The Pangaea Pop-up - Michael Molina

Pop-ap Pangea - Majkl Molina (Michael Molina)

Prevodilac: Tijana Mihajlović Lektor: Mile Živković

Once upon a time,

Nekada davno,

South America lived harmoniously alongside Africa

Južna Amerika živela je u harmoniji pored Afrike

until a crack in the Earth

dok pukotina u Zemlji

drove the two continents apart.

nije odvojila ova dva kontinenta.

This breakup began about 200 million years ago

Ovo razdvajanje je počelo pre oko 200 miliona godina

during the separation of the supercontinent

tokom razdvajanja superkontinenta

known as Pangaea.

poznatog pod nazivom Pangea.

Their proximity back then

Njihova blizina iz tog perioda

explains why the same plant fossils and reptile fossils,

objašnjava iste fosile biljaka i reptila,

like the Mesosaurus,

kao što je Mezosaurus,

can be found on the South American east coast

koji mogu da se nađu na istočnoj obali Južne Amerike

and African west coast.

i zapadnoj obali Afrike.

However, this evidence does not account

Ipak, ovaj dokaz ne objašnjava

for how the continents moved apart.

kako su se ovi kontinenti razdvojili.

For that, we'll need to take a close look

Za to moramo pobliže da se zagledamo

at the earth below our feet.

u zemlju ispod naših nogu.

Though you may not realize it,

Iako možda to ne znate,

the ground below you is traveling across the Earth

tlo ispod vas putuje širom Zemlje

at a rate of about 10 cm/year,

brzinom od oko 10 cm po godini,

or the speed at which your fingernails grow.

ili brzinom kojom rastu nokti na vašim nogama.

This is due to plate tectonics,

Ovo se dešava zbog tektonike ploča

or the large-scale movement of Earth's continents.

ili globalnog kretanja Zemljinih kontinenata.

The motion occurs within the top two layers

Kretanje se dešava u okviru zadnja dva sloja

of the Earth's mantle,

Zemljinog omotača,

the lithosphere and asthenosphere.

litosfere i astenosfere.

The lithosphere,

Litosfera,

which includes the crust and uppermost mantle,

koja uključuje koru i gornji omotač,

comprises the land around you.

čini tlo oko vas.

Beneath the lithosphere

Ispod litosfere

is the asthenosphere

je astenosfera,

the highly viscous but solid rock portion

krajnje viskozan, ali čvrst kameni deo

of the upper mantle.

gornjeg omotača.

It's between 80 and 200 km

Nalazi se između 80 i 200 km

below the Earth's surface.

ispod Zemljine površine.

While the asthenosphere wraps around the Earth's core

Dok je astenosfera obavijena oko Zemljinog jezgra

as one connected region,

kao jedan povezani region,

the lithosphere is separated on top

litosfera je razdvojena na vrhu

into tectonic plates.

u tektonske ploče.

There are seven primary tectonic plates

Postoji sedam osnovnih tektonskih ploča

that compose the shape of the planet we know today.

koje čine izgled planete kakav poznajemo danas.

Like the other smaller tectonic plates,

Kao i druge male tektonske ploče,

the primary plates are about 100 km thick

osnovne ploče su oko 100 km debljine

and are composed of one or two layers:

i sastoje se od jednog ili dva sloja:

continental crust and oceanic crust.

kontinentalne kore i okeanske kore.

Continental crust forms the continents

Kontinentalna kora obrazuje kontinente

and areas of shallow water close to their shores,

i područja plitkih voda blizu obala,

whereas oceanic crust forms the ocean basins.

dok okeanska kora formira okeanska korita.

The transition from the granitic continental crust

Prelaz sa granitne kontinentalne kore

to the basaltic oceanic crust

na bazaltnu okeansku koru

occurs beyond the continentel shelf,

javlja se iznad epikontinentalnog pojasa,

in which the shore suddenly slopes down

kojim se obala iznenada spušta

towards the ocean floor.

prema okeanskom koritu.

