Friday, February 23, 2007

SOME FACTS ON EARTHQUAKE & TSUNAMI

NATURAL CALAMITIES

Natural calamities cause great damages to human beings, cattle, crops, buildings, vital installations, utility services and industries. The major problems faced are:

j) Many people succumbing to injuries

ii) People rendered homeless

iii) Panic and rumor which in turn create more problems of law and order.

iv) Casualties buried under the debris or marooned in the

flooded areas.

v) Road blockade due to debris of the damaged buildings causing hindrance to rescue operations & essential services.

vi) Problem of law and order and the maintenance of morale of the public.

vii) Family members separated from each other requiring

information about their near and dear ones.

ECONOMIC LOSSES

Cost of disasters over the last 25 years stands at

over US$ 87 billion a year. Recent earthquake in the Northern Sumathra which also initiated several Tsunamis have resulted in killing more than 200,000 lives in addition to heavy property and infrastructural damages. A massive earthquake in China during 1976 has resulted in about 655,000 deaths.

CAUSES OF SOME OF THE NATURAL DISASTERS:

EARTHQUAKE:

There are two general categories of earthquakes

VOLCANIC

Quake are generated by volcanic activity beneath the earth’s surface.

TECTONIC

Result of shifts in the plates of the earth’s subterranean crust.

There are different basic theories involved. One is that the continents, ocean basins, mountains and plains are in a state of balance by nature. When there are dynamic disturbances, these masses try to keep their balance by slowly adjusting and that results in quakes. Another theory behind this is that earth having separated from the sun is getting cooled off and hence is shrinking. These disturbances cause earthquakes.

VOLCANO:

When the volcanic eruption inside the earth’s surface finds a path to release the energy, the hot and burning earth mass that comes out is called a “Volcano”. Depending on the depth from which it comes out, the intensity and characteristics of the volcano differ.

TSUNAMI:

Japanese term, “tsu” means port or harbour and “nami” means waves. These waves cause severe damages in the coastal areas.

Some facts about tsunami:

• An earthquake may generate a tsunami if it is of sufficient

force and there is violent movement of the earth, causing sudden displacement of water. This also depends on the depth of the water at the earthquake site.

• A tsunami is not a single wave but a series of waves, also known as a wave train. The first wave in a tsunami is not necessarily the most damaging.

• Tsunami can take from a few minutes to as much as a day to travel to a shore. The closer the land is to the event

that generated the tsunami, the sooner it will be struck.

• Tsunamis are not tidal waves. Tsunamis can be very long (as much as 60 miles or 100 kilometers) and be as far as

one hour apart. They are able to cross entire oceans without great loss of energy.

• When the ocean is deep, tsunamis can travel unnoticed at speeds up to 800 kmph, crossing the entire ocean in a day or less.

• Boats and rigs are safe from tsunamis when they are out on the open ocean.

• A tsunami may be less than 30 centimeters in height in the open ocean, and may not even be noticed. But the powerful energy of the wave travels rapidly through the ocean. Once a tsunami reaches shallow waters it is slowed down, compressing the wave energy and causing the top of the wave to heighten dramatically.

EARTHQUAKES:

Earthquakes strike suddenly, violently and without warning. Identifying potential hazards ahead of time and advance planning can reduce the dangers of serious injury

or loss of life from an earthquake. Seismographic maps of the inner plates of the earth give some clue to assess the risk of possible earthquakes and their intensities at different parts of the earth. Based on the potential for earthquakes and their likely intensities, “Earthquake Zones” are notified by geological research institutions. This would give some idea on the urban planning including activities like construction of dams, factories, nuclear installations and other geologically sensitive constructions. This will at least control the calamities that might occur in future.

SAFETY TIPS

EARTHQUAKE.

(i) Check for hazards of falling objects and keep them secured.

(ii) Make sure all family members know how to respond immediately to an earthquake.

(iii) Keep essential supplies like medicines, flash light, portable radio, first aid kit, emergency food and water for ready use.

(iv) Develop an emergency communication plan.

(v) In case family members are separated from one another during an earthquake (a real possibility during the day when adults are at work and children are at school), develop a plan for reuniting after the disaster. Ask an outside relative or friend to serve as the “family contact”. Make sure everyone in the family knows the name, address and phone number of the contact person.

(vi) Leave the area if you smell gas or fumes from other chemicals.

(vii) Get next to an object, next to a sofa, next to a large bulky object that will compress slightly but leave a void next to it. This will minimize the chances of getting crushed.

(viii) If you are in bed during the night and an earthquake occurs, simply roll off the bed. A safe void will exist around the bed.

(ix) Never hideout under the stairs. The stairs have a different “moment of frequency” (they swing separately from the main part of the building) and may collapse even before the building.

(x) It is much better to be near the outside of the building rather than the interior. The farther inside you are from the outside perimeter of the building the greater the probability that your escape route will be blocked.

TSUNAMI:

Be aware of the following warning signs and quickly move

out to safer high ground areas nearby:

(i) An earthquake is a natural tsunami warning. Be aware that a massive earthquake can trigger a tsunami thousands of miles across the ocean many hours after the seismic event.

(ii) An approaching tsunami is sometimes preceded by noticeable fall or rise in the water level. If the ocean recedes unusually rapidly or far it’s a good sign that a big

wave is on its way. Go to high ground immediately.

(iii) Tsunamis can approach the shore as fast as 160 kmph it is often too late to get away after seeing - A tsunami cannot be outrun.

(iv) Tsunami waves can travel not only upto the coastal areas but also to far off inland places through the river mouths and streams leading to the sea.

(v) If you feel or hear a strong earthquake do not wait for an official tsunami warning. (It may be too late when you get a warning). Tell your family and friends to join you in leaving for high grounds to be on safe side.

COMMUNITY DISASTER PREPAREDNESS PLAN:

Planned way of tackling natural disasters will enable timely action and prevent and control some of the potential losses. As part of the plan:

The community should:

* know alarm signals / sirens, if any

* follow evacuation plans as advised

* know what to do in an accident

* connect to appropriate news services in a crisis (radio or television)

Rescue services needed:

* equipment and training

* local hazard maps
* to be linked with private rescue services

* arrangements for traffic management

* communication channels with public during crisis

Government authorities shall take steps for:

* safe evacuation, refuge and shelter

* making public information available

* creating emergency services and activating them when

required

* having medical services ready for a crisis

* maintaining law and order

Occurrence of natural disasters are difficult to be predicted. Research work through advanced science and technology is trying to bridge the gap. Knowing the existing limitations and considering the massive destruction caused by these natural calamities, what at best can be done is to look into the ways and means of mitigating the hardship and sufferings resulting from them.

Focus on mitigating the effects of natural disaster should be:

* Monitoring

* Forecasting

* Awareness raising

* Disaster Preparedness Plan

* Relief and rehabilitation

* Crisis management

* Long term plans

* Sharing of information and pooling of resources.

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