The epicenter of each
earthquake was located using the distance to the
seismic station and the back azimuth, based on
the first P-wave arrival in all three components.
Figure 4 Full seismogram (upper window) and details (lower window, filtered as a Wood-Anderson
equivalent) showing the Z-component of the 8 Feb 2007 (UTC time 01:56:17 origin time) for
a local earthquake recorded at Thap Put Station. P = arrival of P-wave; S = S-wave arrival. xaxis
= UTC time; y-axis = amplitude in counts; Maximum (max) amplitude used for local
magnitude (