2013年芦山7.0级地震一年尺度预测的回顾性研究——基于三性法、静中动和垂震底继模式

Retrospective Study on One-year Prediction for 2013 Lushan M_S7.0 Earthquake

摘要:

对2013年中期地震预测的研究结果(一年尺度)进行了阐述与分析。该预测综合了三性法判据、静中动判据和垂震底继模式,给出了2013年左右在鲜水河断裂带上发生7级以上大震的可能性很大的结论。重点预测了两个具体发生的区域,预测的区域与2013年4月20日芦山7.0级地震的震源区相差70～80km左右。预测结果震级与时间吻合,但地点上发生了偏离。文中重点回顾研究了基于三性法,静中动、垂震底继方法的预测过程。

Abstract:

The medium-term prediction(one-year scale) is focused on and mainly considered for the master's thesis written by the first author and his student in 2012.Before the earthquake,it predicted that an MS7.0 earthquake would occur in the Xianshuihe seismic belt by means of a triplet method and the regularity of "an earthquake on the bottom follow-up earthquake on the perpendicular fault," and the prediction location was approximately 70~80 km from the accurate circle.In the medium-term(one-year) predictions that aimed at predicting the Yaan MS7.0earthquake,the predictions should be the closet one.The triplet method,the"activity in quiescence" method,and the regularity of"an earthquake on the bottom follow-up earthquake on the perpendicular fault" are retrospectively researched in this paper,and they are shown to have good prediction efficiency.The triplet method is an analysis method based on the time frequency of the M >7.0earthquakes.A specific approach is used for studying the time series of great earthquakes occurring in the past in a certain region by using a time series composed of periodicity,multiple periodicity,and golden section.If they fit well,we can use it for predicting the time of a future earthquake by the time series." Activity in quiescence" was a method for analyzing the seismic activity on the basis of considering the earthquakes in a low-tide period as a precursory index for predicting the earthquakes in a high-tide period.It calls approximately one decade when no M >7.0earthquakes occurred in the Mainland China intermittent period,then subtracts two years from both ends of the intermittent period to eliminate the influence of the start and the end of the earthquake climax;hence,the rest of the period is called the quiet period.In the places where M6.0earthquakes occurred in the quiet period,the M ≥ 7.0earthquakes may occur when the climax of the next earthquakes is reached.The regularity of"an earthquake on the bottom follow-up earthquake on a perpendicular fault" is based on the theory that seismogenic faults interact with each other and then affect another seismogenic fault,and thus,an earthquake is caused.It states that the Wenchuan MS8.0 earthquake in 2008exhibited a shock-adding effect on the intersecting Xianshuihe fault.