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Lava flows in the Holuhraun Fissure, Bardarbunga Volcano, Iceland. Getty Images
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About 183 million years ago, there was a massive volcanic eruption that emitted greenhouse gases and caused mass extinctions on Earth. This natural phenomenon, which occurs in the Jurassic period of the first Toarcian stage, became known as an oceanic anoxic event (T-OAE), in which the lack of oxygen in the water caused the extinction of a large number of living beings. However, the cause of the volcanic eruptions continues to be a mystery.
A new study suggests that a slowdown in continental movement appears to have caused the eruption. Led by Micha Ruhl, Professor of Sedimentology at Trinity College Dublin, England, the findings are detailed in Science advances.
Ruhl and colleagues suspect that these changes cause magma to escape from the bowels of the earth and create great igneous provinces (LIP), a large expanse of volcanic rock that has so far been etched into the landscape of South Africa and Antarctica.
This research provides new insight into the events that rocked the Jurassic period, when dinosaurs still roamed the Earth and the supercontinent Pangea was entering its twilight years. Furthermore, says Ruhl’s team, the reduction in continental velocities has wider implications because “the mechanism is consistent with the timing of some of the largest volcanic LIP events in Earth’s history, and therefore could be related to global climate change and past mass extinctions, “the study reads.
“We have started studying other major volcanic events in the past and have seen the same thing happen to most of them. So we think this model is valid for most of Earth’s history,” Ruhl told Motherboard, the tech section. by VICE. But apparently, the pattern observed by Ruhl et al. it looks new.
Violent volcanic activity is known to trigger the formation of LIPs from magma plumes that reach the earth’s surface. And now, the research team has found that the events that occurred during this period coincided with the speed at which the continental plates were moving.
Continents are moving at a rate of inches per year and have been moving at a relatively fast pace for millions of years before the T-OAE occurred.
The research team studied the sediments created during this period, which were deposited at a depth of one mile in Wales, England. Who would have guessed, the results of the analysis linked the data with the pattern of plate movement before and after the eruption. They attribute the slowing of the continental drift to the north that triggered the T-OAE, followed by the cessation of movement, to a timeline of violent volcanic eruptions.
Ruhl calls the process as if we were paper on a candle. The paper will burn if we swing it quickly over the fire and will have holes if we move it slowly. In an eruption that causes a mass extinction, the slow-moving continents exposes the plates to magma for a longer time, so that the mantle plumes that melt the undergrowth explode to the surface.
Ruhl’s team points out that the slowdown or cessation of continental movement coincided with the most serious mass extinction event of all time, known as the Great Dying, which wiped out more than 90 percent of life on Earth. 250 million years ago, plus several other mass extinctions that occurred over the past 500 years over the past million years.
The new findings could also serve as an illustration of how human-caused climate change will change our future. Although volcanic activity differs from the use of fossil fuels, they both release carbon dioxide and other gases that can cause global warming in large quantities and occurs in a relatively short period of time. By studying the effects of greenhouse gas spikes on Earth’s habitats, as well as the variety of life forms on them, we can anticipate what could happen as global temperatures rise in the decades to come.
“Volcanoes release large amounts of carbon and greenhouse gases into the atmosphere,” Ruhl said. “Therefore, it is important for us to know the relationship with environmental and climatic disturbances. We can study how much carbon is released and what impact it has on rising sea levels, decreasing pH and so on. “
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