地震前兆还是降雨干扰？

——与“宁强5.7级地震前陕西定点形变的异常现象”作者商榷

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摘要： 在宁强MS5.7地震（2008年5月27日）发生前2天，宝鸡台洞体应变NS和EW分量分别记录到了大幅应变异常，有研究认为该异常是宁强地震的短临前兆[1]。为客观验证该结论的真伪性，本文采用重复地震检验和统计实证等方法，对该异常进行了较系统的归因分析，结果表明降雨干扰才是主因。

关键词： 宁强MS5.7地震;定点形变;地震前兆;降雨;宝鸡台;洞体应变

中图分类号： P315.72+5 文献标志码：A 文章编号： 1000-0844（2023）01-0138-07

DOI：10.20000/j.1000-0844.20210720004

Earthquake precursor or rainfall interference？—Discuss with authors of the paper “Anomaly phenomenon of pointing deformation in Shaanxi Province before Ningqiang MS5.7 earthquake”

YANG Xiaolin1， DING Xiaoguang1， YANG Jinling2， WEI Zigen3

（1.Shaanxi Seismic Station， Xi'an 710068， Shaanxi， China; 2. Fujian Seismic Station， Fuzhou 350003， Fujian， China; 3. Innovation Academy for Precision Measurement Science and Technology， Chinese Academy of Sciences， Wuhan 430077， Hubei， China）

Abstract： Approximately two days prior to the Ningqiang MS5.7 earthquake （May 27， 2008）， a large amount of cave strain anomalies were recorded in the NS and EW components at Baoji station. A previous study showed that these phenomena were short-imminent earthquake precursors of the Ningqiang MS5.7 earthquake[1]. By means of repeated earthquake tests and empirical statistics， the attribution of these anomalies was analyzed systematically to objectively verify the authenticity of this conclusion. Results showed that rainfall interference was the main cause of the remarkable strain anomalies.

Keywords： Ningqiang MS5.7 earthquake; fixed-point deformation; earthquake precursor; rainfall; Baoji station; cave strain

0 引言

就地震前兆观测和机理研究而言，虽然可从岩石力学实验[2]、数值模型[3]、统计模型[4]和观测实证[5]等视角，来揭示前兆过程的形态及演化模式，但真实的震源物理、地壳介质、场地效应和非构造影响因子等要远比理想假设复杂，故而在这些影响因子的驱动下，地震前兆往往会涌现出多样性和复杂性，这也使得地震预测预报业务长期面临艰巨的挑战[6]。（剩余8785字）