Why are there so many earthquakes every day

Can there be earthquakes in Germany too?

Weak point of the Upper Rhine Graben

The strongest earthquake ever recorded in the USA occurred more than 1,500 kilometers from the nearest plate boundary in 1811. There have also been very strong earthquakes in Central Europe. For example, the Swiss city of Basel was hit by a devastating earthquake in 1356, with hundreds of deaths.

Although these quakes were registered far from the nearest plate boundary, the plates still have something to do with it. If the stresses at the boundaries get too high, they are transferred to the entire plate, exerting a lot of pressure in the process.

An earthquake can then occur at geological weak points within the plate. Such weak points can be, for example, old cracks or plate edges that have meanwhile migrated into the interior of the plate.

This is exactly the situation in Germany. The African plate is slowly advancing north and pressing itself on the Eurasian plate, on which Germany lies. As a result of this plate movement, for example, the Alps were formed over millions of years.

Southern Germany in particular is affected by this mountain formation. The regions of southern Germany and eastern France are lifted up several millimeters a year.

Between southern Germany and eastern France, however, there is a geological weak point in the Upper Rhine Rift, which can break open again and again due to great pressure. Then the earth will shake in Germany too.

It shakes frequently but weakly

Anyone who thinks that an earthquake occurs relatively rarely in our regions is wrong. Most earth tremors, however, are so weak that only sensitive seismological instruments register them.

In addition, the herds of earthquakes are distributed very differently from region to region. In northern Germany there are almost no tremors worth mentioning. Most of the registered earthquakes are concentrated in the Upper Rhine Valley, the Lower Rhine Bay, the Swabian Alb and the Vogtland.

Several hundred earthquakes are measured in Germany every year. They rarely cause damage. Really destructive vibrations that leave traces on buildings occur in this country on average every 30 years.

Some may still remember the night of April 12th and 13th, 1992. That night a tremendous tremor shook the entire Rhineland. The epicenter was near the Dutch city of Roermond at a depth of 18 kilometers.

Houses shook, chimneys and roof tiles fell, trees fell. More than 30 people were injured, and the property damage was estimated at around 150 million Deutschmarks on the German side alone. You could even feel the tremor in London and Munich. An earthquake of this magnitude only occurs in Germany every 80 to 100 years.

Man-made tremors

But not only geological processes can cause the earth to shake. Humans are also responsible for many a great shock inside the earth. In particular, regions in which large-scale mining is or has been carried out are highly prone to earthquakes. The reason for this are underground cavities that were created by mining.

If, for example, a tunnel driven into the mountain is no longer economically viable, the supporting supports are removed so that they can be used again elsewhere. The cavity is left to its own devices.

In most cases, the rock moves slowly and fills the tunnel over time. However, if the rock moves up in one fell swoop and in large quantities, the resulting tremors can be as strong as earthquakes.

This happened, for example, in February 2008 in Saarland. A quake triggered by coal mining shook the entire region around the town of Bilsdorf. People did not die in the strongest mining quake ever, but property damage to houses and a church was considerable.

In the past, residents had repeatedly complained about mining-related damage to their houses. The earthquake of 2008 was the reason for the operators of the hard coal mining in Saarland to only operate coal production until 2012 and to a significantly reduced extent.