The peculiar “annual rings” in crystals present in rocks in the vicinity of volcanoes contain information about how quickly their new eruptions occur after the appearance of the first tremors, according to an article published in the journal Nature Communications.
“Our discovery is good news for every tenth inhabitant of the Earth living in the vicinity of active volcanoes.We can not yet say that we have solved this problem completely and created a” working “methodology for predictions, but the data we obtained will help us to make significant progress in studying those processes , which precede the eruption, “- tells Teresa Ubide (Teresa Ubide) from the University of Queensland in Brisbane (Australia).
The main parameter in the preparation for the eruption of the volcano, as scientists explain, is the speed with which its magma chamber – in fact, a very porous stone “sponge”, is filled with fresh hot melt, rising from the depths of the Earth. The higher it is, the faster eruption will occur, and therefore it is important to know it in order to assess the time that humanity has to prepare for the cataclysm.
In recent years, geologists have realized that this parameter can be assessed by studying the impurities of certain elements in crystals that appeared in the magmatic chamber before the eruption. Accordingly, knowing the rate of magma rise, one can prepare for the beginning of the eruption and evacuate the population from potentially dangerous areas in the vicinity of the volcano in advance.
Ubid and her colleague Balz Kamber of Trinity College in Dublin (Ireland) found out that the outer layers of these crystals contain information about what is happening inside the volcano in the last moments before the eruption, studying the rocks in the vicinity of Mount Etna in Sicily.
Etna, as scientists note, erupts almost continuously, which allows using its emissions to search for patterns between their properties and when and how the next eruption occurs. Guided by this idea, scientists collected samples of fresh deposits on its slopes, extracted crystals from them and analyzed their composition, radiating them with a laser and observing how the spectrum of its beam changed.
As these observations have shown, magmatic crystals are similar in structure to a layered pie or tree trunk, each ring of which contains information about the temperatures at which they formed and how quickly the magma moved at the time when it was “preparing” to leave one of the several vents of Etna.
“We found, observing Etna, that when magma rises to a depth of about 10 kilometers under the Earth, 90% of the cases in one two weeks there is a new eruption.” It should be understood that these estimates and forecasts concern only Etna, but Similarly, we can and are planning to carry out similar measurements for volcanoes in New Zealand and Indonesia, “concludes Ubide.