GabyScientists have learned to determine whether a volcano is preparing to erupt by observing the greenery of nearby trees. Brighter leaves indicate a potentially imminent lava release. Until now, these subtle color changes could only be detected from the ground, but recently, volcanologists have begun tracking them from space. This advancement is the result of a recent collaboration between scientists at NASA and the Smithsonian Institution. The new discovery could be a game changer in detecting the early signs of volcanic eruptions, as noted in a statement released by NASA. This breakthrough will help protect people from the devastating consequences of volcanic explosions, including lava flows, falling rocks, landslides, and clouds of ash and toxic gas. The goal of the researchers is to improve early warning systems for volcanic eruptions, emphasized Florian Schwandner, a volcanologist and head of the Earth Sciences Division at NASA’s Ames Research Center in California.
Satellites to the Rescue
Signs of an impending eruption visible from space include seismic activity, changes in the Earth’s surface elevation, and sulfur dioxide emissions. Scientists also monitor carbon dioxide (CO2) emissions associated with magma activity. However, satellites find it more challenging to detect CO2 than sulfur dioxide due to the widespread presence of CO2 in the Earth’s atmosphere. “The release of a small amount of carbon dioxide that could signal an eruption won’t be visible in satellite images,” noted graduate student volcanologist Robert Bog. Nevertheless, researchers are highly interested in detecting CO2 emissions, as they are one of the earliest signs of an approaching eruption. To this end, scientists have developed a method for monitoring carbon dioxide using trees around volcanoes, as reported by Live Science. The reason is that CO2 clouds emitted from soon-to-erupt volcanoes enhance the health of surrounding trees and plants, making their leaves greener and lusher.
Previously, scientists wanting to measure CO2 levels had to travel to volcanoes. But now, it’s not necessary to visit these often remote and potentially dangerous locations. Researchers can utilize satellites to capture the brightness of tree foliage—a key indicator of volcanic gas concentration. A recent study published in the journal Remote Sensing of Environment found a strong correlation between carbon dioxide levels and the intensity of tree color around Mount Etna in Italy. Using images taken by Earth observation satellites from 2011 to 2018, the study’s authors observed 16 distinct spikes in CO2 levels and notable brightness in the greenery, coinciding with magma migrations within the volcano.
To expand the potential of this new method, researchers recently decided to conduct the Airborne Validation Unified Experiment: Land to Ocean (AVUELO), during which satellite images of trees around volcanoes will be compared with ground observations. This will provide greater data accuracy and help scientists better calibrate space instruments. Unfortunately, measuring the intensity of greenery from space is not a universal method for predicting eruptions. Not all volcanoes have neighboring trees, or there may not be enough for satellite observation. Additionally, some trees affected by fires, diseases, or abnormal weather conditions may respond unexpectedly to changes in carbon dioxide levels.
