Tsunami

Made By:- Poorva Priyadarshini

B.Arch 5th yr (ar)

What is a tsunami? Tsunami is the Japanese name given to large waves that sometimes devastated the shores and ports of Japan. A tsunami is a wave in the ocean but it is very different to normal waves. Tsunamis have very long wavelengths. Crest to crest they measure between 10 and 500 km and they travel through the ocean at more than 700 km/h. Sometimes there appears to be just one wave but often there are multiple waves travelling a few minutes apart.

Causes of Tsunami

• Earthquake

• Volcanoes

• Underwater explosions

• Meteorite impacts

Facts about Tsunami • Before tsunami hits the water along the shoreline recedes

dramatically, exposing normally submerged areas.

• A tsunami may be less than a foot (30 cms) in height on the surface of the open ocean which is why they go unnoticed. But powerful shock waves of energy travel rapidly through the ocean. Once a tsunami reaches shallow water near the coast, it is slowed down. The top of the wave moves faster than the bottom, causing the sea to rise dramatically.

• Geological features such as reefs, bays, river entrances, and undersea formations may dissipate the energy of a tsunami. In some places a tsunami may cause the sea to rise vertically only a few inches or feet.

• Flooding can extend inland by a thousand feet

(300 meters) or more. • The 2004 Indian Ocean tsunami could rank as the most devastating on record. More than 200,000 people lost their lives, many of them washed out to sea.

Warning signals • An earthquake is a natural tsunami warning. If you feel a strong

quake do not stay in a place where you are exposed to a tsunami.

• Witnesses have reported that an approaching tsunami is sometimes preceded by a noticeable fall or rise in the water level.

• Many people were killed by the Indian Ocean tsunami because they went down to the beach to view the retreating ocean exposing the seafloor. Experts believe that a receding ocean may give people as much as five minutes' warning to evacuate the area.

• A tsunami surge may be small at one point of the shore and large at another point a short distance away. Do not assume that because there is minimal sign of a tsunami in one place it will be like that everywhere else. • Tsunamis can travel up rivers and streams that lead to the ocean. Stay away from rivers and streams that lead to the ocean as you would stay away from the beach and ocean if there is a tsunami. • It's always a good idea to keep a store of emergency supplies that include sufficient medications, water, and other essentials sufficient for at least 72 hours.

How to protect your

property ?

• Avoid building or living in buildings within several hundred feet of the coastline.

• Make a list of items to bring inside in the event of a tsunami.

• Elevate coastal homes.

• Follow flood preparedness precautions. Tsunamis are large amounts of water that crash onto the coastline, creating floods.

• Have an engineer check your home and advise about ways to make it more resistant to tsunami water.

What to do after a Tsunami ? • Help injured people.

• Use telephone for emergency calls only.

• Stay out of building if water remains around it.

• Examine walls, doors, windows, staircases etc to make sure that the building is not collapsing.

• Inspect foundations for cracks and other damage.

• Check for fire hazards, electrical system damage & gas leaks.

• Check for food supplies and any food that comes in contact with flood water should be thrown because it may be contaminated.

• Disaster Management Information System must be built in every district of the country linked with each other, available on the web and also in public libraries. Location of critical equipments, skills, resources and information and how can one access them on voluntary or payment basis should be known. The database of various services should be updated regularly.

Disaster management.

• Set up national disaster management volunteers who would receive training to organize themselves as effective teams for helping local communities around them

• Resources would be required for repairing and building the primary school buildings, primary health centres, livestock, clinics, tree climbing devices for palm workers, herbal and other medicines, mat making machines, and machines which can use materials from damaged trees and bio waste, old bamboo scrap, processing machine for various edible and non-edible oilseeds, etc.

• In cases where fishing communities or island based indigenous / tribal communities have been affected very severely, long term rehabilitation plans have to be initiated.

• There is very important need to document the experience of the damage caused and ensuing suffering along with the coping strategies of local communities and administration.

• One of the major problems in relief is that what is needed where is often not known to the people

who want to provide support. The result is that lot of materials get wasted or misdirected. We need to put a spreadsheet immediately on the web pointing out village wise needs, contact persons’ names and addresses so that civil society efforts can be targeted more efficiently

• The psychological rehabilitation is no less important. The children affected the by the shock and tragedy are particularly vulnerable. The arrangements for adoption of orphan children with proper community care have to be put in place.

• Proper records should be maintained. It might save

the state and central governments some money from the compensation fund but it would certainly inflict damage on the social conscience of the society

• A proper rehabilitation plan will have to be built for each village affected by the disaster with proper accountability structure. The mobilization and use of funds should be made public.

2004 Tsunami in the Indian subcontinent

• The December 26, 2004 Indian Ocean tsunami was caused by an earthquake that is thought to have had the energy of 23,000 Hiroshima-type atomic bombs.

• The epicentre of the 9.0 magnitude quake was located in the Indian Ocean near the west coast of Sumatra.

• The violent movement of the Earth’s tectonic plates displaced an enormous amount of water, sending powerful shock waves in every direction.

• The tectonic plates in this area had been pushing against each other and building pressure for thousands of years. They continue to do so and will likely cause underwater earthquakes and tsunamis in the future.

• The rupture was more than 600 miles long, displacing the seafloor by 10 yards horizontally and several yards vertically. As a result, trillions of tons of rock moved, causing the largest magnitude earthquake in 40 years.

• Within hours of the earthquake, killer waves

radiating from the epicenter slammed into the coastlines of 11 countries, damaging countries from east Africa to Thailand.

• The Indian Ocean tsunami travelled as far as 3,000 miles to Africa and still arrived with sufficient force to kill people and destroy property.

• The tsunami resulted in at least 227,898 fatalities.