_{0},p

_{1},…,p

_{n}是不同尺度岩石块体中产生或扩展裂隙的概率,根据重整化群理论,数列{p

_{0},p

_{1},…,p

_{n}}有极限。其极限值可能是0或1。选定一个临界值p

^{*},如果p

_{0}>p

^{*},则p

_{n}→1;反之,若p

_{0}

*,则p_{n}→0。在地震平静期内,必有p_{0}

*,而在地震活跃期内,p_{0}>p^{*}。在本文中,作者根据地震资料研究了青藏高原北部地区的临界概率p^{*}值,得到大震前p_{0}值大约为0.3-0.8,平静期p_{0}约为0.1-0.2,所以p^{*}值约为0.2-0.3。利用重整化群模型给出了p^{*}为0.2324,预报期限为3年。

_{0},P

_{1},…,P

_{n}be the probability of the form or ex-tension of fracture in diverse size rock bodies with certain scales. According to renormalization group theory,sequence {P

_{0},P

_{1},…,P

_{n}} has a limit that may be 0 or 1,and if P

_{0}=P

_{1}=…=P

_{n}, the limit will get the constant(P

^{*})。The P

^{*}is a critical value,and if P

_{0}>P

^{*}then P

_{n}approaches to 1;if P

_{0}

*, P_{n} approaches to 0.

P_{0} can be determined by statistics of earthquake catalogue. There should be P_{0}

* during the earthquake quiet period,and P_{0}>P^{*} during the active,therefore,P^{*} can be determined as the value between the quiet period P_{0} and the active P_{0}.Based on the conclution,a lot of renor-malization medels may be calculated and a model that its P^{*} is within the range is choosen to gain a exact P^{*} value. To predict earthquake,the P_{0} is worked out using recent data and judged if P_{0}>P^{*} not.

The data were calculated in northern district of Qinghai-Xizang plateau and the P_{0} is about 0.3-0.8 before strong earthquakes,while it is about 0.1-0.2 during quiet. Therefore,the P^{*} is about 0.2-0.3 and the medel that was choosen gives a exact P^{*} as 0.2324.

By this train of thought,a new way to predict strong earthquake is established.