1. See königsberger ratio.

2. The ratio of the frequency at the mid‐point of a band‐pass filter to the filter width.

3. The ratio of the peak energy in a waveform to the energy lost by dissipation. As a measure of seismic absorption it has been used effectively in delimiting Benioff zones using natural earthquake events (high Q implies low absorption and is associated with crust and deep mantle; low Q implies high absorption and is associated with the sub‐crustal low‐velocity layer.