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The forearc in Northeast Japan subsided (3–4 mm/year) in the interseismic ~100 years before the 2011 Tohoku earthquake (MW9.1) just like it did during this event. This study attempts to understand the mechanism of the vertical displacement of the forearc during gigantic earthquake cycles via numerical modeling. The results suggest that the interseismic subsidence rate in the forearc increases with the duration of the locking of the asperity of the gigantic earthquake over several hundred years, due to the increasing slip deficit rate on the deeper parts of the plate interface. The increasing slip deficit rate is caused by both the decreasing the shear stress in the shear zone owing to the continuous locking of the asperity and the increasing the mobility of the continental lithosphere owing to the viscoelastic relaxation in the mantle wedge. The deep slip deficit rate extending to ~100 km depth of the plate interface is necessary to explain the observed interseismic forearc subsidence rate. The results also suggest hundreds of years of continuous locking of the asperities of a gigantic earthquake in the western Kuril subduction zone, where fast forearc subsidence has been observed as well., 東北地方太平洋沿岸域が沈降するメカニズムを解明 --超巨大地震サイクル後半の沈降速度の増加--. 京都大学プレスリリース. 2019-04-09.

Using two-dimensional finite element modeling, we reproduced the observed postseismic deformation of the 2011 Tohoku-Oki earthquake. Our model, which accounts for the lithosphere-asthenosphere boundary and weak zones beneath volcanoes, was able to reproduce small-scale (

In order to improve the cutting ability of fine-grain abrasive stone, the relation between the cutting mechanism in the superfinish and the working condition of superfinish has been investigated. Thus, the following results are obtained. As to the cutting motion in the superfinish, it is found that the frequency of stone oscillation has an upmost influence to the cutting mechanism among the various conditions of cutting motion, secondly the surface speed of work and amplitude of stone oscillation influence in same order to the cutting mechanism. When the superfinishing fluid (mixture of kerosene and oil) of higher viscosity is prefered, it is necessary to increase the cutting direction angle in order to get the most efficient condition of cutting performance. In addition, the characteristics of honing process may be classified into "cutting", "semicutting" and "mirror-finishing" according to the values of stone pressure and cutting direction angle.