2017-04-13. What Led to the Largest Volcanic Eruption in Human History?

posted Apr 16, 2017, 6:31 PM by Alan Gould
By Sarah Witman, Earth & Space Science News (AGU). For GSS Energy Flow chapter 2. Excerpt: A mineral-dating project at the Toba caldera in Indonesia sheds light on the science of supereruptions. In the northern part of the Indonesian island of Sumatra lies the Toba caldera, a massive crater formed by what scientists think is the largest volcanic eruption ever experienced by humanity. The eruption, called the Youngest Toba Tuff supereruption, took place about 74,000 years ago. By dating zircon, a diamond-like gemstone, and other minerals in the area such as quartz, Reid and Vazquez https://doi.org/10.1002/2016GC006641 have pieced together clues about the activity of magma below the surface prior to the supereruption. ...Because zircon does not gain or lose uranium or lead even at magmatic temperatures, zircon typically contains high uranium and low lead levels, and scientists may use the ratio of these two elements in the zircon to determine the age of the sample. ...The team’s findings are significant for modern-day humans, given that aerosols and ash that erupted from Youngest Toba Tuff are thought to have entered the atmosphere, causing global cooling and the near extinction of the human race. A supereruption of equal or greater magnitude today could therefore have similarly drastic consequences. By better understanding the conditions that led up to the Youngest Toba Tuff supereruption, scientists can help paint a clearer picture of the future. (...https://doi.org/10.1002/2016GC006641, 2017)  https://eos.org/research-spotlights/what-led-to-the-largest-volcanic-eruption-in-human-history