New forest growth may have caused the mass extinction 360 million years ago

0

New forest growth may have caused the mass extinction 360 million years ago by fueling massive plankton blooms that sucked up all the oxygen from the oceans – and experts say this is now happening at an even faster rate.

  • Sediment records indicate that new forests caused the Devonian mass extinction
  • There was a link between new growth and an explosion of planktonic blooms
  • Experts suggest that new vegetation grew worldwide some 360 ​​million years ago
  • This pushed new nutrients into the soil that seeped into the oceans in waves
  • It was enough to fuel plankton that grew to enormous sizes around the world
  • The flowers then devoured all the oxygen and choked sea creatures

The Devonian Mass extinction wiped out 70 percent of our planet’s life some 360 ​​million years ago, but what triggered the deadly event has remained a mystery until now.

The animals, mostly marine species, have due to a lack of oxygen in Earth’s oceans and previous work suggests a volcanic eruption or even a supernova, but a new study finds they were new forests that grew in the ancient world.

An international team of scientists has found evidence that fresh vegetation releases nutrients into the seas that fed massive algal blooms, devouring all the oxygen and choking anything and everything in the salt water.

Separate studies show hundreds of ‘dead zones’ where life around the world currently cannot survive for the same reason that led to the extinction of the Devonian, and experts say’ it is happening at a rate much faster than what happened during the Late Devonian ‘.

The Devonian mass extinction wiped out 70 percent of our planet's life some 360 ​​million years ago, but what triggered the deadly event has remained a mystery.  But a study suggests it was new forest growth around the world that triggered the deadly event

The Devonian mass extinction wiped out 70 percent of our planet’s life some 360 ​​million years ago, but what triggered the deadly event has remained a mystery. But a study suggests it was new forest growth around the world that triggered the deadly event

The mass extinction is one of the big five to ravage the Earth and has previously been attributed to asteroid impacts, climate change, sea level changes and large-scale volcanic activity.

“ Progressive volcanism is believed to be responsible for the intermittent pattern of oceanic anoxia during the late Devonian, but the frequency of volcanic activity is unlikely to be related to orbital cycles, ” reads the study published in the May issue of Earth and Planetary. Science Letters.

“Volcanic eruptions may have previously altered the chemistry of terrestrial environments (eg, fertilizing soils) that could contribute to eutrophication and anoxia from Earth orbiting land inputs.”

However, the team said InsideScience that volcanic activity may have played a role in amplifying the extinctions that lasted for some 20 million years.

An international team of scientists has found evidence that fresh vegetation releases nutrients into the seas that fed massive algal blooms, devouring all the oxygen and choking anything and everything in the salt water.

An international team of scientists has found evidence that fresh vegetation releases nutrients into the seas that fed massive algal blooms, devouring all the oxygen and choking anything and everything in the salt water.

An international team of scientists has found evidence that fresh vegetation releases nutrients into the seas that fed massive algal blooms, devouring all the oxygen and choking anything and everything in the salt water.

The Devonian mass extinction wiped out 70 percent of our planet's mammals some 360 ​​million years ago, but what triggered the deadly event has remained a mystery until now.  Depicted is what our planet looked like about 360 million years ago

The Devonian mass extinction wiped out 70 percent of our planet's mammals some 360 ​​million years ago, but what triggered the deadly event has remained a mystery until now.  Depicted is what our planet looked like about 360 million years ago

The Devonian mass extinction wiped out 70 percent of our planet’s mammals some 360 ​​million years ago, but what triggered the deadly event has remained a mystery until now. Depicted is what our planet looked like about 360 million years ago

This study examined the Upper Devonian Chattanooga Shale of Tennessee, where they found evidence showing that new forests over the period are to blame.

This is a geological formation that stretches through Alabama, Arkansas, Kentucky, Missouri, and Tennessee, and is home to a wealth of fossils dating back to the Devonian.

About 65 samples were collected on site and taken to a laboratory to measure concentrations of molecules known to be related to ocean oxygen levels, plankton blooms, plant matter, and soil and sediment erosion.

And a fluctuation in these chemical fingerprints, or “proxies,” led the team to an answer.

They could see a connection when large amounts of nutrients flowed into the oceans and when plankton activity increased.

Separate studies show hundreds of 'dead zones' where life around the world currently cannot survive for the same reason that caused the Devonian extinction and experts say 'it is happening at a rate much faster than what happened during the Late Devonian'.

Separate studies show hundreds of 'dead zones' where life around the world currently cannot survive for the same reason that caused the Devonian extinction and experts say 'it is happening at a rate much faster than what happened during the Late Devonian'.

Separate studies show hundreds of ‘dead zones’ where life around the world currently cannot survive for the same reason that caused the Devonian extinction and experts say ‘it is happening at a rate much faster than what happened during the Late Devonian’.

“The initial radiation from forests has likely significantly altered weathering patterns on land and released massive amounts of nutrients flushed from continents into the ocean,” the study reads.

The Late Devonian was plagued by intense monsoons that sparked the growth of new forests around the world.

With such vegetation sprouting in trumpets, the soil became rich in new nutrients that trickled into the oceans in waves, producing massive plankton blooms that sucked up all the oxygen.

However, the team warns that a similar process is happening today and appears to be happening much faster than some 360 ​​million years ago.

WHEN WERE THE ‘BIG FIVE’ OUTPUT EVENTS OF THE EARTH?

Traditionally, scientists have referred to the ‘Big Five’ mass extinctions, including perhaps the most famous mass extinction caused by a meteorite impact that caused the end of the dinosaurs 66 million years ago.

But the other major mass extinctions were caused by phenomena that originated entirely on Earth, and while they are less well-known, researching them allows us to learn something that could shed light on our current environmental crises.

  1. The late Ordovician: This ancient crisis, about 445 million years ago, saw two major extinction waves, both caused by climate change associated with the rise and retreat of ice sheets in the Southern Hemisphere. This makes it the only major extinction related to global cooling.
  2. The late Devonian: This period is now considered a series of “pulses” of extinction spanning 20 million years, starting 380 million years ago. This extinction has been linked to major climate change, possibly caused by an eruption of the volcanic Viluy Traps area in what is now Siberia. A major eruption may have caused rapid sea level swings and decreased oxygen levels in the oceans.
  3. The Middle Permian: Scientists recently discovered another event 262 million years ago that rivals the ‘Big Five’ in size. This event coincided with the Emeishan eruption in what is now China, and is known to have caused simultaneous extinctions in the tropics and higher latitudes.
  4. The late Permian: The late Permian mass extinction, about 252 million years ago, overshadows all other events, with about 96% of species extinct. The extinction was caused by a massive eruption of the Siberian Traps, a massive and long-lasting volcanic event that covered much of today’s Siberia, leading to a cascade of environmental impacts.
  5. The late Triassic: The Late Triassic event, 201 million years ago, shares some similarities with the Late Permian event. It was triggered by another large-scale eruption, this time from the Central Atlantic Magmatic Province, which heralded the split of the supercontinent Pangea and the first opening of what would later become the Atlantic Ocean.

Advertisement