Hiding beneath the massive Antarctic Ice Sheet lies one of the densest clusters of volcanoes in the world. In total, scientists have identified 91 new volcanoes, adding to the 47 already known to exist in the region.
A group of geologists at the University of Edinburgh has identified 91 new volcanoes concentrated along the West Antarctic Rift System axis. This research has recently been published in a special series of the Geological Society of London.
A variety of analysis techniques has been used in the research process. These included satellite measurements for slight perturbations in ice morphology, radar that penetrated the ice to provide clues as to what lies beneath the ice, and general knowledge of Antarctica’s rift system.
These volcanoes are buried beneath the Antarctic ice sheet, with some as deep as two miles. They range in height from 325 to 12,600 feet, with the largest being as tall as the Eiger in Switzerland. The Antarctic rift system stretches 2,200-miles from the Ross ice shelf to the Antarctic peninsula.
The density of volcanoes is approximately one volcano per 4,800 square miles. This concentration is bigger than East Africa’s volcanic ridge, making it the densest concentration of volcanoes in the world.
In fact, the discovery of such a significant number of previously-unknown volcanoes changes our conception of Antarctica as a volcanic region. Scientists can tell that the volcanic range is relatively young due to lack of significant evidence of glacial erosion and the volcanoes remain conical in shape.
Unfortunately, the outcomes do not indicate which of these volcanoes might be active or have the potential to erupt. Nonetheless, this new study should inspire further research and seismic monitoring in the area. This will enable geologists to better understand how volcanoes might impact changes in ice sheets over long time periods. Besides, it will also enhance our comprehension of the continent’s climatic past.
The likelihood of the volcanoes becoming active may increase over time. This is because the ice over top these active volcanoes contains the pressure building up in these volcanoes. As the ice melts, this will reduce overlying pressure on the volcanoes and make it easier for them to erupt if they have an over-pressured magma chamber.
Scientists are not totally sure what happens when under-ice volcanoes erupt. Nevertheless, these events could cause underground magma and fluids to force open new paths and fracture rock. A serious eruption could melt the bottom of the ice sheet immediately above the volcano’s vent. Yet it is not possible to know what would happen after that.
What is worrying scientists is the ability for these volcanoes, if they erupted, to cause wide scale melting and destabilising of the Antarctic Ice Sheet. This would, in turn, accelerate the stream of meltwater into the ocean and aggravate the effects of climate change on the frozen continent.
This could lead to a positive feedback loop! Increased melting of ice sheets increases volcanic activity, which thus increases melting. This is a situation where we would see ice melt rates quickly increase compared to previous melting rates. As an analogy, this situation is occurring on Iceland as ice continues to melt and volcanism increases. We can use analogies like the East African Rift to understand how rift systems develop over time. Like rifts seen around the world, where the Earth is ripping apart and allowing magma to reach the surface, we are probably going to see more eruptions from Antarctica’s volcanic system.
On the other side, the volcanoes act as fixing points for the movement of glaciers. They limit its ability to easily flow down towards the sea. Both are likely contributing factors and will continue to play a role in the melting of Antarctica’s ice in the coming decades and centuries.
Red-hot magma bursting through the Antarctic ice sheet inspires a particularly powerful mental picture. Maybe one of these newfound volcanoes will blow within our lifetimes, and we will actually get an opportunity to see it. It would definitely be a song of fire and ice!