A tsunami-proof building is a purposefully designed building which will, through its design integrity, withstand and survive the forces of a tsunami wave or extreme storm surge. It is hydrodynamically shaped to offer protection from high waves. This thus causes the building to be dubbed 'tsunami-proof'. (Full article...)
An impact event is a collision between astronomical objects causing measurable effects. Impact events have been found to regularly occur in planetary systems, though the most frequent involve asteroids, comets or meteoroids and have minimal effect. When large objects impact terrestrial planets such as the Earth, there can be significant physical and biospheric consequences, as the impacting body is usually traveling at several kilometres a second (a minimum of 11.2 km/s (7.0 mi/s) for an Earth impacting body), though atmospheres mitigate many surface impacts through atmospheric entry. Impact craters and structures are dominant landforms on many of the Solar System's solid objects and present the strongest empirical evidence for their frequency and scale. (Full article...)
The following are images from various tsunami-related articles on Wikipedia.
Image 1An illustration of the rhythmic "drawback" of surface water associated with a wave. It follows that a very large drawback may herald the arrival of a very large wave. (from Tsunami)
Image 2Tsunami Early Warning Tower board in Hikkaduwa, Sri Lanka (from Tsunami warning system)