its last eruption.
The announcement came in November last year. And Ebindzher immediately flew to Ethiopia with some the same as she did the researchers. "The volcano is literally seething, bubbling, red-hot lava shot up into the sky" — Spiegel Online reported Ebindzher (Shpegel Online — online version of the famous German newspaper "Der Spiegel" — annotated. Translator).
Earth as it is raised, is shifted to 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 speed rarely seen 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 fracture, stretching from the south of Ethiopia to Mozambique, is known as the East African Rift Valley, along 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), northern region of Ethiopia, the ocean can appear much earlier (in comparison to the sea). There are 25-meter hill — the only thing that somehow resisted the advance of the Red Sea. Ground level to the rear of them, already dropped a few feet (from the previous levels), and the existing white, salty deposits indicate past incursions of the sea, the occurrence of which still prevented lava.
While no one can say with certainty when the sea take over 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 five years, the geological transformation of northeastern Africa has accelerated sharply," — said Wright. Indeed, these processes are much faster than many expected. In recent years, geologists have recorded only a few millimeters of movement each year. "But now, these values increased to meter" — says Lorraine Field, scientists 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 Tadjoura, which acts in Djibouti (A state in north-eastern Africa) Gulf of Aden, has recently 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 lava flows from the 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 extends on both sides of the ocean, thereby moving tectonic plates and causing tremors.
In recent months, tremors in the Gulf of Tadjoura was getting closer and closer to shore. As explains 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 conclusion that the desert landscape is gradually transformed into the sea bed, according to a recent article in the journal Geophysical Research, published by Zhaohui Yang and Wang-Ping Chen — two geologists from the University of units. Illinois. These researchers have recorded several strong earthquakes at shallow depths in the north-east Africa, which was similar to the record of earthquakes occurring at mid-ocean ridges far out at sea.
In recent months, researchers have recorded growth of volcanic activity. Indeed, geologists have discovered volcanic eruption close to the surface in 22 points in the Afar Triangle in northeastern Africa. Magma has increased the cracks of up to 8 meters, reports Derek Keir from the University of Leeds. While most of the magma remains beneath the surface, in other places, such as the volcano Erta Ale, 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 sort of a kind of magma erupting at mid-ocean ridges deep water. One of its features — low in silica. In magma, leaving Erty Ale, the same chemical compound that has a 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 of 60 km suddenly formed in the Afar Depreshn (Remote area of Ethiopia).
Since going on the expiry of the magma volume of 3.5 cubic kilometers, which according to Tim Wright, enough that cover the whole of London, and the coating thickness is approximately corresponded to the average growth of a person.
From a geological point of view, the speed with which the magma is moving, impressive. Its rate of navigating its way through the rock below the surface about 30 meters per second, reports Eric Jacques from the Paris Institute of Earth Physics. Satellite measurements have recorded the presence of the earth's surface, raised magma area of approximately 200 km, similar to the asphalt on a hot summer day. Magma also spread under the volcano Dabbahu (North of Ethiopia, this volcano is considered the hottest spot on the surface of the Earth — annotated. Translator), distribution area is comparable to the size of Lorraine (France) as reported at a conference in San Francisco.
"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 in the east of Egypt, as recently reported by 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. Translator). At the Conference in San Francisco, James Geerti Columbia University, reported that as a result of the expiration of the magma in the desert in the north of Malawi occurred 17 kilometers deep ditch, and that arising from the sides of the ditch of the land uplift pressure was 50 cm
The greatest increase, growth in the number of magma in recent years, however, there was in the place where it was 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 moderate tremors, causing about 30,000 people were forced to seek refuge. Area magma was approximately the square together in Berlin and Hamburg, according to the conference which was the Sigerdzhon Jonsson from the King Abdullah University of Science and Technology. "The fact that the eruption took place almost 200 miles of the fault line in North Africa, has 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, explaining that "the underground is an 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.
> In Africa born Ocean — Afar triangle. Photo
> In the west the Gulf of Aden have been more than a dozen earthquakes
> Whirlpool Gulf of Aden
> Earthquakes in the Afar Triangle
All photos are clickable.
Translation: Anna Krasnova — article Antoshkina Anastasia — photos
Source: SPIEGEL ONLINE