Microearthquake detection and seismicity analysis of the 2020 Guye MS 5.1 earthquake sequence
On July 12,2020,a MS5.1 earthquake(epicenter:39.78°N,118.44°E)with a depth of～10 km struck Guye,Tangshan,Hebei province.In this paper,we performed microearthquake detection and seismicity analysis using the three-month continuous waveform data(from June 1,2020 to August 31,2020)recorded by 84 stations within 500 km radius around the epicenter.Firstly,we selected 118 high-quality events as templates from 362 events listed in the China Earthquake Network Center(CENC)catalog.By scanning through the three-month continuous data using the Graphic Processing Unit based Match and Locate(GPU-M&L)technique,a total of 1017 events were detected,which is approximately 2.8 times the number in the CENC catalog.Secondly,669 earthquakes were relocated by applying the double difference relocation algorithm(hypoDD).We then analyzed the temporal-spatial distribution,focal mechanism solutions,and spatial variation of the b-value for the Guye earthquake sequence.Our results reveal that the Guye MS5.1 earthquake sequence exhibits a NE-striking pattern on the surface and a subvertical distribution in depth,which is spatially coincident with the eastward extension of the Tangshan-Guye Fault.Since both the seismogenic faults of the Guye MS5.1 earthquake and the 1976 MS7.8 Tangshan earthquake belong to the Tangshan fault system,we suggest that the Guye earthquake was triggered by stress adjustment of the Tangshan MS7.8 earthquake.
The Guye earthquakeMicroseismic detectionTemplate matchingThe magnitude of completenessSeismicity
NETL
NSTL
万方数据
