Is It Possible for Humans to Trigger a Volcanic Eruption?

During its most recent eruption in March 2016, Alaska's Pavlof Volcano spewed a massive ash cloud stretching 400 miles (640 kilometers) and reaching 37,000 feet (11,277 meters) into the atmosphere. The dense plume of fine, abrasive rock disrupted air travel and forced the closure of major roadways.

On July 28, the U.S. Geological Survey elevated the alert status for Pavlof, signaling that the volcano appeared poised for another eruption.

However, predicting volcanic eruptions remains a significant challenge. Despite the USGS raising the alert level for Pavlof in May as well, no eruption occurred. Hans Lechner, a geology and engineering sciences doctoral candidate at Michigan Technological University, notes that scientists are still unable to accurately determine the timing of such events.

"A volcano might display all the typical warning signs of an imminent eruption," Lechner explains via email, "such as heightened seismic activity, elevated gas emissions, and ground deformation, yet it may never erupt and eventually settle back to normal levels."

Alternatively, he notes, a volcano might erupt suddenly without showing any prior indications of activity.

Some experts in the field speculate about taking proactive measures—essentially a volcanic 'preemptive strike.' The concept involves humans altering the eruption process, either by triggering an eruption under controlled circumstances or by reducing the intensity of an impending eruption to minimize potential damage.

Unfathomable Power

The sheer energy released during a volcanic eruption is staggering. During its four-month eruption in 1983, Italy's Mount Etna expelled approximately 350 cubic feet (10 cubic meters) of lava every second. Lechner also highlights that the initial explosion of Mount Pinatubo in 1991 ejected around 2.4 cubic miles (10 cubic kilometers) of material, reaching heights of about 25 miles (40 kilometers).

Lechner describes this phenomenon as "enormous amounts of energy." This energy originates deep within the Earth, where intense heat and pressure can melt solid rock.

Magma, or molten rock, is less dense than solid rock, causing it to ascend and accumulate in a "magma chamber" that pushes through the Earth's crust. As the magma volume expands, the pressure within the chamber builds, driving the magma through the volcano's "vents"—pathways created by previous eruptions and sealed at the surface by a cap of solid rock.

When the pressure reaches a critical point and a vent abruptly opens to the atmosphere, the sudden release of pressure causes dissolved gases to escape, triggering an explosive eruption. This eruption expels magma, volcanic ash (finely crushed rock), steam, and various gases. For example, during the 1980 eruption of Mount St. Helens, Lechner explains that immense pressure caused the vent's cap to bulge outward—a clear indicator of an impending eruption—before a landslide removed it.

Never Nuke a Volcano

To alter the course of an eruption, Lechner speculates, "Humans might have been able to induce the landslide or remove the overlying rock ["lid"] through methods like excavation or even detonating a nuclear device."

However, using a nuclear device on a volcano would be an extremely reckless decision. The volcano would still erupt explosively, following its natural timeline, but with the added devastation of nuclear contamination.

Attempting to drill into the magma chamber to relieve pressure is also impractical. As volcanologist Erik Klemmeti noted in a 2012 Wired article, this idea is comparable to "trying to bleed to death with a needle prick."

Similarly, gradually reducing the pressure in the chamber to prevent an eruption is not feasible.

"We must move beyond the false notion that a magma chamber is akin to a fluid-filled balloon or soda bottle, where we can simply insert a straw and extract the lava and gases," Lechner explains. "The pressures and volumes involved are far beyond the capabilities of human-made technology."

He explains that drilling several kilometers deep with enormous pipes—hundreds of meters wide—would be necessary to manage the volcanic material surging from the chamber. These pipes would need to endure temperatures exceeding 3,600 degrees Fahrenheit (2,000°C) and pressures that are "beyond our ability to control or even fully understand."

Additionally, he points out, there's the challenge of dealing with "gases rapidly escaping as they come out of solution, causing sudden depressurization and violent release."

Lava, on the Other Hand

In general, the primary obstacle to human intervention in volcanic eruptions is that it seems utterly unfeasible. Volcanoes are simply too massive, and their eruptions too overwhelmingly powerful.

However, Janet Babb, a geologist at the USGS Hawaiian Volcano Observatory, notes that humans do have some limited options for influencing volcanic activity.

"Humans cannot halt or manipulate an eruption," Babb explains in an email, "but they have managed to influence some of the materials ejected during a volcanic event."

One example is redirecting lava flows. Babb references Mount Etna and its 1983 eruption, which sent molten lava toward populated regions. With three towns at risk of being engulfed, workers urgently built large barriers made of rubble to alter the lava's path. Oregon State's Volcano World describes a photo of this monumental effort: "Two hundred men built a rubble barrier approximately 30 feet high (10 meters), 100 feet wide (30 meters), and 1,200 feet long (400 meters). Note the advancing aa [lava] flow." The barriers effectively redirected the lava.

However, efforts to influence lava flows by bombing them have largely been unsuccessful. Cooling the lava, on the other hand, has shown potential: In 1973, when lava from a volcano on Iceland's Heimaey island threatened nearby towns, authorities constructed barriers to halt its advance and used seawater to cool the lava, slowing its movement and aiding solidification. The barriers successfully contained the lower-energy flow.

Regarding controlling lava before it begins to flow, Lechner describes it as "mostly science-fiction speculation." No serious research is being conducted in this area. Instead, volcanology focuses on improving monitoring and prediction techniques.

"Nevertheless," he writes, "it's not unreasonable to imagine that human arrogance might drive us to attempt altering a volcanic eruption. History shows that humans have achieved large-scale engineering projects that have permanently reshaped the Earth's surface."

On August 8, the USGS lowered the heightened alert level for Alaska's Pavlof Volcano. It turned out to be a false alarm.