Name: 如果地球上所有的火山都開始同時噴發怎麼辦？ (What If All Volcanoes on Earth Start Erupting at Once)
Uploaded: 2021-01-14T08:52:29.000Z
Duration: 9 min 20 s
Description: 【看影片學英語】數萬部 YouTube 影片，搭配英漢字典即點即查，輕鬆掌握單字發音與用法，長久累積看電影不必再看字幕。

Approaching the shores of Sicily, you're enjoying the views. The wind brings pleasant coolness,

情態副詞

and you anticipate your vacation. But suddenly, the boat shakes, and you lose balance. You

look up and see a huge plume of black smoke rising above the Etna volcano...

I'll switch from your perspective now because you won't like what happens to you in the

next several minutes. Let's take a look at the planet from the space. All across its

surface you see billowing spots of smoke - that's all the volcanoes on Earth starting to erupt

at once. Smoke is kind of a herald of what's to come: it rises first, warning us of the

danger. And then it varies for different volcanoes.

The active ones, like Etna in Sicily, will start spitting fire and rocks. They haven't

been slumbering to start with, so the magma at their core is hot and volatile. Smoking

boulders will fire up from the crater and fall on the ground nearby, while a fountain

of lava spews up and swiftly goes down the slopes. The temperature of this hot mess is

anywhere from 1,300 to 2,200 degrees F, which is a bit too warm for comfort. Anything this

stream touches will burst into flames at once, but not for long: lava is molten rock, and

outside the Earth's hot core it will soon cool down and become solid. What is left afterwards

is a greyish black mass that looks kinda wavy. Other volcanoes will have been sleeping for

too long, and their stock of lava wasn't that huge to begin with, so they won't really make

a blast. Rather, lava will slowly flow over the edge of the crater and pour down their

slopes. With a bit of luck, everyone in the vicinity will be safe because the hot stream

won't reach much further than the foothills - or shall I say, footvolcanoes?

Others still - and they're actually a vast majority - are underwater, so their eruptions

will be very different. When a submerged volcano erupts, no one on the surface will even notice

it if they're just a bit away. The water right above the volcano will start bubbling, and

its temperature will rise a lot. You'll probably also smell the stench of rotten eggs - that's

methane and sulfur coming from down below. If you're unfortunate enough to be in that

exact spot, though, you'll want it to be about a couple of hundred degrees cooler. There

might also be a hefty amount of pumice floating around - that's lava that cooled down in the

water and got filled with air bubbles. And then there are supervolcanoes. There are

only four of them on the planet, the most famous being the Yellowstone supervolcano.

If even one of these giants erupts, it will do so much damage it will change the landscape

of large part of the continent it's on. Now, like I said, all volcanoes on Earth start

erupting at once. It’s a bad day -- I’m guessing a Monday. Almost immediately they

bring disaster to their surrounding areas with hot lava and rockfall. As soon as that

stops, smoke rises into the atmosphere, and ash starts falling to the ground. It looks

like snow, only black. But ash is heavy and clingy, so when it falls onto roofs of the

buildings, it clumps together and soon makes them collapse under its weight. It's also

very dangerous to inhale this ash because it blocks the airways, not letting you breathe.

Quite soon ash covers everything. It blankets all surfaces, smothering grass, trees, and

bushes, and they stop producing oxygen. Smoke, on the other hand, creates a full-blown veil

in the skies above. This veil doesn't let the sunshine through, so the planet starts

to cool down by degrees. It becomes colder and colder, until a new ice age begins. If

there's still someone alive by this point, they'll have to deal with freezing cold and

huge glaciers far beyond their typical area. Closer to the equator, though, it might be

warmer than elsewhere, so there’ll still be hope.

But the irony is that CO2 is a greenhouse gas, and after a while its high concentration

in the atmosphere will warm up the planet again. The ice will draw back, and for some

time Earth will have a good inhabitable climate, but not nearly long enough for life to thrive.

Soon, the temperatures will rise to unbearable values, and it’ll be scalding hot until

CO2 goes away at least in part. Only then the planet might begin to return to normal,

but it may take thousands of years. Meanwhile, the oceans boil too. There are

hundreds of underwater volcanoes, and they erupt as well, throwing out thousands of tons

of gas and magma. And if magma stays mostly on the bottom of the sea, gases go up and

make the water hot and acidic. Much of the marine life can’t adapt to the changing

conditions this fast, and lots of species face mass extinction. Only the sturdiest remain,

and those are microscopic creatures that somehow survive boiling temperatures at the crevices

in the ocean’s bottom. In the next few hundred or even thousand years,

life on Earth is virtually nonexistent. About 95% of all living things are gone — it’s

basically the same as what happened when a meteorite struck the planet in the era of

dinosaurs. Volcanoes have wiped out life, leaving only a veil of darkness in the sky,

plains of ash and solid magma on land, and acid instead of water in the ocean. If you

looked at the Earth from above, you would only hardly recognize the once blue and green

planet. But then, after sufficient time has passed,

Earth will begin recovering. At first, when carbon dioxide dissipates and the temperature

returns to more or less normal, plants will start appearing. Solid magma and ash might

make the land look desolate, but in fact they’re a rather good soil for the green. If you look

at Kamchatka, for example, you’ll see there’s grass and flowers and bushes springing from

the black mass around the less active volcanoes. So given enough time, the lands will become

lush and booming with plant life — probably more than ever.

With the return of grass and trees, oxygen will start pumping into the atmosphere. When

it’s rich enough, the air will once again become breathable for creatures with lungs.

But it will be a very long time before they appear once more. Since most life is gone,

the cycle will have to begin anew, from the smallest critters you can’t even see with

a naked eye. Thousands of years pass, and evolution kicks

in. New and bigger species appear. They continue evolving and growing, different animal families

pop up, and chances are very high they don’t resemble anything we’ve ever seen on our

planet. They might have six legs instead of four, for all we know, or even two heads!

Possibilities are endless. And finally, at some point in the distant

future, there appears the first species that learns to use tools. For us, these were primates.

For the Earth of the future, they could be anything. In any case, when they find sticks

and stones and start sharpening them to make stakes and primitive axes, it will be the

first step towards a new civilization. In a few more thousand years, a new intelligent

species will begin building their homes on the planet we used to claim for our own. Let’s

just hope they won’t have to deal with a massive all-out volcanic eruption same as

our civilization did. Well, hypothetically, of course.

Anyway, back to the now: what are the chances of having such a disaster? Next to none, in

fact. Scientists point out there has never been an eruption of this kind on Earth, and

there’s no indication it might happen in the future. You see, magma comes from the

upper layer of the Earth’s mantle. As it is, mantle is solid, but it’s so hot that

some part of it melts down, becoming fluid rock. When a volcano erupts, it means that

the pressure of this molten layer has become too much, and it needs to get out on the surface.

Once it does, the volcano it sprang from falls into slumber once more, only leaving traces

of lava down its slopes and, hopefully, no calamities nearby.

So, if all volcanoes on Earth were to erupt, it would take an extraordinary amount of excess

magma in the mantle. And since there’s not so much of it in the first place, such a collective

explosion is next to impossible. Ah, that’s a relief.

Now, about that big asteroid approaching from over there…ha just kidding.

Hey, if you learned something new today, then give the video a like and share it with a

friend! And here are some other videos I think you'll enjoy. Just click to the left or right,

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如果地球上所有的火山都開始同時噴發怎麼辦？ (What If All Volcanoes on Earth Start Erupting at Once)

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