How can we predict an earthquake?

Earthquake for students

Earthquake prediction

It is very difficult to predict earthquakes, if at all. With great effort, geologists and seismologists, as earthquake researchers are also called, can determine stresses or strains in the rock. However, it is still a long way from predicting when the stresses will be discharged in an earthquake or when the strain will be so great that the rock will tear. At best, one can say that an earthquake could take place at any time. In general, experience shows in which areas there is a high risk of earthquakes. In this regard, long-term records of the occurrence of earthquakes help to discover areas at risk. Often centuries pass after a strong earthquake before another occurs in the same place.

Before some earthquakes foreshocks occur, which can be used as warning signals of a strong earthquake. But there are innumerable weak earthquakes every day without a stronger one following. Therefore this method is also useless.

Animals often get restless before a strong earthquake and behave differently than normal. It is believed that the animals can perceive the finest earthquakes that we humans do not notice. The strange animal behavior could now be used as an early warning system, but in the end it is based on the presence of foreshocks and is accordingly unreliable.

Ants are also said to behave unusually before earthquakes and volcanic eruptions. Their behavior could be influenced by the gas carbon dioxide, which is released especially in volcanic areas before a volcanic eruption. In addition, they are sensitive to ground vibrations.

All in all, it is very difficult to predict earthquakes. In general, there seem to be only two approaches: to register the slightest ground vibrations and earthquakes, or to collect gas samples



Image: There was no warning about this earthquake in Indonesia. The man is looking for useful things in the ruins of his house. © Marc Szeglat