A slight earthquake shook parts of the Swabian Alb during the night. The epicenter of the quake of magnitude 3.8 was north of Albstadt in Zollernalbkreis, halfway between Stuttgart and Lake Constance, as the Seismological Service southwest announced. The earthquakes at 1.59 clock were probably within a radius of about 30 kilometers felt.
The police in Tuttlingen reported that several residents had called at night because of the earthquake. Any damage should be reported, it said. So far, the police were not aware of any damage.
Only in the summer had the earth shaken several times in the Lake Constance region. The strongest earthquake hit 3.7 at the end of July.
The Richter scale
The magnitude of an earthquake is described using the Richter scale and other scales. The specified value, the magnitude , indicates the released energy.
Seismographs are used to determine the maximum amplitudes (that is, the deflections of the needle) that would have been converted by earthquakes 100 km away. The decadic logarithm of the measured maximum amplitudes gives the magnitude. The increase of the magnitude by 1 means a 33 times higher energy release - an earthquake with a magnitude of 5.0 is thus 33 times as strong as one with a magnitude of 4.0. The scale was developed in 1935 by Charles Francis Richter and Beno Gutenberg at the California Institute of Technology.
Strictly speaking, however, earthquake strengths are given today in the moment magnitude scale . In addition to the energy, it also takes into account the size of the broken rock. The fracture surface can be calculated from the seismic measurement of many seismographs.
Roughly, the typical effects of the earthquakes near the epicenter can be described as follows:
- - Strength 1-2: only detectable by instruments
- - Strength 3: rarely felt near the epicenter
- - Strength 4-5: 30 kilometers around the center noticeable, slight damage
- - Strength 6: moderate quake, death and serious damage in densely populated areas
- - Strength 7: strong earthquake that can lead to catastrophes
- - Strength 8: Great Quake
Germany is located in the middle of the Eurasian plate, plate borders are far away here - and yet in this country again and again the ground shakes. Reason are breaks and weaknesses in the underground, which can cause problems.
That in quakes but also in this country quite more damage can occur, have shown about the shocks that were registered in April 1992 in the border area between Germany and the Netherlands. The so-called earthquake of Roermond at that time had a strength of 5.3 and caused damage in the hundreds of millions. It was the strongest earthquake in Germany for almost 250 years.