The motion of conductive seawater by tsunamis can generate magnetic fields in the presence of the background geomagnetic main field. Previous studies found that, using the tsunami-generated seafloor magnetic field, it is possible to predict the propagation direction and wave height prior to the actual arrivals of tsunamis. This study correlates the tsunami magnetic field and the tsunami sea level change using observed data and three-dimensional simulations of the 2009 Samoa and 2010 Chile tsunamis. Our direct comparison of the tsunami observed magnetic field and tsunami sea level change illustrate that the vertical tsunami magnetic component, , arrived earlier than the sea level change. The “initial rise” signal in the observed horizontal tsunami magnetic component, , which was arrived even earlier than also is found by combing the observation with the three-dimensional simulations. We further examine the precision of conversion of the tsunami magnetic field to the sea level change and find that the magnetic field derived tsunami sea levels are as precise as those obtained from differential pressure gauge data. However, our simulation shows that existing tsunami source models are incompatible with our tsunami magnetic data. Therefore, it is necessary to include magnetic field derived tsunami sea level changes to improve those source models.

中文翻译：

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2009 年萨摩亚和 2010 年智利海啸海啸产生的磁场与海平面变化的直接比较

在存在背景地磁主场的情况下，海啸引起的导电海水的运动会产生磁场。之前的研究发现，利用海啸产生的海底磁场，可以在海啸实际到来之前预测传播方向和波高。本研究使用 2009 年萨摩亚和 2010 年智利海啸的观测数据和三维模拟，将海啸磁场与海啸海平面变化相关联。我们对海啸观测磁场和海啸海平面变化的直接比较表明，垂直海啸磁场分量比海平面变化更早到达。观测到的水平海啸磁分量中的“初始上升”信号，甚至早于也可以通过将观察与三维模拟相结合来发现。我们进一步检查了海啸磁场转换为海平面变化的精度，发现磁场导出的海啸海平面与差压计数据获得的磁场一样精确。然而，我们的模拟表明，现有的海啸源模型与我们的海啸磁数据不兼容。因此，有必要包括磁场衍生的海啸海平面变化以改进这些源模型。