CataIogue compIeteness anaIysis on aftershock sequence of the 2013 Minxian-Zhangxian,Gansu,MS6.6 earthquake based on Iocation and magnitude estimation of singIe-station earthquake events
Tan Yipei
Chen Jifeng
Cao Jingquan
Deng Li
Dong Demiao
Abstract：Catalogue of aftershock sequences of moderate-strong earthquakes provide important basic data for the study on aftershock sequence characteristics analysis,postseismic trend quick judgement and strong aftershock prediction. The completeness of catalogue and accuracy of source parameters have direct influence on the reliability of research results.There are a lot of single-station earthquake events in the catalogue of the Minxian-Zhangxian,Gansu,MS 6.6 earthquake on July 22,2013,whose epicenter locations are not given in earth-quake observation report.According to the waveforms mutual interference of the aftershocks,magnitude are not reliable enough due to the lager error of amplitude measurement.Accurate estimation of location and magnitude of single-station earthquake events can supplement and improve the existent catalogue so as to enhance the completeness of the catalogue.In this paper we estimate the location and magnitude of single-station earthquake events not only using the waveforms of one station,but also those of multi-station in the network. Taking the larger aftershocks with high signal noise ratio as template,we detect phase arrival times of single-station earthquake events in multi-station using waveform cross-correlation phase detection technique.Therefore we can esti-mate the location and magnitude based on multi-station phase arrival times and amplitude ratios by using waveform cross-correlation phase detection technique. Then the formula between the minimum completeness magnitude and time is obtained by catalogue completeness analysis.Comparison with artificial phase picking error as well as the magnitude repetition estimation result indicate that the phase detection and magnitude estimation results in this paper are reliable. In total we obtained the magnitude estimation of 253 single-station events and epicentral location of 177 events.The spatial distribution of single-station earthquakes is consistent with the distribution of other aftershocks.However, the magnitude of single-station earthquakes occurred in a short time after the main shock or the largest aftershock are underestimated in catalogue,which may be affected by the interference of subsequent phase of the main shock and the biggest aftershock and interaction of aftershocks.In the time interval between 0.02 days and 0.3 days after the main shock,the minimum complete-ness magnitude exhibits a linear decreasing with time in log,and then becomes stable at about ML 1.1 after 0.3 days since the main shock.
Keywords：catalogue completenesssingle-station earthquake eventphase detectionwaveform cross-correlation2013 Minxian-Zhangxian MS 6.6 earth-quake
Publication Date：2015-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：14( 806-819 )