Collaborative Research: Postseismic deformation for the Izmit-Duzce, Turkey earthquakes: Implications for the mechanics of the earthquake cycle and rheology of the continent

合作研究：土耳其伊兹米特-迪兹杰地震的震后变形：对地震周期力学和大陆流变学的影响

• 批准号: 1045487
• 负责人: Robert Reilinger
• 金额: $ 6.5万
• 依托单位: Massachusetts Institute of Technology
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-03-01 至 2012-02-29
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1045487&HistoricalAwards=false
• 关键词: Collaborative; Research; Postseismic; deformation; Izmit

The 1999 Izmit, Turkey earthquake sequence (M=7.5, August, Gulcuk and M=7.1, November, Duzce earthquakes) occurred within a pre-existing GPS network making it one of the most geodetically well observed seismic events on a major continental strike slip fault. Well-defined pre-earthquake strain accumulation, coseismic motions (reaching ~2 m), short-term (days - months) postseismic afterslip, and longer-term (years - 10 years) postseismic relaxation are all well imaged by geodetic observations. In addition, the earthquake appears to have altered the character of interseismic motions in unexpected ways (i.e., not easily ascribed to standard postseismic processes) as far as 200 - 300 km from the coseismic fault. As such, this event is providing fundamental constraints on the earthquake deformation cycle (inter-, pre-, co-, and postseismic) with direct implications for forecasting future earthquakes on this fault system, and by analogy for understanding the dynamics of similar strike slip faults, including the San Andreas Fault in California.The 1999 sequence occurred along the eastern segment of a seismic gap that extends south of Istanbul across the Sea of Marmara, raising serious concerns about a future earthquake on the western Marmara segment that could have devastating effects on this vulnerable mega-city ( 20 million people). Uncertainty persists about the possible magnitude of future earthquakes in the Marmara Sea, as well as how strain is transferred from the Izmit segment to the Main Marmara Fault (MMF) within the Sea (i.e., the geometry, degree of locking, slip rate on the connecting fault). The Princes Islands are located within the Marmara south of Istanbul and approach within less than 5 km of the Izmit-Marmara connecting fault segment. Two islands (Sivriada and Büyükada) located very near the connecting segment have been selected for ICDP borehole sites (GFZ, Germany are leading this ICDP initiative). In cooperation with this work, we are focusing our initial efforts on installing GPS stations at both borehole sites. Data from these stations will be downloaded by our Turkish partners at the Marmara Research Center and by UNAVCO. Over three years, these GPS observations will provide improved constraints on the dip, locking depth, and present-day rate of strain accumulation on this fault segment. These anticipated results together with analyses of postseismic deformation throughout the Marmara region, promise to provide improved understanding of the earthquake deformation cycle, and accordingly, estimates of the timing and magnitude of future earthquakes in the Sea of Marmara.This project is funded by the Geophysics and Tectonics Programs of NSF.

1999年的伊兹米特（Izmit）土耳其地震序列（M = 7.5，八月，古尔库克（Gulcuk）和m = 7.1，11月，杜兹切（Duzce）地震发生在预先存在的GPS网络中，这是在重大连续罢工断层中，它是最高地球上观察到的地震事件之一。定义明确的地球菌株的积累，同震动作（达到〜2 m），短期（天 - 月）下滑后的后（天数）和长期（10年-10年）后视力放松。此外，地震似乎已经以意外的方式（即不容易归因于标准的地震过程）改变了跨界运动的特征。 As such, this event is providing fundamental constraints on the earthquake deformation cycle (inter-, pre-, co-, and postseismic) with direct implications for forecasting Future earthquakes on this fault system, and by analogy for understanding the dynamics of similar strike slip faults, including the San Andreas Fault in California.The 1999 sequence occurred along the Eastern segment of a seismic gap that extends south of Istanbul across the Sea of马尔马拉（Marmara）对西部马尔马拉（Marmara）领域的未来地震引起了严重的关注，这可能会对这一脆弱的巨型城市（2000万人）产生毁灭性影响。不确定性仍然存在于马尔马拉海未来地震的可能程度，以及如何从izmit段转移到海中的主要马尔马拉断层（MMF）（即几何，几何，锁定程度，连接断层的滑动速率）。王子群岛位于伊斯坦布尔以南的马尔马拉（Marmara）内，在Izmit-Marmara连接断层细分市场不到5公里内接近。已经为ICDP钻孔地点（德国GFZ，正在领导ICDP倡议）的两个岛屿（Sivriada和Büyükada）已被选为ICDP钻孔站点。与这项工作合作，我们将最初的努力集中在两个钻孔站点上安装GPS电台上。这些电台的数据将由我们的土耳其合作伙伴在Marmara研究中心和UNAVCO下载。在三年的时间里，这些GPS的观察结果将在此断层细分市场上的倾斜，锁定深度和当今应变积累率的限制。这些预期的结果以及整个马尔马拉地区的后地震变形的分析，有望提高人们对地震变形周期的了解，因此，对马尔马拉海中未来地震的时间和幅度的估计。该项目由NSF的地球物理学和构造计划资助。