Undersea volcanic activity caused an ancient disaster of extinction

According to a new study, seabed volcanic eruption about 93 million years ago depleted the amount of oxygen in the sea, causing widespread extinction of life in the ocean.

The catastrophic event buried a variety of creatures living on the seabed - from big boys to small unicellular algae, which today become the main source of oil.

The new discovery allows scientists for the first time to identify ghost activity in the ocean - the formation of rocks from cold ghosts - during the period of dinosaurs extinction.

Experts say the study also opens new directions for Earth's response to large amounts of greenhouse gases.

According to co-author of the study Steven Turgeon - an Earth scientist at the University of Alberta in Edmonton (Canada), at the time of widespread extinction, the Earth's climate was warm and muddy, the sea flow slow.

Palm trees grow in the Northern Slope of Alaska, and carbon dioxide levels are 3 to 12 times higher than today. Turgeon said the increase in carbon dioxide is the result of volcanic activity involving the rapid shifting of Earth's plate tectonics.

He said: 'We have a ghost activity that happened at that time on a large scale, it is the agent of a series of reactions that push all oxygen out of the sea and cause widespread extinction. '.

Turgeon and his colleague Robert Creaser published their findings in the journal Nature.

Sea exhausted oxygen

Scientists have long suspected that undersea volcanic activity could cause marine extinction, a severe lack of oxygen - or the depletion of oxygen - this phenomenon is called the OAE2. However, Turgeon stressed, the evidence obtained so far is still incomplete.

Seabed volcanic eruption, which occurred 93 million years ago, depleted oxygen, leading to widespread extinction of the ocean's living organisms.(Photo: National Geographic)

The lack of oxygen, the essential gas for life, is the cause of death for many marine species. Geological records show that this phenomenon occurs when the concentration of carbon dioxide is much higher than the current concentration.

Turgeon and Creaser analyzed rocks in Northeastern South America and Central Italy in the seabed during the Cretaceous period, which lasted from 145 million to 65 million years ago.

The researchers looked for evidence of the metallic element Osimi, hoping that it would bring about an understanding of the cause of the OAE2.

A type of osmium originates first from river sediments flowing into the sea. Another type comes from sources of ghost and extraterrestrial activity, such as meteorites and cosmic dust.

Scientists found that just before the strong attack of OAE2, Osimi signs shifted from river-derived osmium to osmium originating from geological or extraterrestrial activity.

Since there is no evidence of a comet or comet collision 93 million years ago, 30 to 50 times more ghost activity was thought to be the cause of widespread extinction.

Timothy Bralower, geological scientist at Pennsylvania State University, wrote an article supporting the Nature study. He said the study helped clarify the overall picture of the OAE2.

Caribbean strata

According to Bralower, the OAE2 seemed to be pinned down to wait for ghost activity to create a blade structure in the Caribbean, now located beneath Central America and the Caribbean Sea.

The volcanic eruption on the sea floor brings a large amount of metals into the ocean. This promotes the development of microscopic marine plants called phytoplankton (phytoplankton), which produce an excess of organic matter.

Bralower said: 'When plants die, the rain of these organic substances falls through the sea column and drains out oxygen. The phenomenon of oxygen depletion in this deep sea water leads to extinction of the flora and fauna of the sea floor. '

Turgeon said today the organic layer becomes black shale, accounting for nearly a third of recoverable oil reserves.

The focal point of the phenomenon warms up

During the OAE2, excess organic matter absorbs a large amount of greenhouse gases carbon dioxide in seawater and the atmosphere and buries this amount of gas in the seabed.

Other studies have found that it takes about 10,000 to 20,000 years for carbon dioxide levels to reach today's carbon dioxide concentrations.

Turgeon acknowledged that the impact of that phenomenon was temporary. After the volcano erupted, carbon dioxide concentrations and temperatures returned to normal levels in the Cretaceous.

He concluded: 'This phenomenon really exists but in a short time, it provides some understanding of the activity of the atmosphere'.

According to Bralower of Pennsylvania, no horrible phenomenon like the OAE2 will appear in the near future.

He said: 'We are only at the starting line, there is no way but to build a model to predict what will happen in the future'.