Let us imagine that the Seismological Service is a large fishing boat whose primary goal is to fish for earthquakes and icequakes. As the SED also aims to record very weak signals with a view to facilitating more accurate scientific statements, it operates a dense network of highly sensitive seismometers, in a similar way to a fine-mesh fishing net. This has the result that, in addition to the intended main catch, a large bycatch also finds its way into the net.
In our case, the bycatch consists of seismic signals caused by humans. The diagram below provides an overview of various man-made quakes. Their characteristic waveform makes them clearly distinguishable from natural seismic tremors by a practiced eye. In addition to the geophysical phenomena mentioned above, it is important to remember that earthquakes can also be caused by humans. More about this in next month’s snapshot on the topic of man-made earthquakes.
Other events recorded by devices of the SED in addition to icequakes: