Plants and trees are able to predict volcano eruptions

Volcanoes hold incredible power, but similar to plants and their root systems, most volcanic activity that occurs before an eruption happens beneath the surface.

Traditional monitoring tools focus on measuring seismic activity and collecting gas samples, yet these methods can miss subtle warning signs hidden in rugged landscapes.

Researchers have been searching for additional ways to detect signs of unrest before eruptions happen, especially for volcanoes that are far from inhabited areas. They are now turning to plant life for clues and signs that a volcano is close to erupting.

Carbon dioxide, plants, and volcanoes

Volcanic gases, like carbon dioxide, are often released as magma pushes upward. Detecting them can be tricky because the same gases also appear in everyday life.

Certain remote volcanoes lack permanent sensors or easy access, which leads scientists to test creative approaches that might reveal small changes long before other instruments notice them.

One project was led by Robert Bogue from McGill University in Montreal, Canada, who worked with colleagues to measure patterns in vegetation health near hydrothermal areas in the Yellowstone Caldera.

The results reveal how plants respond to changes in the ground beneath them, which may point to rising magma and a heightened risk of volcanic activity or the imminent eruption of a volcano.

Plants and volcanoes as allies

Plants adjust how they grow when their surroundings shift. This adjustment includes changes in photosynthesis and patterns in leaf structure.

Variations in carbon dioxide, sulfur, and soil temperature can affect how trees flourish, and these factors often emerge in volcanic settings.

Scientists reason that such signals might appear in plant tissues months or years before major events occur.

In the field, it can be hard to see small changes in vegetation by eye alone. Forests are vast, and weather can alter growth in ways unrelated to volcanoes.

That is why satellite imaging has become popular. It can scan large areas and detect subtle hints of stress or unusual greening that might not stand out on the ground.

Looking beneath the canopy

One helpful technique is the Normalized Difference Vegetation Index (NDVI). This calculation captures how vigorously plants are photosynthesizing by measuring chlorophyll levels.

Scores range from negative numbers up to 1, with higher numbers pointing to healthy leaves. By comparing these values in different spots over time, researchers can see if there are trends that may connect to shifts in the subsurface environment.

Studies in volcanic regions suggest that small bursts of carbon dioxide and heated fluids can initially fertilize local plants. But higher concentrations of harmful gases or very hot soil can stress and even kill them.

Tracking these ups and downs over multiple years can reveal a story of underground changes that unfold gradually.

Tern Lake as a proving ground

In Wyoming, the Tern Lake thermal area sits in the Yellowstone Caldera. From 1984 to 2022, archived Landsat images showed that tree health in this hydrothermal zone improved for about 16 years.

Scientists believe the initial benefit may have come from extra nutrients reaching the soil. Then around the early 2000s, the satellite record captured a shift, with tree health dipping and many lodgepole pines dying near the center of activity.

Infrared data suggested that soil temperatures in parts of the site exceeded 122°F, and that poisonous gases and acidic fluids were breaking down plant tissues.

Over time, the zone of stress spread outward, and a bare patch of dead trees became more visible. This persistent change confirmed that a deeper process was heating the ground and altering the chemistry that plants depend on.

Signs from plants that a volcano is waking up

The research team linked these findings to pathways of hydrothermal fluids moving toward the surface. In some areas, mineral buildup may have clogged old routes, forcing new channels to open.

Earthquake data supported this interpretation. Small tremors can indicate that magma or hot fluids are seeking different escape routes.

Collectively, these events point to activity that might have begun well before on-the-ground surveys took note.

Observations also suggest that this expansion reached a limit. Some recent field checks found signs of new seedlings taking hold in once-barren terrain.

This could mean the local system is calming, at least for the moment. Changes in vegetation and plant life can serve as a reminder that volcanoes and their processes are not always linear. Conditions can shift as gases and fluids come and go.

What does all of this mean?

These discoveries illustrate how forests can serve as eyes on a hidden world. Researchers have often relied on thermal cameras and gas detectors to evaluate volcanic hazards, but those instruments have limitations.

In some places, there is no easy way to install or maintain them. Harsh weather, dense canopies, and rough slopes can hamper efforts to collect reliable data.

Satellite imagery provides wide coverage without the need for a permanent presence in challenging locations.

Vegetation-based monitoring is not a standalone method, but it can offer valuable hints for scientists. If the data show unusual patterns of greening or die-off, teams can schedule closer inspection or deploy instruments before any major event.

Volcanoes, plants, and a safer tomorrow

Every volcano is unique. Some are surrounded by thick forests, while others sit in deserts or at high elevations.

Where conditions support enough plant life, scientists can try vegetation indexes to look for shifts that might signal building magma.

In other areas, this strategy may be less useful or confounded by drought, wildfires, or different species that react in unexpected ways.

The hope is to combine these plant observations with other signals. Minor quakes, ground swelling, and changes in gas composition all help create a clearer picture of what lies beneath the surface.

Scientists continue to refine these approaches. As they gather more information, they can figure out how to focus resources on volcanoes that pose the greatest risk.

The story at Tern Lake shows that forests can act as an early warning system, revealing shifts that might mean an eruption is more likely. By studying these patterns, experts might someday issue alerts sooner than ever before.

The full study was published in the journal Geochemistry, Geophysics, Geosystems.

—–

Like what you read? Subscribe to our newsletter for engaging articles, exclusive content, and the latest updates.

Check us out on EarthSnap, a free app brought to you by Eric Ralls and Earth.com.

—–