Tree rings can be used as a warning system to forecast volcanic eruptions, scientists discovered

By Mharia Emmareen / 2017.03.13
Age rings are shown on a cut section of a Coastal Redwood tree at Muir Woods National Monument on August 20, 2013 in Mill Valley, California.

Scientists before only rely on seismic waves and any volcanic activities in predicting volcanic eruptions. Now it seems that volcanologists found a new tool to help forecast looming volcanic eruption as cited by ETH Zurich and the Swiss Federal Institute for Forest, Snow, and Landscape Research WSL.

An ETH Zurich geophysicist, Nicolas Houlié first knew about the possibility of this warning system way back in 2001. While watching at a satellite image, he spotted a three-kilometer long green line along the northeast Mount Etna border. The said line manifests the Normalised Difference Vegetation Index or NDVI.

If the system indicates greater value it means that there is increased vegetation that flourishes the area. An unexpected phenomenon surprised the scientists because, after a year, the volcano erupted in the area where the exact line is located, Science Daily reported.

Because of the discovery, volcanologists and dendrochronologists alike team up. Dendrochronologists recognize the link between NDVI values and tree growth which is suggested in the width of tree rings. Houlié along with geographer and WSL Ph.D. student, Ruedi Seiler, and dendrologist and WSL Head of

Dendrochronology, Paolo Cherubini joined forces four years ago to plunge into a cross-disciplinary research project where Swiss National Science Foundation will financially support the study. The researchers' idea that tree rings can provide details regarding volcanic activities before an eruption is now published in the Scientific Reports journal.

"If volcanic activity does influence tree rings, then the pre-eruptive phase of the 1974 eruption can only have begun when the trees had already ceased their seasonal growth," Seiler assumes.

According to Paleontological Research Institute, tree rings are considered as well to begin discerning about how climate change researchers gather details about previous climates. In particular instances, trees can exist for hundreds of years and in an unusual case, such as the bristlecone pine which could live for thousands of years. Every year, trees increase growth rings that indicate the kind of growing season the tree has underwent.

Dendrochronology is the analysis of climate change as documented by the growth on tree rings. Every year, trees put in another layer of growth separating the older wood and the bark. Growth rings likewise record cloud over and temperature as it affects tree growth.

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