Tsunami generated by rapidly changing gravity field

2010年智利地震的断层模型引起的大地水准面变化是在震中附近几厘米处，而不是大海啸的起因。2010年智利和2011年东北冲地震海啸穿越太平洋的时间比预测时间延迟了20分钟，这是由于海水的可压缩性、固体地球的弹性以及海啸传播过程中与质量运动相关的地势变化引起的长周期海啸的异常分散。考虑长周期海啸速度降低后，计算的远距离位置海啸波形与观测波形吻合较好，传播时间延迟消失。

Geoid change by the mass re-distribution caused by the fault model of the 2010 Chilean earthquake is a few cm near the epicenter and not the cause of the large tsunamis. 20 min delay of the 2010 Chilean and the 2011 Tohoku-Oki earthquakes tsunami traveltime across the Pacific relative to the predicted time was due to anomalous dispersion of long-period tsunami caused by the compressibility of seawater, the elasticity of the solid earth, and the geo-potential change associated with mass motion during tsunami propagation. The computed tsunami waveform at distant locations taking into account the tsunami velocity reduction at long-period shows good agreement with the observed waveform and the traveltime delay has disappeared.