帕米尔地区地震活动及震源机制解的分布特征
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摘要
帕米尔地区存在一个明显的NE—SW向中、深源地震带，中、深源地震震源机制分布具有明显的区域特征。兴都库什地区震源断错以倾滑道断层为主，T轴仰角几乎垂直。帕米尔弧形构造东侧分布的地震以走滑性质为主，P轴仰角接近水平，当深度为100～200km时在弧形构造南侧形成了一个明显的北东向的正断层分布。中、深源地震主压应力方向随深度增加由NW向逐渐变为NE向，主压应力P轴仰角平缓。
There obviously exists a intermediate and deep-focus earthquake zone striking northeast-southwest in the Painter region. The distribution of its focal-mechanism solutions is of apparent regional characteristics. In the Xindukushi region, the focus offsets are mainly the form of dip-slip thrusts, the elevation angles of axis T almost vertical; at the eastern side of the Painter arcuate structure, the earthquakes are of striking-slip character, the elevation of axis P nearly horizontal. In addition, a nomal fault in NE direction distributs at 100～200 km depth southern side of the arcuate structure. The principal compressive stress direction of the intermediate and deep-focus earthquakes varies from NW to NE gradually with the depth rising. The axis P elevations of principal compressive stress are gentle.
There obviously exists a intermediate and deep-focus earthquake zone striking northeast-southwest in the Painter region. The distribution of its focal-mechanism solutions is of apparent regional characteristics. In the Xindukushi region, the focus offsets are mainly the form of dip-slip thrusts, the elevation angles of axis T almost vertical; at the eastern side of the Painter arcuate structure, the earthquakes are of striking-slip character, the elevation of axis P nearly horizontal. In addition, a nomal fault in NE direction distributs at 100～200 km depth southern side of the arcuate structure. The principal compressive stress direction of the intermediate and deep-focus earthquakes varies from NW to NE gradually with the depth rising. The axis P elevations of principal compressive stress are gentle.
引文
1宁杰远.藏绍先.帕米尔-兴都库什地区地震空间分布特征及应力场特征.地球物理学报,1990,33(6);658~668.
2束沛镒,林邦佐.喀喇昆仑地区构造应力场的基本特征.地球物理学报,1983,26(5):446～457.
2束沛镒,林邦佐.喀喇昆仑地区构造应力场的基本特征.地球物理学报,1983,26(5):446～457.
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