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Natural gas and earthquakes
This is Loppersum. The earth here may tremble as a result of gas extraction...
in Groningen-field, Europe's largest natural gas field.
These earthquakes have a major impact on local people.
A couple of years ago we restored the whole facade of our house...
and now we have all these cracks running through it.
Selling your house is difficult, but I'm not worried about that.
Houses don't sell anymore.
It affects the living environment, creating a lot of uncertainty.
Houses are hard to sell, and this area is already declining economically.
People also feel that this gas drilling keeps businesses from settling here.
NAM is doing a couple of things: We're repairing earlier earthquake damage...
and we prepare people for new earthquakes by giving them information.
We also look at prevention. After identifying potential risk sites...
we address this by installing reinforcements.
We'll map potential earthquake sites to perform risk assessments.
And we'll also try to work out how to prevent or reduce earthquakes.
The Nature Trust points out the dangers to the nearby Wadden Sea area.
The risks are considerable. This is a listed world heritage site.
Nearby Eems-Dollard is a nature reserve protected by weak dikes.
Chemical industries in the vicinity are a potential hazard if earthquakes occur.
New insights tell us that earthquakes may become stronger in force.
It prompts us to look at possible effects on safety, landscape...
and infrastructure. We certainly need to keep a close watch on our dikes.
The Groningen-field accounts for 75% of the Dutch natural gas supply.
There are also smaller gas fields, some which on land.
Are earthquakes a risk there too? Another question.
Can we prevent or reduce earthquakes? Can we stop the gas drillings?
Can we import natural gas? Are there alternative options? First some facts.
Ever since gas extraction began here, subsidence has been a common effect.
Countervailing measures were put in place. Since the 1990s we know...
it involves an earthquake risk. Dozens of earthquakes are recorded each year.
Most of these are minor and cause no damage.
Until this year, a maximum of 3.9 Richter had been predicted for Groningen-field.
Once again, we're talking about gas extraction effects.
Gas drilling itself cannot cause an earthquake.
August last year, in the town of Huizingen a 3.6 Richter quake was recorded...
the strongest earthquake so far.
Following research by mining and gas authorities the minister wrote a letter...
In which he raised the acceptable earthquake limit to between 4-5.
It came as a surprise to us all. We went public with it right away.
It brings uncertainty, now that we know we can expect quakes stronger than 3.9.
We're still investigating how strong they may be.
We're talking about a logarithmic scale. From 3 to 4 means a tenfold increase...
from 3 to 5 a hundredfold increase.
An earthquake force 3 feels as if a train is speeding past nearby.
A Richter 5 earthquake can actually cause chimneys to come down.
The vibrations are much stronger then.
97% of the Dutch population use natural gas at home...
most of which comes from the Groningen-field...
as well as some 250 minor fields both on land and under the sea.
Could these small fields also produce earthquakes?
Out of the 175 small gas fields, in three or four cases quakes were felt.
It's a result of the geology. Chances of an earthquake in these areas are small.
But we need to look at each field individually.
Natural gas from small gas fields is high-caloric and is used by industries.
Groningen gas, the type of gas we use at home, is low-caloric.
This means our central heating systems would need to be adapted.
So getting more gas from small gas fields would not be the obvious solution.
Less gas drilling is not a solution, as it would not reduce the earthquakes.
There will be a long-term effect instead. What's even more important...
is that we aim to produce 16% sustainable energy by 2020...
but even then we still need to get 84% of our energy elsewhere.
Dutch gas is the most obvious option.
Reducing gas drilling must not lead to higher carbon emissions.
So it's not a good idea to try and go for less gas drilling.
Current extractions resulted in subsoil pressure differences...
the effects of which have not worn off yet.
Even if we stopped drilling today, earthquakes may still occur.
Should we import more natural gas then? Or liquid gas, LNG, from Africa?
Or drill for shale gas, or inject CO2, nitrogen or water into a gas field?
Minister Kamp wants to evaluate all options first before deciding.
For a review of these options please watch the other Natural Gas Update.