Seismic measurements

A typical saturating «event»

Strong events saturate the sensors of our seismic station at the present sensitivity setting (ground velocity exceeding 100 µm/s):

However, it is not so easy to correlate the size of the eruption to the energy of the seismic signal: The total energy of the event goes into kinetic, heat, seismic and other forms of energy and the relative importance of these may vary. For an example, a shallow explosion may produce lots of ejecta (a "big eruption") but a very small "seismic footprint". In some cases, the seismic waves may even be too small to trigger the acquisition of our seismic station (and the eruption is, therefore, not detected at all).