Collaborative Research: How Constant are Fault Slip Rates in Time and Space? An Analysis of the North and East Anatolian Faults, Turkey

合作研究：断层滑动率在时间和空间上的恒定程度如何？

• 批准号: 0409767
• 负责人: James Dolan
• 金额: $ 28.3万
• 依托单位: University of Southern California
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-07-01 至 2008-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0409767&HistoricalAwards=false
• 关键词: Collaborative; Research; How; Constant; Fault

The research team is studying the degree to which fault loading and strain release rates are constant (or non-constant) in time and space. Their work in addressing this fundamentally important issue focuses on the generation of fault slip rates at a variety of time scales a long the North and East Anatolian faults in Turkey. These faults are particularly attractive targets for the proposed research because of the relative structural simplicity of the Anatolia-Eurasia-Arabia plate boundary in Turkey. Specifically, geodetic and geologic data suggest that in central and eastern Turkey almost all plate boundary strain is accommodated by slip on these two faults. The investigators are focusing their efforts on what increasingly appears to be a critical time scale of observation - the time range between the temporally irregular strain release documented by historical and paleoearthquake data, and longer time scales over which fault slip rates appear to be relatively constant. By using cosmogenic nuclide dating of offset geomorphic features, a technique that yields the duration of time that a geomorphic surface has been exposed to cosmic rays at the earth's surface, they will determine slip rates at eight or more sites along these two faults at a variety of time scales ranging from approximately 1.500 to greater than 10,000 years. Their results, in combination with ongoing paleoseismolgic analyses of these faults by U.S., Turkish, and Japanese researchers, will allow determination of the variability of strain release in time and space within the Anatolia-Eurasia-Arabia plate boundary. These data, in turn, will provide basic constraints necessary for realistic geodynamic models of fault loading mechanisms. Equally importantly, the data from the relatively simple plate boundary in Turkey will provide an important point of comparison with similar data from more mechanically complex plate boundaries (e. g., the Pacific-North America plate boundary in California).

研究团队正在研究时间和空间中故障负载和应变释放率在多大程度上是恒定（或非恒定）的程度。他们在解决这个根本重要问题上的工作重点是在各种时间尺度上产生断层滑移率，这是土耳其北部和东安纳托利亚断层的长期。这些断层是拟议研究的特别有吸引力的目标，因为土耳其的Anatolia-Eurasia-Arabia板块边界具有相对的结构简单性。具体而言，地质和地质数据表明，在土耳其中部和东部，几乎所有板块边界应变都是通过这两个断层的滑动来容纳的。研究人员将精力集中在越来越多的观察时间尺度上 - 历史和古质量数据记录的时间不规则的应变释放之间的时间范围，以及更长的时间尺度，而断层滑移速率似乎相对恒定。通过使用偏移地态特征的宇宙基因核素日期，这种技术得出的技术持续时间是，地球表面的地貌表面已暴露于宇宙射线，它们将确定沿着这两种故障的八个或更多位置的滑移速率时间尺度的范围从约1.500到10，000年不等。它们的结果以及对美国，土耳其和日本研究人员对这些断层进行的古sismismolgic分析，将允许确定Anatolia-eurasia-Arabia-Arabia板块边界内的时间和空间中应变释放的变异性。这些数据反过来将为故障负载机制的现实地球动力学模型提供必要的基本约束。同样重要的是，来自土耳其相对简单的板边界的数据将与来自更复杂的板界边界的相似数据（例如，加利福尼亚州的Pacific-North America Plate边界）提供重要的比较点。