It is not easy to understand the nature of tsunamis because there are many circumstances which affect them. One approach to explain them is as ordinary water waves with lengths of hundreds of kilometers. In such an explanation, this depiction may legitimately be fit for tidal waves. Instead of considering them as ordinary, conventional water waves, they may be more similar to the edges of water or solitary waves. The major difficulty is that scientists are exploring not one-dimensional shallow waves, but two-dimensional waves of deep oceans. There is presently continuous research, both hypothetically and experimentally, to comprehend precisely the tsunami generation mechanisms and their behavior. In that sense, tsunami still remains unresolved. This chapter is devoted to deliver modern findings and theories beyond tsunami generation mechanisms.