Earthquake is one of the most important natural events. There are lots of earthquake researches to learn more about the earthquakes and to mitigate its harmful results. Paleoseismology is the only way to define the paleoearthquakes and to guess the possibilities for the future destructive events. But in many cases, paleoearthquake is interpreted without a proper understanding of the relationship between its size and results. To do so, stratigraphic evidences which are the mimics of the geology is used to investigate the large earthquakes during the trenching. When the stratigraphic evidences are issued, the question comes out; What kinds of features can be applicable to decide the past earthquakes and what is their reliability? This book gives the chance for reader to learn about the mimics of the geology to attain the evidences of paleoearthquakes during the application of trenching. Moreover, trenching steps and case studies from Japan are explained for the procedure. It is also essential reading for advanced undergraduate students and graduate earth scientists interested in paleoseismology.