• Solving the problem of earthquakes

    More balance! That's the real answer

    The future of gas extraction and earthquakes in Groningen looks quite different when seen through the lens of physical or social geography. Professors Rien Herber and George de Kam represent these respective fields and both agree that no matter what the future holds, more research is vital.

    Surrounded in his office by charts and graphs interpreting the Dutch underground, Professor Rien Herber’s description of the Slochteren gas field is downright enthusiastic.

    ‘It’s a golden combination if you think in gas terms: deep down you have coal that generates gas, a sandstone reservoir which contains the gas and salt that forms a seal, making sure that it stays there’, says Herber.

    ‘The gas production causes the pressure in the sandstone to go down which leads to compaction of the reservoir. Of this, a portion is converted into seismic energy, but that’s a finite amount’, he explains. The production life of the field itself is also finite, and the seismicity will go down again.

    ‘The thousand dollar question is – of course – are we at the peak or are we still increasing? When will it go down?’, Herber asks. Despite his expertise, he doesn’t have an answer.

    A magnitude of 3.6

    Up until two decades ago, seismology focused purely on tectonic quakes rather than human-induced quakes, which have different behavior. The study of manmade tremors is a marked change in the century-long science.

    ‘A lot more research needs to be done’

    ‘That’s why a lot more research needs to be done on this’, Herber says. Herber was awarded the IBM Faculty Award in 2011 for research into tremor prediction: by placing sensors below the surface of the earth that would register even the slightest tremors, the system could give advance warning for bigger quakes.

    ‘I won this prize with the idea to do it together with NAM, but then, after the magnitude 3.6 quake occurred in Huizinge, NAM was asked by the Minister at the beginning of 2013 to develop a new production plan for the gas field by year end. They were supported by a lot of other institutes like KNMI, so I didn’t pursue it anymore because they had a lot of other institutes that were involved. A university like ours is just too slow to do this in six months. It would already take me that time just to get a post doc.’

    At the heart of the discussion

    Spatial sciences professor emeritus George de Kam is another researcher of the RUG who finds himself at the heart of the public discussion through his research. He unknowingly set himself up to do comparative research into the societal impact of the earthquakes in Groningen by encouraging one of his students in 2009 to conduct a survey on the subject. He is completing another survey in the same locations in 2013, giving insight into how people’s experiences have changed over time.

    ‘I’m really concerned with what’s going on here with the people and the anxiety they have’

    ‘I’m really concerned with what’s going on here with the people and with their real estate, and the anxiety they have because of that’, he says.

    While the initial purpose of Professor De Kam’s emeritus work – begun in November and being analyzed now – was to determine property value losses in the province, what he found was more than just economic costs. Hundreds of homeowners have lost faith in the government and have lost any hope of being able to leave. ‘Many people selling their homes said to me, ‘We cannot sell our houses anymore. No one is even coming to look.’ Even though they have reduced the asking price 3 or 4 times, nothing has helped.

    Contain the problem

    ‘People try to contain the problem to the area of north-east Groningen or small places, a small area,’ De Kam says. ‘Up to now, most people in the city have thought that we are safe.’

    He suspects that sense of security is unfounded and that the threat is underestimated. One piece of compelling evidence for his concern is the fact that earthquake meters have been installed in the ultimate icon of the city, the Martini church.

    ‘We want to combine all the expertise there is in the university’

    Among De Kam’s hopes for the future is the plan to start a think tank – ‘to combine all the expertise there is in the university’ – and the institution of a government body to guarantee state money to the homeowners.

    Basically, the Dutch government could either buy the property from the residents or at least guarantee that damages will be repaired if people choose to stay. He believes that the people in Groningen deserve to have the security and freedom of knowing that they can move when and if they choose. ‘A solution like that would be a blessing for the people’, De Kam says.

    1.2 billion Euros

    The promises which the Dutch government has made recently to those affected – namely, the reservation of 1.2 billion Euros for damage repairs – may give some the appearance that at least this part of the issue is finally being addressed.

    Nevertheless, the tremors continue. Cabinet guidelines, based on the NAM studies and the subsequent review by the State Supervision of Mines, include reducing extraction for the next three years by roughly 80 percent in the area of Loppersum. Herber has some reservations about this approach. ‘Curtailing the production there may help Loppersum, but it can also create a pressure differential with the south. Whether or not it will help is yet to be determined.’

    ‘The challenge is how to operate the field in such a way that you can do it in a balanced manner’, Herber says.