Determination of surface wave magnitude. Needs measurement of amplitude of one or more S waves before. These S amplitude measurements are usually done on SRO-LP simulated seismograms. The steps to perform to get an MS magnitude are:
The MS magnitudes are determined from all S amplitudes found using the Prague formula:
ms = log10(ampl/period) + 1.66*log10(distance) + 3.3
Depending on the epicentral distance there is a minimum period of the signal used for amplitude measurement. Periods smaller than this minimum period are not accepted.
This page last modified 26-Jul-2000