Abstract: In this paper, using surface wave data of 48 shallowstrong earthquakes (MS>5) occurred in Taiw an region and recorded at 7 broad b and seismic stations by using Fuji and igital seismic network, we measured the maximum synthetical amplitudes of horizontal directional Love waves and the epicentral distance, and calculated their surface eave magnitudes MS. We alsocompared the results with the average M_S published by national seismic networks well as carried out statistical analysis. The results show that thedetermined M_S magnitudes between regional and national networks have larger difference. The larger the magnitude is, the smM_S aller the difference. It is necessary tomake certain correction for M_S magnitudes of regional network so that they could be close to the resultsdetermined by the national network. In this paper, we also discussed the cause of the difference of M_S magnitudesdetermined by near stations and rem ote stations as well as its correct methods. It might provide the reference for the regional digital seismic networks that rapidly report M_S magnitudes of those strong earthquakes occurred in neardistance.

Key words: regional broad-b and digital seismic network, Waveform emulation, Neardistant surface wave, M_S magnitude correction