海水加载引起的厦门台地倾斜变化

GROUND TILT VARIATION CAUSED BY SEAWATER LOADING AT XIAMEN SEISMOSTATION

根据内海与外海海水加载模型,运用弹性理论定量计算了海水加载引起的厦门台地倾斜变化。结果表明:1)地倾斜对近距离的加载极为敏感,随着观测点与海水距离的增加,加载的影响程度逐渐减弱,超过200 km,其影响可以忽略不计;2)海潮对厦门台地倾斜南北分量的干扰主要是海水的加卸载;而对东西分量的干扰则较为复杂;3)外海与港内湾流对厦门台地倾斜的干扰机制不同:外海的影响主要在幅度方面;而港内湾流则在幅度与相位两方面都有,尤其对后者的干扰更为明显。

On the basis of the seawater loading models of inland and outside sea, the variations of ground tilt caused by sea water loading/unloading at Xiamen seismostation have been calculated quantitatively by applying the elasticity theory. The results show that ： 1 ） the ground tilt at Xiamen seismostation is extremely sensitive to close seawater load, the loading effect disappears gradually with the increase of distance. If the distance exceeds 200 kin,the loading influence can be neglected;2）the disturbance of sea tide on NS component of ground tilt observations at Xiamen seismostation comes from seawater loading and unloading mainly, while on EW component, the disturbance is very complicated;3）the disturbance mechanism outside sea and of gulf flow in harbor affect ground tilt observations at Xiamen seismostation is different, for the former, the effect is on the magnitude mainly; for the later, is both on phase and magnitude, especially the disturbance on phase is more obvious.