Acehtsunami

As a tsunami approaches shore, we’ve learned in the “What happens to a tsunami as it move towards to land?” section that it begins to slow and grow in height. Just like other water waves, tsunamis begin to lose energy as they rush onto land — part of the wave energy is reflected offshore, while the shoreward-propagating wave energy is dissipated through bottom friction and confusion. Despite these losses, tsunamis still reach the coast with tremendous amounts of energy. Tsunamis have great erosional potential, stripping beaches of sand that may have taken years to accumulate and undermining trees and other coastal vegetation. Capable of inundate, or flooding, hundreds of meters inland past the typical high-water level, the fast-moving water related with the inundating tsunami can crush homes and other coastal structures. Tsuna-mis may reach a maximum vertical height onshore above sea level, often called a run-up height, of 10, 20, and even 30 meters.