In Situ Measurements of the Mechanical Properties of Active Fault Zones

9804834 Agnew该基金将支持对活动断层带（加州南部的圣安德烈亚斯断层）的力学性质进行现场测量。 测量是使用长基线激光应变计测量断层带内的地球潮汐，并与均匀地球的潮汐进行比较。 潮汐的测量值和预测值之间的差异表明，断层带的弹性特性与其周围的物质不同。该项目最初得到了英国国家海洋局仪器和设施部门的支持，该部门支持建造用于测量潮汐的“便携式”应变仪。 第一次安装显示出潮汐变形的明显证据;目前的赠款是将应变计重新安置到一个新的方位角，以便确定完整的应变张量，并更好地约束断层带弹性性质的性质。

9804834AgnewThis grant will support in situ measurements of the mechanical properties of an active fault zone (the San Andreas fault in southern California). The measurements are made using a long-base laser strainemeter to measure the earth tides inside the fault zone, which are compared against the tides expected for a homogeneous Earth. Differences between the measured and predicted tides indicate that the fault zone has different elastic properties than the material around it. This project was originally supported by EAR Instruments and Facilities, which supported construction of a "portable" strainmeter for measuring tides. This first installation showed clear evidence of tidal distortion; the present grant is to relocate the strainmeter to a new azimuth, so as to determine the full strain tensor and better constrain the nature of the fault zone elastic properties.