地震证据表明,美国西部广泛的深层地变形是由延伸引起的
M P Moschetti1, M H Ritzwoller, F Lin
1Center for Imaging the Earth's Interior, Department of Physics, University of Colorado at Boulder, Campus Box 390, Boulder, Colorado 80309, USA. mmoschetti@usgs.gov
Nature
|April 9, 2010
概括
地球地的地震波速度异构性揭示了广泛的变形. 这项研究将美国西部的深层地的辐射异构性与纪扩展性构造过程联系起来.
科学领域:
- 地质物理学 地质物理学
- 地震学 地震学
- 构造学 构造学 构造学 构造学
背景情况:
- 地球物质中的地震波速度通常是异构的.
- 上层地幔的异质性与来自变形和流动的橄状方位有关.
- 在地的放射性异构性观测是有限的,这阻碍了对地变形的理解.
研究的目的:
- 调查大规模地的辐射异构性.
- 了解地的变形和流动模式.
- 将异构性与美国西部的构造过程联系起来.
主要方法:
- 环境噪声断层扫描在美国西部.
- 对地震波速度变化的分析.
- 异构与地质省份的相关性.
主要成果:
- 检测到强烈的深层 (中至下) -地的辐射异质性.
- 不同向性仅限于中纪的延伸地质省份.
- 巧合表明矿物质的方向来自扩展变形.
结论:
- 在美国西部的深层地的辐射异构性与纪扩展有关.
- 延伸变形可能导致地矿物质的格子偏好方向.
- 在延伸和稀薄过程中支持深层地中广泛,均的应变.
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