在不完整地震目录下的未来缺震数估计

ESTIMATING EARTHQUAKE NUMBER IN FUTURE ON UNTEGRAL CONTENT

依据所关心地区的地震目录,建立起古登堡-里克特关系,并据此而推断该地区未来的缺震数,是一种常用的做法。然而,如果该地区的震级-频度关系是非古登堡-里克特的,或者即使是但由于地震目录不全(指历史地震目录的中小地震缺失和现代仪器记录的弱小地震缺失)而使震级-频度曲线呈系统性上凸,都将严重影响对未来缺震数的估计。本文指出,无论是哪一种情况,甚至是两种情况的耦合,折线型震级-频度关系都是合乎逻辑的处理方法。本文侧重于概念、实例,而在下文中则致力于算法推导和理论试验。

To establish a G—R relation for a special region,it is a usual method to estimate future numbersof earthquake according to earthquake contents.If the magnitude—frequency curve doesnot obey the G—R relation,or if the unintegral contents of earthquake event owing to the loss of records in the pasthistory(middle—small event)or in modern recording instrument(weak—small event),a bulgyupward curve will be shown.So we shall fail to get the real result.This paper points out that whetherthe first or second case goes singly,or the both,or the both don't,the polygon relation of magnitude—frequency is alogical treating method.Here we stress the concept and pratice and we shall deduct itstwo sets algorithms(the least square method and the likelihoodmethod)and some theoretical tests inanother paper whose title is“PolygonRelation of Magnitude-Frequency:Its Algorithm andSignification”.