Natural Earthquake Laboratory in South African Mines (NELSAM)

南非矿山自然地震实验室 (NELSAM)

• 批准号: 0409605
• 负责人: Ze'ev Reches
• 金额: $ 159.68万
• 依托单位: University of Oklahoma Norman Campus
• 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: 2004-10-01 至 2008-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0409605&HistoricalAwards=false
• 关键词: Natural; Earthquake; Laboratory; South; African

0409605RechesThis is a project to investigate seismogenic processes at the focal-depth of earthquakes. This will be conducted in the deep gold mines of South Africa that offer unique advantages: (1) Mining operations control the location, magnitude and timing of the earthquakes and the investigation can be focused at sites where earthquakes are guaranteed; (2) The mine infrastructure allows access to earthquake-producing faults and permits monitoring fault activity before, during and after earthquakes at distances of 1-100 m from the hypocenter; (3) The size of mine earthquakes (M = 3-4) bridges the gap between the small samples used in the laboratory (M0) and large earthquakes along crustal faults (M6); and (4) The effects of catastrophic earthquakes on subsurface life (microbial ecology) could be monitored. The South African mines are, in essence, a natural earthquake laboratory with opportunities to make fundamental contributions to earthquake science by near-field, three-dimensional monitoring of the earthquake process. There is no other natural environment where this is possible.Specifically, the project will involve: (1) Drilling through three active fault zones at depths of 1.5 - 3.0 km in mines. The faults will be chosen to optimize the structure and seismic activity for research; i.e. they will have a high probability of generating small to moderate earthquakes during the life of the project; (2) A dense array of instruments will be deployed to monitor the three-dimensional, nearfield processes of the earthquakes. The instruments will include seismometers, strainmeters, temperature sensors, displacement-meters, and devices to monitor strong-ground motion, electromagnetic radiation, acoustic emission, and time-variations of microbial communities and fault fluid and gas chemistry; and (3) The physical and chemical conditions of the active faults will be characterized by in-situ stress measurements and 3D mapping, and by extensive chemical and rock mechanics

0409605Rechesthis是一个研究地震焦点的地震生成过程的项目。 这将在南非的深金矿中进行，该矿石具有独特的优势：（1）采矿作业控制地震的位置，大小和时机，调查可以集中在保证地震的地点； （2）矿山基础设施允许访问产生地震的断层，并允许在距离距离距离距离距离1-100 m的距离之前，期间和之后监视断层活动； （3）地震的大小（M = 3-4）弥合了实验室中使用的小样本（M0）和沿着地壳断层（M6）的大地震之间的差距； （4）可以监测灾难性地震对地下寿命（微生物生态学）的影响。 从本质上讲，南非矿山是一家自然地震实验室，有机会通过近场，三维监测地震过程对地震科学做出基本贡献。 没有其他自然环境可以可能。特别是，该项目将涉及：（1）在矿山中以1.5-3.0 km的深度钻探三个活动断层区。 将选择断层以优化研究的结构和地震活性；也就是说，在项目生命的一生中，他们很有可能产生小到中等地震的可能性； （2）将部署一系列密集的工具来监视地震的三维近场进程。 这些仪器将包括地震仪，应变仪，温度传感器，位移计和设备，以监视强域运动，电磁辐射，声发射以及微生物群落以及故障流体和气体化学的时间变化； （3）活动断层的物理和化学条件将以原位应力测量和3D映射为特征，以及广泛的化学和岩石力学