Accurate Three Dimensional Calculations for Advancing Slip Zones in the Earth's Crust

精确的三维计算以推进地壳中的滑移带

• 批准号: 8707392
• 负责人: John Rudnicki
• 金额: $ 17.76万
• 依托单位: Northwestern University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1988
• 资助国家: 美国
• 起止时间: 1988-02-01 至 1991-10-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=8707392&HistoricalAwards=false
• 关键词: Accurate; Three; Dimensional; Calculations; Advancing

An accurate and efficient method for the three-dimensional analysis of cracks in elastic solids is applied to the study of quasi-statically advancing slip zones in the earth's crust. Calculations are done to determine stresses and surface deformations due to the advance of shear faults into and around locked, or more resistant, portions of the shallow crust. Of particular interest are conditions for which non-uniformities in the advancing front are unstable, in the sense that they give rise to rapid spontaneous propagation of slip, and conditions that may distinguish small from large earthquakes. These calculations also make it possible to relate measurements of surface deformation to increases in seismicity that may be triggered by the elevation of stresses that accompanies slip zone advance. Other effects considered are the possibility of breakout at the free surface and the coupling of normal and shear stress due to the presence of the free surface. Initial studies will be for strike-slip geometries for possible application to the Parkfield region of southern California, but the versatility of the method allows study of thrust-faults, as well.

一种精确有效的弹性固体裂纹三维分析方法应用于地壳中准静态前进滑移区的研究。 进行计算以确定由于剪切断层推进到浅地壳的锁定部分或更具抵抗力的部分及其周围而产生的应力和表面变形。 特别令人感兴趣的是前进锋中的不均匀性不稳定的条件，即它们引起滑移的快速自发传播，以及可以区分小地震和大地震的条件。 这些计算还使得将表面变形的测量与地震活动性的增加联系起来成为可能，地震活动性的增加可能是由伴随滑移带前进的应力升高而触发的。 考虑的其他影响包括自由表面破裂的可能性以及由于自由表面的存在而导致的法向应力和剪切应力的耦合。 初步研究将针对可能应用于南加州帕克菲尔德地区的走滑几何形状，但该方法的多功能性也允许研究逆冲断层。