滇西北断裂带痕量氢地震异常特征分析及预报效能评价OA

Based on the statistical analysis,correlation fitting and preprocessing of high-precision con-tinuous observation data of four trace hydrogen observation points in fault zones of northwestern Yun-nan over the past five years,we evaluate the seismic prediction efficiency of observational data,and analyze the characteristics and causes of trace hydrogen concentration anomalies related to earthquakes combining with previous studies.The results show that:1)The concentration variations of hydrogen escaping from hot springs in northwestern Yunnan are correlated with temperature and air pressure,showing distinct annual variation features.In contrast,hydrogen escaping from soil is essentially un-correlated with meteorological elements.Comparison with previous studies,there is a significant spa-tial heterogeneity in the distribution of trace hydrogen concentration in fault zones,which is not con-trolled by a single factor.2)All of four trace hydrogen observation points in northwestern Yunnan are effective seismic prediction indicators with statistical significance.The short-term prediction effect of hydrogen escaping from soil is better but with relatively lower credibility.The prediction efficiency of hydrogen escaping from hot springs is mainly in medium to long term,with relatively higher credibili-ty.3)There is a close correlation between hydrogen anomalies in fault zones and seismic activities in northwestern Yunnan.Seismic precursory anomalies typically manifest as sudden increases or saw-tooth fluctuations.Due to differences in hydrogen sources,escaping processes,and geothermal stor-age temperatures in different regions,the geochemical background values of hydrogen escaping from hot springs and soil also exhibit significant spatial heterogeneity.