After the Ming Dynasty moved its capital to Beijing,it faced even tougher challenges:being closer to the border,farther away from the Mother River,and falling into the earthquake zone.North China entered the 3rd period of high seismicity(1484-1730).Seismicity in North China is constrained by two active seismic belts:the NE-oriented Tangshan-Cixian belt and the NW-oriented Zhangjiakou-Penglai belt.The pair of conjugate fractures is cross-shear zones formed under the action of a uniform tectonic stress field with different orientations and opposite shear directions.The presence of conjugate fracture adds to the diversity of seismicity,and simulation experiments and field observations have investigated its mechanical mechanisms.The rupture networks in Eurasian continent also show the predominantly NE-and NW-oriented configuration,which can guide the analysis of stress trans formation and earthquake precursors.
关键词
迁都北京/张家口—蓬莱地震带/共轭断裂/破裂网络
Key words
relocation of capital to Beijing/Zhangjiakou-Penglai seismic zone/conjugate fracture/rupture network
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