GPS and geologic estimates of the tectonic activity in the Marmara Sea region, NW Anatolia
GPS and geologic estimates of the tectonic activity in the Marmara Sea region, NW Anatolia
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DOI：
10.1029/97jb02563
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发表时间：
1997-12
影响因子：
--
通讯作者：
C. Straub;H. Kahle;C. Schindler
中科院分区：
文献类型：
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作者：
C. Straub;H. Kahle;C. Schindler
由 52 个全球定位系统 (GPS) 站点组成的密集网络用于确定安纳托利亚西北部马尔马拉海地区北安纳托利亚断层带 (NAFZ) 西端的速度场和应变率模式。根据1990年至1996年间每两年进行的四次GPS活动，计算出地壳运动的详细运动场。最南端的站点显示相对于伊斯坦布尔（欧亚大陆）向西的平均速率为 22±3 毫米/年。该值表明安纳托利亚西北部相对于黑海的右旋走滑运动。 GPS 速度场显示，位于色雷斯-黑海区块的地点相对于伊斯坦布尔的运动可以忽略不计。将基于 GPS 的穿过 NAFZ 向西延伸部分的三个剖面的变形模式与新构造数据进行了比较。 GPS 和新构造数据都提供了明确的证据，表明大部分变形发生在相对狭窄的东西向区域。该带从 NAFZ 的单一断层线延伸，穿过伊兹米特湾、马尔马拉海、萨尔科伊地区和沙罗斯湾，进入北爱琴海槽 (NAT)。此外，横截面显示爱琴海地区南北向延伸的影响越来越大。通过将 GPS 数据推导出的剪切和法向应变的方向和速率与地质和地震观测进行比较，我们得出结论，右旋剪切最活跃的区域沿着穆杜尔努河谷、马尔马拉海北部和与 NAT 交汇处的沙罗斯海槽的一条线。
A dense network of 52 Global Positioning System (GPS) sites is used to determine the velocity field and strain rate pattern at the western end of the North Anatolian Fault Zone (NAFZ) in the Marmara Sea region, NW Anatolia. Based on four GPS campaigns carried out biannually between 1990 and 1996, the detailed kinematic field of crustal motion is calculated. The southernmost station shows an average rate of 22±3 mm/yr oriented westward relative to Istanbul (Eurasia). This value is indicative of the dextral strike-slip motion of NW Anatolia relative to the Black Sea. The GPS velocity field reveals that the sites located on the Thrace-Black Sea block show negligible motion relative to Istanbul. The GPS-based deformation pattern of three sections crossing the westward prolongation of the NAFZ is compared with neotectonic data. Both the GPS and the neotectonic data give clear evidence that most of the deformation occurs along a relatively narrow E-W oriented zone. This belt extends from the single fault trace of the NAFZ through the Gulf of Izmit, the Marmara Sea, the Şarkoy region, and the Gulf of Saros into the North Aegean Trough (NAT). In addition, the cross sections show the increasing influence of the N-S oriented extension in the Aegean Sea region. From the comparison of the directions and rates of shear and normal strain deduced from GPS data with geologic and seismic observations we conclude that the most active zone of dextral shear follows a line along Mudurnu Valley, the northern Marmara Sea and the Saros Trough where it joins the NAT.