Elastic oscillations of water column in the 2003 Tokachi-oki tsunami source: in-situ measurements and 3-D numerical modelling
Elastic oscillations of water column in the 2003 Tokachi-oki tsunami source: in-situ measurements and 3-D numerical modelling
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DOI：
10.5194/nhess-7-243-2007
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发表时间：
2007-01-01
影响因子：
4.6
通讯作者：
Kolesov, S. V.
中科院分区：
文献类型：
--
作者：
Nosov, M. A.;Kolesov, S. V.
在2003年的Tokachi-Oki海啸性地震期间，JAMSTEC实时观测站获得了记录，为深入了解海啸源提供了独特的机会。考虑到水柱是一种可压缩介质，我们对井底压力记录进行了处理，以估计井底位移的幅值、持续时间和速度。谱分析显示了水柱低频弹性振荡的明显表现。为了更好地理解海啸震源的动力过程，我们还提出了在理想可压缩流体线性势理论框架下建立的三维有限差分数值模型。该模型较准确地再现了主谱极大值的位置。然而，由于对地壳弹性的忽略和对海底运动时空规律的缺乏准确认识，使得现场观测光谱与计算光谱存在本质差异。
During the 2003 Tokachi-Oki tsunamigenic earthquake the real-time JAMSTEC observatory obtained records which provided a unique opportunity to have a look deep inside the tsunami source. Considering water column as a compressible medium we processed the bottom pressure records in order to estimate amplitude, duration and velocity of bottom displacement. Spectral analysis of the records revealed a clear manifestation of the low-frequency elastic oscillations of water column. We also presented 3-D finite-difference numerical model developed in the framework of linear potential theory of ideal compressible fluid to better understand dynamical processes in the tsunami source. The model reproduces position of the main spectral maximum rather correctly. However, due to neglecting of crust elasticity and to lack of exact knowledge of spatiotemporal laws of bottom motion, there is an essential difference between in-situ observed and computed spectra.