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Last Updated on Jan. 30, 2009 – 12:59 PM
Keywords:magnetic, field, life, earth
Moscow, 01/30/2009 (People online) – A new study suggests that the Earth’s protective magnetic field may have been on the verge of extinction about 565 million years ago, but was restored thanks to the strengthening of the inner core, which prevented the disappearance of life on our planet, RT Highlights.
The study, which was published on January 28 in the online journal Nature Geoscience, indicates that the Earth’s magnetosphere extends into space and removes most of the high-energy particles from the Sun, which could otherwise bombard the surface. of our planet, making it practically uninhabitable.
Geomagnetism occurs in the depths of the Earth, where there is a solid core of iron and nickel, whose surface reaches 5500 degrees Celsius.
It is surrounded by an outer liquid core, the material of which cools and sits continuously, forming solid layers in the center. This causes the hot conductive alloy of the liquid core to mix and creates a geomagnetic field.
Traces of magnetism in ancient iron-rich rocks suggest that the Earth’s magnetic field already existed 4.2 billion years ago. However, at first it was created by a completely liquid and boiling core, the temperature of which at some moment began to decrease gradually, which caused a weakening of the magnetosphere to a life-threatening level on the planet.
Although the Earth’s core is not available for direct research, all changes in the global magnetic field are reflected in the orientation of particles of certain iron-rich minerals. As part of a new study, scientists analyzed plagioclase and clinopyroxene crystals, formed 550-600 million years ago in eastern Quebec (Canada).
The crystals showed that at that time the magnetosphere was going through difficult times as it weakened and its polarity changed ten times faster than it is happening now. However, some time later (about 565 million years ago), the process stopped and suddenly began to develop in a completely different direction. Then the magnetic field of our planet began to recover. The authors of the new study suggest that this dramatic change was due to the solidification of the inner core of the Earth.
It should be noted that the stage of weakening of the magnetosphere coincides with the first mass extinction, the so-called “extinction of Ediacaran organisms”, which occurred 540 million years ago. On the other hand, the subsequent restoration and improvement of the magnetic field coincided with the following important stage in the evolution of life: the Cambrian explosion of biodiversity, during which the ancestors of all types of modern animals appeared.