Tom and Jerry satellites have compiled a high-precision gravity map of Europe. Scientists added ground-based observations to it and measured the groundwater level in the Old World. It has remained low since 2018.
Tom and Jerry observe the groundwater
Scientists have concluded that groundwater in Europe remains at a very low level since 2018. This situation was noted in an article published in 2020, but since then the situation has not improved at all. Moreover, scientists obtained such a result in a rather original way.
The geodesists relied on data from Tom and Jerry satellites, which had been flying in low Earth orbit with a height of 490 km for several years. At the same time, satellites at a speed of about 30 thousand km/h make 15 orbits around the Earth per day.
However, the distance between them remains constant all the time — 200 km. That’s why they are so similar to the heroes of the cartoon of the same name — they also can never catch up with each other. The distance can change only when they fly over a gravitational anomaly, for example, a mountain.
In this case, the front satellite accelerates slightly and the distance increases. Using this, you can make a detailed map of the gravitational field. And then the researchers came to the aid of observations made directly on the surface of the Earth.
How has the groundwater level changed in Europe
Water is quite a heavy thing, and when a certain number of centimeters of precipitation falls on the ground or the water level rises by a meter in the river, this significantly affects the local gravitational field. It was this data that the researchers “took away” from the Tom and Jerry map.
They have only water left, which is under the surface of the Earth. In fact, there is a lot of it there, because it feeds a significant part of the rivers and provides soil moisture. It turns out that despite all the floods that have occurred in Europe over the past five years, the groundwater level, which decreased during the drought in 2018, has not recovered.
Scientists are still surprised that water can be a problem in Europe. After all, the groundwater level is not only a matter of agriculture. As the drought has shown this year, reservoirs are also very sensitive to it.
And the decrease in water in rivers and ponds is not only the death of numerous aquatic species, but also problems with energy. Nuclear power plants need a lot of water for cooling. Hydroelectric power plants simply do not have enough mass of liquid to turn its fall into electricity.
According to phys.org
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