Monday, November 12, 2018

The Seafloor Is Dissolving Away. And Humans Are to Blame.

By Stephanie Pappas, Live Science Contributor | November 5, 2018 
Carbon emissions are dissolving the seafloor, especially in the Northern Atlantic Ocean. Shown here, Azkorri beach in Basque Country in northern Spain.Credit: Inaki Bolumburu/Shutterstock 

Climate change reaches all the way to the bottom of the sea.
The same greenhouse gas emissions that are causing the planet's climate to change are also causing the seafloor to dissolve. And new research has found the ocean bottom is melting away faster in some places than others.

The ocean is what's known as a carbon sink: It absorbs carbon from the atmosphere. And that carbon acidifies the water. In the deep ocean, where the pressure is high, this acidified seawater reacts with calcium carbonate that comes from dead shelled creatures. The reaction neutralizes the carbon, creating bicarbonate.

Over the millennia, this reaction has been a handy way to store carbon without throwing the ocean's chemistry wildly out of whack. But as humans have burned fossil fuels, more and more carbon has ended up in the ocean. In fact, according to NASA, about 48 percent of the excess carbon humans have pumped into the atmosphere has been locked away in the oceans.

-- 7 Ways the Earth Changes in the Blink of an Eye]
All that carbon means more acidic oceans, which means faster dissolution of calcium carbonate on the seafloor. To find out how quickly humanity is burning through the ocean floor's calcium carbonate supply, researchers led by Princeton University atmospheric and ocean scientist Robert Key estimated the likely dissolution rate around the world, using water current data, measurements of calcium carbonate in seafloor sediments and other key metrics like ocean salinity and temperature. They compared the rate with that before the industrial revolution.

Their results, published Oct. 29 in the journal Proceedings of the National Academy of Sciences, were a mix of good and bad news. The good news was that most areas of the oceans didn't yet show a dramatic difference in the rate of calcium carbonate dissolution prior to and after the industrial revolution. However, there are multiple hotspots where human-made carbon emissions are making a big difference — and those regions may be the canaries in the coalmine.

The biggest hotspot was the western North Atlantic, where anthropogenic carbon is responsible for between 40 and 100 percent of dissolving calcium carbonate. There were other small hotspots, in the Indian Ocean and in the Southern Atlantic, where generous carbon deposits and fast bottom currents speed the rate of dissolution, the researchers wrote.

The western North Atlantic is where the ocean layer without calcium carbonate has risen 980 feet (300 meters). This depth, called the calcite compensation depth, occurs where the rain of calcium carbonate from dead animals is essentially canceled out by ocean acidity. Below this line, there is no accumulation of calcium carbonate.

The rise in depth indicates that now that there is more carbon in the ocean, dissolution reactions are happening more rapidly and at shallower depths. This line has moved up and down throughout millennia with natural variations in the Earth's atmospheric makeup. Scientists don't yet know what this alteration in the deep sea will mean for the creatures that live there, according to Earther, but future geologists will be able to see man-made climate change in the rocks eventually formed by today's seafloor. Some current researchers have already dubbed this era the Anthropocene, defining it as the point at which human activities began to dominate the environment. 

"Chemical burndown of previously deposited carbonate-rich sediments has already begun and will intensify and spread over vast areas of the seafloor during the next decades and centuries, thus altering the geological record of the deep sea," Key and his colleagues wrote. "The deep-sea benthic [bottom] environment, which covers ~60 percent of our planet, has indeed entered the Anthropocene." 
Originally published on Live Science.
Thanx Stephanie Pappas

Knight Sha

2 comments:

  1. Greetings Knight Sha
    Good article and great explanation that anyone can understand. Not a lot of scientific jargon. It is very disturbing news however. We so depend on the sea for food and other products. We are destroying ourselves from the inside. And still, not too many folks seem to be too disturbed. That is what troubles me the most.
    Nice to have you back, my friend.
    Love Knight Aunt Jeannie

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  2. Hello Aunt Knight Jeannie ,
    I knew this article has a lot of depth to it I wanted to share it with our readers and maybe the will get the how serious this situation .
    Something drastic has to happen to wake the deniers up , we discuss that there is ans was a lot of older people out there , they were fighting but was almost to lose the batter until the younger people got involved and now they have a voice , the deniers had more money and more people in high places and it seem to them they were fighting a losing battle .
    Now anymore the new breed is here , we don't care about who has money or people in high places we will be heard and we are here to stay .
    MeMa said we have a lot of poppa in us , when we what something to happen we take hold and don't turn loose .
    We are glad to be back , we got side tracked by Aunt Mae and her foolishness , Uncle Harvey joined us in our meeting and he set us straight . Uncle Harvey told us not to let anyone take control and make us lose sight of what our main goal is and not to be mad at Aunt Mae , she see all the love we give mama and she just want her kids to give her some love Uncle Harvey said Aunt Mae should have learned from past experience that will never happen . He said he thinks poppa had more pity for her and tried to keep her safe but Aunt Mae is on her own now and daddy won't go to her aid . Uncle Harvey said if Uncle Gregg had his way daddy wouldn't have defended her in Dallas , he said daddy did it because poppa asked him .
    Thank you and glad to be back .
    Lots of love
    Knight Sha

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