Lateral segmentation of the subducted plate at the Hikurangi Margin, New Zealand: Seismological evidence
Lateral segmentation of the subducted plate at the Hikurangi Margin, New Zealand: Seismological evidence
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新西兰希库朗吉边缘俯冲板块的横向分割：地震证据
DOI：
10.1016/0040-1951(83)90218-4
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发表时间：
1983
期刊：
影响因子：
2.9
通讯作者：
M. Reyners
中科院分区：
文献类型：
--
作者：
M. Reyners
新西兰希库朗吉边缘俯冲太平洋板块横向分割的地震学证据包括：1.(1) 倾斜地震带的地震活动和应力分布；2.(2) 历史上大型板间地震的破裂程度以及伴随这些事件的地震活动模式；3.(3) 近期浅层地震活动的分布； 4.(4)浅层应力模式。地震数据表明俯冲板块存在六个下倾撕裂。这些裂缝位于克马德克海沟的南端、霍克湾北部、霍克湾南部（最明确的裂缝）、库克海峡地区、马尔堡中部和凯库拉地区。这种俯冲板块中下倾断裂区域的模型被证明有助于解释 1980 年在 Hikurangi 边缘中部发生的一次重大地震应变释放事件。分段表现为“撕裂”地震（即俯冲板块平面内的走滑断层作用，断层面向下指向板块倾角），这些必须与板间“解锁”地震（逆冲）区分开来。断层事件（断层面与板块界面重合）和“弯曲”地震（正常断层事件，aT 轴指向俯冲板块的倾角），以解释边缘的当前构造。
Seismological evidence for lateral segmentation of the subducted Pacific plate at the Hikurangi Margin, New Zealand, includes:1.(1) the distribution of seismicity and stresses in the dipping seismic zone;2.(2) the extent of rupturing of large historical interplate earthquakes and the patterns of seismicity accompanying these events;3.(3) the distribution of recent shallow seismicity; and4.(4) the stress pattern at shallow depth.Six down-dip tears in the subducted plate are suggested by the seismological data. These are located at the southern end of the Kermadec Trench, northern Hawke's Bay, southern Hawke's Bay (the best-de-fined tear), the Cook Strait region, central Marlborough and the Kaikoura region. Such a model of down-dip fractured regions in the subducted plate proves useful in interpreting a significant episode of seismic strain release which occurred in the central part of the Hikurangi Margin in 1980. Segmentation is manifest by “tearing” earthquakes (i.e. strike-slip faulting in the plane of the subducted plate with the fault plane oriented down the dip of the plate) and these must be distinguished from interplate “unlocking” earthquakes (thrust faulting events with a fault plane coinciding with the plate interface) and “bending” earthquakes (normal faulting events with aT-axis directed down the dip of the subducted plate) in an interpretation of the present tectonics of the margin.