Analysis of Abnormal Changes in Strain Observation Data Before the M5.5 Pingyuan Earthquake

Abnormal changes were recorded by the RZB-2 component strainmeter in the JX station in Shandong Province and the TJ-2 volume strainmeter in the XZ station in Jiangsu Province before the M5.5 Pingyuan earthquake. A correlation and wavelet analysis of the data from these two sets of instruments suggests that the abnormal pre-earthquake changes are related to the earthquake.At 02:33 on August 6, 2023, a M5.5 earthquake occurred in Pingyuan County, Dezhou City, Shandong Province. This earthquake, located at the intersection of the Liaocheng-Kaocheng and Tancheng-Lujiang fault zones, was the largest seismic event in Shandong Province in nearly 40 years. The Pingyuan M5.5 earthquake was a shallow-focus tectonic earthquake with a focal depth of about 10 kilometers. The seismic waves had a wide reach, with noticeable tremors felt in many parts of Shandong Province as well as in neighboring provinces like Jiangsu, Hebei, Henan, and Anhui. By analyzing the characteristics of the abnormal pre-earthquake changes recorded by the RZB-2 component strainmeter at the JX station and the TJ-2 volume strainmeter at the XZ station, this paper explores the relationship between these anomalies and pre-seismic information, providing a reference for studying seismic activity in the North China region.