Scientists Find 91 Volcanoes Underneath Antarctica's Melting Ice
Scientists Find 91 Volcanoes Underneath Antarctica's Melting Water ice
Geologically, Antarctica isn't piece of cake to study. Nearly all of it (98 percent) is covered by water ice, with an average depth of 1.ane miles.. This has certain obvious impacts on our ability to measure annihilation that isn't tall enough to suspension through that water ice, and we don't have a thorough agreement of the ground underneath the ice sheet as a consequence. Researchers, pouring information from ice-penetrating radar, have identified 91 new volcanoes that dot the face up of the continent, which means Antarctica now has the densest population of discovered volcanoes on Globe; significantly higher than Africa, the previous tape-holder.
There are limits to what we tin can written report from almost a mile "to a higher place" the features in question. The written report just looked for evidence of cone volcanoes, fifty-fifty though in that location'southward adept reason to think there are other types of volcanic features in the surface area. There's a known, major, active rift valley between West and East Antarctica, and rift valleys in other parts of the globe brandish different types of volcanism than y'all see from Mt. Vesuvius or Kilauea. Westward Antarctica is currently moving abroad from East Antarctica at 2mm per year, or 500,000 years per kilometer (0.62 miles). Information technology'due south not exactly sprinting, but it'southward definitely moving.
Here's why the study is sobering: There are signs that at least some of these volcanoes accept erupted, even with Antarctica frozen solid. That's impressive in and of itself. Without wanting to oversimplify volcanism, at that place's a human relationship to the amount of force per unit area inside the magma chamber below a volcano and the weight and pressure of whatever'due south higher up it. A mile of ice is very heavy, just it's not every bit heavy as a mile of stone. And the melting bespeak of water, even under high force per unit area, is far below the temperature of your average magma.
The earth is yet rebounding from the last water ice age
Most people are aware that continents break autonomously, move together, and break apart once more over a span of hundreds of millions of years. Less discussed is the impact ice ages have on the top of continents. The sheer weight of all the ice forces continents down. As the ice melts, the state rebounds. This is called isostatic rebound, or glacial rebound, and you can see evidence of it at the Bathurst Inlet, Nunavut. Those lines on the shore aren't sand; the inlet receives piffling to no tide. That'southward where the embankment used to be, with each line college on the shore corresponding to a lower tiptop of the state.
Currently, Antarctica is believed to have sunk by nearly three,000 feet thank you to the sheer weight of the ice sheet on peak of information technology. Inland Greenland, for comparing, is believed to accept sunk by just under 2,000 anxiety in some areas. We think of Antarctica as a monolithic field of white, cheers to its delineation on most maps, only were the ice sheet removed, it would look something more than similar this:
In the very long term, Antarctica would rebound, leading to a map more like this:
But before we get at that place, there's a minor outcome to be dealt with starting time. Due to global warming, some parts of Antarctica are warming faster than others — or, to be a bit more specific about it, the area with all the volcanoes is melting faster than any of the others.
Research in Iceland has shown that a reduction in ice canvas thickness has an impact on activity in the pall below volcanos. Again, this makes sense. The less heavy the weight, the easier it is for magma to erupt. The report authors aren't sure if the prevalence of volcanic cones would advance ice sheet melting (through eruption) or actually assistance to stabilize the ice sail by providing a barrier to water ice sheet movement.
Either way, magma upwelling underneath the glacier will melt some corporeality of ice — and there's some evidence to suggest that 1 or more hotspots may exist under Western Antarctica, similar to the hotspot beneath Hawaii. Ice sheets are absolutely capable of flowing and using water as a lubricant. And we know at that place'due south liquid water under the ice already, cheers to research into Lake Vostok.
A surge in volcanic activity within ane of these rifts could pb to water ice melt and accelerate ice melting on the continent.
Source: https://www.extremetech.com/extreme/254270-scientists-find-91-additional-volcanos-antarctica-densest-concentration-earth
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