Research on the Selection Method of Seismic Hot Spring Observation Network Points and Exploration of Geochemical Selection Indicators in Fujian Region
Hot springs are closely related to tectonics and earthquakes.There is a consen-sus that hot spring geochemistry can be used for tectonic research and earthquake predic-tion.However,there is little disclosure on how to select continuous observation points for hot springs.Based on the correlation analysis between the hot springs in Fujian and the earthquakes in Taiwan,China from September 2020 to September 2023,this paper sum-marizes the methods for selecting hot spring observation sites and determining the sensitive components of seismic reflection.Based on this,a fluid geochemical observation network was constructed and applied to prediction practice,successfully predicting the ML6.8 earthquake in Taiwan,China on September 18,2022.The core of the method is to use he-lium,neon,and carbon isotopes from hot springs to explore hot springs with deep circula-tion and rich deep information.The outstanding characteristics of these hot springs are the large contribution of mantle source fluid in hot spring gas,reflected in the high ratio of mantle source helium and the mean value of the δ13CCO2 double high region,the significant deviation of δ13CCO2 measured value from the fitting line with CO2 volume percentage,the intersection of structural fault zones,and the fact that most faults reach deep into the Moho plane.Water samples were collected from these hot springs for continuous observa-tion of water chemical major ions,and the gas flow rate of Nancheng spontaneous spring with abundant escaping gas was continuously observed.The correlation analysis between the observation results and the earthquakes above M6 in the Taiwan,China was carried out by using the threshold analysis method.The seismic mapping capability of each obser-vation point and each measurement item was calculated,and the R-value evaluation method was applied to evaluate prediction efficiency.Those with high evaluation results and high seismic mapping efficiency could be finally selected as potential effective fluid geochemical seismic monitoring points.The results can be used as a reference for selecting sites for hot spring geochemical monitoring stations and effective earthquake precursor observation pro-jects in the earthquake industry.
Geochemistry of hot springsThe proportion of mantle derived heliumδ13CCO2Short term and imminent predictionReflective seismic sensitive componentsSelection indicators
万方数据
维普
