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  • Deep beneath the thick layer

  • of million-year-old ice,

  • something is lurking quietly,

  • waiting to rip through the rigid ice sheets.

  • No, not that.

  • This enormous icy wasteland

  • is sitting on top of a volcanic ridge.

  • And in our hypothetical world,

  • these volcanoes are about to wake up.

  • Antarctica is the coldest continent on Earth.

  • And it's quite mysterious.

  • We didn't know it had active volcanoes

  • buried underneath it until 2013,

  • when scientists accidentally detected

  • two clusters of small earthquakes.

  • Now that we've scanned Antarctica

  • with ice-penetrating radar,

  • we know that there are many more

  • volcanoes hiding below the ice.

  • One hundred and thirty-eight, to be precise.

  • But that's only the ones we know of.

  • And how much trouble would we be in

  • if all those volcanoes suddenly decided

  • their slumber was over?

  • It shouldn't be too surprising that these

  • ash-breathing ruptures have been

  • buried underneath Antarctica's ice shield this whole time.

  • After all, volcanoes are easy to come by

  • even outside our home planet.

  • There are volcanoes on Jupiter's moon Io,

  • Saturn's moon Enceladus,

  • and on our planetary neighbor Venus.

  • But let's not waste our time there.

  • We've got our own world to save.

  • Do you know what happens when a volcano erupts?

  • There are usually warning signs

  • before the real action begins, like,

  • the waves of earthquakes.

  • They indicate that there's molten rock

  • moving beneath the surface.

  • Then lava and ash join the party,

  • accompanied by heated gases.

  • It depends on a variety of scenarios

  • and the kind of lava involved, but on average,

  • lava moves at about 10 km (6 mi) per hour.

  • Pretty easy to outrun.

  • But when a major eruption occurs,

  • a volcano releases superheated gases and ash.

  • Combined, they create something called a pyroclastic cloud.

  • These things are hot, reaching up to 700°C (1300°F),

  • and they can move at 80 km/h (50 mph).

  • Being trapped by one of these

  • would mean the end of days for you.

  • But Antarctica's volcanoes are a different story.

  • They're buried under layers of ice

  • that are more than 4 km (2.5 mi) thick in places.

  • We wouldn't be dealing with volcanic gases

  • making their way to the surface.

  • At least as far as one eruption goes.

  • The heat released would melt

  • massive caverns in the ice,

  • creating substantial amounts of meltwater.

  • And that's when things would start getting ugly.

  • The newly created meltwater

  • would cause the ice above it to move more rapidly.

  • The Antarctic ice cover would begin heading into the ocean.

  • From there, the domino effect would kick in.

  • The huge weight of the ice puts all that

  • pressure on volcanoes, keeping them stable.

  • But decrease that pressure,

  • and a volcano gets limbered up,

  • and magma finds a way out through an eruption.

  • In the case of Antarctica,

  • multiple volcanic eruptions could wake up

  • over a hundred other volcanoes,

  • and destabilize the entire region.

  • As the volcanoes continued to blow their tops,

  • more meltwater would be created,

  • causing more of the Antarctic ice to slide into the ocean.

  • Antarctic ice would be enclosed by warmer ocean currents.

  • On one hand, we'd get a new look at

  • Antarctic bedrock that's been hiding

  • under the ice this whole time.

  • On the other hand, the ice wouldn't

  • just disappear into thin air.

  • It would melt.

  • And if all of Antarctica's ice melted,

  • it would raise the global sea level

  • by about 60 m (200 ft).

  • Rising sea levels could contribute

  • to major storms moving slower and dropping more rain.

  • Hurricanes and typhoons would wreak

  • havoc on the Earth's surface.

  • Wildlife along coastal areas would lose their habitats,

  • and agricultural soil would become

  • contaminated with salt.

  • Extensive flooding would push

  • millions of people away from the coastline.

  • If the eruptions happened in a span of one day,

  • we'd be looking at thousands of deaths,

  • and storms wiping out everything floating in the oceans.

  • But let's go back to Antarctica for a second.

  • Now that all the ice has melted,

  • what about the rampaging magma?

  • The good news is, it wouldn't

  • turn the Earth into a lava world.

  • After all, the eruptions would occur underwater.

  • The hot magma would solidify

  • in the cold water of the Antarctic Ocean,

  • and maybe add more real estate

  • to Antarctica's own bedrock.

  • But things don't end there.

  • When volcanoes erupt on land,

  • they spew out heated gases, including

  • carbon monoxide, methane, carbon dioxide and nitrogen.

  • To go along with this, there is usually

  • some water vapor thrown into the mix.

  • By some estimates, volcanoes are responsible

  • for the release of 645 million

  • tons of carbon dioxide every year.

  • If the Antarctic volcano eruptions turned out to be powerful enough,

  • they would blow open huge expanses of ice,

  • allowing the release of even more toxic greenhouse gases.

  • When one of Antarctica's surface volcanoes,

  • Mount Takahe, erupted some 18,000 years ago,

  • it spewed out the chemicals that

  • ate a hole in the ozone layer.

  • That hole warmed up the Southern Hemisphere

  • and caused glaciers to melt.

  • It helped wrap up the last ice age.

  • Now imagine over one hundred volcanoes

  • erupting all at once.

  • That can't be good for our planet.

  • But don't worry.

  • Antarctica's volcanoes won't erupt all at once.

  • If they start to wake up,

  • it would take decades for anything substantial to happen.

  • Me? I still think we should be ready for anything.

  • Even adapting to living underwater when sea levels rise.

  • But that's a story for another WHAT IF.

Deep beneath the thick layer

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南極の休火山が目覚めたら? (What If Antarctica’s Dormant Volcanoes Woke Up?)

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    林宜悉 に公開 2021 年 01 月 14 日
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