Science Alert November 6, 2021
An international team of researchers (China, Taiwan, Switzerland, Malaysia, Indonesia) conducted a a detailed study of the Toba volcano in Sumatra, Indonesia analyzing the chemistry of zircons minerals produced by explosive volcanic eruptions to determine the age of the minerals. Their findings suggest that the gigantic eruptions from Toba some 840,000 years ago and 75,000 years ago were not preceded by a sudden influx of magma into the volcano’s reservoir. Instead, the magma collected steadily and silently ahead of the blasts. The second super-eruption needed less than half the time for magma to build up than the first because of the gradual increase in temperature of the continental crust around the magma reservoir. Using the timelines of the eruptions and the preceding buildup of magma they calculated that around 320 square kilometers (124 square miles) of magma could be lurking under Toba Lake today. The island is gradually increasing in height, indicating that the volcano is active, and that magma is accumulating underneath. The researchers estimate that there are around 5-10 volcanoes around the world capable of a super-eruption – one that would catastrophically affect the global climate. The study shows that no extreme events occur before a super-eruption…read more. TECHNICAL ARTICLE
Lake Toba occupies a supervolcano’s caldera. (Satria Dhesto/EyeEm/Getty Images)