An Integrated Approach to Monitoring and Interpreting Ground Deformation at the Currently Active Hengill Volcanic System in Southwest Iceland, Using GIS to Analyze GPS, Seismic

监测和解释冰岛西南部当前活跃的亨吉尔火山系统地面变形的综合方法，使用 GIS 分析 GPS、地震

• 批准号: 9901486
• 负责人: Amy Clifton
• 金额: $ 7.2万
• 依托单位: Fellowships
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-01-01 至 2003-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9901486&HistoricalAwards=false
• 关键词: Integrated; Approach; Monitoring; Interpreting; Ground

9901486CliftonThe goal of the research is to quantify the evolution of fracture systems in oblique rift zones using a combination of measurements from scaled clay analog models and field data to determine length-frequency distribution, spatial distribution, geometry, linkage and, connectivity of fractures. Numerous studies conducted during the past 10 years have led to a new and better understanding of how faults grow and how fault populations evolve in extensional tectonic settings. In rifts that are highly oblique to the spreading, whereas in rifts of less obliquity spreading perpendicular faults make a greater contribution to strain accommodation. Scaled physical models are ideal for time-series analysis that can reveal the temporal and spatial evolution of fault systems. Analog models have charted the evolution of rift sub-parallel and spreading perpendicular fractures. The field area selected for study of oblique rifting is the Reykjanes fissure swarm on the Reykjanes Peninsula in Iceland. This first on-shore segment of the Mid-Atlantic Ridge consists of four en echelon fissure swarms. The models represent distributed brittle deformation above a narrow discontinuity that deforms continuously, analogous to the deformation on the peninsula which comprises normal faults, opening mode fissures, and dike-induced grabens narrowly distributed over a volcanic system. Using a combination of field data and data obtained from air photos, the investigator will deduce a temporal evolution similar to what is seen in clay models by analyzing fractures in lava flows of different ages.

研究的目标是通过结合黏土模拟模型和现场数据的测量，量化斜裂带裂缝系统的演化，以确定裂缝的长度-频率分布、空间分布、几何形状、连接和连通性。在过去10年中进行的大量研究使人们对伸展构造背景下断层如何生长和断层群如何演化有了新的更好的理解。在高度斜向扩展的裂谷中，垂直断层对应变调节的贡献更大，而在倾角较小的扩展裂谷中，垂直断层对应变调节的贡献更大。比例物理模型是时间序列分析的理想选择，可以揭示断层系统的时空演化。模拟模型绘制了裂谷次平行裂缝和扩展垂直裂缝的演化图。研究斜裂作用的野外区域是冰岛雷克雅内斯半岛的雷克雅内斯裂缝群。这是大西洋中脊的第一个岸上部分，由四个雁梯形裂缝群组成。这些模型代表了连续变形的狭窄不连续面的分布脆性变形，类似于半岛上由正断层、张开型裂缝和狭窄分布在火山系统上的脉生地堑组成的变形。结合现场数据和航空照片，研究人员将通过分析不同年龄熔岩流的裂缝，推断出与粘土模型相似的时间演变。