Scientists at the University of Southampton have discovered that stretching of the continents is likely to have caused one of the most extreme and abrupt episodes of global warming in Earth history.
The researchers, working with colleagues at the University of Edinburgh, the University of Leeds, the University of Oldenburg, the University of Florence and the Chinese Academy of Sciences, studied the effects of global tectonic forces and volcanic eruptions during a period of extreme environmental change 56 million years ago.
During this time, some sequence of events caused the planet to warm by 5-8˚C, culminating in the ‘Palaeocene-Eocene Thermal Maximum’ or PETM, which lasted about 170,000 years. This caused the extinction of many deep-sea organisms, reshaping the course of evolution of life on Earth.
The team propose that the extensive stretching of the continental plates in the northern hemisphere – rather like the pulling of a toffee bar that thins and eventually separates – massively reduced the pressures in the Earth’s deep interior. This then drove intense, but short-lived melting in the mantle – a layer of sticky, molten rock just below the planet’s crust. The team show that the resulting volcanic activity coincided with, and likely caused, a massive burst of carbon release into the atmosphere linked to PETM warming.
Read more at: University of Southampton
The team studied volcanic ash layers and lavas in the laboratories of the Integrated Ocean Drilling Program’s (IODP) Bremen Core Repository, Germany. (Photo Credit: Dr Tom Gernon/University of Southampton)