In Situ Measurements of the Mechanical Properties of Active Fault Zones

[804834][译文]这笔拨款将支持对活动断裂带（南加州的圣安德烈亚斯断层）的机械特性进行现场测量。测量是使用长基激光应变仪来测量断层带内的潮汐，并将其与均匀地球的潮汐进行比较。测量到的潮汐和预测到的潮汐之间的差异表明，断裂带与它周围的物质具有不同的弹性特性。这个项目最初是由EAR仪器和设施支持的，它支持建造一个用于测量潮汐的“便携式”应变仪。第一个装置显示了潮汐扭曲的明显证据；目前的授权是将应变计重新定位到一个新的方位，以便确定全应变张量，更好地约束断裂带弹性性质的性质。

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.