Don't Panic

What are the warning signs of some of the world's natural disasters and how should you react?

Thanks to a geography lesson, 10-year-old British schoolgirl Tilly Smith saved the lives of at least 100 holiday-makers on Phuket's Maikhao Beach on Dec 26. She raised the alarm after recognising signs of a tsunami, and the beach cleared out before the waves hit.

Here's how to spot brewing natural disasters and survive them.

Avalanche

What is it: A large mass of snow, ice and other debris that suddenly slides down from a mountain slope. This can be caused by a rise in temperature or an earthquake. It is prevalent in the European Alps.

Warning signs: If the snow beneath you collapses or sends cracks across the ground, get ready to flee. Watch out also for heavy snowfall and strong winds.

Survival tips:

• Call for attention and discard all equipment.
• Grab on to trees and rocks and stay on the surface of the avalanche by using a swimming motion. Work towards its side where the force is the weakest.
• As the avalanche slows, kick to the surface while cupping your hands over your face to create breathing space. Thrust an arm towards the surface so that rescuers can find you quickly.

(Source: Canadian Avalanche Association - www.avalanche.ca)

Blizzard

What is it: It is a severe weather condition where strong winds of more than 56km per hour bear a great load of snow, reducing visibility drastically.

According to the National Weather Service in the United States, most blizzard-related deaths are caused by traffic accidents on icy roads or hypothermia - low body temperature - due to prolonged exposure to cold. Blizzards occur in Northern Europe, North America and Japan.

Warning signs: Strong, sustained winds and a lot of snow, which reduces visibility.

Survival tips:

• Stay indoors with a heat source, but don't put on too many layers of clothes as overheating can cause you to perspire and subsequently, feel chilly.
• If you're out in the open, set up a shelter to shield yourself from the wind. But don't eat the snow unless you melt it as it will lower your body temperature.
• If you're in a vehicle, run the engine for 10 minutes every hour for heat and leave the window slightly open to avoid carbon monoxide poisoning.

(Source: The University of Illinois Extension Disaster Resources)

Bushfire

What is it: Bushfires start when fuel, in the form of leaves and wood, is ignited by a lightning strike, a flame or, in some cases, spontaneous combustion. Also known as wildfires, they can spread as quickly as 20km per hour. The speed depends on the kind of fire - grass fires spread more quickly than forest fires.

Warning signs: If you encounter persistent hot and dry weather in fire-prone countries like Australia, get set to face the heat.

Survival tips:

• If you are in a house, turn off the gas and close all vents, windows and doors, blocking gaps with wet towels.
• As the main fire-front approaches, enter the house and wait away from the windows. The fire takes five to 15 minutes to pass.
• If you are on foot, cover all exposed parts of the body.
• Move away from the fire-front and find open or already burnt ground. Don't try to outrun the fire.
• If you can't avoid the fire, get into a dam or stream, or lie face down under a bank, loose earth or in a hollow.

(Source: Emergency Management Australia)

Cyclone

What is it: Also known as hurricane or typhoon, the tropical storm causes winds that hit speeds of 119km per hour or more, according to the US-based Federal Emergency Management Agency (Fema). They are common in countries such as China, Japan and the Philippines, as well as in America's southern East Coast, the Caribbean and the Gulf of Mexico.

Warning signs: Hurricanes also spawn tornadoes and trigger off floods. As they approach, the skies will darken and winds will gain speed. The best defence is to check the weather forecast before going on a trip as typhoons can be predicted at least a day in advance.

Survival tips:

• Leave low-lying areas, especially beaches, since strong waves may flood the coastal regions.
• Enter a building and protect yourself from flying glass by taping up the windows.

(Source: Fema and Mr Lam Keng Gaik, Changi Airport's chief meteorological officer)

Earthquake

What is it: Tectonic plates which form the Earth's outer surface are constantly pushing against each other. An earthquake occurs when the stresses caused by these movements are released and the plates move violently.

According to Geoscience Australia, 80 per cent of all recorded earthquakes occur around the edge of the Pacific Plate, including New Zealand, Papua New Guinea, Japan, Canada, the US and South America.

Warning signs: Although modern equipment can predict where an earthquake is likely to strike, there is no method to determine exactly when. The theory that animals can sense earthquakes is still unproven.

Survival tips:

• If you are in the house, hide under a sturdy table away from windows.
• If you are outside, stand away from buildings, trees or any object that can collapse on you.

(Source: Associate Professor David Higgitt of the National University of Singapore's geography department)

Hailstorm

What is it: Hailstones are formed when raindrops pass through a belt of cold air on their way to earth. These raindrops freeze into small blocks of ice as they fall, but violent updrafts push them back into the higher and colder portions of the cumulonimbus clouds, causing more layers of ice to form. The hailstones start falling when they are too heavy to be supported by the air currents.

Hailstones can occur in tropical Singapore, too. In 2003, residents in Tampines and Sembawang experienced falling ice chips during a 15-minute hailstone shower. However, the hailstones that fall here are unlikely to cause much damage as they are usually softer and smaller.

Hailstorms can hit anywhere with thunderstorms, particularly the mid-western US, China and Australia.

Warning signs: There are no concrete signs although in some cases, the sky is seen to turn green prior to a hailstorm.

