Response Study of Surface Pressure Change and Deep Well Water Level in Yunnan Caused by Tonga Volcanic Eruption in 2022
Tonga volcano violently erupted at 12∶26∶30 on January 15,2022.The atmospheric pres-sure observation station of Yunnan Geophysical Network clearly recorded the intense pressure change process caused by the eruption.The atmospheric pressure change forms and characteristics of all ob-servation stations were highly consistent,with the average peak amplitude of 2.16 hPa and the aver-age propagation velocity of 314.30 m/s.The wave train has the properties of Lamb wave propagation,and the atmospheric pressure observation data are basically reliable.The water level observation in Yunnan deep well clearly recorded the water level change caused by the short-time pressure change.The static pressure efficiency of the observation well was estimated by the ratio of peak water level change to the amplitude of pressure change.We analyze by regression the short-time pressure change and well water level data,and take the determination coefficient,regression line slope and static pressure efficiency as indicators.Then we analyze the bearing property and stress-strain sensitivity of the borehole water-bearing system.The results show that the water level and pressure observation data of 25 wells,such as Kunming station,have high goodness of fit,small lag time,and good permeability of aquifer.The atmospheric pressure efficiency of 7 wells in Kunming station,Daguanxijiagou,Tengchong station,Ludianciyuan,Nanhua,Shi-ping and Zhaotong SK3 is slightly higher,and the sensitivity of well water level to stress and strain may be low.The larger the coefficient of determination for an observation well,the higher the probability that its monitoring and forecasting performance will be assessed as qualified.
Tonga volcanoatmospheric wavewell water levelatmospheric pressure efficiency
万方数据
维普
