Two-dimensional simulations of the tsunami dynamo effect using the finite element method
Two-dimensional simulations of the tsunami dynamo effect using the finite element method
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DOI：
10.1002/grl.50823
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发表时间：
2013-09-16
影响因子：
5.2
通讯作者：
Toh, Hiroaki
中科院分区：
文献类型：
--
作者：
Minami, Takuto;Toh, Hiroaki
导电海水在地磁主磁场中运动，在海洋中产生电动势。这种效应被称为海洋发电机效应。最近，有报道称海啸也与海洋发电机效应有关，并且在海底实际观察到了海啸引起的电磁场变化。例如，我们的研究小组在2011年东北地震时成功地观测到了海啸引起的西北太平洋海底磁场变化。在这项研究中，我们开发了一个时域海啸发电机模拟代码使用有限元方法来解释海啸引起的电磁变化在海底观察。我们的模拟成功地再现了观测到的海底磁场变化高达3nT。它还表明，在海啸到来之前，水平磁分量的初始上升高达1nT是由海啸引起的。
Conductive seawater moving in the geomagnetic main field generates electromotive force in the ocean. This effect is well known as the oceanic dynamo effect. Recently, it has been reported that tsunamis are also associated with the oceanic dynamo effect, and tsunami-induced electromagnetic field variations were actually observed on the seafloor. For instance, our research group succeeded in observing tsunami-induced magnetic variations on the seafloor in the northwest Pacific at the time of the 2011 Tohoku earthquake. In this study, we developed a time domain tsunami dynamo simulation code using the finite element method to explain the tsunami-induced electromagnetic variations observed on the seafloor. Our simulations successfully reproduced the observed seafloor magnetic variations as large as 3nT. It was also revealed that an initial rise in the horizontal magnetic component prior to the tsunami arrival as large as 1nT was induced by the tsunami.