The South American Plate is an example

Južnoamerička ploča je primer

of a tectonic plate made of two crusts:

tektonske ploče koju čine dve kore:

kontinentalna kakvu poznajemo sa sadašnje mape

the continent we know from today's map

and a large region of the Atlantic Ocean around it.

i prostran region Atlantskog okeana oko nje.

Collectively comprising the lithosphere,

Kolektivno obuhvatajući litosferu,

these plates are brittler and stiffer

ove ploče su krtije i kruće

than the heated, malleable layer of the asthenosphere below.

od zagrejanog, pokretljivog sloja astenosfere ispod njih.

Because of this,

Zbog ovoga,

the tectonic plates float on top of this layer,

tektonske ploče plutaju po površini ovog sloja,

independently of one another.

nezavisno jedna od druge.

The speed and direction in which these tectonic plates move

Brzina i pravac u kom se ove tektonske ploče pomeraju

depends on the temperature and pressure

zavise od temperature i pritiska

of the asthenosphere below.

astenosfere ispod.

Scientists are still trying to nail down

Naučnici još uvek pokušavaju da shvate

the driving forces behind this movement,

sile koje stoje iza ovih kretanja

with some theories pointing towards mantle convection,

kroz neke teorije koje ukazuju na konvekciju omotača,

while others are examining

dok druge ispituju

the influence of the Earth's rotation

uticaj Zemljinog okretanja

and gravitational pull.

i silu gravitacije.

Though the mechanics have not been sorted out,

Iako način delovanja još nije sređen,

the scientific community agrees

naučna zajednica se slaže

that our tectonic plates are moving

da se naše tektonske ploče pomeraju

and have been for billions of years.

i da su se pomerale milijardama godina.

Because these plates move independently,

Pošto se ploče pomeraju nezavisno,

a fair amount of pushing and pulling

prilična količina guranja i povlačenja

between the plates occurs.

dešava se između ploča.

The first type of interaction

Prvi tip interakcije je

is a divergent boundary,

divergenciona granica,

in which two plates move away from one another.

kod koje se dve ploče udaljavaju jedna od druge.

We see this in the Mid-Atlantic Ridge

Ovo vidimo kod Srednjeatlantnog grebena,

between South America and Africa.

između Južne Amerike i Afrike.

The next interaction is when two plates collide,

Sledeća interakcija je kada se dve ploče sudaraju,

known as a convergent boundary.

što je poznato pod nazivom konvergenciona granica.

In this instance, the land is pushed upward

U ovom slučaju, tlo se gura naviše

to form large mountain ranges,

da bi stvorilo prostrane planinske vence,

like the Himalayas.

kao što su Himalaji.

In fact, the Indian Plate is still colliding

U stvari, indijska ploča se i dalje sudara

with the Eurasian Plate,

sa evroazijskom pločom,

which is why Mount Everest

zbog čega Mont Everest

grows one cm/year.

poraste centimetar po godini.

Finally, there's the transform boundaries,

Na kraju, postoje transformne granice,

where two plates scrape past one another.

pri čemu se dve ploče okrznu kada prolaze jedna pored druge.

The grinding of the transform boundary

Trenje u transformnoj granici

leads to many earthquakes,

dovodi do mnogih zemljotresa,

which is what happens

a to se dešava

in the 810 mile-long San Andreas Fault.

u rasedu San Andreas dugom 1300 kilometara.

Zemlja koja se kreće se ne može zaustaviti

The moving Earth is unstoppable,

and, while a shift of 10 cm/year may not seem like a lot,

i dok pomeranje od 10 cm po godini može da deluje kao malo,

over millions of years our planet will continue

naša planeta će tokom miliona godina

to dramatically change.

nastaviti da se dramatično menja.

Mountains will rise,

Planine će se podizati,

shorelines will recede,

obale će se povlačiti,

islands will pop up.

ostrva će isplivavati.

In fact, one projected map shows

U stvari, jedna projektovana mapa pokazuje

the cities of Los Angeles and San Francisco

da su Los Anđeles i San Francisko

on top of each other.

jedan preko drugog.

Maybe South America and Africa

Možda će se i Južna Amerika i Afrika

will come together again, too.

opet spojiti.

Only time will tell.

Samo će vreme pokazati.