How high above normal sea level can tsunami water rise near a coast?

When a tsunami approaches a coast, the interaction between the wave and the rising seafloor causes the wave's velocity to decrease while its amplitude increases significantly. As a result, water can rise as high as 30 meters (about 100 feet) above normal sea level within 10 to 15 minutes.12

In specific geographic features, such as U- and V-shaped harbors and inlets, these waves can occasionally reach heights of 20 to 30 meters above mean sea level. These powerful surges, often referred to as run-ups, are capable of causing catastrophic destruction to low-lying coastal areas by inundating land, uprooting vegetation, and damaging infrastructure.312