Strong Ground Motion Inferred from Liquefaction Caused by the 1811–1812 New Madrid, Missouri, Earthquakes
Strong Ground Motion Inferred from Liquefaction Caused by the 1811–1812 New Madrid, Missouri, Earthquakes
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根据 1811 年至 1812 年密苏里州新马德里地震引起的液化推断出强烈的地面运动
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发表时间：
2015
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影响因子：
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通讯作者：
M. Bennett
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作者：
T. Holzer;T. E. Noce;M. Bennett
1811-1812年密苏里州新马德里地震震中区的峰值地面加速度（PGA）由液化推断不大于0.35 g。据推测，1811-1812年，阿肯色州和密苏里州的密西西比河下游流域有11，380平方公里的区域存在液化。PGA是通过将液化概率曲线应用于Obermeier（1989）的详细液化图来推断的，液化概率曲线最初是为液化危险图而开发的。低PGA的推断，因为浅（1.5米深）的地下水位和一个大的矩震级（M7.7）地震假设在分析中。如果假定地下水位深（5.0 m），震级小（M6.8），则推断的最大PGA为1.10 g。这两个推断的PGA值是基于一个假设和约束不良的校正砂老化。如果不假设老化校正，则推断的PGA不大于0.22 g。低PGA值可以用非线性场地响应来解释。研究区土壤的平均VS 30为220±15 m/s。低推断PGA与根据新马德里地震带提出的地震动预测方程估计的PGA值一致，当这些估计值针对非线性土壤场地效应进行校正时。液化概率曲线的这种应用表明了它们在古地震学中的潜在用途。
Peak ground accelerations (PGAs) in the epicentral region of the 1811–1812 New Madrid, Missouri, earthquakes are inferred from liquefaction to have been no greater than ∼0.35 g . PGA is inferred in an 11,380 km2 area in the Lower Mississippi Valley in Arkansas and Missouri where liquefaction was extensive in 1811–1812. PGA was inferred by applying liquefaction probability curves, which were originally developed for liquefaction hazard mapping, to detailed maps of liquefaction by Obermeier (1989). The low PGA is inferred because both a shallow (1.5 m deep) water table and a large moment magnitude ( M 7.7) earthquake were assumed in the analysis. If a deep (5.0 m) water table and a small magnitude ( M 6.8) earthquake are assumed, the maximum inferred PGA is 1.10 g . Both inferred PGA values are based on an assumed and poorly constrained correction for sand aging. If an aging correction is not assumed, then the inferred PGA is no greater than 0.22 g . A low PGA value may be explained by nonlinear site response. Soils in the study area have an average V S 30 of 220±15 m/s. A low inferred PGA is consistent with PGA values estimated from ground‐motion prediction equations that have been proposed for the New Madrid seismic zone when these estimates are corrected for nonlinear soil site effects. This application of liquefaction probability curves demonstrates their potential usefulness in paleoseismology.