Volcanic Supereruptions: A Less Apocalyptic Outlook Than Previously Feared
Amidst the doom and gloom often associated with climate change and potential global catastrophes, a glimmer of optimism has emerged concerning volcanic supereruptions. For years, scientists have painted a potentially devastating picture of these massive explosions, suggesting they could trigger environmental changes so severe as to wipe out a significant portion of life on Earth. However, a new study analyzing geological records indicates the aftermath of a supereruption might not be as catastrophic as once believed.
The study, conducted by environmental scientists at the University of St. Andrews, examined ice cores extracted from Greenland and Antarctica, as well as sediment cores collected near the equator in the Pacific Ocean. These cores contained minuscule particles of ash embedded in layers corresponding to the period of the Los Chocoyos supereruption. This eruption occurred within the Atitlán caldera in present-day Guatemala. While the Smithsonian’s Global Volcanism Project places the eruption approximately 84,000 years ago, the St. Andrews team has refined the dating, suggesting it occurred closer to 79,500 years ago.
To provide context, consider the eruption of Mount Pinatubo in the Philippines on June 12, 1991. This eruption, preceded by months of seismic activity and magma movement, ejected an ash cloud soaring 22 miles (35 kilometers) into the atmosphere. Approximately 20 million tons of sulfur were released, causing a global temperature drop of 1 degree Fahrenheit (0.5 degrees Celsius) between 1991 and 1993, according to the U.S. Geological Survey. The sheer volume of rock and magma expelled irrevocably altered the mountain’s shape, creating a caldera 1.6 miles (2.5 kilometers) in diameter. Thanks to early warning signs, evacuations and air travel adjustments mitigated potential disasters. However, the force of the eruption still resulted in $100 million in damages to aircraft flying hundreds of kilometers away.
The Mount Pinatubo eruption registered a 6 on the Volcanic Explosivity Index (VEI). The Los Chocoyos supereruption is estimated to be an 8, the minimum VEI score for a supereruption, which would mean it was 100 times more powerful than Pinatubo.
The St. Andrews scientists, whose findings were published in Communications Earth and Environment, analyzed the effects of the Los Chocoyos eruption. Their research indicated a cooling effect lasting between 10 and 20 years. This is significantly less severe than the worst-case scenarios previously envisioned, which predicted plummeting temperatures lasting for centuries or even millennia. The eruption likely led to an increase in sea ice, but conditions appear to have returned to normal within approximately 30 years.
Importantly, modern humans were present during the Los Chocoyos eruption. The fact that Homo sapiens survived, along with numerous other species, suggests a capacity to endure such cataclysmic events. Supereruptions are rare; the last one occurred approximately 25,500 years ago in New Zealand (Oruanui eruption).
"Our findings improve our understanding of how resilient the climate can be to supereruption-scale injections of stratospheric sulphate," stated Helen Innes, a research fellow at the University of St. Andrews, who led the study. "Continuing to identify the largest volcanic eruptions in ice cores and assign high-precision ages is essential to our understanding of the risk that major stratospheric sulphate injections pose to global climate."
The research suggests that the effects of even the most powerful volcanic eruptions on Earth may not be an extinction-level event. While these events can cause significant environmental disruptions, the planet, and its inhabitants, have a greater capacity for resilience than previously understood.
It’s vital to remember that this research doesn’t negate the very real and present dangers of climate change brought about by human actions. The study’s findings provide a basis for understanding the effects of such catastrophic events and the Earth’s ability to recover from them.
Ultimately, the research offers a different perspective on potential global catastrophes. Mother Nature, at her most destructive, might not be the force that wipes us out. The more significant threat may be the environmental damage we are inflicting upon ourselves, damage that could have long-lasting consequences. This suggests that our future is in our own hands. Whether this is a positive realization or not is based on one’s optimism about humanity’s collective ability to act in its own best interest and preserve the planet for future generations.
