Edward Capuano
Millions of years ago the first major cracks appeared, but in recent months in North Africa the seismic activity has been a sudden increase causing an acceleration of the evolution of cracks in the ground with earthquakes. Geologists and volcanologists argue that the lava in the region is in line with the magma normally present on the seabed and the water finally cover the desert.
Dr. Cynthia Ebinger, a geologist at the University of Rochester New York, was incredulous when an employee at a company of mineralogy, informed him of what was happening in the Ethiopian desert, the famous volcano Erta Ale, located in north eastern Ethiopia was in full swing eruption. At that point, Dr. Cynthia Ebinger, who studied for years the Erta Ale volcano, was taken aback. The crater of the volcano had always been filled with a 'soup' of boiling lava silver-black, but after its last eruption was always left for decades in a state of low activity.
Last November (2010), after receiving a phone call, Dr. Cynthia Ebinger took the plane and went to Ethiopia with some fellow researchers. "The volcano was overflowing; flaming lava was thrown into the sky," said Dr. Ebinger corresponding to the online magazine 'Der Spiegel'. In the north-east of Africa the land is in turmoil and this is comes a change in the morphology of this area. The desert is shaken continuously causing a widening of the fracture, the volcanoes are in full eruption, and the waters are draining the land.
scholars argue that the African rift leads to a division at a rate that occurs very rarely in geology. The Red Sea and the Gulf of Aden were created milioni di anni fa dalla prima frattura. Dall'Etiopia al Mozambico si estende la seconda frattura, fiancheggiata da molti vulcani, chiamata Great Rift Valley che, secondo le teorie scientifiche, rischia di essere sommersa dal mare.
Secondo gli studiosi le acque del mare potrebbero inondare le terre molto prima a causa della depressione della Dancalia, situata a settentrione della valle. Il luogo è profondo circa 25 metri e le acque del Mar Rosso sono trattenute solo dalle colline. La zona dietro le colline ha già subito uno sprofondamento di alcune decine di metri rispetto i livelli precedenti e la presenza di sale sul deserto testimonia inequivocabilmente che il mare abbia già in passato inondato la zona. La lava ha successivamente poi fatto ritirare the sea.
the moment no one can hazard any assumptions about when the sea will cover the desert again. In a recent conference organized by the American Geophysical Union (AGU) in San Francisco, Tim Wright, University of Leeds School, says that when this event will happen will manifest itself very quickly: the sinking of the hills could also be in a few days. The change in geology of North Africa, the last five years has increased sharply, and the course you are speeding in an unexpected way, contends Tim Wright.
In a few years geologists - Loraine says Field, a researcher at the University of Bristol, in the conference - has discovered that the movement annually has grown from a few millimeters to nearly a meter. The land-based activities digs deep cracks in the flat desert territory caused to look like a broken glass. The Gulf of Tadjoura, stretching from Djibouti in the Gulf of Aden, was affected by a massive earthquake activity. Dr. Cynthia Ebinger argues that the seismic activity extends along the mid-ocean ridge. In
seabed lava comes from volcanoes continually creating new crust, once it has hardened. Earthquakes are developed with the shifting of tectonic plates when the magma extends upwards and then spread on both sides on the seabed. This activity has given rise in recent months, a sharp increase in earthquakes in the Gulf of Tadjoura. Dr. Cynthia Ebinger says that this splitting of the ocean floor is gradually extending to the continent. A recent article in the Journal of Geophysical Research, edited by Zhaohua Yang and Wang-Ping Chen, two geologists at the University of Illinois at Urbana-Champaign, he theorized that the desert is slowly turning into a deep seabed. Shaped by a myriad of deep earthquakes in north Africa comparable to the earthquakes that occur only on mid-ocean ridges in the open sea.
Volcanic activity has increased sharply in recent months, geologists have recorded in 22 places in the triangle di Afar, nel nord Africa, eruzioni vulcaniche in prossimità alla superficie terrestre. Nei rapporti di Derek Keir, presso l'Università di Leeds, si legge che questa attività vulcanica ha permesso la creazioni nel terreno di fenditure anche di otto metri di larghezza. La maggior parte della struttura magmatica rimane sotto per poi eruttare altrove, come a Erta Ale.
Anche lo studio del magma ha permesso ai vulcanologi di scoprire che la sua tipologia, caratterizzata da una bassa percentuale di acido silicico, è la medesima di quella che caratterizza le eruzioni nei dorsali medio-oceanici posti nelle profondità marine. La lava che fuoriesce dal vulcano Erta Ale ha questa composizione chimica. In pratica, secondo i ricercatori, tutta la paradoxically in a region like the ocean floor without water.
The massive volcanic activity began in 2005. Then he formed, along a stretch in the Afar depression, a crack 60 km long and 3.5 kilometers of magma erupted well. Dr. Tim Wright argues that the volume of magma was enough to flood the entire city of London under a blanket of five feet of lava material.
According to a report by researcher Eric Jacques, Institute of Earth Physics in Paris, the magma is moving at a speed of 30 meters per minute. A very unusual speed from a geological point of view. Derek Keir says that images from satellites are striking: a clear enlargement della zona interessata alla formazione delle crepe. Inoltre fiumi sotterranei di magma sono localizzati nell'Egitto orientale.
Il ricercatore James Gaherty, della Columbia University, ha detto alla conferenza AGU che a nord del Malawi le eruzioni hanno causato uno squarcio di 17 chilometri nel deserto. Ciò ha procurato un innalzamento della terra circostante che, in alcuni punti, ha raggiunto fino a 50 centimetri.
Nel mese di maggio 2009 in Arabia Saudita è scoppiato un vulcano sotterraneo. Trentamila persone hanno dovuto abbandonare i luoghi di residenza a causa di un terremoto con una magnitudo di 5,7 e di decine di migliaia di scosse di assestamento. Il magma fuoriuscito ha ricoperto un'area di un diametro pari alle città di Berlino e Hamburg put together. According to Dr. Cynthia Ebinger the thing that surprised everyone is that the eruptive phenomenon has taken shape at about 200 km away from the fault line in North Africa.
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translation and linguistic revision by: Edoardo Capuano / Source: spiegel.de
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