Death From Below: Will Earthquakes Ever Be Predicted?

Severe earthquakes occur all over the world without warning.

Death From Below: Will Earthquakes Ever Be Predicted?

Severe earthquakes occur all over the world without warning. If densely populated areas are hit, mass death and destruction will result. ntv.de asks an expert: Will earthquakes be able to be predicted at some point?

At the beginning of February 2023, a severe earthquake with a magnitude of 7.8 shook Turkey and Syria. Tens of thousands of people perish in the densely populated region. The megacity of Istanbul, with its roughly 16 million inhabitants, faces a similar fate - it lies close to the North Anatolian Fault, a large tectonic plate boundary known for destructive earthquakes with many victims. Most recently, in 1999, near Izmit near Istanbul, there was a severe earthquake that killed almost 20,000 people. Tremors around the world repeatedly claim the lives of thousands of people. Will earthquakes ever be predicted?

"Earthquakes are inherently unpredictable," says Patricia Martínez-Garzón, who researches at the German Research Center for Geosciences (GFZ) in Potsdam, to ntv.de. She has dedicated herself to exploring the geological region around the Turkish mega-city of Istanbul. According to Martínez-Garzón, the unpredictability of earthquakes is partly due to the complexity of tectonic plates and faults. Science has made progress. "But we still know too little about the physical processes that cause earthquakes."

It is therefore a long way from being able to warn the residents of Istanbul in advance of a severe earthquake, says Martínez-Garzón. "We have to rely on the early warning systems, which are essentially based on the first wave of the earthquake before the second comes, which is more destructive." With earthquakes, the so-called compression wave or P-wave occurs first, which oscillates only slightly but can already be measured. Only then does the destructive shear wave (S-wave) follow, which can cause buildings to collapse.

An early warning system based on this already exists for Istanbul: ten sensors are installed along the coast. If three neighboring stations report an earthquake, the headquarters of the Turkish earthquake authority is informed, which then decides whether an alarm situation is present. Measures can then be taken, such as shutting off power and gas lines, stopping trains and closing bridges.

However, with the existing systems, the time between the warning and the earthquake is very short. In the case of Istanbul, it could be between a few and a few dozen seconds, according to Martínez-Garzón. That depends on how close the city's epicenter is. Early warning systems have also been installed in the earthquake hotspots of Japan and Mexico with their megacities of Tokyo and Mexico City. However, the situation there is a bit different because the earthquakes occur much deeper and farther from the cities, so there is more time available.

But researchers are not letting the previously unsolved problem of earthquake prediction rest. There are various approaches to being able to say even further in advance when it will crash. With a new generation of so-called near-fault observatories (NFOs), for example, scientists want to better monitor earthquake hotspots around the world. These NFOs consist of many measuring stations and also drillings in endangered areas. The long-term goal behind this is to be able to predict earthquakes and their effects.

There are also other approaches: It has long been suspected that the behavior of animals can predict an earthquake. The Greek historian Thucydides reported that rats, dogs, snakes and weasels were killed in 373 BC. had left the ancient city of Helike in the days before a cataclysmic earthquake. Shortly before the 1906 San Francisco earthquake, horses are said to have run away in panic. At the Max Planck Institute, the "Icarus" project was used to research an early warning system for earthquakes based on animal behavior - but this is currently on hold because of the Ukraine war.

Electromagnetic turbulence in the ionosphere, that part of the atmosphere above an altitude of about 80 kilometers, could also provide indications of imminent earthquakes. An extremely strong earthquake in Chile in May 1960 had drawn geophysicists onto the trail of electromagnetic turbulence measured there six days earlier. However, it has not been possible to develop a reliable prediction for earthquakes from this to date.

Martínez-Garzón himself is researching a new approach: With the help of artificial intelligence (AI), it should be possible to determine whether an earthquake is imminent. Because the AI ​​is able to detect smaller earthquakes hidden in seismic data. In their most recent study, Martínez-Garzón, together with other researchers, was able to prove small earthquakes that were triggered by even small changes in the water level in the Sea of ​​Marmara. These mini-tremors, in turn, could indicate that the Istanbul fault is about to slide.

"The hope is that at some point we will be able to predict with a certain degree of certainty, based on small activities, that the fault will rupture in the relatively near future," says Martínez-Garzón. However, we are still a long way from that at this point in time. However, further investigations in the region are planned to further explore the potential of this technique.

Could there be technical possibilities in the future to accurately predict earthquakes? Minutes or maybe days in advance? "At the moment I don't see that for the near future," says Martínez-Garzón. "But maybe there will be new discoveries."

By the way: The strongest earthquake ever measured had a magnitude of 9.5 and was recorded on May 22, 1960 in Chile. However, according to the USGS, there should not be any earthquakes that are significantly more serious. Because: The strength of an earthquake depends on the length of the fault on which it occurs. However, there is no fault on Earth long enough to trigger a magnitude 10 tremor - it would have to span most of the planet.