Name: 科學家發現了地球上最低的土地 (Scientists Have Found the Lowest Land on Earth)
Uploaded: 2021-01-14T08:51:01.000Z
Duration: 8 min 53 s
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程度副詞

The Earth's lowest known place is the Challenger Deep, almost 36,000 ft below the ocean's surface!

情態助動詞 B1

But however incredible it may sound, dry land also has some extreme points which lie way,

And the lowest of them, previously hiding under a massive glacier, has been discovered

But how about we work up to this awesome aha moment?

First, let me tell you about other, probably not so deep but no less amazing places!

- Death Valley One of the world's hottest and driest national

parks, Death Valley knows a thing or two about extremes.

Snow-covered mountain peaks in the middle of a scorching desert, burning sun - and meadows

But the most amazing thing about Death Valley is that it's home to the lowest point in North

This place lies 282 ft below sea level, which is just a bit smaller than the Statue of Liberty!

When you see this surreal place for the first time, you won't believe your eyes: how come

snow doesn't melt under such blazing sun?

Several moments later, you'll realize your mistake - it's not snow!

A huge chunk of the desert is covered with a thick layer of salt that's been gathering

- The Dead Sea Even though it has the word "sea" in its name,

the Dead Sea is actually one of the most intriguing and unusual lakes on Earth.

You don't need any flotation device to swim in this lake - the water is so salty and dense

that its surface will keep you afloat without any effort from your side!

The Dead Sea has the highest salt concentration among all water bodies in the world and is

The lake's made it to this list because until recently, its surface and shores were considered

The Dead Sea is on average more than 1,400 ft below sea level - that's just a bit less

than the height of the Empire State Building!

And yes, I did say "until recently," and I do hope that you're thoroughly intrigued!

- Lake Baikal The next mega-deep place on land is also covered

with water because it's a freshwater lake.

The Baikal is a unique water body that contains more than 20% of all unfrozen surface freshwater

Situated in south-eastern Siberia in Russia, Lake Baikal is also considered to be the world's

And no wonder - the thing is about 25 million years old!

The amount of water in the lake would be enough to fill the Grand Canyon five and a half times.

The Baikal's area is as large as Belgium and almost as large as Massachusetts!

The lake's total depth is more than five Eiffel Towers piled on top of each other.

And if we talk about the lake's lowest point below sea level, at 4,000 ft, it's more than

- The Krubera Cave No one knows for sure how deep this cave really

Believe it or not but this abyss may drop down to 7,200 ft underground.

Imagine 17 Great Pyramids of Giza stacked up on top of each other, and you'll understand

why there aren't too many volunteers eager to explore the Krubera Cave!

This ancient formation is likely to be more than 5 million years old.

It's an almost vertical system of tunnels plenty of which are flooded.

That's why if you want to explore this wondrous place, remember to take your diving gear!

Even though the world's lowest natural underground point is in the Krubera Cave, it's only the

The record-holder is the Veryovkina cave which is just one Hollywood sign deeper than the

- Denman Glacier Antarctica's massive ice sheet effectively

But scientists don't give up: they've been using radar equipment to crack Antarctica's

And recently, their efforts have paid off!

Previous radar instruments sent off small microwave pulses that helped researchers to

But this method didn't allow them to measure the full depth of some regions.

A new technology called BedMachine solved this problem.

That's when researchers made an astonishing discovery: stretching more than 11,500 feet

below sea level, a canyon under Denman Glacier turned out to be 8 times deeper than the Dead

BedMachine's technology allowed scientists to combine radar readings with the information

about seismic activity and ice flows in the region and make this conclusion.

- Mponeng & TauTona Gold Mines But even though the newly-discovered canyon

under Denman Glacier is the deepest natural point on land, it doesn't mean that there

They DO exist, but these places were created by people, just like the two world's deepest

Being almost the same in size, Mponeng and TauTona mines are as deep as 700 giraffes

and filled with complicated mazes of underground tunnels.

Do you really want me to say 700 giraffes?

Combined, each mine's tunnels are longer than the New York subway system – filled with

Thousands of workers use elevators, called cages, to get down to the mines.

These triple-decked constructions (which DO look unnervingly similar to cages) transport

- By the way, few people know the mines are so deep that the rock at their bottom can

heat up to 140˚ F. To keep these underground temperatures from becoming too dangerous,

surface workers have to pump down ice mixed with salt.

When this salted ice gets into the shafts, giant fans blow air over the mixture - and

this huge DIY AC cools the tunnels down to an almost tolerable 85˚ F. To keep this complicated

system running, above-ground plants produce more than 6,000 tons of ice every day!

- KTB Borehole But even gold mining hasn't taken people as

deep as their curiosity - or should I say thirst for knowledge?

One of the lowest underground points in the world appeared thanks to a scientific drilling

The main KTB borehole (that's a hole branching from the main hole) reached a mind-blowing

depth of almost 30,000 ft, which is the cruising altitude of passenger airliners – filled

Down there, scorching temperatures reached 500˚F!

Luckily, drill heads used in the project could withstand up to 570˚F - otherwise, the drilling