A group of researchers has recently published a paper revealing that the Earth's heated liquid outer core has been leaking into the upper layer of our planet, called the mantle, over the course of the last two billion years. They detected that newer mountains and rocks formed on the Earth's surface feature a combination of two wolfram isotopes, wolfram-182 and wolfram-184, which are typically found in the planet's outer core.
This fact intrigued the scientists, as the material that erupts from volcanoes and which forms new mountains comes directly from the planet's mantle, a layer situated above the Earth's core. The fact that such a combination of isotopes has been found in rock formed by relatively recent eruptions indicates that the outer core’s 5,000 degree Celsius liquid contents started leaking into the mantle around 2.5 billion years ago. Scientists have found no evidence of leaks prior to this.
However, despite being able to detect the leaks, scientists don't yet know what is causing them. According to one of their hypotheses, it's caused by certain oxygen-rich materials making their way from the surface into the mantle's lower levels, bordering the outer core of the planet. There the oxygen, brought from the Earth's surface, causes wolfram from the core to ascend to the mantle.
Another hypothesis suggests that the same process is caused by the gradual solidification of the inner core, which originally consisted entirely of liquid metal. It is the solidified spinning part of the core that is responsible for the existence of the planet's magnetosphere, which protects the Earth from deadly particles bombarding it from space, including those coming from the Sun.
It remains unclear whether the leaks from the outer core of the planet into the mantle could affect the inner core's functioning and ultimately impact our magnetosphere. However, as the group of researchers said, the latest finding could help scientists to better understand the nature and mechanisms behind how the Earth’s core functions.
