Chapter 6 describes detailed analyses of P seismograms of a small selection of earthquakes and explosions, and for some of these seismic disturbances synthetic seismograms are shown that are attempts to match the observed. For the earthquakes, the match between synthetic and observed is generally satisfactory but for the explosions the match is often poor. These analyses cannot show anything of the variety of P seismograms from explosions and particularly earthquakes. The seismograms shown in this appendix, which are principally array recordings, are chosen to demonstrate something of this variety. The arrays referred to in the appendix are, unless otherwise stated, the UK-designed arrays, EKA, GBA, WRA and YKA. The epicentres of all the earthquakes and explosions referred to in the book are shown in Figures M.1 and M.2.

There is no such thing as a typical seismogram and it is difficult to search in a systematic way for examples of seismograms to illustrate properties predicted from theoretical models. Only by chance is it usually possible to find, for example, PP seismograms that are clearly Hilbert transforms of the radiated source pulse, or seismograms with truly emergent onsets, or seismograms showing strong Doppler effects. Chance has played a large part in the choice of earthquake seismograms for inclusion here.

Of the earthquakes chosen for inclusion, half are the subject of earlier studies. The remainder are principally further examples of seismograms showing Doppler effects or Hilbert transforms.