Recent temporal change in the stress state and modern stress field along the North Anatolian Fault Zone (Turkey)
Recent temporal change in the stress state and modern stress field along the North Anatolian Fault Zone (Turkey)
复制标题
北安纳托利亚断裂带沿线应力状态和现代应力场的近期变化（土耳其）
DOI：
10.1111/j.1365-246x.1997.tb00595.x
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发表时间：
1997
影响因子：
2.8
通讯作者：
J. Andrieux
中科院分区：
文献类型：
--
作者：
O. Bellier;Semir Över;A. Poisson;J. Andrieux
总结
北安纳托利亚断层（NAF）是一条右旋走滑断层，自东向西延伸约1400 km，从Karliova三联点到爱琴海域。它是活跃在上新世-第四纪作为欧亚板块和阿拉伯板块之间的碰撞的结果。NAF陆内变形带与左行东安纳托利亚断层一起，由于阿拉伯半岛向北漂移，导致安纳托利亚向西挤出。中央NAF区形成一个向北的凸形弯曲，其中从Karliova延伸的东部NAF N110° E走向段连接到西部NAF N75° E走向段，延伸到爱琴海。通过对北大西洋断裂带附近大地震滑动的分析，发现现今北大西洋断裂带沿着的应力图象与应力大小和走向自东向西的变化一致。沿着NAF的应力状态为：在NAF东部为NNW向σHmax（σ1）转换压;在安纳托利亚中部逐渐向西转变为NW向σ1转换张。这种横向变化意味着σHmax震级的相对降低，并逐渐演化为NAF最西端附近的伸展体制（σ1垂直），其特征是NNE向的σhmin（σ3）。北安纳托利亚地块区域应力状态由挤压向伸展的剧烈变化，在NAF中央弯曲内是有效的。
通过在不同尺度的断层面上测量的滑移矢量反演确定的应力状态证实了NAF弯曲中心部分的现今扭张状态。然而，在中央NAF第四纪应力状态的断层运动学分析表明，这种应力状态是不连续的整个第四纪。事实上，断层滑动矢量年表提供了两个不同的第四纪区域走滑应力状态在这个区域内的证据。两种状态分别具有一致的NE和NW向σ3和σ1轴，但具有显著不同的R值。走滑应力状态的变化可能发生在中更新世。较老的平均应力状态的特征是N142 ± 8° E向的σ1，N52 ± 13° E向的σ3，平均算术Rm值为0.75，这表明区域应力状态为压扭性。年轻的走滑体制以N142°± 14°E σ1轴、N52°± 10°E σ3轴和平均Rm为0.24为特征，表明该体制具有扭张性质。与近期应力状态有关的应力偏量的低R值反映了法向分量滑动。这些时空应力变化沿着NAF的结果，由于爱琴海俯冲在西部和向北漂移的阿拉伯半岛在东部的力量的同时代的影响。在这些边界力之上，剪切力沿着NAF叠加，NAF容纳安纳托利亚挤压。然而，时间应力变化的时间允许北安纳托利亚第四纪应力状态变化的建议，主要是由于爱琴海域的影响。
SUMMARY
The North Anatolian Fault (NAF) is a dextral strike-slip fault which runs about 1400 km from east to west, from the Karliova triple junction to the Aegean domain. It was active during the Plio-Quaternary as a consequence of the collision between the Eurasian and Arabian plates. The NAF intracontinental deformation zone contributes with the sinistral East Anatolian Fault to the westward extrusion of Anatolia as a consequence of the northward drift of Arabia. The Central NAF zone forms a northward convex bend where the eastern NAF N110°E-trending segment extending from Karliova is connected to the western NAF N75°E-trending segment running to Aegea. Analysing the slip occurring in major earthquakes around the NAF, we show that the present-day stress pattern along the NAF agrees with stress magnitude and strike variations from east to west. The stress regime along the NAF is NNW-trending σHmax (σ1) transpression in eastern NAF; this progressively changes westwards to NW-trending σ1, transtension in central Anatolia. This lateral variation means a relative decrease of the σHmax magnitude, which evolves progressively to an extensional regime (σ1 vertical) around the westernmost NAF, characterized by a NNE-trending σhmin (σ3). The drastic change in the tendency of the regional stress state in the North Anatolian block, from compressional to extensional, is effective within the central NAF bend.
The stress regime determined by inversion of slip vectors measured on fault planes of various scales confirms the present-day transtensional regime in the central part of the NAF bend. However, the fault kinematic analysis of Quaternary stress states within the Central NAF indicates that this stress state was not continuous throughout the Quaternary. Indeed, chronologies of fault slip vectors provide evidence for two distinct Quaternary regional strike-slip stress states within this zone. Both states have consistent NE- and NW-trending σ3 and σ1 axes, respectively, but have significantly different R values. The change in the strike-slip stress regime probably occurred in the middle Pleistocene. The older mean stress state is characterized by a N142 ± 8°E-trending σ1, a N52 ± 13°E-trending σ3 and a mean arithmetic Rm value of 0.75, which indicates that the regional stress regime is transpressional. The younger strike-slip regime is characterized by a N142°± 14°E σ1 axis, a N52°± 10°E σ3 axis and a mean Rm of 0.24, which indicates the transtensional character for this regime. The low R values of the stress deviators related to the recent stress state reflect normal-component slips. These temporal and spatial stress changes along the NAF result from the coeval influence of forces due to the Aegean subduction in the west and to the northward drift of Arabia in the east. Over these boundary forces, shear is superimposed along the NAF, which accommodates the Anatolia extrusion. However, the timing of the temporal stress change permits the suggestion that the Quaternary stress regime variation in North Anatolia is mainly due to the influence of the Aegean domain.