How ESA uses space data to explore deep Earth
ESA missions are helping scientists to better understand how Earth's core, mantle and crust and the processes within them affect the changing environment of the planet.
A fundamental component of the Earth system is the "solid Earth", meaning, the inner core, the (liquid) outer core, the lower and upper mantle and the crust. Processes within this component are critical to understanding the Earth system as a whole.
Many of ESA's Earth observation satellites provide key information on the structure of these internal layers and their interactions with each other and with the cryosphere, hydrosphere, atmosphere and ionosphere.
For example, the Earth Explorer research missions have long contributed to our understanding of solid Earth. The first Earth Explorer, called GOCE, used a state-of-the-art gradiometer to build a detailed global model of Earth's gravity field.
Thanks to GOCE data, we are improving our understanding of Earth’s interior. In a recent study, for example, scientists combined GOCE data with surface measurements to create a new model of Earth's crust and upper mantle.
Another mission providing interesting insights is ESA’s Swarm: an operational Earth Explorer tasked with mapping Earth’s magnetic field.
Our planet's magnetic field exists thanks to Earth’s core. Electric currents from the swirling, conductive iron in Earth's liquid outer core generate the magnetic field.
In a recent project, researchers used data from the three Swarm satellites to study rapid changes in the geomagnetic field. This helped them to better understand the core dynamics that drive the Earth's dynamo.
Swarm's global maps of the magnetic field are also helping scientists understand how the iron in the core moves. This helps explain why the north magnetic pole is steadily drifting towards Siberia.
Missions that collect and provide radar data, such as Copernicus Sentinel-1, are also important for studying Earth's crust. This is because the data from these missions can be used by scientists to study earthquakes.
By combining Synthetic Aperture Radar (SAR) images of an area before and after an earthquake, the phase change of the radar waves can be used to create an interferogram. Researchers use this technique to map deformations and analyse earthquakes.
This technique has made great progress using images from Copernicus Sentinel-1. However, it can also make use of the large amount of data acquired by non-operational ESA radar satellites of the Heritage Space Programme, such as ERS and Envisat.
Other radar missions available through ESA's Third Party Missions programme - such as COSMO-SkyMed and TerraSAR-X and Tandem-X - provide frequent SAR measurements.
These measurements are useful for tracking tectonic activity, which causes permanent changes in surface elevation. Understanding these changes is key to ensuring that protective measures taken are appropriate.
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