A team of US researchers has published a study that shows how progressive fusion of the glacial cap in Antarcticadue to the current global warming, face Increase the activity of volcanoes of the continent. Antarctic volcanoes are at least a hundredof which many completely hidden under the cap while others (like Monte Erebus) emerge on the surface. When the weight of the ice that covers them decreases, in their magmatic chambers the Magma can expand giving rise to eruption also very intense. The phenomenon has serious consequences because, in turn, eruptions merge more ice and feed global warming by emitting carbon dioxide.
The studio on the volcanoes of Antarctica
In their study, the researchers took into consideration the glaciers of theWestern Antarcticawhere the glacial cap is particularly at risk of fusion. One of the reasons is linked to the fact that this area is crossed by West Antarctic Rift Systema system of fractures about 3000 km long at which there is anHigh concentration of active volcanoes. These volcanoes are located mostly below the cap and their magma, when it comes into contact with the ice, accelerates its merger. This factor adds to global warming, which is determining the progressive decrease in thickness of the glacial cap.

The search team used computer simulations To verify the consequences that the thinning of the ice has on the activity of the underlying volcanoes. The link between these phenomena It is known: for example, there is evidence that in the Andes 18,000 years ago, towards the end of the last glacial era, the beginning of the fusion of the Calotta della Patagonia increased the activity of volcanoes such as Calbuco. As part of the new study, they were simulated variations in ice thickness Above the magmatic chambers of the Antarctic volcanoes. It was so ascertained that, when the cap merges, determining the lifting of the earth’s crust, the reduction of the pressure exerted on the magmatic chambers allows the magma to expand. In particular, less pressure on the magmatic chamber means that the solubility of the gases present in the magma decreases, leading them to free itself. THE gas expand forming increasingly large bubbles, which exert pressure in the magmatic chamber, until they can go up through the fractures of the rocks by dragging the magma to the surface: thus occurs avolcanic eruption. It was also discovered that the larger the magmatic chamber and the more it undergoes the consequences of the decrease in pressure. The speed with which the merger of the ice takes place also has a decisive role. The phenomenon determines both a greater number of eruptions be a increase in their intensity.

The consequences of the eruptions of the Antarctic volcanoes
Antarctic volcanoes, since they are often under the ice, could give rise to eruptions that cannot be observed on the surface but equally dangerous. The heat emitted can do melt the ice in depth: This phenomenon in turn reduces the pressure on the magmatic chambers and makes new eruptions more likely. The current fusion of the Antarctic cap has as its primary cause, global warming in progress and to turn it. In fact, where the cap merges by discovering the rocks, these being dark they reflect much less the sun radiation and absorb much more than the ice. Consequently, a greater quantity in the form of heat also re -emerge, doing Increase the air temperature. In turn, the increase in temperature increases the melting of the ice. It is a so -called “feedback” mechanismthat self -birds. In addition, volcanic eruptions emit carbon dioxidethe main greenhouse gas responsible for global warming.