A multidimension source model for generating broadband ground motions with deterministic 3D numerical simulations is proposed in this article. In this model, the source is composed of several superimposed layers, and the total seismic moment is assigned to these layers in different proportions. Each layer exactly fills up the seismic fault and is uniformly divided into subsources with size decreased progressively to reflect different levels of rupture details. Hence, the proposed multidimension source model may consider the realistic rupture process of an earthquake, that is, the spatial and temporal heterogeneity of source parameters, and generate broadband ground motions. To verify this source model, the 1994 Northridge earthquake is simulated with four multidimension source models, based on different source inversion results. The amplitudes, durations, and spectral characteristics of the observed ground motions of the 1994 Northridge earthquake are respectably reproduced in a range of frequencies up to 5 Hz. In addition, a scenario earthquake is also simulated with four multidimension source models, with different synthetic rupture process. The simulated ground motions of the scenario earthquake are generally in good agreement with the Next Generation Attenuation‐West 2 ground‐motion prediction equations. This demonstrates that it is promising to simulate realistic broadband ground motions of strong earthquakes with a proper source description and realistic Earth models.

中文翻译：

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具有确定性3D数值模拟的生成宽带地面运动的多维源模型

本文提出了使用确定性3D数值模拟生成宽带地面运动的多维源模型。在此模型中，震源由几个叠加层组成，总地震矩按不同比例分配给这些层。每层精确地填满了地震断层，并被均匀地划分为子源，其大小逐渐减小以反映不同级别的破裂细节。因此，提出的多维震源模型可以考虑地震的真实破裂过程，即震源参数的时空异质性，并产生宽带地震动。为了验证该震源模型，根据不同的震源反演结果，使用四个多维震源模型对1994年的Northridge地震进行了模拟。振幅 在高达5 Hz的频率范围内，均能再现1994年Northridge地震的持续时间和观测到的地震动的频谱特征。此外，还用四个多维震源模型模拟了情景地震，并采用了不同的合成破裂过程。场景地震的模拟地面运动通常与“下一代衰减-西部2”地面运动预测方程式非常吻合。这表明用适当的震源描述和真实的地球模型模拟现实的强地震宽带地面运动是有希望的。还用四个多维震源模型模拟了一个情景地震，具有不同的合成破裂过程。场景地震的模拟地面运动通常与“下一代衰减-西部2”地面运动预测方程式非常吻合。这表明用适当的震源描述和真实的地球模型模拟现实的强地震宽带地面运动是有希望的。还用四个多维震源模型模拟了一个情景地震，具有不同的合成破裂过程。场景地震的模拟地面运动通常与“下一代衰减-西部2”地面运动预测方程式非常吻合。这表明用适当的震源描述和真实的地球模型模拟现实的强地震宽带地面运动是有希望的。