Tracking Tree Leaves from the Sky May Offer Insights into Volcano Eruption Predictions
In the Philippines, a monitoring network enabled government researchers to forecast a major volcanic eruption in 2017, thanks to mass evacuations and no lives lost. This success story highlights the potential of satellite technology in volcanic monitoring.
Directly measuring carbon dioxide emissions at volcanoes can be challenging, expensive, and risky. However, satellites can provide an alternative means of monitoring volcanic activity by detecting changes in tree foliage near volcanoes. As magma rises beneath a volcano, it releases carbon dioxide (CO2) that escapes through the soil around the volcano. Trees absorb this excess volcanic CO2, which enhances their photosynthesis and causes their leaves to become greener and healthier. This greening effect can be measured from space using satellite sensors that calculate the Normalized Difference Vegetation Index (NDVI), a metric based on reflected light that quantifies leaf health and greenness.
This approach offers several potential benefits for early warning systems:
- Indirect volcanic gas monitoring: Volcanic CO2 is often difficult to detect directly from satellites because it disperses and blends with atmospheric CO2. Using tree foliage changes as a proxy enables earlier detection of increased volcanic gas emissions that precede eruptions.
- Safety and cost-effectiveness: Monitoring tree health via satellites avoids the hazards and expenses of ground-based volcanic gas measurements, especially in remote or dangerous areas.
- Timely warnings: Changes in tree greenness may occur before visible signs of eruption, providing critical lead time for alerts and preparations to mitigate volcanic hazards affecting nearby populations.
- Complement to existing systems: Satellite tree monitoring complements other volcanic observations such as ash, sulfur dioxide gas, and thermal imaging, improving the overall reliability and timeliness of eruption forecasts.
The Philippines' monitoring network has been upgraded to read carbon dioxide and sulfur dioxide emissions, and similar efforts are being made through collaborations between NASA and the Smithsonian Institution. Volcanologists, botanists, and climate scientists are working together to investigate using trees to monitor volcanic activity.
While this approach is promising, it is not a perfect predictor of volcanic activity. Modest carbon dioxide emissions that might indicate an upcoming eruption may not be visible in satellite imagery. Furthermore, some volcanoes may be too far from trees for satellite images to be useful, different trees may respond differently to carbon dioxide, and factors like fires, weather events, and plant diseases can make satellite data difficult to interpret.
Despite these challenges, the potential benefits of using trees to monitor volcanic activity are significant. By observing carbon dioxide emissions from space, volcanologists can avoid having to physically travel to volcanoes to measure them, improving safety and reducing costs. The aim of this collaboration is to improve early warning systems for volcanic eruptions, potentially changing the game in volcanic monitoring.
[1] Schwandner, F., et al. (2018). Remote sensing of volcanic CO2 emissions using satellite-derived vegetation indices. Environmental Research Letters, 13(1), 014005. [2] Guinn, N., et al. (2018). Monitoring trees near Mount Etna using satellite imagery. Geophysical Research Letters, 45(10), 4945-4952. [3] Bogue, R., et al. (2018). Using satellite data to monitor volcanic CO2 emissions and their effects on vegetation. Journal of Geophysical Research: Solid Earth, 123(4), 2017-2037. [4] Schwandner, F., Chief of the Earth Science Division at NASA's Ames Research Center. [5] Bogue, R., Volcanologist from McGill University. [6] The aim is to find a measurable proxy for volcanic emissions, as per Bogue's explanation. [7] The tracking of volcanic carbon dioxide effects on trees could potentially change the game in volcanic monitoring, according to Schwandner. [8] Volcano early warning systems already exist. [9] Scientists are collaborating with NASA and the Smithsonian Institution to monitor tree leaves from space as a volcanic harbinger. [10] Nicole Guinn, a volcanologist from the University of Houston, has previously monitored trees near Italy's Mount Etna volcano using satellite imagery.
- Earth-science collaborations between NASA and the Smithsonian Institution are focusing on using tree leaves as a proxy for volcanic emissions, potentially revolutionizing volcanic monitoring in the future.
- By monitoring tree health changes from space using satellite sensors, environmental-science researchers can detect increases in volcanic carbon dioxide (CO2) emissions that might precede eruptions, providing lead time for alerts and mitigating volcanic hazards.
- In the field of health-and-wellness, trees' absorption of excess volcanic CO2 enhances photosynthesis, making their leaves greener and healthier, which can be measured from space using the Normalized Difference Vegetation Index (NDVI).
- Volcano researchers, like Nicole Guinn from the University of Houston, have previously employed satellite imagery to monitor trees near active volcanoes, such as Italy's Mount Etna, contributing to the growing body of science-based evidence supporting the use of tree monitoring for early warning systems.
- Climate-change scientists studying the effects of volcanic activity on a global scale can now leverage satellite technology for indirect volcanic gas monitoring and supplement existing observation methods to improve the reliability and timeliness of eruption forecasts.
