NASA has been investigating something together with the German Aerospace Agency (DLR) for years. Since 2007 specifically, under the eastern Atlantic they have detected gravitational anomalies. It was first recorded by the GRACE mission, and these satellites showed that the inside of our planet is much more dynamic than we thought, and has mass movements capable of altering gravity and the magnetic field! Relax, we are not in danger (yet), but they want to keep investigating why this happens, and we are going to tell you everything we know!
How it was discovered
Between 2006 and 2008, the GRACE satellites captured a strange pattern under the sea, a strip of reduced gravity and another with increased gravity that stretched over 7,000 kilometers under the Atlantic, very strange. So they kept observing, that signal coincided with a geomagnetic shake in the same area, so it could not be a simple surface change, there was something more. Everything pointed to a deeper phenomenon, but what could it be?
The role of the mantle and bridgmanite
The key is in the Earth’s mantle and in a little-known but abundant mineral called bridgmanite.
At about 3,000 kilometers deep, this mineral can transform from perovskite to post-perovskite, a phase change that radically alters its density. That transition explains how large masses are redistributed inside the planet, generating the gravitational anomalies that the satellites managed to record, wow!!!
Connection with the outer core
What most caught the scientists’ attention is that this anomaly coincided with some alterations inside the planet’s magnetic field, then they came to the conclusion that there was a link between the deep mantle and the liquid outer core, and perhaps this relationship is key to understanding the internal cycles of our planet and how it has evolved throughout history.
Does anything change for us?
Well, for us, I don’t know. But for scientists it opens the heart of the Earth, they seek to understand how the mass distribution is under our feet. Is it slow? Is it predictable? Clearly it is not, but… what consequences could it have for the surface? And of course, they also want to investigate what consequences it could have for the magnetic field, which is the one that makes life possible on our planet, is it in danger then?
There are many questions that arise, right? Well, scientists still do not know clearly how often these anomalies occur or to what extent they influence processes like plate tectonics, volcanic activity or even the climate. Everything is a huge unknown, but they are clear that the combination of satellite data and seismic studies will be fundamental to keep deciphering what these hidden signals are.
To understand space we first have to understand our planet, and its depths hold so many things!
What is happening? The summary
- NASA and DLR satellites detected something strange under the Atlantic, it was 2007.
- A 7,000 km strip showed areas with abnormal gravity.
- What is a gravitational anomaly? It is when gravity changes in a region of the planet.
You don’t notice it when walking, but satellites do detect it. - And the water? The change cannot be explained by oceans or underground water. It would require moving impossible amounts.
- What was it? Everything points to the Earth’s mantle.
- A mineral called bridgmanite changed shape at 3,000 km depth.
- In that same area, a geomagnetic shake was recorded. Gravity and magnetism, altered at the same time. Coincidence?
- The Earth changes from within, in ways we had never seen before.
- Can it happen again? Nobody knows. But this event showed that with satellites and seismic studies, we can see what happens even in the planet’s depths.