Here\u2019s what you\u2019ll learn when you read this story:<\/p>\n
A new study shows a dramatic reversal of flow in the liquid outer core beneath the Pacific Ocean from a weak westward direction to a strong eastward one.<\/p>\n
Scientists pieced together nearly thirty years of data from satellite and ground observations and noticed that the directional change occurred around 2010 and was possibly linked with deeper processes in the Earth\u2019s inner core.<\/p>\n
The study also concluded that the eastward flow was already slowing down as of 2020 and shows how major geomagnetic changes can occur over incredibly short timescales.<\/p>\n
Hidden roughly 1,400 miles beneath our feet is a churning engine of molten iron<\/a> that makes all life on Earth possible. This electrically conducting molten iron core surrounds our planet\u2019s more solid inner core<\/a>, and forms what scientists call a \u201cgeodynamo.\u201d It produces a magnetic field strong enough to protect Earth from a majority of the Sun\u2019s harmful radiation. Just take a look at Earth\u2019s planetary neighbor Mars, which possesses no magnetic field, and you\u2019ll get an idea why this churning engine is so vital<\/a>.<\/p>\n Because of the magnetic field\u2019s immense role in our continued survival, scientists have spent centuries trying to understand the dynamics and behaviors of our life-sustaining geodynamo\u2014and it turns out we have a lot more to learn. In a new study published in the Journal of Studies of Earth\u2019s Deep Interior<\/a>, scientists from the University of Edinburgh discovered that the molten flow of the Earth\u2019s outer liquid core<\/a> dramatically switched directions in roughly 2010 around the equatorial Pacific. This goes against the assumption that the flow of the outer core mostly travels in a westward direction (though it does tend to be weak in the middle of the Pacific).<\/p>\n \u201cThe large-scale flow reversal beneath the Pacific raises new questions about the behaviour of Earth\u2019s deep interior,\u201d University of Edinburgh\u2019s Frederik Dahl Madsen, lead author of the study, said in a press statement<\/a>. \u201cScientists now want to understand whether the reversal represents a short-lived fluctuation, part of a repeating oscillation, or a new stable equilibrium for core circulation.\u201d<\/p>\n Madsen and his team stitched together nearly 30 years of data from ground observations and satellites, including ESA\u2019s CryoSat and Swarm missions, as well as the German-launched CHAMP and \u00d8rsted satellites. When all the information was assembled, the team noticed an unmistakable flow reversal in the Pacific Ocean<\/a>, which moved weakly westward from 1997 until roughly 2010 before strongly reversing course eastward. The authors note that this eastward flow has ebbed since 2020 and could be tied to behavior in the inner core.<\/p>\n Although the outer liquid core flows in a relatively predictable westward direction, the planet is prone to what scientists call \u201cgeomagnetic jerks<\/a>.\u201d The ESA\u2019s Swarm mission, which consists of three satellites equipped with extremely sensitive magnetometers, can distinguish magnetic signals that come from the core versus other possible sources, including the crust, ionosphere, or even the ocean. In 2017, this trio of satellites discerned that these \u201cjerks\u201d occur due to rising blobs of metal that formed in the planet\u2019s core around 25 years earlier<\/a>.<\/p>\n \u201cLong-duration satellite magnetic measurements allow researchers to follow changes in the geodynamo in near-realtime and improve models of Earth\u2019s magnetic field evolution,\u201d ESA\u2019s Swarm Mission Manager Anja Stromm, who didn\u2019t participate in the study, said in a press statement. \u201cFuture observations from missions such as Swarm will play a crucial role.\u201d<\/p>\n