The 2018 US Geological Survey National Seismic Hazard Model (NSHM) incorporates new data and updated science to improve the underlying earthquake and ground motion forecasts for the conterminous United States. The NSHM considers many new data and component input models: (1) new earthquakes between 2013 and 2017 and updated earthquake magnitudes for some earlier earthquakes; (2) two updated smoothed seismicity models to forecast earthquake rates; (3) two suites of new central and eastern US (CEUS) ground motion models (GMMs) to translate ground shaking for various earthquake sizes and source-to-site distances considered in the model; (4) two CEUS GMMs for aleatory variability; (5) two CEUS site-effect models that modify ground shaking based on alternative shallow site conditions; (6) more advanced western US (WUS) lithologic and structural information to assess basin site effects for selected urban regions; and (7) a more comprehensive range of outputs (22 periods and 8 site classes) than in previous versions of the NSHMs. Each of these new datasets and models produces changes in the probabilistic ground shaking levels that are spatially and statistically analyzed. Recent earthquakes or changes to some older earthquake magnitudes and locations mostly result in probabilistic ground shaking levels that are similar to previous models, but local changes can reach up to +80% and −60% compared to the 2014 model. Newly developed CEUS models for GMMs, aleatory variability, and site effects cause overall changes up to ±64%. The addition of the WUS basin amplifications causes changes of up to +60% at longer periods for sites overlying deep soft soils. Across the conterminous United States, the hazard changes in the model are mainly caused by new GMMs in the CEUS, by sedimentary basin effects for long periods (≥1 s) in the WUS, and by seismicity changes for short (0.2 s) and long (1 s) periods for both areas.

2018年美国地质调查局国家地震灾害模型（NSHM）结合了新的数据和更新的科学知识，以改善美国本土的潜在地震和地面运动预报。NSHM考虑了许多新的数据和成分输入模型：（1）2013年至2017年之间的新地震以及某些早期地震的更新地震震级；（2）两种更新的平滑地震模型来预测地震发生率；（3）两套新的美国中部和东部（CEUS）地面运动模型（GMM），用于转换模型中考虑的各种地震规模和震源到站点距离的地震动；（4）两个CEUS GMM用于偶然性变异；（5）两个CEUS场地效应模型，它们根据替代性浅场地条件修改地面震动；（6）更先进的美国西部（WUS）岩性和构造信息，以评估选定城市地区的流域场地影响；（7）比以前版本的NSHM更全面的输出范围（22个周期和8个站点类别）。这些新的数据集和模型中的每一个都会产生概率性地震动水平的变化，这些变化会在空间和统计上进行分析。最近的地震或某些较早的地震震级和震级的变化大多会导致概率地震动水平与以前的模型相似，但与2014年的模型相比，局部变化可能高达+ 80％和-60％。最新开发的针对GMM的CEUS模型，偶然性变异和部位效应导致整体变化高达±64％。WUS盆地放大的增加导致深层软土上覆的站点在更长的时期内最多可发生+ 60％的变化。在整个美国范围内，该模型的危害变化主要是由CEUS中的新GMM，WUS中长期（≥1 s）的沉积盆地影响以及短期（0.2 s）和长期的地震变化引起的。两个区域的持续时间为（1 s）。