About 40,000 years ago, Earthâs magnetic field changed direction dramatically. Now, scientists have managed to turn this change into terrifying sounds, using information collected by European Space Agency (ESA) satellites. They used satellite data and other evidence of the movement of Earthâs magnetic field lines to create a âsoundtrackâ of the event, complete with sounds like creaking wood and crashing rocks.
What is Earthâs Magnetic Field”
Earthâs magnetic field is generated by the movement of liquid metals in the planetâs core. It extends thousands of miles into space and protects us from particles from the Sun, which could destroy our atmosphere. Normally, the magnetic field lines form loops that run from south to north above the surface and from north to south inside the Earth.
Every now and then, Earthâs magnetic field reverses direction. If this were to happen today, compasses would point to the South Pole instead of North.
What Happened During the Last Reversal”
The last time the magnetic field reversed was about 41,000 years ago. This event left marks on lava rocks in France, called the âLaschamps lava flows.â During this time, the magnetic field became much weaker, down to just 5 percent of its current strength. This allowed more cosmic rays to enter the Earthâs atmosphere.
These cosmic rays caused changes in the atmosphere, doubling the levels of special atoms, such as beryllium-10. These atoms are formed when cosmic rays react with air, damaging the ozone layer. Some scientists believe that this may have contributed to changes in the global climate and even the extinction of large animals in Australia.
https://youtu.be/6Tc7XI0iUYU
Why is this important”
Understanding these extreme events is important for predicting how the Earthâs magnetic field might behave in the future. This can help protect the environment and the technological systems we use.
How Long Did the Reversal Last”
The magnetic field reversal process took about 250 years, and the new orientation lasted about 440 years. During that time, the magnetic field was only 25% of its current strength.
Is the Magnetic Field Changing Today”
Scientists have recently observed changes in the magnetic field, such as a weakening over the Atlantic Ocean, which has led some to question whether a new reversal is imminent. However, research suggests that these changes do not necessarily indicate a reversal.
The “South Atlantic Anomaly” is exposing satellites in that region to higher levels of radiation.
How Are Scientists Studying the Magnetic Field”
Since 2013, satellites from the European Space Agency’s Swarm mission have been measuring magnetic signals coming from Earth’s core, mantle, crust, oceans, ionosphere, and magnetosphere. This helps scientists better understand our planet’s magnetic field and predict its changes.
Publicado em 10/21/2024 16h52
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