Swiss researchers identify means to reduce risk of man-made earthquakes
Injection of pressurised water underground creates a lot of pressure in the spaces between the rocks and is believed to be responsible for minor tremors.
Keystone / George Frey / Raser Technologies
Identifying the kind of fault or tectonic forces in an underground reservoir can reduce the risk of tremors caused by geothermal energy or carbon storage.
This content was published on
2 minutes
swissinfo.ch/ac
The injection of cold pressurised water into hot impermeable rocks several kilometres underground is how underground reservoirs are created for geothermal energy. The super heated water is then pumped up and used to powers turbines in a geothermal plant. However, the process creates a lot of pressure in the spaces between the rocks and this horizontal stress is believed to be responsible for minor tremors.
Enhanced Geothermal Stimulation (EGS), as the technology is known, has faced setbacks in Switzerland after triggering earthquakes in Basel in 2006 and in St. Gallen in 2013. Scientists at the Swiss Federal Institute of Technology in Lausanne (EPFL) believe that faults or tectonic forces have an important role to play in such human-induced tremors.
According to the researchers, different types of faults require different approaches. For reverse faults – where two sections push against each other- they suggest injecting cold fluid underground for at least 12 months to cool the reservoirs and cause the rocks to contract.
“This lowers the horizontal forces acting on it, thereby reducing differential stress and making earthquakes less likely,” says study lead Barnaby Fryer.
For normal faults – where two sections pull away from each other – Enhanced Geothermal Stimulation can actually help stabilise the fault by increasing the horizontal stress. In such faults earthquakes are caused where there is a great difference between horizontal and vertical stresses.
“That’s why it’s so important to understand the properties of a reservoir before you start injecting,” says Fryer.
Train vs plane: would you take a direct train between London and Geneva?
Eurostar is planning to run direct trains from Britain to Germany and Switzerland from the early 2030s. Would you favour the train over the plane? If not, why not?
Swiss martyr beatified in Barcelona by Catholic Church
This content was published on
François-Benjamin May (1870-1909), a member of the Marist Brothers congregation, has been recognised as a 'blessed' by the Catholic Church.
Prevention and tech could help save billions on Swiss healthcare costs, says Deloitte
This content was published on
By focusing on prevention and technology, it would be possible to reduce Switzerland's healthcare bill by CHF30 billion a year by 2040, according to Deloitte Switzerland.
Environment director warns of increasing climate-related risks in Switzerland
This content was published on
The director of the Swiss Federal Office for the Environment (FOEN) has warned of increasing climate-related risks in Switzerland in an interview with SonntagsBlick on Sunday.
Gotthard traffic queue hits 11km at start of holiday season
This content was published on
The start of the summer holidays saw a long traffic jam in front of the Gotthard tunnel on Saturday. Traffic jams between Erstfeld and Göschenen in canton Uri were up to 11 kilometres long early in the morning.
This content was published on
The water temperature of the Rhine River could rise by up to 4.2° degrees Celsius by the end of the century due to the warming planet, scientists warn.
This content was published on
The Federal Council wants to explore the possibilities of joining the European Union’s €800-billion rearmament programme without compromising Swiss neutrality.
If you want to start a conversation about a topic raised in this article or want to report factual errors, email us at english@swissinfo.ch.
Read more
More
St Gallen geothermal power project abandoned
This content was published on
Officials on Wednesday said the risks of further, small-scale earthquakes and financial issues had contributed to the decision. Drilling work at the site outside St Gallen has been on hold since July 2013 when a tremor, measuring 3.5 on the Richter scale shook the earth. The borehole was later sealed. The authorities are however considering…
Revolutionary idea to store green power for the grid
This content was published on
What do we do when there is no sun or wind? Energy Vault seems to have found the answer to that oft-repeated question from nuclear power and oil-industry lobbyists and all those sceptical about or opposed to renewable energies. That question seemed to pinpoint the Achilles’ heel of new energy technologies: the varying yield of…
You can find an overview of ongoing debates with our journalists here . Please join us!
If you want to start a conversation about a topic raised in this article or want to report factual errors, email us at english@swissinfo.ch.