An upheaval of the ground occurred with this earthquake from the Boso Peninsula to the coast of Sagami Bay. This upheaval is thought to have reached about 5 m at its highest point. The volume of this upheaval was the greatest on the Boso Peninsula (Fig.5-17). There is a coastal terrace on this peninsula that is thought to have been created by the upheaval of the seashore with this earthquake. Four levels of coastal terraces have been created in about 6,000 years, including this terrace. Other earthquakes that caused an uplift of the seashore in the same manner as the Genroku Earthquake are thought to have occurred in the past (Fig.5-18, Fig.5-19).
Both the Genroku Earthquake and the 1923 Kanto Earthquake were great earthquakes of M 8 that occurred along the Sagami Trough. These earthquakes resemble each other in the extent of the damage caused and the conditions of the crustal deformation. Both earthquakes are thought to have occurred in the same location or very near to each other. The extent of the damage and the crustal deformation on the Boso Peninsula was greater during the Genroku Earthquake, however, and the tsunami during that earthquake reached as far as the Sotobo area. Therefore, the source region of the Genroku earthquake is thought to have extended closer to the Boso Peninsula than that of the Kanto earthquake.