由于岗布尔(Gunbel)第三极值分布模型的独特优点(例如其震级上限ω等),地震专家把该模型应用到地震危险性研究.然而由于其复杂的非线性分布,以及地震数据的局限,极大地限制了在地震研究中的应用.为此,论述了以下两个方面的研究:挖掘拓宽和有效利用观测数据;确定初始参数以确保非线性拟合模型的收敛.该方法还能应用于弱震区地震发生规律的研究,为了阐述该方法的独特优点,对不同地震构造背景下的两组--中国东南的弱震区及希腊西部强震区地震数据进行了分析.研究证明对以上两个地震区的结果稳定且拟合误差小.%The Gumbel extreme model, especially the third distribution G(M)=exp[-(ω-m/ω-μ)1/λ] is used usually to earthquake risk research because of its prominent advantages, such as the upper bound to magnitude ω etc. Due to the complications of nonlinearity and the limitation of sparse observations, however, its importance has been largely underestimated. The methodology developed here concentrates on two aspects: exploring widening and adaptable use of the observations and finding the proper starting parameters to guarantee the convergence in the nonlinear fitting. Moreover,this new method makes it possible to study the occurrence pattern of large earthquakes in low seismicity regions. In order to expound the distinctive advantage of this method, two data sets from different seismotectonic backgrounds, a low seismicity region from southeastern China and a high seismicity region from western Greece, are analysed. Both of these results are good and stable, as with low fitting errors.
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