The Science Behind Predicting Volcanic Eruptions Using Tree Leaf Colors
Volcanic eruptions pose a significant threat to human lives and property, making accurate prediction crucial for saving lives. Recent research has shown that changes in tree leaf colors can serve as early warning signals for impending volcanic activity.
As volcanoes become more active and approach eruption, magma rises closer to the surface, leading to increased levels of carbon dioxide emissions. This elevated carbon dioxide can enhance the health of surrounding trees, causing their leaves to appear greener.
Scientists have discovered that these changes in tree foliage, particularly in a measurement known as the normalized difference vegetation index (NDVI), can be detected by satellites orbiting in space. This breakthrough could potentially establish an early warning system for volcanic eruptions that does not rely on ground sensors, making it suitable for monitoring remote and inaccessible volcanic regions.
According to volcanologist Nicole Guinn from the University of Houston, “There are plenty of satellites we can use to do this kind of analysis.” Guinn was involved in a recent study that examined carbon dioxide levels around Mount Etna in Italy. By comparing data from sensors near the volcano with satellite imagery, the researchers found a strong correlation between increased carbon dioxide emissions and greener tree foliage.
Over a two-year period, the research team identified 16 distinct spikes in carbon dioxide levels and the NDVI, corresponding to underground magma movements. These patterns were even observed at greater distances from fault lines on the mountain.
Prior research in 2019 by volcanologist Robert Bogue of McGill University demonstrated that carbon dioxide emissions from active volcanoes in Costa Rica influenced the color of leaves on tropical trees in the vicinity.
Currently, Guinn, Bogue, and other researchers are collaborating on a project led by NASA and the Smithsonian Institution to analyze changes in plant life colors around volcanoes in Panama and Costa Rica. This initiative is part of the Airborne Validation Unified Experiment: Land to Ocean (AVUELO) mission, which aims to develop advanced satellite-based methods for monitoring Earth’s ecosystems.
Robert Bogue emphasizes the importance of finding proxies to detect changes in volcano emissions, as satellite imagery may not capture modest carbon dioxide emissions that precede eruptions. In addition to traditional seismic and ground monitoring methods, the greening of leaves due to carbon dioxide emissions offers a valuable signal for eruption prediction.
The AVUELO researchers are also investigating the broader implications of increased carbon dioxide on tree health. As global temperatures rise due to human-induced carbon dioxide emissions, understanding how vegetation responds to elevated carbon dioxide levels can provide insights into the planet’s future climate dynamics.
Climate scientist Josh Fisher from Chapman University, part of the AVUELO team, highlights the significance of tree responses to volcanic carbon dioxide emissions as indicators of potential eruptions and their role in regulating atmospheric carbon dioxide levels.
The findings from the Mount Etna study have been published in the journal Remote Sensing of Environment, showcasing the potential of using tree leaf colors as a novel approach to predicting volcanic eruptions.
