New research reveals that the usual signs before a volcano erupts do not have to appear. In particular, studying the Toba volcano in Sumatra, Indonesia, geologists found that in two eruptions 840,000 years ago and 75,000 years ago, there was no sudden increase in magma in the caldera of the volcano, but it accumulated silently until the eruption.
In fact, the second eruption took half a year to increase the magma due to the gradual increase in temperature in the continental crust near the magma.
“It’s a vicious circle of explosions. “The more magma heats the crust, the slower it cools and the faster the magma accumulates,” said geologist Ping-Ping Liu.
As reported by , researchers estimate that today there are about 320 square kilometers of magma under Lake Toba, a caldera that was created by previous eruptions and is now filled with water from snow and rain. The island in the center of the lake has risen in height, indicating that the volcano is active and magma is accumulating.
It is estimated that there are 5-10 volcanoes around the world capable of a super-eruption, one that would catastrophically affect the global climate and Toba is one of them. The latest estimates say a Toba eruption could cover all of Southeast Asia with ash, while its most recent eruption caused a decade-long winter with temperatures dropping around the world.
“Our study shows that there are no extreme events before the super-explosion. At Toba, everything happens silently underground and the analysis gives us an idea of ​​what to expect “, points out the geologist, Luca Caricchi.
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