乌拉特后旗地震窗预测指标优化

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中图分类号：P315.7 文献标识码：A 文章编号：2096-7780（2025）09-0514-07

doi：10.19987/j.dzkxjz.2024-106

Optimization of earthquake prediction indicators in Urad Rear Banner seismic window

CuiFengzhi，Yang Hongying，LiJuan，Pei Dongyang，Zhang Fan，Bai Yihang

Earthquake Agency of Inner Mongolia Autonomous Region， Inner Mongolia Hohhot O1oo51， China）

AbstractThe Urad Rear Banner region is located at the intersection of the Alxa，Ordos，and Yanshan blocks. Seismic activity in this area is influenced by changes in the tectonic stressfield and is corelated with the occurrenceof moderate to strong earthquakes.Since October 2O22，theregion has experienced asignificant increase in smallearthquake activity，exceeding background levels.In this study，we analyzed aseismic window within the Urad Rear Banner area. The cumulative frequency of earthquakes with a magnitude of M2.0 or greater in 180 days was used as the windowopening indicator. The target events were earthquakes with M≥5.0 events occurring along the northwestern edge of the Ordosblock.Prediction effectivenesswas evaluated using the R -valuemetric.By examining the distribution of R -values withinthe two-dimensional parameter space of the prediction window length and threshold，prediction rules were established based on the highest R -value.The results showed that the highest R -value was O.43，with an optimal prediction window length of2Oo days and an alarm thresholdof eight events. Under these parameters，thefrequency-based prediction indicator demonstrated good predictive performance and high reliability.

Keywordsseismic window; Urad Rear Banner; Ordos block; prediction indicator

0 引言

地震窗是一些地震活动集中、频度较高的区域，其地震活动水平的变化可能预示着周边区域的地震活动变化，因此可以作为地震预测的参考指标。（剩余7970字）