Spatial clustering and repeating of seismic events observed along the 1976 Tangshan fault, north China
Article first published online: 13 DEC 2007
Copyright 2007 by the American Geophysical Union.
Geophysical Research Letters
Volume 34, Issue 23, December 2007
How to Cite
2007), Spatial clustering and repeating of seismic events observed along the 1976 Tangshan fault, north China, Geophys. Res. Lett., 34, L23309, doi:10.1029/2007GL031594., , , and (
- Issue published online: 13 DEC 2007
- Article first published online: 13 DEC 2007
- Manuscript Accepted: 12 NOV 2007
- Manuscript Revised: 10 NOV 2007
- Manuscript Received: 8 AUG 2007
- repeating earthquakes
 Spatial and temporal features of the seismicity occurring along the Tangshan fault in 2001–2006 were investigated with data recorded by the Beijing metropolitan digital Seismic Network. The relocated seismicity with the double difference method clearly exhibits a dextral bend in the middle of the fault. More than 85% of the earthquakes were found in the two clusters forming the northern segment where relatively small coseismic slips were observed during the 1976 M7.8 earthquake. The b values calculated from the seismicity occurring in the northern and southern segment are 1.03 ± 0.02 and 0.85 ± 0.03, respectively. The distinct seismicity and b values are probably the collective effect of the fault geometry and the regional stress field that has an ENE-WSW oriented compression. Using cross-correlation and fine relocation analyses, we also identified a total of 21 doublets and 25 multiplets that make up >50% of the total seismicity. Most of the sequences are aperiodic with recurrence intervals varying from a few minutes to hundreds of days. Based on a quasi-periodic sequence, we obtained a fault slip rate of ≤2.6 mm/yr at ∼15 km, which is consistent with surface GPS measurements.