Seismic Attenuation at High Frequencies in Southern California from Coda Waves Recorded at Depth at Cajon Pass, California

9418754阿伯克龙比这项研究是利用在卡洪山口井记录的地震数据来研究散射和本征地震衰减的深度和频率依赖性。以前大多数将散射与本征衰减分开的研究都假定它们在半空间中是恒定的。然而，最近的研究表明，在2.5公里深处，Qs至少比地表研究预测的高出100倍。将研究对地表低Q层尾波的影响，以及与脆韧性转变相关的衰减的深度变化。这些结果将应用于地震前Q变化的研究和震源研究中使用的路径校正。这项研究是国家减少地震灾害计划的一部分。*？？

9418754 Abercrombie This research is to investigate both the depth and frequency dependence of both scattering and intrinsic seismic attenuation using seismic data recorded at the Cajon Pass borehole. Most of the previous studies separating scattering from intrinsic attenuation assumed that they are constant throughout the half space. However, recent work indicates that at least Qs is about 100 times higher at 2.5 km depth than surface studies have predicted. Effects on coda waves of a low Q layer at the surface and also depth variations of attenuation associated with the brittle-ductile transition will be investigated. The results will apply to studies of variations of Q before earthquakes and to path corrections used in earthquake source studies. This research is a component of the National Earthquake Hazard Reduction Program. *** ??