Texas is considered the new earthquake hotspot in the USA. Blame it on fracking. In Germany, the controversial method of extracting natural gas and oil for commercial purposes is banned for other reasons. A seismologist explains that the earthquake problem can be dealt with.
As early as six years ago, researchers determined in a study that around seven million people in the USA are threatened by earthquakes without natural causes. Fracking is shaking the ground in parts of the United States. For example in Oklahoma. A few years ago, the Midwestern state saw a boom in the industry that drills and breaks up deep rock for valuable natural gas. Between 2008 and 2016, the earth trembled in Oklahoma even more often than in California, the American earthquake hotspot for many years.
In the meantime, however, Oklahoma has been replaced as the main region for earthquakes in the USA. The situation in the "Sooner State" has calmed down. Texas, bordering to the south, is the new number one. Drilling takes place here on an "incredibly large scale", says Marco Bohnhoff in the ntv podcast "Learned something again". The seismologist and geophysicist is head of the Geomechanics and Scientific Drilling department at the Geoforschungszentrum in Potsdam. "The ground is stimulated in order to be able to produce the oil and gas better. And then this service water, which comes back to the surface, is pumped in incredibly large quantities into extra-deep boreholes underground. It's called wastewater disposal. And that's what we're doing creates seismicity." In extreme cases, these tremors can also cause slight damage to the earth's surface, explains Bohnhoff.
However, the problem can be solved with increased safety regulations. The risk of earthquakes is therefore not a good argument against fracking in Germany. From a seismological point of view, there is actually nothing to be said against it, geophysicist Bohnhoff clarifies. But there are some other arguments against the controversial oil and gas production method: the high costs and high environmental risks due to many leaks. The bottom line is that fracking is even more harmful to the climate than conventional natural gas or oil.
After the Russian attack on Ukraine, alternatives to Russian gas are being discussed in Germany. "We have to talk about fracking in Germany," says Michael Hüther, director of the German Economic Institute, in the "Zero Hour" podcast.
If commercial fracking is allowed in Germany, you can rely on a large number of rules, says expert Bohnhoff in the podcast "Learned again". "The general conditions and safety regulations in the USA are very different from ours."
"Monitoring the processes would make appreciable seismicity very unlikely to occur. Though not impossible." According to Bohnhoff, there is never "100 percent certainty" with high technology, but there is a high probability "that these processes will be contained" if such projects are scientifically supported.
Fast-growing megacities that are close to active plate margins cause seismologists much more concern. Sooner or later, earthquakes there cannot be prevented, and they are also difficult to predict, so that some cities in unfavorable locations are at risk. "There are a number of metropolitan areas: Tokyo, Istanbul, San Francisco, Tehran, Quito."
In these cities, earthquake activity is monitored day and night, reports Bohnhoff. "One of our research priorities at the Geoforschungszentrum Potsdam is in Istanbul, where we have set up a measuring network in close cooperation with the Turkish authorities. And since the physical processes that lead to these larger or smaller earthquakes are the same, it is important to Compare research foci. Physically, it doesn't matter whether an earthquake occurs on the San Andreas Fault in California, in Istanbul, or off Taiwan or Japan."
The San Andreas Fissure in California is one of the most famous earthquake hotspots in the world. Here, too, it is only a matter of time before the earth trembles. Although things have been quiet in recent years, an earthquake of moderate or severe magnitude will definitely occur on the west coast of the United States sooner or later, predicts expert Bohnhoff.
Current hotspot for natural earthquakes is Taiwan. This year there have already been five tremors with a magnitude greater than six. At this level damage to buildings is considered possible. No major damage, injuries or even deaths have been reported in Taiwan, but earthquakes of this magnitude can be felt across the island. Trains must stop immediately or slow down significantly in the event of an earthquake. Earthquakes of this magnitude affect people's everyday lives.
"Taiwan is right on the circum-Pacific Ring of Fire. That's an area that encircles almost the entire Pacific Ocean. The Pacific Ocean is a geologically very old ocean and is being surrounded by the Eurasian Plate and the American Plate, so to speak, a few centimeters a year. This process leads to that sometimes large earthquakes also occur," explains seismologist Bohnhoff.
The number of earthquakes in Taiwan is currently unusually high. But that doesn't mean that there are generally more earthquakes in the world than there used to be. This is possible locally and for a short time because plates shift and get stuck, but in the long term this is out of the question. "We look at the long-term average over thousands or even hundreds of thousands of years. And you can say very clearly that earthquake activity on Earth is not changing," explains Bohnhoff in the podcast. "That's because the process of continental drift is constant over the long term." These tremors are unpreventable, unlike fracking-induced tremors in Oklahoma or Texas.