We image the shallow structure across the East Bench segment of the Wasatch fault system in Salt Lake City using ambient noise recorded by a month‐long temporary linear seismic array of 32 stations. We first extract Rayleigh‐wave signals between 0.4 and 1.1 s period using noise cross correlation. We then apply double beamforming to enhance coherent cross‐correlation signals and at the same time measure frequency‐dependent phase velocities across the array. For each location, based on available dispersion measurements, we perform an uncertainty‐weighted least‐squares inversion to obtain a 1D VS model from the surface to 400 m depth. We put all piece‐wise continuous 1D models together to construct the final 2D VS model. The model reveals high velocities to the east of the Pleistocene Lake Bonneville shoreline reflecting thinner sediments and low velocities particularly in the top 200 m to the west corresponding to the Salt Lake basin sediments. In addition, there is an ∼400‐m‐wide low‐velocity zone that narrows with depth adjacent to the surface trace of the East Bench fault, which we interpret as a fault‐related damage zone. The damage zone is asymmetric, wider on the hanging wall (western) side and with greater velocity reduction. These results provide important constraints on normal‐fault earthquake mechanics, Wasatch fault earthquake behavior, and urban seismic hazard in Salt Lake City.

中文翻译：

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临时线阵环境噪声双波束形成盐湖城Wasatch断层浅层损伤带结构

我们使用由 32 个台站组成的为期一个月的临时线性地震阵列记录的环境噪声对盐湖城瓦萨奇断层系统东台段的浅层结构进行成像。我们首先使用噪声互相关提取 0.4 到 1.1 s 周期之间的瑞利波信号。然后，我们应用双波束成形来增强相干互相关信号，同时测量阵列中与频率相关的相速度。对于每个位置，基于可用的色散测量，我们执行不确定性加权最小二乘反演以获得从地表到 400 m 深度的一维 VS 模型。我们将所有分段连续的 1D 模型放在一起以构建最终的 2D VS 模型。该模型揭示了更新世邦纳维尔湖海岸线以东的高速度，反映了较薄的沉积物和低速度，特别是在与盐湖盆地沉积物相对应的西面 200 m 处。此外，还有一个约 400 米宽的低速带，随着深度靠近东台断层的表面痕迹而变窄，我们将其解释为与断层相关的损坏带。损伤区是不对称的，在上墙（西）侧更宽，速度降低更大。这些结果为盐湖城的正断层地震力学、Wasatch 断层地震行为和城市地震灾害提供了重要的约束。有一个约 400 米宽的低速带，在东台断层的表面痕迹附近随着深度变窄，我们将其解释为与断层相关的损坏带。损伤区是不对称的，在上墙（西）侧更宽，速度降低更大。这些结果为盐湖城的正断层地震力学、Wasatch 断层地震行为和城市地震灾害提供了重要的约束。有一个约 400 米宽的低速带，在东台断层的表面痕迹附近随着深度变窄，我们将其解释为与断层相关的损坏带。损伤区是不对称的，在上墙（西）侧更宽，速度降低更大。这些结果为盐湖城的正断层地震力学、Wasatch 断层地震行为和城市地震灾害提供了重要的约束。