Why is Mount Everest so tall? - Michele Koppes

Translator: Klavdija Cernilogar Reviewer: Matej Divjak

Vsako pomlad

Every spring,

hundreds of adventure-seekers dream of climbing Qomolangma,

na stotine avanturistov sanja o vzponu na Čomolungmo,

also known as Mount Everest.

znano tudi kot Mount Everest.

At base camp, they hunker down for months

Mesece čakajo v baznem taboru,

waiting for the chance to scale the mountain's lofty, lethal peak.

da bi dobili priložnost za vzpon na veličastni in smrtonosni vrh.

But why do people risk life and limb to climb Everest?

Zakaj ljudje tvegajo življenje in zdravje, da bi osvojili Everest?

Gre za izziv?

Is it the challenge?

The view?

Za razgled?

The chance to touch the sky?

Za možnost, dotakniti se neba?

Mnoge privlači status Everesta kot najvišje gore na svetu.

For many, the draw is Everest's status as the highest mountain on Earth.

There's an important distinction to make here.

A treba je biti natančen.

Mauna Kea is actually the tallest from base to summit,

Najvišja gora od vznožja do vrha je Mauna Kea,

but at 8850 meters above sea level,

vendar ima z 8850 m

Everest has the highest altitude on the planet.

Everest najvišjo nadmorsko višino na svetu.

Da bi razumeli, kako je ta očak nastal,

To understand how this towering formation was born,

we have to peer deep into our planet's crust,

moramo prodreti globoko v skorjo planeta,

where continental plates collide.

kjer se stikajo kontinentalne plošče.

Zemljina površina je kot oklep pasavca.

The Earth's surface is like an armadillo's armor.

Pieces of crust constantly move over,

Deli skorje se stalno gibljejo,

under,

nad, pod in okoli drug drugega.

and around each other.

For such huge continental plates, the motion is relatively quick.

Za tako velike kontinentalne plošče se gibljejo relativno hitro.

They move two to four centimeters per year,

Premikajo se dva do štiri centimetre letno,

about as fast as fingernails grow.

približno tako hitro, kot rastejo nohti na rokah.

When two plates collide,

Ko dve plošči trčita,

one pushes into or underneath the other, buckling at the margins,

se ena zarine v ali pod drugo, se ob straneh upogne

and causing what's known as uplift to accomodate the extra crust.

in povzroči dvig, da napravi prostor za dodatno skorjo.

That's how Everest came about.

Tako je nastal Everest.

Pred 50 milijoni let se je indijska plošča pomaknila proti severu

50 million years ago, the Earth's Indian Plate drifted north,

bumped into the bigger Eurasian Plate,

in trčila v večjo, evrazijsko ploščo.

and the crust crumpled, creating huge uplift.

Skorja se je nagubala in se močno dvignila.

Mountain Everest lies at the heart of this action,

Everest je v osrčju te dejavnosti,

on the edge of the Indian-Eurasian collision zone.

na robu trka med indijsko in evrazijsko ploščo.

A gore oblikujejo tudi druge sile.

But mountains are shaped by forces other than uplift.

As the land is pushed up, air masses are forced to rise as well.

Ko zemlja rine navzgor, se dviga tudi zrak.

Rising air cools, causing any water vapor within it to condense

S tem se zrak hladi in povzroči kondenzacijo pare,

and form rain or snow.

kar tvori dež ali sneg.

Padavine preoblikujejo površje,

As that falls, it wears down the landscape,

dissolving rocks or breaking them down in a process known as weathering.

razgradijo skale ali povzročijo, da razpadejo zaradi vremenskih vplivov.

Water moving downhill carries the weathered material

Voda po pobočjih odnaša tovrsten material

and erodes the landscape,

ter povzroča erozijo,

carving out deep valleys and jagged peaks.

s čimer tvori globoke doline in razbrazdane vrhove.

This balance between uplift and erosion gives a mountain its shape.

