Plant health as a new effective monitoring system for volcanic activity
[...]
New research, published in Geochemistry, Geophysics, Geosystems, has investigated the link between carbon dioxide uptake by plants in response to elevated volcanic degassing, something which has previously been challenging to detect using satellites in space and to differentiate from normal atmospheric levels.
Robert Bogue, a Ph.D. researcher at McGill University, Montreal, Canada, and colleagues monitored plant responses to volcanic emissions in the Tern Lake thermal area of the Yellowstone Caldera, Wyoming, U.S., to determine their reaction to hydrothermal activity (circulating fluids in the vicinity of a magma source producing hot water and steam).
The research team used remotely-curated Landsat images from the United States Geological Survey across an area of ~33,000 m2, taken from satellites orbiting the Earth between 1984 and 2022, and compared plant health in the hydrothermal area with that in nearby forests unaffected by volcanic activity.
They used the Normalized Difference Vegetation Index (NDVI), a measure of chlorophyll abundance in a given area, which acts as a proxy for photosynthesis and therefore plant health. NDVI uses unitless values between -1 and 1, where healthy vegetation scores 0.6–1 and anything less healthy will have lower values.
[...]