Why is it so difficult for scientists to accurately predict earthquakes?

With every major earthquake-related event, people question its predictability.

For example, science has developed to the extent that it allows it to predict the weather accurately, and we can also study the orbits of the most distant comets and examine the extent of their danger to the planet, so why do we lack the ability to predict earthquakes?

The ability to predict earthquakes means that a person or a device can predict where the earthquake will start, when it will occur, and the degree of its strength.

The Earth's crust is made up of about 20 pieces that overlap each other, like pieces of paper puzzles (Shutterstock)

Earth's crust

To understand the matter, we must begin with how earthquakes occur.

Where it is related to the earth's crust, which is the highest layers of the planet.

If the Earth were the size of an apple, the Earth's crust would be about as thick as an apple's crust.

But the crust that covers the earth is not a single mass extended like the crust of an apple, but rather consists of about 20 pieces that overlap with each other, as pieces of paper puzzles overlap to make a complete picture of an animal or a historical figure.

These pieces are called "tectonic plates," and they move very slowly relative to each other, at rates of 1 to 20 centimeters each year.

Earthquakes occur when two of these plates overlap violently that can lead to cracks and rock shattering in one of them, which is the cause of seismic tremors.

The magnitude of the earthquake is proportional to the length of the fault produced by this overlap.

Various reasons

But the occurrence of these cracks is related to a large number of factors that scientists cannot limit in an accurate prediction system. For example, some rocks may overlap violently, but they are soft enough to withstand shocks, or they may be dry enough to shatter upon impact and cause a major earthquake, and scientists do not have any way. To predict the condition of those rocks that extend over thousands of kilometers.

In addition, these cracks do not move within the rocks in one direction, but rather diverge like the branches of a tree.

The occurrence of these ramifications is related to the nature of each piece of rock within the earth's crust and its temperature, which is a matter of great magnitude and complexity that cannot be fully studied.

In fact, the thickness of the earth's crust is between 30 and 70 kilometers in the continents, while it is 6 to 12 kilometers in the depths of the oceans, and scientists cannot reach this depth everywhere in order to study it. The deepest hole that humans were able to dig was only 12 kilometers, It is the deep Kola well, and it was a scientific project to explore the earth's crust conducted by scientists of the Soviet Union and started in 1970.

All this, and we have not yet talked about the effect of earthly gravity, which differs from one place to another, and the movement of the mantle layer below the crust layer, which is the layer that lies between the dense, extremely hot Earth core and its thin outer crust. The thickness of the mantle layer is about 2,900 kilometers, and it varies in temperature and humidity. And viscosity affects a variety of influence on the crust swimming above it at the top.

In addition, the nature of tectonic plate movements is not fully understood. As mentioned above, they are very slow and move in a manner that appears to scientists to be completely random. Therefore, the overlap of any region between tectonic plates is theoretically possible at any time.

But we try

Over several decades, a wide range of possible signals have been studied that are expected to be associated with the onset of earthquakes, such as increases in concentrations of radon and some other gases, for example, that are released to the Earth's surface from small cracks in the Earth's crust before an earthquake occurs.

In addition, scientists have researched the relationship between earthquakes and changes in electromagnetic activity, geochemical changes in groundwater, and even unusual animal behavior in the moments leading up to a major earthquake.

But until now, scientists in this range have not been able to replicate these results, meaning that there may indeed be a relationship between any of these criteria and the occurrence of earthquakes, but when scientists conduct experiments on the matter, the results are not repeated in the same pattern every time.

For example, animals may behave strangely before an earthquake, but not behave strangely in other earthquakes, and they may behave strangely when there are no earthquakes.

Because of the very large number of parameters that must be taken into account to predict earthquakes, scientists are now hoping to use artificial intelligence tools that can read patterns that humans cannot read in order to improve earthquake prediction.

As of this writing, scientists only have the ability to give probability estimates for each region in the world without achieving the basic prediction criteria (location, time, and intensity). For example, it is likely that some regions in the world will experience large earthquakes with a specific average every several decades.