江苏宿迁台断层气CO_(2)浓度特征及影响因素分析

Concentration Characteristics of Fault Gas CO_(2) and its Influencing Factors at the Suqian station,in Jiangsu

选用江苏宿迁台2021年4月1日至11月26日观测数据,分析断层气CO_(2)浓度与地质构造、土壤覆盖层及气象等因素的关系。研究结果显示:宿迁台断层气CO_(2)测点位置优良,高值出现在每年的10、11月,低值出现在每年的1、2月,7月的观测值有轻微下降趋势,8—11月的观测值有上升趋势;断层气CO_(2)浓度变化主要受气压和降雨量影响,与气压呈正相关性,具有较好的同步性,与降水关系密切,由于降水会阻碍地下气体的运移和释放,从而影响观测数据的稳定性,出现突跳或台阶,导致测值不能真正反映测点CO_(2)的释放情况。通过对干扰因素及特征的研究,丰富了断层气观测手段,为研究宿迁市及郯庐断裂带中段的断裂活动与断层气关系积累资料。

The relationship between CO_(2) concentration of the fault gas at the Suqian station,and geological structures,soil cover,and meteorological factors is analyzed.The results show that the measurement location of the Suqian fault gas CO_(2) is good.The high value is shown in October and November annually,whereas the low value is shown in January and February annually.Moreover,a slight downward trend shows in July whereas an upward trend appears from August to November.The concentration change is affected primarily by atmospheric pressure and rainfall,which is positively correlated with atmospheric pressure.The good synchronization is closely related to precipitation.Precipitation can hinder migration and release of underground gas,affect the stability of observation data,and jump steps.The abovementioned factors resulted in the measurement value failure in reflecting the release of CO_(2) at the measurement point.Through the study on influencing factors and characteristics,we suggest that fault gas observation methods are enriched,which is helpful for obtaining a large amount of data in studying the relationship between fault activity and fault gas in Suqian City and the middle segment of the Tanlu Fault Zone.