As far back as4.4 billion years , we think Earth was an ocean world . This was partly patronize by enquiry last year , looking at some of the former rocks on the planet . A new study has now suggest when the first land might have come out .
In this Modern written report published inNature , scientist led by Ilya Bindeman from the University of Oregon choke a step further . They enounce that Earth ’s first supercontinent , Kenorland , in all probability emerged from the ocean about 2.4 billion years ago . And it convert our planet dramatically .
" What we speculate is that once large Continent emerge , ignitor would be meditate back into space and initiate runaway glaciation , " Bindeman said in astatement . " Earth would have seen its first snow . "
They came to this ending after study chemical signatures in Earth ’s most unwashed aqueous rock , shale . look at the change in oxygen in the shale , they nail the clip when Earth ’s crust was debunk to weathering as it emerge from the sea .
And about 2.4 billion years ago , it ’s thought that the total amount of landmass on Earth would have been about two - thirds of what we see today , with the emergence of new state materialize speedily .
This timing also coincides with the reaching of Kenorland , when our planet contract its first high - plenty chain of mountains and plateaus . The Earth’s crust needed to be duncish to dumbfound out of the water , but when Earth was live earlier in its life , it was unable to support such large landmass .
“ Our datum indicate that this change exponentially 2.4 billion years ago , ” said Bindeman . “ The cooler mantle was able to support declamatory swaths of land above ocean level . ”
The temperature would have been much hotter when this land emerged , by tens of degrees . But the land would have nurse atomic number 6 dioxide out of the atmosphere , cooling the planet . And the farming would also have made Earth more reflective , bouncing more of the Sun ’s rays back into space and further cool down the planet , finally leading to the first snow .
The emergence of land 2.4 billion age ago is also around the time when living moved from water - base thing like bacteria to country - based like fungus kingdom and plants . The arriver of land may also have kickstarted theGreat Oxygenation Event2.4 to 2.2 billion long time ago , as our atm changed dramatically .
