摘要
在过去的10年中,基于统计模型的Nowcasting方法被引入地震危险性评估工作中,形成了一种新的评价方法:Earthquake Nowcasting.该方法计算简便,可以快速给出对应时间点的地震危险性,目前已在全世界多个地震频发地区开展应用.为了探索该方法在中国地震科学实验场的适用性,本文将Earthquake Nowcasting应用于云南地区,基于高频的“小地震”数目,定义“自然周期”并构建地震复发模型,估算自上一次破坏性地震发生至今该地区的应力累积水平,实现大地震发震风险的定量评估.结果表明:(1)2021漾濞M_(S)6.4地震前,震中所在区域有较高的大地震风险;(2)云南省西北部、东北部、南部以及中部的城市和地区存在较高的破坏性地震可能性,后续地震事件与预测结果具有较好一致性;(3)震级相对较高的前震可能会影响主震的危险性评价.因此,Earthquake Nowcasting具有一定的使用价值,可为云南地区的地震危险性评价工作提供参考,但因Earthquake Nowcasting方法未考虑地震的丛集性特征,在实际使用时还必须结合前震、余震的发震规律才能给出更科学、准确的地震危险性评价.
Over the past decade,nowcasting method based on statistical models have been introduced into seismic hazard assessment,forming a new approach called Earthquake Nowcasting.This method offers a convenient way for rapidly seismic hazard assessment at specific time points.It has already been applied in many earthquake-prone regions all over the world.To explore the applicability of this method in China Seismic Experimental Site,this study applies Earthquake Nowcasting to the Yunnan region.By utilizing the amount of small earthquakes,defining a natural period,and constructing an earthquake recurrence model,we estimate the stress accumulation level in the region since the last destructive earthquake,enabling a quantitative assessment of major earthquake occurrence risks.The results indicate that before the 2021 Yangbi M_(S)6.4 earthquake,the epicentral regions exhibited significantly high seismic risks.Cities and regions in the northwest,northeast,south,and central parts of Yunnan Province have high possibilities of destructive earthquakes.Subsequent seismic events show good consistency with our prediction.Additionally,a relatively large foreshock may influence the hazard assessment of the mainshocks.These findings reveal that Earthquake Nowcasting can provide scientific reference for the Yunnan region.Since the Earthquake Nowcasting method does not consider the cluster characteristics of earthquakes,it is necessary to combine the foreshock and aftershock in practical use to provide a more scientifically seismic risk assessment.
作者
张欣乐
缪淼
韩鹏
王蕤
常莹
ZHANG XinLe;MIAO Miao;HAN Peng;WANG Rui;CHANG Ying(Department of Earth and Space Sciences,Southern University of Science and Technology,Shenzhen Guangdong 518055,China;Institute of Risk Analysis,Prediction and Management(Risks-X),Academy for Advanced Interdisciplinary Studies,Southern University of Science and Technology,Shenzhen Guangdong 518055,China;Institute of Mining Engineering BGRIMM Technology Group,Beijing 102600,China)
出处
《地球物理学报》
北大核心
2025年第8期3149-3161,共13页
Chinese Journal of Geophysics
基金
国家重点研发计划(2023YFC3012005)
国家自然科学基金(41804049,42222405)共同资助
