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新西兰2016年凯库拉M_W7.8地震地表破裂带分布在1个长约170km、宽35km的范围内,总体呈NE-SW走向,至少有12条断裂产生了m量级的地表位错,跨过了2个活动方式与活动强度存在明显差异的地震构造区。地震地表断裂大致可分为NE—NEE向和NNW—近SN向2组,NE—NEE向断裂之间的贯通性差,最大相隔距离为25~30km,即使首尾相连,走向上也有约30°的差异,运动性质以右旋走滑为主,最大位错量10~12m;NNW—近SN向断裂近于平行分布,相距可达40~50km,以逆断裂活动性质为主,最大垂直位错量5~6m。走滑类地表破裂带的组合特征非常复杂,主要表现为3种形式:雁列、分叉和平行分布。其中,雁列地表破裂(段)既可以表现为数m至数十m尺度上的张剪性破裂与鼓包、挤压剪切破裂组合,也可表现为百余m长的左阶斜列张剪性破裂组合;地表破裂段之间阶区规模差异明显,可以是数十m、数百m到数km不等。平行的地表破裂(段)可以相距数m、数十m至数km。凯库拉地震地表破裂带对已知活动断裂分布格局的突破也是1种比较显著的特点,既可以是在原先认为不活动的断裂上或没有活动断裂的位置上产生了地表破裂带,也可以是在走向或横向上突破了先前认识到的活动断裂分布范围。对凯库拉地震地表破裂带发育特征的初步分析结果,对于理解地表活动断裂与深部发震构造之间复杂的对应关系,以及跨活动断裂的抗震设防等问题具有一定的借鉴意义。
The surface rupture zone of the Kaikoura M_W7.8 earthquake in 2016 in New Zealand distributed in a length of 170km and a width of 35km with an overall NE-SW strike. At least 12 faults produced m-level surface dislocations, After two activities and activity intensity there is a clear difference between the seismic structure zone. The earthquakes can be roughly divided into two groups: NE-NEE and NNW-near SN, and the connectivity between NE-NEE and faults is poor. The maximum distance between them is 25 ~ 30km. Even if they are connected end to end, they are about 30 ° In the NNW-nearly SN-trending faults, they are nearly parallel to each other, with a distance of up to 40-50 km. The nature of the reverse fault activity is dominated by the largest vertical dislocation Volume 5 ~ 6m. The slippery surface rupture zone has a very complex combination of features, mainly in three forms: geese, bifurcation and parallel distribution. Among them, the geese column surface rupture (section) can be expressed as the number of m to tens of m on the scale of Zhang shearing rupture and bulge, extrusion shear rupture combination can also be expressed as more than 100 m long left oblique oblique shear The combination of sexual rupture and surface rupture has significant differences in scale, which can range from tens of m to hundreds of m to several km. Parallel surface ruptures (sections) can be several meters apart, tens of meters to several kilometers. Breakthrough in the distribution pattern of known active faults in the surface rupture zone of the Kaikoura earthquake is also a notable feature. It can be either a surface rupture zone at a position previously considered inactive or without active rupture, or Is in the trend or horizontal break through the previously recognized range of active fracture distribution. The preliminary analysis of the developmental characteristics of the surface rupture zone in the Kaikoura earthquake is of some reference for understanding the complicated correspondence between surface active faults and deep seismogenic structures and the seismic fortification across active faults.