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Space

How Earth's magnetic field is changing

By Chris Wood
May 10, 2016
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A new study has made use of data gathered by ESA's Swarm satellites, which have been studying the Earth's magnetic field for more than two years
ESA/ATG medialab
Since launching at the tail end of 2013, ESA's Swarm satellites have been studying the different magnetic signals that emanate from the planet's core, mantle, crust, oceans, all the way out to the ionosphere and magnetosphere
ESA/ATG Medialab
The first animation shows changes in field strength between 1999 and May 2016, with red regions indicating where it got stronger, while the blue regions show a weakening
DTU Space
The second animation describes the rate of change between 2000 and 2015, with slowing regions are seen in blue, and those speeding up visible in red
DTU Space
A new study has made use of data gathered by ESA's Swarm satellites, which have been studying the Earth's magnetic field for more than two years
ESA/ATG medialab
View gallery - 4 images

The European Space Agency (ESA) launched its trio of Earth-facing satellites – the Swarm satellites – more than two years ago. Since then, the three probes have been tirelessly making measurements of the Earth's magnetic field, mapping it out in detail. Now, that data has been used in a new study of how the magnetic field has changed over recent years, with the results echoing what's happening at the planet's core.

Earth's magnetic field might be invisible, but it's complex and ever-changing, protecting us from cosmic radiation and solar winds. Since launching at the tail end of 2013, ESA's Swarm satellites have been studying the different magnetic signals from the planet's core, mantle, crust, oceans, all the way out to the ionosphere and magnetosphere.

All that data was recently used in a study to describe where the magnetic field is getting weaker, where it's strengthening, and perhaps most importantly – how fast those changes are occurring. The findings are presented at the Living Planet Symposium, which is being held this week, and include two animations showing the changes.

The first animation shows changes in field strength between 1999 and May 2016, with red regions indicating where it got stronger, while the blue regions show a weakening
DTU Space

The first animation, which also makes use of data from CHAMP and Ørsted satellites, shows changes in field strength between 1999 and May 2016. The red regions are where it got stronger, while the blue regions show a weakening.

Overall, the magnetic field has weakened by some 3.5 percent over North America, but has become around 2 percent stronger over Asia. The absolute weakest area of the field, known as the South Atlantic Anomaly, also weakened by some 2 percent as it moved steadily to the west.

The second animation is a little different, describing the rate of change between 2000 and 2015. Similar to the first animation, slowing regions are seen in blue, while those speeding up are visible in red. It's a complex picture, with changes increasing in speed over Asia, while they slow down around South Africa.

The second animation describes the rate of change between 2000 and 2015, with slowing regions are seen in blue, and those speeding up visible in red
DTU Space

What's causing all of those changes? Well, the magnetic field is thought to be the result of the vast quantities of molten iron moving around some 3,000 km (1,860 miles) beneath the surface. The changes, it's thought, are caused by alterations in how the liquid is flowing.

"Swarm data are now enabling us to map detailed changes in Earth's magnetic field, not just at Earth's surface but also down at the edges of its source region in the core," said senior scientist Chris Finlay. "Unexpectedly, we are finding rapid localised field changes that seem to be a result of accelerations of liquid metal flowing within the core."

As they continue to move through their third year of taking measurements, the Swarm satellites will continue to study the magnetic field. In so doing, they will continue to provide valuable insights into how the field is changing, while helping us to improve our understanding of what drives those changes.

