Erratum to: Importance of rheological heterogeneity for interpreting viscoelastic relaxation caused by the 2011 Tohoku-Oki earthquake
Erratum to: Importance of rheological heterogeneity for interpreting viscoelastic relaxation caused by the 2011 Tohoku-Oki earthquake
复制标题
勘误表：流变异质性对于解释 2011 年东北冲地震引起的粘弹性松弛的重要性
DOI：
10.1186/s40623-017-0639-x
复制
发表时间：
2017
期刊：
影响因子：
--
通讯作者：
H. Suito
中科院分区：
文献类型：
--
作者：
H. Suito
本研究使用有限元法开发了三维粘弹性模型，以了解2011年东北冲地震后的震后变形。理解粘弹性介质的哪些元素影响表面变形的问题是特别重要的。我们首先研究了两种不同的粘弹性介质，地幔楔和海洋地幔，产生几乎相反的变形模式的个别影响。地幔楔控制着向东的运动、太平洋沿岸和近海地区的隆升，以及横跨广阔区域的伸展。相反，海洋地幔主要控制近海向西的运动，沉降在一个广泛的地区，周围地区的轻微隆起，和收缩离岸。这些差异是理解俯冲地震引起的粘弹性松弛的最重要的问题。然后，我们开发了四种不同的模型，以澄清哪些元素的粘弹性介质影响所观察到的表面变形。最简单的模型，所有的粘弹性介质的均匀粘度，可以解释水平变形，但不能解释垂直变形。第二个模型，地幔楔和海洋地幔不同的粘度，可以解释陆上观测，但不能解释海底观测。第三个模型，其中包括一个薄的薄弱层下的俯冲板，基本上可以解释近场陆上和海底观测，但不能解释远场数据。最终的深度依赖模型能够解释远场数据以及近场数据。在这些典型的模型中，特别重要的是要考虑地幔楔和大洋地幔之间的不同粘度，并包括板片下的薄的薄弱层，这对海底变形有显着的影响。远场数据以及近场数据也是重要的约束粘弹性结构;前者是敏感的粘弹性松弛在更大的深度。显然，粘弹性松弛本身不能解释所观察到的变形。要建立完整的震后变形模型，必须采用粘弹性和后滑相结合的模型。
This study develops a three-dimensional viscoelastic model using the finite element method to understand the postseismic deformation that followed the 2011 Tohoku-Oki earthquake. The question of understanding which elements of the viscoelastic media affect the surface deformation is of particular importance. We first examined the individual effects of two different viscoelastic media, the mantle wedge and the oceanic mantle, which produce almost opposite deformation patterns. The mantle wedge controls eastward motion, uplift of the Pacific coastal and offshore regions, and extension across a broad area. In contrast, the oceanic mantle controls dominantly offshore westward motion, subsidence across a broad area, minor uplift of the surrounding areas, and contraction offshore. These differences are the most important issues for understanding the viscoelastic relaxation caused by subduction earthquakes. We then developed four different models to clarify which elements of the viscoelastic media affect the observed surface deformation. The simplest model, with uniform viscosity for all viscoelastic media, could explain the horizontal deformation but not the vertical deformation. The second model, with different viscosities for the mantle wedge and the oceanic mantle, could explain the onshore observations but could not explain the seafloor observations. The third model, which includes a thin weak layer beneath the subducting slab, could essentially explain the near-field onshore and seafloor observations but could not explain the far-field data. The final depth-dependent model was able to explain the far-field data as well as the near-field data. In these typical models, it is of particular importance to consider the different viscosities between the mantle wedge and the oceanic mantle and to include a thin weak layer beneath the slab, which has a dramatic impact on the seafloor deformation. Far-field data as well as near-field data are also important for constraining the viscoelastic structure; the former is sensitive to viscoelastic relaxation at greater depths. Clearly, viscoelastic relaxation alone cannot explain the observed deformation. A combined viscoelastic and afterslip model is necessary for constructing a complete postseismic deformation model.