Tsunami. The Earth's lithosphere is broken up into a bunch of discrete pieces, called plates that move around the surface of the planet. There. Global Disaster Management: Tsunamis Tsunamis are ocean waves triggered by large earthquakes that occur near or under the ocean. A tsunami can kill or injure people and damage or destroy buildings and infrastructure as waves come in and go out. A tsunami is a series of enormous ocean.


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Analysis of the effects of shallow and deep underwater explosions indicate that the energy of the explosions doesn't easily generate the kind of deep, all-ocean waveforms which are tsunamis; most of the energy creates steam, causes vertical fountains above the water, and creates compressional waveforms.

Characteristics When the wave enters shallow water, it slows down and its amplitude height increases. The wave further slows and amplifies as it hits land. Only the largest waves crest. Tsunamis cause damage by two mechanisms: This is the formula used for calculating the velocity of shallow-water waves.

Even the deep ocean is shallow in this sense because a tsunami wave is so long horizontally from crest to crest by comparison. The reason for the Japanese name "harbour wave" is that sometimes a village's fishermen would sail out, and encounter no unusual waves while out at sea fishing, and come back to land to find their village devastated by a huge wave.

Since the wave still has the same very long periodthe tsunami may take minutes to reach full height. Except for the very largest tsunamis, the approaching wave does not breakbut rather appears like a fast-moving tidal bore. When the tsunami's wave peak reaches the shore, the resulting temporary rise in sea level is termed run up.

Run up is measured in metres above a reference sea level. The first disaster management tsunami to reach the shore may not have the highest run-up. They are caused by earthquakes, landslides, volcanic explosions, glacier calvings, and bolides.


Drawback An illustration of the rhythmic "drawback" of surface water associated with a wave. It disaster management tsunami that a very large drawback may herald the arrival of a very large wave.

All waves have a positive and negative peak; that is, a ridge and a trough.

Major Areas :: Disaster Management :: Tsunami

In the case of a propagating wave like a tsunami, either may be the first to arrive. If the first part to arrive at the shore is the ridge, a massive breaking wave or sudden flooding will be the first effect noticed on land.

However, if the first part to arrive is a trough, a drawback will occur as the shoreline disaster management tsunami dramatically, disaster management tsunami normally submerged areas. The drawback can exceed hundreds of metres, and people unaware of the danger sometimes remain near the shore to satisfy their curiosity or to collect fish from the exposed seabed.


A typical wave period for a damaging tsunami is about twelve minutes. Thus, the sea recedes in the drawback phase, with areas well below sea level exposed after disaster management tsunami minutes.

Tsunami | Global Disaster Preparedness Center

For the next six minutes, the wave trough builds into a ridge which may flood the coast, and destruction ensues. During the next six minutes, the wave changes from a ridge to disaster management tsunami trough, and the flood waters recede in a second drawback.

Victims and debris may be swept into the ocean.

Marking items and filing cabinets to distinguish which are top priority to be removed first after a tsunami subsides or prior to a disaster management tsunami striking, if adequate warning time is given. Planning with local authorities if their business has the potential to leak hazardous disaster management tsunami into the environment during and after a tsunami.


Community Organization By educating residents on when and how to evacuate for tsunamis, disaster management tsunami local government to be prepared to coordinate and mobilize the evacuations and generating awareness of safe community development practices to lessen the destruction caused disaster management tsunami tsunamis, community organization plays a critical role in increasing community resilience to a tsunami.

While every community may need a different approach when preparing for a tsunami, below are some basic steps that can be taken by community organizers to promote tsunami awareness.

What does "tsunami" mean?

Learn disaster management tsunami basics of tsunami behavior and promote educational awareness. Organize your efforts based on what your community needs are and on the partners and resources that are available to help.

Make hazard and evacuation maps to guide all your tsunami preparedness efforts.