新西兰2016年凯库拉M_W7.8地震地表破裂带特征初析

发布时间：2018-06-02 00:42

本文选题：凯库拉MW.地震 + 地表破裂带　；参考：《地震地质》2017年04期

【摘要】：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。
[Abstract]:The surface rupture zone of the 2016 Kaikula M_W7.8 earthquake in New Zealand is distributed in the range of about 170 km long and wide 35km, and is generally NE-SW strike. At least 12 faults have produced surface dislocations of m magnitude. Two seismic tectonic areas with obvious differences in activity patterns and activity intensities have been crossed. The seismic surface faults can be roughly divided into two groups: NE-NEE direction and NNW-near SN direction. The maximum distance between them is 25 ~ 30km. Even if the top and the tail are connected, there is a difference of about 30 掳on the strike, and the movement is mainly dextral strike-slip. The maximum dislocation amount is 10 ~ 12 m ~ (-1) NNW-NNW-NNW-NNW-NNW-NNW-NNW-NNW-NNW-NNW-NNW-NNW-NNW-NNW-NNW-NNW-NNW-NNW@@ The assemblage characteristics of strike-slip surface rupture zones are very complex, mainly in three forms: geese, bifurcation and parallel distribution. Among them, the echelon surface rupture (segment) can be shown either as tensional shear rupture and bulge on the scale of several meters to tens of meters, compression shear rupture combination, or the left-order diagonal tensional shear fracture combination with a length of more than 100 m. The scale of the order of the surface rupture segment is obviously different, which can be tens of meters, hundreds of meters to several kilometers. Parallel surface rupture (segments) can be separated by several meters, tens of meters to several kms. The breakthrough of the surface rupture zone of the Kaikula earthquake to the known active fault distribution pattern is also a relatively remarkable feature, which can be characterized by the occurrence of the surface rupture zone on the previously considered inactive fault or in the position where there is no active fault. It can also break through the previously recognized range of active faults in the direction or transverse direction. The preliminary analysis of the development characteristics of the surface rupture zone of the Kaikula earthquake has certain reference significance for understanding the complex corresponding relationship between the surface active faults and the deep seismogenic structures, as well as the seismic fortification across the active faults.
【作者单位】：中国地震局地质研究所;Institute
【基金】：国家自然科学基金(41372219,41172193)资助
【分类号】：P315.2

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