Study of great earthquakes by means of satellite altimetry and Synthetic aperture radar.

1.利用JMA区域数值模式进行了SAR数据差分干涉测量中气象干扰的消除研究。这项技术使我们能够利用ERS-1卫星雷达干涉仪探测朝鲜半岛西海岸的长波起伏条纹。虽然得到的干涉图的幅度大于预测值，但其空间分布与黄海内陆挠曲对海潮响应的理论计算结果相似。我们发展了一个公式来计算球状、粘弹性和自引力地球中由点位错引起的重力/大地水准面高度变化和垂直位移。它使我们能够追踪由大地震引起的地壳形变。位于弹性岩石圈的点源的时间演化与位于粘弹性软流圈的点源的时间演化明显不同。作为全球内潮场数值模拟的第一步，利用三维原始方程数值模式研究了北太平洋M2内潮的分布。数值模拟表明，高能内潮在印度尼西亚群岛、所罗门群岛、阿留申群岛以及东中国海的陆架斜坡、伊豆-小川海脊和夏威夷海脊的突出海底地形上产生。特别是，计算的夏威夷海脊周围M2内潮的空间分布与Topex/Poseidon测高得到的结果很好地吻合。

1. We carried out a research to eliminate the meteorological disturbance on the differential interferometry of SAR data by using a JMA regional numerical model. The technique enables us to detect long wavelength undulated fringes at western coast of Korean Peninsula by ERS-1 satellite radar interferometry. Though the amplitude in the derived interferogram is larger than that of prediction, the spatial pattern is similar to the theoretical computation of inland flexural response to the ocean tide in the Yellow Sea.2. We developed a recipe to compute gravity/geoid height change and vertical displacement caused by a point dislocation in a spherical, viscoelastic and self-gravitating earth. It enables us to trace the crustal deformation excited by a great earthquake. Time evolutions for a point source located in the elastic lithosphere is distinctively different from that when a source is in the viscoelastic asthenosphere.3. As a first step toward a numerical modeling of global internal tide field, the distribution of the M2 internal tide in the North Pacific is examined using a three-dimensional primitive equation numerical model. The numerical simulation shows that energetic internal tides are generated over the prominent bottom topographies in the Indonesian Archipelago, the Solomon Archipelago, the Aleutian Archipelago as well as over the continental shelf slope in the East China Sea, the Izu-Ogasawara Ridge and the Hawaiian Ridge. In particular, the calculated spatial distribution of the M2 internal tide around the Hawaiian Ridge agrees very well with that obtained from the Topex/Poseidon altimetry.