Experts are on red alert as 100 volcanoes in Antarctica move closer to erupting
Experts are on edge after uncovering a ticking time bomb in Antarctica that would reshape the continent and dramatically raise global sea levels.
More than a hundred volcanoes lie beneath the surface of the West Antarctic Ice Sheet, which is “particularly vulnerable to collapse, yet its position atop an active volcanic rift is rarely considered,” the study said.
Scientists have warned that as climate change causes the ice sheet to melt, it will lead to increased volcanic activity that accelerates melting at the surface, creating a ‘positive feedback loop’.
As the ice sheet melts, the amount of mass pressing on the surface decreases, creating an uplifting effect in the subsurface.
This allows magma chambers deep within the continent to expand, speeding up the processes that lead to an eruption by putting pressure on the chamber walls and releasing gas trapped in the magma.
When volcanoes erupt, it causes more melting at the surface and the process starts over.
The researchers modeled this phenomenon using more than 4,000 advanced computer simulations, finding that surface melting speeds up the process that initiates the first stages of an eruption by tens to hundreds of years.
In one of the modeling scenarios, the team removed a 900-meter-thick ice sheet over 300 years, which is considered moderate melting for West Antarctica, and found a significant increase in volcanic activity and the size of eruptions.
Some chambers released enough heat to melt more than three million cubic meters of ice per year.
Experts have warned of a newly discovered phenomenon in Antarctica that could increase volcanic activity and global sea level rise. Pictured is Mount Erebus, the largest active volcano on the continent
Increased eruptions from the numerous volcanoes of the West Antarctic Ice Sheet would not directly harm human communities, as the continent is largely uninhabited.
But they can cause indirect damage by accelerating sea level rise, which threatens coastal communities.
If the ice sheet were to collapse completely, sea levels could rise catastrophically by 60 meters.
This would completely flood entire coastal cities such as New York, Tokyo and Shanghai, making them uninhabitable.
Fortunately, scientists believe that an apocalyptic scenario is still far away.
The latest estimate predicts a near-total collapse of the West Antarctic Ice Sheet by the year 2300, giving humanity 275 years to try to slow its decline.
But because the models that generated this estimate did not take into account the melt-volcanism feedback loop, the actual date of collapse may be earlier, according to the researchers, although more research is needed to determine if that is the case.
Still, the new study suggests that volcanic activity beneath the ice sheet may play a bigger role in its decline than experts previously thought.
Current sea level rise predictions depend on scientists’ ability to predict the stability of the West Antarctic Ice Sheet, which is nearly twice the size of Alaska and is particularly vulnerable to collapse for a number of reasons.
The researchers used a model to simulate how different decreases in magma chamber pressure affect the melting of the ice sheet.
More than 100 volcanoes lie beneath the surface of the West Antarctic Ice Sheet. What appears to be a frozen wasteland is actually the largest volcanically active area on Earth
Although experts have known about these volcanoes for years, researchers recently discovered that the interaction between volcanic activity and the melting of surface ice creates a “positive feedback loop.”
They also explored how the loss of surface mass due to melting allows magma chambers to expand, reducing pressure within and ultimately changing the trajectory of future eruptions in a number of different ways.
The first is through the expansion itself, which puts pressure on the walls of the magma chamber and therefore makes eruptions more likely.
The second mechanism is more complex. Many magma chambers contain gases such as water vapor and carbon dioxide, which are dissolved in the magma under high pressure.
But when melting surface ice causes the pressure to drop, those gases escape in bubbles.
As those gases escape, the pressure in the chamber quickly builds back up, increasing the chance of an eruption.
These eruptions – even the ones that never break the surface – generate enormous amounts of heat that cause more ice to melt, which in turn causes more eruptions.
The researchers found that some of the eruptions simulated by the model would never have occurred without the influence of surface melting.
This could result in a greater total release of magma over the lifetime of a chamber, they concluded.
Climate change is already causing rapid melting of the West Antarctic Ice Sheet and other glaciers around the world.
But the researchers’ model identified a feedback loop that suggests the melting drives itself indirectly by increasing the frequency of volcanic eruptions in the ice sheet.
The researchers’ model suggests that surface melting speeds up the process that initiates the first stages of an eruption by tens to hundreds of years, causing more melting.
Increased eruptions from the numerous volcanoes of the West Antarctic Ice Sheet would not directly harm human communities, but could cause indirect damage by accelerating sea level rise
They even found evidence for this phenomenon in real-world research conducted in the Andes Mountains of South America, where the Patagonia ice sheet formed atop the southern volcanic zone 18,000 to 35,000 years ago.
Although only remnants of this ice sheet remain today, the researchers used geochronological data from the last two ice ages to identify a link between the melting of the surface ice and increased eruptions from three different volcanoes on the ice sheet .
The researchers published their findings in the journal Geochemistry, geophysics, geosystems
They emphasized that the process they identified is slow and takes place over hundreds of years. But this means the feedback loop could continue even if human-induced climate change slows.