study reveals role of volcanoes in evolution
Last Updated : GMT 05:17:37
Emiratesvoice, emirates voice
Emiratesvoice, emirates voice
Last Updated : GMT 05:17:37
Emiratesvoice, emirates voice

Magma rise released oxygen into Earth

Study reveals role of volcanoes in evolution

Emiratesvoice, emirates voice

Emiratesvoice, emirates voice Study reveals role of volcanoes in evolution

Lava flows from Kilauea volcano on Hawaii
London - Arabstoday

Lava flows from Kilauea volcano on Hawaii Oxygen-breathing life exists on Earth today because of changes in the planet\'s magma 2.5 billion years ago, two geologists say. Oxygen currently makes up 21 percent of our atmosphere. But for the first half of Earth\'s existence, the air had almost no oxygen—if any humans could travel back to that ancient environment, they\'d need spacesuits to survive.
Mysteriously, bacteria such as blue-green algae—which produce oxygen through photosynthesis—had existed for several hundred million years before oxygen finally managed to enrich the air during a period called the Great Oxidation Event.
Now, a new study of 70,000 rock samples from around the world may have solved the mystery of oxygen\'s long delay.
The rocks show a dramatic change in Earth\'s magma composition at the end of the Archean, which lasted from 4 to 2.5 billion years ago.
\"This was actually somewhat unexpected to us,\" said study co-author C. Brenhin Keller of Princeton University.
That\'s because the discovery implies magma formed at greater depths during the Archean than it has anytime since.
Magma Gases Sopping Up Oxygen
Keller and his co-author Blair Schoene, also of Princeton, speculate that the change in where magma forms triggered the different chemical compositions seen in their rock samples.
Importantly, the scientists propose, such a shift could have altered the balance of iron in magma from ferrous to ferric—versions of the element that react differently with oxygen.
When volcanoes were producing magma with ferrous iron, they emitted gases that readily sopped up atmospheric oxygen, Keller said.
By contrast, when volcanoes started spewing magma with ferric iron, the gases consumed less oxygen, and photosynthesis was able to enrich the air with the element, the thinking goes.
William White of Cornell University reviewed the paper for publication but was not involved in the study. He notes that the newfound change in magma composition occurred around the same time as the rise of oxygen.
\"I suspect that this isn\'t coincidental,\" he said, echoing the study\'s conclusions.
Some two billion years later, Earth\'s oxygen-rich air allowed animals—including humans—to emerge and thrive. What\'s more, the freshly abundant element gave rise to our planet\'s protective ozone layer, which shields surface life from damaging solar radiation.
First, though, the rise of oxygen subjected our planet to a mid-life crisis: Oxygen readily reacts with methane, a greenhouse gas that had been warming the world before the oxidation event.
With a drop in atmospheric methane, Earth and its inhabitants suffered the planet\'s first major ice age.

Name *

E-mail *

Comment Title*

Comment *

: Characters Left

Mandatory *

Terms of use

Publishing Terms: Not to offend the author, or to persons or sanctities or attacking religions or divine self. And stay away from sectarian and racial incitement and insults.

I agree with the Terms of Use

Security Code*

study reveals role of volcanoes in evolution study reveals role of volcanoes in evolution

 



Name *

E-mail *

Comment Title*

Comment *

: Characters Left

Mandatory *

Terms of use

Publishing Terms: Not to offend the author, or to persons or sanctities or attacking religions or divine self. And stay away from sectarian and racial incitement and insults.

I agree with the Terms of Use

Security Code*

study reveals role of volcanoes in evolution study reveals role of volcanoes in evolution

 



GMT 09:54 2018 Wednesday ,24 January

'Friendly and kind' N. Korean skaters

GMT 09:36 2017 Thursday ,07 December

Heidy Karam’s contract to present talk show close

GMT 10:50 2012 Friday ,20 January

Dusty weather expected in UAE on Friday

GMT 09:35 2018 Saturday ,13 January

New Zealand bat first in third ODI against Pakistan

GMT 10:48 2017 Saturday ,23 December

Meryl Streep's brand under threat

GMT 06:53 2017 Thursday ,11 May

17th Doha Forum To Begin Sunday

GMT 10:30 2017 Thursday ,23 November

Reports underline proliferation of weapons in Arab world

GMT 07:46 2017 Monday ,30 October

Catch it early, treat it early and move on

GMT 08:05 2015 Tuesday ,17 February

Conan O'Brien is first late night host to film in Cuba

GMT 16:17 2018 Thursday ,30 August

Five Saudi women pilots granted GACA licences
 
 Emirates Voice Facebook,emirates voice facebook  Emirates Voice Twitter,emirates voice twitter Emirates Voice Rss,emirates voice rss  Emirates Voice Youtube,emirates voice youtube  Emirates Voice Youtube,emirates voice youtube

Maintained and developed by Arabs Today Group SAL.
All rights reserved to Arab Today Media Group 2021 ©

Maintained and developed by Arabs Today Group SAL.
All rights reserved to Arab Today Media Group 2021 ©

emiratesvoieen emiratesvoiceen emiratesvoiceen emiratesvoiceen
emiratesvoice emiratesvoice emiratesvoice
emiratesvoice
بناية النخيل - رأس النبع _ خلف السفارة الفرنسية _بيروت - لبنان
emiratesvoice, Emiratesvoice, Emiratesvoice