The earthquakes that shook the, in addition to the thousands of dead they caused, activated tens of volcanoes more than 1,000 kilometers away. It was not classic eruptions, those of Lava, but mud. The phenomenon, although weird, usually happens in areas with fluids under the earth’s surface. In parallel and related, a group of seismologists shows in the scientific journal, how several failures close to the Caspian Sea moved silently. Until now it had been recorded that an earthquake could have those impacts at so much distance.
Six minutes after the earth opened at the border between Turkey and Syria, in the early hours of February 6, the surface waves of the earthquake arrived on the coast of the Caspian Sea, more than a thousand kilometers from the epicenter. The study of changes in the field detected by radars of the Sentinel-1 satellite constellation, seismographs and other geodesic sensors verified how much of the Kura River terminal basin, the eighth major in Europe and which flows into the Caspian, recorded the impact of the earthquakes.
The authors of this work have confirmed two phenomena that were parallel and that would be connected. They identified up to seven faults in the field prior to the fingers that moved “silently.” By silent, the researcher at the University of Strasbourg (France) and co -author of the research, Cécile Doub, refers to that “the fault slides without emission of seismic waves.” They were just a few millimeters, but the affected area is huge. In these assistory movements, the terrain moves very little, slowly and without rupture, so it does not release energy suddenly that usually causes disaster.
“If its sliding had been seismic, it would have corresponded to a magnitude 6 [el primero de los seísmos en Turquía, el de Pazarcik, tuvo una magnitud de 7,8]; This is the greatest known fault slide [a distancia] To date, ”says Doom mud.
The region where the failures moved silently belongs administratively to Azerbaijan. There are at least 400 extinct or sleeping mud volcanoes, both on land and under water. That day, 56 of them woke up, and new ones formed. Although they are not the same as Lava, they have many similarities. As an ETNA or a, its eruptions can be of the effusive or explosive type. The materials that eject are varied, usually in a gaseous and fluid state, in the form of light sediment fluids (see photography above). The main ingredient of these sludge are clays and other fragments of deep rocks but there are also hydrocarbons (oil) and gases such as methane. Among those that were activated after the earthquakes are small, with an area of about 500 m², but others are observable formations from space, with a base of up to 500 km². According to the authors, it is one of the responses to a more distant documented earthquake.
“We believe that Alexander the Great expedition also met some of these mud volcanoes,” says the professor of internal geodynamics at the University of Granada, Juan Soto I. Soto. “Azerbaijan was known as the land of fire, for the gases that emitted and burned. Marco Polo and other travelers of the sixteenth and seventeenth centuries collected them in their writings, but it was not until the nineteent complete.
Soto is finishing a book about mud volcanoes and ”on the associated diapirs,” he adds. The latter are the most immediate causes of effusion abroad and that could be compared to the magma that feeds the lava volcanoes. “A diapiro is a structure within the earth’s crust, under the surface, in which fluid rocks can be ascending, breaking and drilling those that are above. And the volcano would be the surface emission,” details the professor, a researcher also associated with the Bureau of Economic Geology of the University of Texas in Austin (United States), where the last years have passed.
The professor supports comparing the diapirs with a sponge. “We believe that there are two processes that allow mud diapires and then, mud volcanoes.” In one, the area would be subjected to compression and, “under that compressive effort, fluids within sediments increase pressure, allowing the rocks to break, behaving like a fluid and giving rise to a volcano on its surface.” It is as if pressuring the sponge, the fluids within the pores increase the pressure to overcome a critical point in which the sponge (the rock, in this case), becomes a fluid.
But it is known so little about them, that Soto also bets on another mechanism: “The existence of hydrocarbons and their transformations also favor these processes because hydrocarbons can [pasar] In a gaseous phase, especially methane, which when ascending increases in volume, breaking the rocks, which allows the fluids to escape violently to emerge in the mud volcanoes, ”he explains. The subsoil of Azerbaiyan houses one of the largest hydrocarbon deposits on the planet. In particular, the Kura basin and the South Caspio Sea rest on soft sediments of large sediments of large sediments of large sediments, They can behave like fluids.
