黔江台水管仪与垂直摆预报效能对比分析

水管仪与垂直摆均是通过观测地倾斜变化来捕捉地震前兆信息的定点形变仪器, 但因工作原理和观测频段不同, 其观测结果和异常形态具有一定差异性。 因此, 对两种仪器的不同异常形态进行预报效能评估具有重要意义。 利用异常自动化处理软件, 提取黔江台倾斜仪各测项趋势转折、 速率变化、 破年变和潮汐因子等常见异常, 并结合区域范围内的地震, 对不同异常进行R值评分, 评估不同测项的预报效能。 结果显示: 垂直摆NS分量预报效能最高, 其趋势转折异常和M2潮汐因子异常均具有较好的预报指示意义; 两套仪器的EW分量分别在破年变和速率变化预报效能较高; 而水管仪NS分量预报效能最差, 可能与该测项仪器故障频繁有关。 此外, 不同测项的异常对应的地震分布也具有一定的规律性。

Comparative Analysis of the Prediction Efficiency between Water-tube and Vertical Pendulum Tiltmeters in Qianjiang Station

Both the water-tube and vertical pendulum tiltmeters are deformation instruments for observing the tilt change of the ground to capture the earthquake precursor information. However, due to their different working principle and observation frequency band, there are many differences in the observations and abnormal patterns. Therefore, it’s necessary to evaluate the effectiveness of the abnormalities observed by different instruments. In this paper, the abnormal automatic processing software is used to extract the common anomalies such as trend transition, rate change, annual change and tidal factor of the Qianjiang station tiltmeters, and using R-value scores for different anomalies combined with regional earthquakes to assess the predictive effectiveness of different instruments. The results show that the NS component of the vertical pendulum has the best forecasting performance on the trend turning and the M2 tidal factor, and the EW components of the vertical pendulum and the water-tube have better performance in the annual change and rate change respectively, and the north-south component of the water-tube has the worst performance, which may be related to its frequent instrument failures. In addition, the seismic distribution corresponding to the anomalies of different observation items has a certain regularity.