Source: ESA

View gallery - 4 images

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SpaceSatelliteESAMagnetic field
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Chris Wood
Chris specializes in science and consumer technology for New Atlas, but also likes to dabble in the latest gaming gadgets. He has a degree in Politics and Ancient History from the University of Exeter, and lives in Gloucestershire, UK. In his spare time you might find him playing music, following a variety of sports or binge watching Game of Thrones.
13 comments
OrionMichaelGuy
Earth's Magnetic Field Lines and Patterns
Temperature is going to be the main driving force in the flow, and change of the Core with a correlation to the Suns, and other Cosmic Flows will contribute to the change and alteration of patterns within the magnetic fields within the Planet, the Core and the magnetic field lines that flow from the Core, through the crust (cause of lava tubes and volcanos and "hot spots" ) and all the way out into space, with concentrated naturally occurring focal points or intersecting lines will be revealed (Geometry)
As the planet gets hotter and hotter, the more room there is for the water in the ocean to occupy - thus, even though sea level rise is not currently concerning, the increase of surface temperatures will still wreck havoc on surface conditions including sea level rise
Unchecked this could all pop into a popcorn like scenario, but mankind will by this time already be fully aware of the situation and preparations will already be decades or possibly even centuries in the planning...
The Science is simple - Keep an Eye on Space!
First thing you see is the Magnetic Lines of interaction of Earth's Core, Crust and through out into Space - to the Sun, and other Planets and Cosmic Conditions and Events, and on out from their
Oh My Oh My Keep An Eye On Space, Ohh My!
Orion Michael Guy
ChuckJeffries
Could this be a factor in the growth and shrinking of the 'ozone hole' which caused so much excitement and fear before we found something else to scare us?
Robert in Vancouver
Global warming hucksters will say the magnetic field is changing due to CO2, so we need to give them more money. Meanwhile, Al Gore and his partners at Goldman Sachs will make another $1 or 2 billion selling phony CO2 credits.
RangerJones
As stated; "complex and ever-changing" is the magnetic field. Surrounding solar system will tell you more about the core of the earth and what's going on rather than rely on '2 years of info'. All tests before were approximations and these might be also-who knows.
IndependentResearcher
Earth's magnetic field has been determined to have a half-life of about 1500 years. This means that over that period of time it's strength diminishes by 50%. Interestingly, if you run this in reverse time, it doesn't take long for the field strength to become so powerful that it would play havoc with biological processes, making life difficult if not unlikely. Today there is a growing movement called 'grounding' which, in part, encourages the use of grounding sheets to pull off excess charge from the body for better sleep and homeostasis.
Firehawk70
@ChuckJeffries - the ozone hole was caused directly by CFCs and related compounds. By regulating and removing those compounds, we've made huge headway in reversing that hole - that should be proof enough of the cause. To be clear, the ozone issue is not quite related to climate change issues. Ozone is mostly about blocking UV radiation - we like the ozone layer so we don't get skin cancer (as much). But climate change is more about other layers of the atmosphere. That's not to say the ozone layer has zero effect on the climate, but compared to carbon dioxide, the effect is much less on the "greenhouse effect". The magnetic field does protect us against solar radiation, but again, not so much heat-related like infrared, but more of the atomic particle variety that again would cause cancer. Without the magnetosphere, it'd be like we were walking by uranium deposits all day long. Could we say definitively that the magnetic field has zero effect on the greenhouse effect? Probably not - but I think the evidence of CO2 emissions is so great, that any effect would be minimal in comparison.
MichaelHorton
@OrionMichaelGuy There is no such thing as magnetic field lines. They are a human invention to picture magnetic fields in our heads. They are like topographic maps of magnetic field strength but they are not actually a physical reality. When you see "field lines" in iron filings placed near a magnet, it's because a magnetic field is induced in those iron particles and then they stick together like tiny little magnets. If you put a tiny piece of iron between the "lines," it'll still be attracted (which wouldn't happen if magnetic fields only followed those lines). Because there is no such thing as magnetic field lines, it should be clear that lava tubes and hot spots are not caused by them (besides the fact that field lines would only enter and exit the planet at the poles if field lines did exist).
Douglas Bennett Rogers
Tha aroura consists of ions that travel down the field lines and are stopped by the atmosphere. The connection between CFCs and ozone was never more than circumstantial. CO2 represents about 2% of the greenhouse effect, dessert irrigation, about 3%. The Earth is gradually cooling, although evaporation of the ocean could temporarily heat the surface. The magnetic field has been relatively consistent over millions of years.
Wolf0579
Our civilization has never been more at risk. With the Earth's Magnetic field weakening prior to the flip of the poles, we are seriously vulnerable to a solar flare knocking out the electrical grid. Every single Nuclear Power Plant is reliant on the grid for cooling water pumps, keeping spent fuel rods from catching fire and melting down. There is only so much gasoline available to run generators once the grid goes down. How many potential Fukushimas do we have in the western world? That's just the radioactive tip of the iceberg, should we lose a ton of transformers due to a large flare. Hospitals, elevators, schools, all without electricity for the ten years it would take to replace a majority of the transformers in the country. People need to wake up.
Kpar
Firehawk, it is true that the "ozone hole" diminished after the ban on CFCs went into effect in the USA, but a cause and effect relationship has never been established- more likely a "post hoc, ergo propter hoc" logical fallacy.
Many atmospheric researchers argued at the time, that we had NO data prior to the launch of ozone detecting satellites, and that we did not know if there was a cycle of some sort at play. Many thought that the ozone hole would go away simply from the actions of the Sun.
Add to that the fact that banning CFCs in the US would have taken MANY years to alter the chemistry of the atmosphere over ANTARCTICA, it is unlikely that what we have seen is related in any way.
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