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About Earthquakes | Rescent Earthquakes
Bomb blasts 30-07-2022
On July 30, 2022, five 10-centner bombs, each containing about 140 kg of TNT, were successfully detonated between Leine and Schützenplatz in Göttingen.
Ground shaking was also recorded by the GTTG (with modern STS-2 broadband seismometer) and GTT (with historical Wiechert seismographs) earthquake stations located about 3 km to the east.
The first blast of 3 bombs simultaneously took place at about 21:35:52 CEST, after about 1 s the first waves reached the seismic station. The further blasts of the 4th and 5th bombs occurred immediately afterwards, therefore the waves overlapped.
About 5, 9 and 14 s after the first blast, surface waves reached the earthquake control room. Accordingly, they came with about twice the speed of sound. With a maximum amplitude of only 1…2 micrometers and an oscillation period of about 0.4 s, the wavelength – i.e. the distance from one wave crest to the next – amounted to about 250 m.
The comparisons show very nicely how well one could already register near earthquakes with Wiechert’s 17t pendulum more than 100 years ago. However, at that time only the sooty paper was available as recording unit.
Please click on the images to enlarge.