Seismic Daylight Imaging: A New Passive-Seismic Method to Image Basin and Crustal Structure

提案EAR0106693摘要（PH # 21x）标题：“地震日光成像：一种用于盆地和地壳结构成像的新型被动地震方法”PI：Klemperer和Claerbout，斯坦福大学。我们正在开发一种新的被动地震成像技术，我们称之为“地震日光成像”（SDI），并将测试其对加州圣弗朗西斯科海湾地区的圣克拉拉山谷下的盆地和地壳结构成像的能力。 我们希望SDI可以补充更昂贵的有源（即，通常是小型炸药爆炸）地震成像，甚至可能在建筑物密度和文化噪音极大而无法使用传统有源方法的情况下取代有源射击。 我们将产生圣克拉拉山谷下地壳结构的地震图像，类似于主动源地震勘探产生的图像，但分辨率较低。 因此，我们将通过描绘重要的地壳结构，如中地壳碎屑和沉积盆地深度，来增加对加州中部构造的现有认识。 我们还将通过限制盆地深度和速度剖面来改善圣克拉拉山谷地震危险的小区划。SDI是一个相对简单但耗时的过程。 利用圣克拉拉谷地震实验（SCVSE）最近获得的现有数据，将从垂直通道开始，一小时一次对整个数据集的地震道进行互相关，并进行叠加。 互相关将产生一个虚拟地震炮记录的立方体，然后将其偏移以产生圣克拉拉谷下方地壳结构的三维地震图像。 我们的SDI图像将与美国地质勘探局最近在同一地区进行的线性高分辨率有源地震勘探进行比较。

Abstract for proposal EAR0106693 (PH # 21x)Title: "Seismic Daylight Imaging: A new passive-seismic method to image basin and crustal structure" PI's: Klemperer and Claerbout, Stanford Univ.We are developing a new passive-seismic imaging technique that we call "Seismic Daylight Imaging" (SDI), and will test its ability to image basin and crustal structure beneath the San Clara Valley in the San Francisco Bay area, California. We hope SDI can supplement more costly active-source (i.e., typically small dynamite explosions) seismic imaging, and even possibly supplant active-source shooting in cases where extreme building density and cultural noise precludes the traditional active-source methodology. We will produce a seismic image of the crustal structure beneath the Santa Clara Valley, similar to one produced by an active-source seismic survey, but with less resolution. Thus we will add to existing knowledge of central California tectonics by delineating important crustal structures such as midcrustal detachments and sedimentary basin depths. We will also improve microzonation of earthquake hazards in Santa Clara Valley by constraining basin depths and velocity profiles.SDI is a relatively simple, but time consuming process. Using existing data recently acquired in the Santa Clara Valley Seismic Experiment (SCVSE), seismic traces from the entire data set will be cross-correlated, one hour at a time, beginning with the vertical channel, and stacked. The cross-correlations will result in a cube of virtual seismic shot records, which will then be migrated to produce a 3-D seismic image of crustal structure beneath the Santa Clara Valley. Our SDI image will be compared with a linear high-resolution active-source seismic survey that has recently been conducted by the USGS in the same area.