FOCAL MECHANISMS AND TECTONIC STRESS FIELD OF THE XINFENGJIANG EARTHQUAKES

Altogether 83 events were recorded clearly by all the 8 sub- seismometric stations of the telemetered seismic network in the Xinfeng Jang area during the period from October 1st 1983 to April 30th 1987- Based upon the difference of the initial motion of P waves, the authors divided the 83 earthquakes into 37 pattens. Combining similar pattens, we have got 5 types of focal mechanism solutions. The recent tectonic stress field of the Xinfengjiang region is discussed. The characteristics of the stress axis and the nodal planes are different from which our predecessors got earlier; but the present result is similar to which put forward by the authors in 1981. This paper shows that the tectonic stress field is clearly characteristic by a compression in the NS direction.