Experimental rock physics: fundamental and applied studies in the laboratory and the field

实验岩石物理学：实验室和现场的基础和应用研究

• 批准号: 41768-2009
• 负责人: Schmitt, Douglas
• 金额: $ 4.23万
• 依托单位: University of Alberta
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2010
• 资助国家: 加拿大
• 起止时间: 2010-01-01 至 2011-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=450843
• 关键词: Experimental; rock; physics; fundamental; applied

Rocks are complex and intriguing materials. In the earth, their physical properties vary with mineral composition, fluid content, tectonic straining, and temperature. Geophysicists probe the earth remotely with seismic and electromagnetic waves; but informed assessments of the field observations require knowledge of the relation between rock properties and in situ conditions. Rock physicists strive to learn more about these relationships and to apply them to field data. The Experimental Geophysics Group led by Dr. Schmitt studies these properties in the laboratory and, uniquely, by field measurements. This research uses tools that range from tiny ultrasonic transducers to large truck mounted seismic energy sources. One problem is that the values of, say, a seismic wave speed given by these varied measurements can be quite different. For example, a seismic wave speed at seismic frequencies will often be substantially less than that obtained using ultrasonic waves. We will address this problem two ways. First, we will constrain this seismic dispersion in the laboratory using 'forced oscillation' methods that will partly employ a new instrument being constructed in our laboratory. Second, we will continue to make fundamental measurements of the behaviour of seismic waves as they travel through a liquid-saturated porous medium in order to test the limits of existing theories. A third component of the research studies the factors controlling the propagation of radar waves that are used to probe near earth structure. This work will be integrated as much as possible with parallel field geophysical studies related to scientific drilling, near-surface hazard characterization, and time-lapse monitoring. Students working in the Experimental Geophysics Group are exposed to a wide range of geoscience problems and all are expected to broaden their exposure by participation in field projects; in the last few years these have ranged over 4 continents and both polar regions.

岩石是复杂而有趣的材料。在地球中，它们的物理性质随矿物成分、流体含量、构造应变和温度而变化。地球物理学家利用地震波和电磁波对地球进行远程探测;但是，对实地观测的知情评估需要了解岩石特性与现场条件之间的关系。岩石物理学家努力了解更多关于这些关系，并将其应用于现场数据。由施密特博士领导的实验地球物理小组在实验室中研究这些特性，并独特地通过实地测量进行研究。这项研究使用的工具范围从微小的超声波换能器到大型卡车安装的地震能源。 一个问题是，由这些不同的测量值给出的地震波速度的值可能是完全不同的。 例如，在地震频率下的地震波速度通常将基本上小于使用超声波获得的地震波速度。我们将从两个方面解决这个问题。首先，我们将在实验室中使用“强迫振荡”方法来限制这种地震频散，该方法将部分采用我们实验室正在建造的新仪器。 其次，我们将继续对地震波在液体饱和多孔介质中传播时的行为进行基本测量，以测试现有理论的局限性。 研究的第三个组成部分研究控制用于探测近地结构的雷达波传播的因素。 这项工作将尽可能与与科学钻探、近地表灾害定性和延时监测有关的并行实地地球物理研究相结合。 在实验地球物理组工作的学生接触到广泛的地球科学问题，所有人都希望通过参与实地项目来扩大他们的曝光;在过去的几年里，这些项目遍布四大洲和两极地区。