STRUCTURAL EARTHQUAKE SYSTEM AND STRONG EARTHQUAKE ACTIVITY TENDENCY AROUND EERDUOSI BLOCK

Eerduosi Block is located in the northern part of China's continent and in its surrounding area seismic activity is quite frequent.In this paper basing on historical seismic activity and tectonic development in this area and combining a part of experimental results, this surrounding area of Eerduosi Block is divided into 4 stress concentrated areas: one pair of compressive stress concentrated areas where uplifts are dominative and one pair of tensile stress concentrated areas in which faults are dominative.The uplifted areas are Taiyuan-Beijing area and Haiyuan-Gulang area; the downfaulted areas are Fenwei area and Hetao area.From the analysis of strong seismic activity in each area, it is found that in both northwest and southeast areas bounded by Huhehote-Baoji, earthquakes with M≥6 ocourred alternatively in 134-392 years.It seems that the next seismic active area after the Xingtai earthquake will be moved to Taiyuan-Beijing area and Fenwei area, where strong seismic activity will last more than oneehundred years.The recent quiecent in Fenwie area should attract more attention.