发表机构
University of Rhode Island（罗德岛大学）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究通过场地地球物理表征和台阵观测，揭示纽约州两个强震动台站的地面运动残差分别由深层沉积共振（0.93赫兹）和地形放大（约2赫兹）主导，为解释强震动异常提供了物理机制。
AI 中文摘要
美国中部和东部地区设有强震动台站的场地通常使用基于代理的参数进行表征，这限制了对大地面运动残差物理成因的识别能力。本研究调查了纽约州两个强震动台站的放大机制，这两个台站在2024年新泽西州特克斯伯里Mw 4.8地震期间记录到了一些最大的正1赫兹伪谱加速度残差。台站N4.N62A位于大西洋沿岸平原的考姆塞特州立历史公园，而台站this http URL位于帕利塞兹悬崖顶部的拉蒙特-多尔蒂地球观测站。两个场地的详细地球物理场地表征结合了主动源和被动源面波测试以及HVSR测量。在拉蒙特-多尔蒂，额外部署了跨帕利塞兹山脊的被动源台阵以评估地形放大。在考姆塞特，面波测试解析了覆盖在主要阻抗对比之上的厚沉积柱，其空间代表性的基阶场地频率为0.93赫兹。相同频率范围内的放大也独立地体现在由站点间（S2S）残差计算得到的观测放大中。基阶共振频带也包含了观测到特克斯伯里大残差的1赫兹频率，支持深层沉积共振作为主导机制。在拉蒙特-多尔蒂，面波测试表明为硬岩条件，具有薄且横向变化的沉积覆盖层。被动源台阵显示在this http URL处约2赫兹附近存在可重复的方向性放大，而基于地震的S2S放大显示在约0.6至2赫兹之间存在峰值，这一模式既未被传递函数也未被遍历线性放大模型重现。这些观测支持地形放大作为this http URL处的主要机制。
英文摘要
Sites hosting strong-motion stations in the Central and Eastern United States are commonly characterized using proxy-based parameters, limiting the ability to identify the physical causes of large ground-motion residuals. This study investigates the amplification mechanisms at two New York strong-motion stations that recorded some of the largest positive 1-Hz pseudospectral-acceleration residuals during the 2024 Mw 4.8 Tewksbury, New Jersey, earthquake. Station N62A is located at Caumsett State Historic Park in the Atlantic Coastal Plain, whereas station PAL is located at the Lamont-Doherty Earth Observatory atop the Palisades cliffs. Detailed geophysical site characterization at both sites combined active-source and ambient-noise surface-wave testing with HVSR measurements. At Lamont-Doherty, additional ambient-noise arrays were deployed across the Palisades ridge to evaluate topographic amplification. At Caumsett, surface-wave testing resolved a thick sedimentary column overlying a major impedance contrast, with a spatially representative fundamental site frequency of 0.93 Hz. Amplification in the same frequency range was also independently evident in observed amplifications computed from site-to-site (S2S) residuals. The fundamental-resonance band also encompasses the 1-Hz frequency at which the large Tewksbury residual was observed, supporting deep sediment resonance as the dominant mechanism. At Lamont-Doherty, surface-wave testing indicated hard-rock conditions with a thin, laterally variable sediment cover. The ambient-noise arrays showed repeatable, directional amplification near 2 Hz at PAL, and the earthquake-based S2S amplifications show a peak between approximately 0.6 and 2 Hz, a pattern reproduced by neither the transfer functions nor the ergodic linear amplification models. These observations support topographic amplification as the primary mechanism at PAL.
