India: A team of researchers have created a high-resolution map of Earth’s lithospheric magnetic field. Scientists created the map using a wealth of new data collected by the European Space Agency’s Swarm satellites.
“Magnetic fields have been measured in space by satellites for the last 50 years, but it is the measurement of magnetic ‘gradients’ from the three Swarm satellites and data from a previous German CHAMP satellite that make this the highest resolution possible,” Dhananjay Ravat, a geophysicist and professor at the University of Kentucky, said in a news release.
The gradient shifts in Earth’s lithospheric magnetic field are shorter and lend a more exact portrait of the planet’s magnetic field. When looking at Earth’s magnetic field more broadly, the gradients can be drowned out by magnetic influence of Earth’s core, ionosphere and magnetosphere.
The lithosphere is Earth’s outermost layer, its oceanic and continental crust. The new map revealed evidence of Earth’s “polarity flips,” the reversal of the planet’s magnetic poles. Evidence of the flips are preserved in bands of rock on the ocean floor.
“These stripes are symmetric about the mid-oceanic ridge,” Ravat said. “They tell us about how the Earth’s magnetic field behaved in the past. That is why this map is so important, it’s a continuous record of the last 200 million years of Earth’s history.”
The new map showcases details as small as 155 miles. The impressive resolution will allow scientists to investigate the origins of magnetic anomalies in Earth’s crust. Scientists have already begun exploring the magnetic peculiarities of Africa.
“One of the strong features observed includes the Bangui region of Central Africa and there are a number of different hypotheses regarding its origin, one that includes a giant meteorite impact,” Ravat said. “The high resolution of the new map will be able to discriminate between various competing hypotheses about its origin.”