Effects of Velocity Errors and Arrival Time Errors on the Location Accuracy of Microseismic Monitoring using Dual Waves

The dual-wave location technique in microseismic monitoring can improve the location accuracy in areas outside the monitoring network and near the sensors, increasing the monitoring range with high precision.However, the response of seismic source location accuracy to input parameter errors remains unclear.In this study, numerical simulation methods were employed to understand the impact of wave velocity errors and arrival time errors on location accuracy when the P-S-wave location technique was used.Three points inside and three points outside a typical monitoring network were selected.Then, P waves and dual waves were applied to the seismic source locations, and the variations in location errors in the horizontal and vertical directions were analyzed as the relative wave velocity error ranged from -10% to 10% and the arrival time error ranged from -0.05 to 0.05 s.The results demonstrate that, when P waves are used, the location error outside the monitoring network increases rapidly and rapidly reaches an unacceptable range.By contrast, when dual waves were used, the ability of the microseismic monitoring system to handle input parameter errors was improved; the location errors increased linearly with increasing input parameter errors.Furthermore, for the same wave velocity error or arrival time error, the location results with the dual waves are relatively close to the actual seismic source location and stable, especially outside the network, where the reduction in location error could exceed 90%.The findings provide a scientific basis for accurately assessing and understanding the location results of microseismic monitoring with the use of dual waves.