Scientists made a surprising discovery on their mission to find better indicators for impending volcanic eruptions: it looks like tree rings may be able to predict eruptions, report the Swiss Federal Institute for Forest, Snow and Landscape Research WSL and the ETH Zurich.
Nicolas Houlié, a geophysicist at ETH Zurich, first came to know about this potential early warning system in 2001. While looking at a satellite image, he noticed a three kilometres long green line on the north-east flank of Mount Etna. The line reflects the Normalised Difference Vegetation Index (NDVI): the higher the value, the more vegetation is thriving in the area. But what made the discovery really astonishing is the fact that the volcano erupted along that exact line just one year later.