Ravnotežje med dviganjem in erozijo daje gori značilno obliko.

But compare the celestial peaks of the Himalayas

Primerjajmo nebeške vrhove Himalaje

to the comforting hills of Appalachia.

s pomirjujočimi gorami Apalačev.

Clearly, all mountains are not alike.

Seveda niso vse gore enake.

Upoštevati je namreč treba tudi čas.

That's because time comes into the equation, too.

When continental plates first collide, uplift happens fast.

Ob prvem naletu kontinentalnih plošč do dviga pride hitro.

The peaks grow tall with steep slopes.

Vrhovi so visoki in imajo strma pobočja.

Over time, however, gravity and water wear them down.

Sčasoma pa jih težnost in voda izčrpata.

Eventually, erosion overtakes uplift,

Erozija premaga dviganje

wearing down peaks faster than they're pushed up.

in vrhove uničuje hitreje, kot se dvigujejo.

A third factor shapes mountains: climate.

Tretji dejavnik je podnebje.

In subzero temperatures, some snowfall doesn't completely melt away,

Pri temperaturah pod ničlo se ves sneg ne stopi,

instead slowly compacting until it becomes ice.

temveč postaja kompakten, dokler se ne pretvori v led.

That forms the snowline, which occurs at different heights around the planet

To ustvari snežno linijo, ki po svetu nastaja na različnih višinah,

depending on climate.

odvisno od podnebja.

At the freezing poles, the snowline is at sea level.

Na polih je snežna linija na morski gladini.

Near the equator, you have to climb five kilometers before it gets cold enough

Blizu ekvatorja je šele kakih pet km visoko dovolj hladno,

for ice to form.

da se tvori led.

Gathered ice starts flowing under its own immense weight

Ves ta led začne teči pod lastno neznansko težo

forming a slow-moving frozen river known as a glacier,

in tvoriti počasi tekočo ledeno reko, ki ji rečemo ledenik,

which grinds the rocks below.

ki melje skale pod seboj.

The steeper the mountains, the faster ice flows,

Bolj ko so gore strme, hitreje teče led

and the quicker it carves the underlying rock.

in hitreje oblikuje kamnino pod seboj.

Glaciers can erode landscapes swifter than rain and rivers.

Ledeniki erodirajo pokrajino hitreje kot dež in reke.

Kjer se ledeniki dotikajo vrhov gora, jih spodjedo tako hitro,

Where glaciers cling to mountain peaks, they sand them down so fast,

they lop the tops off like giant snowy buzzsaws.

da vrhove odnese, kot bi jih odrezala ogromna snežna motorna žaga.

So then, how did the icy Mount Everest come to be so tall?

Kako da je potem ledeni Mount Everest tako visok?

The cataclysmic continental clash from which it arose

Kataklizmično trčenje plošč, ki ga je ustvarilo,

made it huge to begin with.

ga je že naredilo visokega.

Secondly, the mountain lies near the tropics,

Poleg tega gora leži blizu tropov,

so the snowline is high, and the glaciers relatively small,

zato je snežna meja visoko, ledeniki pa relativno majhni,

barely big enough to widdle it down.

komaj dovoljšni, da ga malo odškrnejo.

The mountain exists in a perfect storm of conditions

Gora stoji v popolnih okoliščinah,

that maintain its impressive stature.

zaradi katerih ohranja svojo izjemno višino.

But that won't always be the case.

A ne bo vedno tako.

We live in a changing world where the continental plates,

Svet se spreminja in kontinentalne plošče,

Earth's climate,

Zemljino podnebje ter moč erozije

and the planet's erosive power

might one day conspire to cut Mount Everest down to size.

bodo nekoč morda znižali Mount Everest.

For now, at least, it remains legendary in the minds of hikers,

Za sedaj pa ostaja legenda v očeh planincev,

adventurers,

avanturistov ter sanjačev.

and dreamers alike.