Tsunamis. Tsunami refers to a series of enormous waves with long wavelengths and lengthy periods generated in an ocean or a large lake by abrupt vertical movements of the ocean floor that leads to a displacement of a large volume of water within a short time. The name has been derived from the Japanese term 'tsunami,' where 'tsu' means 'port' and 'nami' means 'wave.' Tsunami Types. There are three (3) broad types of tsunamis: Local Tsunami. This is a tsunami where its destructive effects are experienced on coasts within 100 km from the source of the tsunami. In such cases, the travel timefor the tsunami is generally less than one (1) hour. Large tsunamis are significant threats to human health, property, infrastructure, resources, and economies. Effects can be long-lasting, and felt far beyond the coastline. Tsunamis typically cause the most severe damage and casualties near their source, where there is little time for warning. The most common cause of a tsunami is sea floor uplift associated with an earthquake. Tsunamis are also triggered by landslides into or under the water surface, and can be generated by volcanic activity and meteorite impacts. Tsunamis range in size from inches to over a hundred feet. The tsunami on Jan. 15 hit Santa Cruz, California, 12 hours and 12 minutes after the initial eruption in Tonga. Santa Cruz is 5,280 miles (8,528 kilometers) from Tonga, which means that the Essentially, they are dynamically equivalent to seismic tsunamis, the only differences being 1) that meteotsunamis lack the transoceanic reach of significant seismic tsunamis, and 2) that the force that displaces the water is sustained over some length of time such that meteotsunamis cannot be modelled as having been caused instantaneously. CvKF.

2 types of tsunami