Here are some facts about cyclones.
- A cyclone is an area of winds blowing in a circular motion, usually centred on an area of low pressure. They circle clockwise in the southern hemisphere, and anti-clockwise in the northern hemisphere.
- Cyclones often have different names, depending on where they occur. In the north Atlantic Ocean, they are called hurricanes, and they are often called typhoons in the northwest Pacific Ocean.
- Cyclones can occur all year round in the southern hemisphere. The end of February and early March is the most common time for them to happen and is the height of the cyclone season.
- Typhoons often occur on other planets, including Neptune and Mars. These storms have thunder, lightning and rain and can be many times stronger than those on Earth.
- Tropical cyclones typically measure between 100 and 2,000 km across. The smallest occur in the eastern Pacific, while the largest usually occur in the northwest Pacific Ocean.
- Tropical cyclone Bhola, which hit Bangladesh in 1970 may have killed half a million people. This densely populated area has always been one of the most active areas for cyclones.
- In parts of Asia and the South China Sea, cyclones are called typhoons. Like hurricanes, they are named and are often given a name in the local language, based on where they formed.
- Tropical cyclones can cause strong winds and heavy rains. Although they weaken once they reach land, they can cause heavy flooding up to 40 km from the coast.
- In 1979, Typhoon Tip reached wind speeds of about 310 km per hour in the Pacific Ocean. In 1997, Typhoon Paka, which struck Guam in the Pacific, had estimated wind speeds of about 378 kmh.
- There are usually between 75 and 100 tropical cyclones each year. Scientists believe that the strength of these storms is increasing, in some cases by about 15 percent.