Survival tips:

• Umbrellas can ward off most hailstones.
• Seek shelter in a building.

(Source: Singapore's Meteorological Services Department)

Lightning Strike

What is it: Anybody can be struck by lightning while out in a thunderstorm - and Singapore has one of the highest incidences of death by lightning strike in the world. Records from the National Environment Agency here show an average of 1.7 deaths per one million people, compared with 0.6 in the US. Singapore's location near the Equator, coupled with the hot and humid weather, give rise to lightning-producing thunderstorm clouds.

Warning signs: There are no definite signs. But since light travels faster than sound, you will see lightning flashes before you hear thunder. If less than 30 seconds pass before you hear its rumble, take shelter immediately as this indicates that lightning is drawing close.

Survival tips:

• Take shelter in a house, large building or car.
• In open areas, seek shelter in a low area such as a ravine; in a forest, hide beneath a thick cluster of small trees; and on a golf course, put down your clubs, take off your spike shoes and crouch into a ball on the ground.
• Don't use electrical appliances indoors or hold metallic objects such as umbrellas outdoors.

(Source: Singapore's Meteorological Services Department)

Sandstorm

What is it: Caused by strong, dry winds blowing across a desert. Intense desert heat creates strong convection currents which often trigger the winds. In some cases, the combination of heat and an approaching cold front can create tornado-like conditions with winds exceeding 16km per hour.

The leading edge of sandstorms, which can reach 1,500m in height, often appear as a wall of dust. Visibility is often poor. Sand and dust storms are often whipped up in deserts or places where the topsoil is loose and dry.

Warning signs: The only warning is the appearance of the storm, sometimes described as a brown smudge, on the edge of the horizon.

Survival tips:

• Wet a cloth and put it over your nose and mouth.
• Coat your nostrils on the inside with a layer of petroleum jelly to prevent it from drying out.
• Move to higher ground (unless you are in the middle of a thunderstorm where you might be struck by lightning) since sand grains do not bounce high off the ground.

(Source: The Worst Case Scenario Survival Handbook: Travel by Joshua Piven and David Borgenicht)

Tsunami

What is it: A series of waves caused by an underwater disturbance such as an underwater earthquake. Tsunamis can originate hundreds or even thousands of kilometres away from coastal areas, like Dec 26 showed.

Areas at greatest risk are those within 1.6km of the shoreline, which will be affected by flooding and scattered debris, and those located less than 15m above sea level, as striking waves can range between 15m and 3m in height.

Warning signs: A clear sign is sudden low tide and exposure of the ocean floor. The ground may also shake and as the wall of water nears the shore, a loud roar can be heard.

Survival tips:

• If you are on a boat in a harbour, either dock it quickly and move to higher ground. You can also take it out to sea as far as possible since tsunamis only cause damage when they move from deeper to more shallow waters.
• Get away as fast as possible from the coastline and seek higher ground.
• Be aware that the first wave may not be the largest in a series of waves.
• If you are near a high-rise building, head for its upper levels to avoid the water.

(Source: Eddie Bernard, director of the Pacific MarineEnvironmental Laboratory)

Tornado

What is it: A tornado is a violent windstorm marked by a twisting, funnel-shaped cloud. It is spawned by a thunderstorm and occurs when cool air overrides a layer of warm air, forcing the warm air to rise rapidly.

Damage is wrought mostly by high wind velocity and flying debris. Tornadoes are common in southern US states such as Florida during spring.

Warning signs: According to the US Storm Prediction Centre (www.spc.noaa.gov), the sight of a swirling rotation amid a bank of clouds or whirling dust or debris on the ground beneath storm clouds signals an impending tornado. There may also be hail or heavy rain followed by either a dead calm or a fast, intense wind shift.

Survival tips:

• If you are outdoors, seek shelter in a sturdy building. Or lie flat and face-down on low ground, protecting the back of your head with your arms, and stay as far away as possible from trees and cars that could be blown into your path.
• If the tornado is visible from far and traffic is light, drive out of its path by moving at right angles to it. Otherwise, park the car quickly and seek shelter in a sturdy building.
• Seek shelter on the lowest floor, in the middle of a building, or in a hallway with no windows to avoid flying glass. Cover yourself with some sort of thick padding such as a mattress or blankets in case the roof or ceiling collapses.

(Source: The US Storm Prediction Centre)

Volcanic Eruption

What is it: A volcano is essentially a weak spot in the Earth's crust that issues magma - or liquid rock - and gases. Explosive eruptions occur when gases are trapped within the thick magma and force their way out.

Dormant volcanoes can also erupt, as vacationeers found out last June when Indonesia's Mount Bromo exploded, killing a Singaporean schoolboy and an Indonesian youth.

Warning signs: The most reliable sign is earthquakes near the volcano. There may be gas emissions, and the volcano's surface may crack from a build-up of pressure in its magma hamber.

Survival tips:

• Watch out for falling rocks, trees and debris. If you are caught in such a shower, roll into a ball to protect your head.
• If you are caught in the path of lava, don't try to out-run it. Get out of its direct path instead.
• Move indoors and to a higher floor and close all doors and windows. Do not sit or lie on the floor as it could be filled with volcanic fumes, especially carbon dioxide.

(Source: The survival handbook by Piven and Borgenicht)