Key Takeaways
- ESA’s Swarm mission identifies subtle magnetic signals from Earth’s tides to enhance understanding of magma distribution and ocean dynamics.
- The Swarm satellites, originally intended for a four-year mission, are now in their 12th year, improving data collection on ocean water properties.
- Recent findings, published in a prominent scientific journal, utilize data collected during a solar minimum for clearer signals.
Uncovering Ocean Mysteries through Magnetic Signatures
ESA’s Swarm mission, featuring three satellites, has revealed that the magnetic signatures created by Earth’s tides can be instrumental in mapping magma beneath the seabed. This breakthrough not only aids in understanding the geothermal phenomena but potentially addresses long-term variations in global ocean temperatures and salinity.
Swarm has been operational since 2013, working to study Earth’s geomagnetic field, which is primarily generated by the liquid iron in the planet’s outer core, supplemented by magnetized rocks in the crust. While the oceans are not typically perceived as sources of magnetism, their saline water acts as a decent electrical conductor. The movement of ocean tides across Earth’s magnetic field creates minor electric currents that generate weak magnetic signals detectable from space.
With an operating altitude of 462 to 511 kilometers, Swarm excels in capturing these faint tidal signatures while filtering out stronger magnetic signals from deeper within the Earth. Anja Strømme, the Swarm Mission Manager, highlighted the mission’s capability to provide comprehensive data regarding the entire water column of the oceans, facilitating insights into magma distribution. This information could enhance scientific comprehension of volcanic activities, such as the Hunga-Tonga eruption in 2022.
The study that produced these findings gained prominent recognition, appearing on the cover of the world’s oldest scientific journal, Philosophical Transactions of the Royal Society A. The research team comprised experts from the University of Cologne and the Technical University of Denmark, promoting interdisciplinary collaboration in exploring Earth’s complex systems.
Despite its extended operation, Swarm is gradually approaching the end of its lifespan due to orbital drag. However, the extended duration has allowed for the collection of increasingly accurate data. Strømme noted that the extended mission has led to answering scientific inquiries beyond initial plans, as long as the quality of output remains high.
The Swarm satellites benefited from a quieter solar period around 2017, a phase known as solar minimum, when the Sun’s activity is at its lowest. During this time, the electromagnetic interference from solar phenomena, such as auroras, diminishes, allowing the Swarm instruments to detect smaller geomagnetic signals effectively. Lead author Alexander Grayver from the University of Cologne emphasized that these findings represent the most subtle signals captured during the mission.
Looking forward, the Swarm team anticipates continued data collection during the next solar minimum anticipated post-2030. This period could provide further clarity regarding ocean temperatures and salinity, adding invaluable knowledge to the ongoing study of Earth’s geological and oceanic processes.
In summary, the Swarm mission showcases the innovative ways satellite technology can reveal fundamental insights about our planet, its physical processes, and the significant interactions between terrestrial and oceanic systems.
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