Activation of a new zone of destruction of the crust west of Galicia and Portugal close the ocean and bring Europe to North America.
The Atlantic Ocean is just a memory within 220 million years
If there is still someone out here in 220 million years, U.S. will be much closer to the Iberian Peninsula. Sounds like a slogan for a travel agency, but is literal then, if the provisions of the Portuguese geologist Joao Duarte met, Iberia and North America are approximated, and what we now know as the Atlantic Ocean will be a memory for us as old as the are the dinosaurs of the Jurassic.
The world map is only known photo geological instant in which we live. Every schoolchild learns that the earth’s crust is divided into tectonic plates that drift over the mantle, the lower layer, and that these sheets as thin as cream scale floating in the coffee, is created and destroyed, forming supercontinents which is then fragmented and separated. The boundaries between two plates where one dives beneath the other and recycled are called subduction zones.
What Duarte and colleagues have described is that we are witnessing the birth of a subduction zone, and is very close to us, to the southwest of the Iberian Peninsula. There is the edge of the board of Iberia, part of the Eurasian plate. That place was a passive edge, no activity. However, a 3D mapping and high resolution seabed and its fault lines, made by technology s ringing, fractures signs found indicating that this area is being activated. “The idea of starting a subduction has hovered in the geological community for almost 20 years,” says Duarte told Efe. “What we’ve found is the beginning of an active margin, is like an embryonic subduction zone,” says the scientist.
The researcher, who works at Monash University (Australia), this incipient tectonic activity associated with historical earthquakes: “The high magnitude seismic activity, such as the 1755 earthquake [that devastated Lisbon] and 1969 [that hit south Portugal and eastern Andalusia] suggested that something was happening in that area. In 2002, Gutscher [study coauthor] identified an old active subduction beneath Gibraltar. ” “Compiling and reinterpreting data, we found evidence of the birth of a subduction, which probably began between 20 and 5 million years. In addition, we have provided a mechanism for the reactivation of the margin, consisting of forces that spread from the subduction of Gibraltar, together with the convergence between Africa and Eurasia “.
Duarte argues that this is a new phase of the Wilson cycle, the process that in the past four billion years, worked at least three comprehensive reforms in the face of our planet, fragmenting supercontinents and opening the oceans between the pieces and then assemble again in large land masses.
And this time, it will happen: “The Eurasian plate, which now extends continuously to the Mid-Atlantic Ridge, it will break into two along the west margin of Portugal and Galicia,” says the geologist. “The Atlantic side of the crust west of this range will be destroyed by plunging into the mantle below the Iberian Peninsula”.
However, in no haste geology, according to the study published by Duarte and colleagues in the journal Geology, the southwestern edge of the Iberian plate will not become a lady subduction zone to within about 20 million years. A pittance compared to the 220 million years that must pass before the Old World and the New come together.
Due to the lengthy precisely this geologic time scale, “we should not expect an increase in seismic activity,” says Duarte. “The process takes up a few million years and will take many more. Earthquakes such as Granada are related to the old Gibraltar subduction zone, but others like the 1969 are clearly farther west, in the new training area. ” Nevertheless, the geologist warning: “In any case, we should be prepared for massive earthquakes originated in this region, as of 1755, and we are not.”