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).

研究小组正在研究断层加载和应变释放率在时间和空间上恒定（或不恒定）的程度。他们在解决这一根本性的重要问题的工作集中在断层滑动率的产生在各种时间尺度上的土耳其北部和东部安纳托利亚断层。由于土耳其安纳托利亚-欧亚-阿拉伯板块边界的结构相对简单，这些断层是特别有吸引力的研究目标。具体而言，大地测量和地质数据表明，在土耳其中部和东部，几乎所有的板块边界应变都是通过这两个断层的滑动来调节的。研究人员正把精力集中在一个越来越重要的观测时间尺度上--历史和古地震数据记录的时间上不规则的应变释放之间的时间范围，以及断层滑动速率相对恒定的更长时间尺度。通过使用偏移地貌特征的宇宙成因核素测年技术（一种产生地貌表面暴露于地球表面宇宙射线的持续时间的技术），他们将确定沿这两个断层沿着的八个或更多地点的滑动速率，时间尺度从大约1500年到超过10,000年不等。他们的结果，结合美国正在进行的这些断层的古地震分析，土耳其和日本的研究人员将能够确定安纳托利亚-欧亚-阿拉伯板块边界内应变释放在时间和空间上的变化。这些数据，反过来，将提供基本的约束条件，为现实的地球动力学模型的故障加载机制。同样重要的是，来自土耳其相对简单的板块边界的数据将提供一个重要的比较点，与来自更复杂的板块边界的类似数据进行比较。例如，在一个实施例中，位于加州的太平洋-北美板块边界）。