The populations residing near an active or potentially dangerous volcano live with the constant fear of an eruption. But now an unexpected ally could arrive in their aid: the trees. As? Thanks to the color of the leaves. According to a study carried out in collaboration by the Smithsonian Institution and NASA, before the volcanic eruptions the magma in the subsoil releases carbon dioxide in the ground, which is then absorbed by the trees. These become green and lively, a change that, if monitored via satellite, can help improve alert and detection systems,
The trees and signs that anticipate volcanic eruptions
According to scientists, the chromatic change of the leaves can indicate when a nearby volcano is becoming more active and could erupt. In fact, when the volcanic magma dates back through the earth’s crust, it releases carbon dioxide and other gases that rise to the surface. The trees that absorb these gases become more luxuriant, a change that could act as “alarm” and that can be observed by NASA satellites or through tools installed on board the planes used in the airborne validation unified experience: land to ocean (Avuelo).
10% of the world population live in areas subject to volcanic risks, with dangers ranging from the explosion of rock, dust, toxic gases and falling falls. In addition to the risk of eruption. At the moment there is no tool that can prevent volcanic eruptions with precision. When the magma dates back to the surface, carbon dioxide and sulfur dioxide releases: the former, which are emitted in advance, are almost impossible to distinguish from space, but are one of the first clues on a no longer dormant volcano.
Carbon dioxide and color “change”
But now, the detection of the registration of the vegetation due to carbon dioxide can offer a new potential tool, to be added to the seismic waves and to the changes of the subsoil, to understand what is happening in a volcanic area. As pointed out by Florian Schwandner, head of the Earth Science Division at the Ames Research Center of NASA in Silicon Valley, California, the goal is to improve early alert systems for volcanoes.
“Volcani emit a lot of carbon dioxide – explained volcanologist Robert Bogue of McGill University of Montreal -, but there is so much in the atmosphere that it is often difficult to measure it specifically. While the most important error can expel quite carbon dioxide that it is measurable from space with sensors such as the orbiting carbon observatory 2 of NASA, detecting these alarm signals The weakest has remained difficult. To date, to measure carbon dioxide levels, scientists must go directly to the scene. A not simple practice, considering that many of the approximately 1,350 volcanoes active all over the world are in remote and difficult places to reach. Vulcanologists like Bogue have united forces with botanists and climatologists to study trees and monitor volcanic activity. “The idea is to find something that we can measure directly, instead of carbon dioxide to have an indicator to detect changes in volcanic emissions”.
Observation through satellites
As explained by the volcanologist Nicole Guinn of the University of Houston, there are already many satellites that can be used for this type of analysis. The expert compared the images collected by Landsat 8, by the Satellite Terra della NASA, from Sentinel-2 of the ESA (European Space Agency) and other earth’s observation satellites to monitor the trees around the Etna volcano, on the Sicilian coast. Guinn’s study is the first to show a strong correlation between the color of the trees leaves and the carbon dioxide generated by magma. The next step is to compare the data of the satellite images with the reliefs on the trees found around the volcanoes, so as to have a confirmation of the correlation between the release of carbon dioxide and the “chromatic” change of the leaves.
A revolutionary discovery, which however has its limits. In fact, many volcanoes are found in areas with climatic conditions that do not allow the growth of sufficient vegetation for satellite images. In addition, some forest environments react differently to the variations of carbon dioxide levels and events such as fires, weather conditions can complicate the interpretation of satellite data on volcanic gases.