Tsunami waves can continuously flood or inundate low lying coastal areas for hours. Flooding can extend inland by 300 meters (~1000 feet) or more, covering large expanses of land with water and debris. Tsunami inundation is the horizontal, inland penetration of waves from the shoreline.
Inundation distances can vary greatly along the shorelines, depending on the intensity of the tsunami waves, the undersea features, and the land topographic elevations. One coastal community may see no damaging wave activity, while another nearby community can be attacked by large and violent waves. When the tsunami reaches the coast and moves inland, the water level can rise many meters. The first wave may not be the largest in the series of waves.