New research suggests that the stretching of the continents 56 million years ago probably caused one of the most extreme episodes of global warming in Earth’s history.
During this time, the planet experienced a temperature rise of 5-8 ° C (9-14 ° F), which culminated in the Paleocene-Eocene thermal maximum (PETM), which lasted about 170,000 years.
It caused the extinction of many deep-water organisms and reshaped the course of the evolution of life on Earth.
Scientists studied the effects of global tectonic forces and volcanic eruptions during the period of environmental change nearly 60 million years ago.
They believe that the extensive stretching of the continental plates in the northern hemisphere, rather like the stretching of a candy bar that thins and finally separates, massively reduced the pressures deep inside the Earth. .
Then, this caused an intense, but short-lived, melt in the mantle: a layer of sticky molten rock just below the planet’s crust.
The team, which includes experts from the universities of Southampton, Edinburgh and Leeds, suggests that the resulting volcanic activity coincided with, and probably caused, a massive burst of carbon release into the atmosphere related to warming. of the PETM.
New research suggests that the “stretching” of the continents 56 million years ago probably caused one of the most extreme episodes of global warming in Earth’s history. In the photo is a false color satellite image of the Faroe Islands, one of the locations studied by scientists
The team studied the layers of volcanic ash and lava in the laboratories of the Bremen Central Reservoir of the Integrated Ocean Drilling Program (IODP), Germany.
Scientists found that intense episodes of volcanism were probably responsible for the rapid warming during the Paleocene-Eocene maximum thermal warming event. In the photo there is a volcano in Montserrat, Antilles
WHAT WAS THE MAXIMUM PALEOCENE-EOCENE THERMAL?
The Paleocene-Eocene Thermal Peak (PETM) was a global warming event that occurred about 56 million years ago.
During this time, scientists estimate between 3,000 and 7,000 gigatons of carbon accumulated over a period of 3,000 to 20,000 years.
This causes global temperatures to rise by 5 to 8 degrees Celsius (9 to 14 degrees Fahrenheit), making the average as high as 23 degrees Celsius (73 degrees Fahrenheit).
It caused dramatic changes in the Earth’s climate, leading major organisms to extinction and forcing others to migrate.
Dr Tom Gernon, an associate professor of Earth sciences at the University of Southampton and lead author of the study, said: “Despite the importance and broader relevance of PETM to current global change, the underlying cause is very debated.
“It is generally agreed that a sudden and massive release of the greenhouse gas, carbon, from the Earth’s interior must have caused this event, but the scale and rate of warming are very difficult to explain by conventional volcanic processes. “
Scientists found evidence of perforated rock from the seabed for an episode of widespread volcanic activity that lasted 200,000 years, which coincided with the PETM.
Using perforated rock files under the seabed near the shores of the Atlantic Ocean, the team found evidence of an abrupt and widespread episode of volcanic activity in the North Atlantic Ocean that lasted just over 200,000 years. , surprisingly similar to the duration of PETM.
This finding prompted researchers to investigate a wider expanse of the North Atlantic region, including Greenland and the Faroe Islands.
Here, they found that one-kilometer-thick piles of lava that began to explode just before the PETM show unusual compositions that point to a significant increase in the amount of melting of the highest solid part of the Earth’s mantle beneath the continent.
Dr. Gernon said this would have led to a rapid increase in carbon release, which would have caused global warming.
Here are fragments of Atlantic lava under a microscope
Volcanism occurred when the North Atlantic region was in the final stages of rupture, or rupture, in some ways similar to the geological processes taking place today in the East African Rift Valley, pictured.
Intense volcanic activity occurred in the same way that the continental mass linking Greenland and Europe was more intensely stretched by plate tectonic forces.
Eventually, North America and Greenland eventually separated from Europe, leading to the birth of the North Atlantic Ocean.
Scientists believe it was this final stretching phase that caused a substantial melting of the Earth’s mantle, which caused a massive release of carbon and, in turn, global warming.
Dr Thea Hincks, a senior researcher at the University of Southampton and co-author of the study, said: “Using physically realistic estimates of the key features of these volcanic systems, we show that the amount of carbon needed to drive warming could having been is achieved through improved fusion. ‘
Dr. Gernon added, “These rapid events cause a fundamental reorganization of the Earth’s surface environment, altering vast ecosystems.”
The study has been published in the journal Nature Geoscience.
WHEN WAS THE PALEOCENE AND HOW DID IT IMPACT THE BRITISH CLIMATE?
The Paleoscene (‘ancient recent’) is a geological period that stretched from 66 to 56 million years ago.
During this period, the Earth’s climate was up to 15 ° C (27 ° F) warmer than today.
As a result, tropical and subtropical forests spread further north and would have been widespread in the UK.
At that time there had been no ice age for 100 million years.
The distance between Europe and Greenland was a tenth of what it is today.
There was massive volcanic activity between Baffin Island and northwestern Europe that stretched south to the Bristol Channel.
The shape of the continents was similar to today, except that they were arranged differently due to tectonic plates. Britain, Ireland, and Norway had no way out to sea, and the Arctic Sea was almost completely surrounded by land.
Britain, Ireland, and Norway had no way out to sea, and the Arctic Sea was almost completely surrounded by land.
The shape of the continents was similar to today, except that they were arranged differently due to tectonic plates, according to a website dedicated to the Paleocene.
Most of the world’s most famous geological features would not have been recognizable, including mountain ranges such as the Alps and the Himalayas that formed during the Tertiary period.
Before the Paleocene-Eocene thermal maximum (PETM), which occurred about 55 million years ago, non-avian dinosaurs had become extinct for about ten million years.
The first mammals, amphibians, reptiles, insects, and flowering plants were the dominant life forms.
Mammals were generally small, had short legs and five toes on each foot.