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对区域地震活动性的了解是评估地震灾害的关键因素之一。但不幸的是历史地震记录不完备,往往不适于评估地震活动性。古地震学通过使用各种技术,确定地震干扰事件的年代,就可以解决这个问题。树木具有广泛分布,有可鉴定的年增长量,并对环境变化敏感,因此能够提供一种独特的手段来确定往昔地震事件的时间。地震引起的地貌和水文学的变化以及动态应力,可以对单个树木和树木群落造成一系列的影响。年轮分析可以:(1)获得地震事件发生的实际年代甚至季节;(2)确定那些可能在绝对年代测定范围之外的地震的同时性。用树的年轮来确定年代(或称为树木年代学)是指基于年轮在时间进程中的每年变化图象来确定准确的年代。受可能的丢失、微小或虚假年轮的影响,年轮的单纯计数可能不正确并可能导致错误发生。在许多地方树可以生长300～500年,这可以用来确定以前不知道的地震干扰和更好地确定零星所知的地震事件。在有些实际例子中,树龄可覆盖更长的时间跨度。利用年轮分析可以更精确地确定地震的发震地点和时间,或者较好地估计震级。一部分研究结果已经确认,年轮分析应用于古地震学是正确有效的,但只有少量的研究为古地震记录提供了新信息。这门科学现在应当从发现阶段转到较宽的应用阶段。成功的应用将给地震活动性记录和地震灾害评估补充重要的信息。
Understanding the seismicity of a region is one of the key factors in assessing the earthquake disaster. Unfortunately, however, historical records of earthquakes are not complete and are often not suitable for assessing seismicity. Paleoearthology can solve this problem by using various techniques to determine the age of seismic disturbance events. The wide distribution of trees, with identifiable annual growth and their sensitivity to environmental changes, can provide a unique means of determining the timing of past earthquake events. Earthquakes and hydrological changes and dynamic stresses caused by the earthquake can have a series of effects on individual trees and tree communities. The annual growth analysis can: (1) obtain the actual age and even the seasons where the earthquake event occurred; and (2) determine the simultaneity of those earthquakes that may be outside the range of absolute dating. Identifying the year with tree rings (or called tree chronology) refers to determining the exact age based on the annual change image of annual rings over time. Affected by possible loss, tiny or spurious annual rings, mere annual rings may not be counted correctly and may lead to errors. In many places trees can grow for 300-500 years, which can be used to identify previously unknown earthquakes and to better determine sporadic known earthquakes. In some practical examples, tree ages can cover longer time spans. Using annual rings analysis, the location and time of an earthquake's earthquake can be determined more accurately or the magnitude can be better estimated. Part of the research results have confirmed that the use of annual rings analysis is correct and effective in paleose seismology, but only a few studies provide new information for paleoseismic records. This science should now shift from the discovery phase to the broader application phase. Successful applications will complement seismic records and seismic hazard assessments with important information.