Estimation of quarry blast equivalent based on seismic array: Case study in Chuzhou, Anhui Province

Accurately estimated quarry blast equivalents can be compared with the quantity of initiated explosives to detect misfires or undetonated explosive remnants, thereby ensuring safe mining operations. Seismic waves are commonly used to estimate the equivalent; however, the ability of permanent seismic networks to detect low-magnitude events is limited. Therefore, we conducted experiments in the Minglongshan–Shangyao fault segment of the Tan–Lu fault zone in the Chuzhou area of Anhui Province in China, deploying six shallow-borehole short-period seismometers at a burial depth of 1 m for continuous monitoring for 20 days. Forty-two earthquakes were detected using a convolutional neural network, and the detected earthquakes were processed based on the source location, frequency spectrum analysis, time of occurrence, equivalent, and magnitude statistics. Through comparison, we found that one of the earthquakes was the M3.1 Suqian earthquake on March 19, 2022. Unlike this natural earthquake, the remaining 41 earthquakes have not been reported by any seismic network. The source location is concentrated, the frequency spectrum is simple, and the time of occurrence is concentrated in the daytime. Based on these results and the widespread quarries in this area, we speculate that these 41 earthquakes were caused by artificial blasting. Through seismic array monitoring, the precise locations of quarry blasts can be determined. Furthermore, the seismic wave energy-blast equivalent algorithm can be used to accurately estimate the quarry blast equivalent.