The Great Bhola Cyclone
Bangladesh is a delta country that sits on sediments eroded from the Himalayan Mountains. Thirty-five percent of the area is less than 6 metres (20 ft) above sea level. The 575 km-long coastline is contoured in such a way that it funnels cyclones from the warm waters of the Bay of Bengal into the area. About five tropical cyclones per year enter the Bay, both before (April-May) and after (October-November) the southwest monsoon season.
Remnants of a tropical storm in the Pacific contributed to the development of a new depression in the central Bay on November 8, 1970. Although there were not direct measurements of the winds of pressure in the storm, satellite imagery suggests that the storm intensified rapidly, becoming a well-defined cyclone with sustained winds between 137-145 km/h by Nov 11. The system travelled north and intensified, driving into the low-lying delta area overnight on Nov 12, during an above-average lunar high tide. With it, the cyclone brought a 6 metre (20 ft)-storm surge and average winds in excess of 225.3 km/h.
Although meteorologists knew of the approaching storm, there was no way to communicate to most of those living in the coastal plain and on the islands of the Ganges River delta. As a result, an estimated 500,000 people were killed (many had been asleep when the storm surge struck), making this storm the deadliest tropical cyclone of all time and one of the deadliest natural disasters in recent history.
In the 20th century, seven of the nine most deadly weather events in the world were tropical cyclones that struck Bangladesh. On April 30, 1991, another severe cyclone, packing winds up to 250 km/h and 6-metre storm surge, hit Chittagong district, killing 140,000 people and leaving 10 million others homeless.
Worlds 12 Deadliest Cyclones
Rank Name / Areas of Largest Loss Year Ocean Area Deaths
1. Great Bhola Cyclone, Bangladesh 1970 (Nov 12) Bay of Bengal 300,000 - 500,000
2. Hooghly River Cyclone, India and Bangladesh 1737 Bay of Bengal 300,000
3. Haiphong Typhoon, Vietnam 1881 West Pacific 300,000
4. Coringa, India 1839 Bay of Bengal 300,000
5. Backerganj Cyclone, Bangladesh 1584 Bay of Bengal 200,000
6. Great Backerganj Cyclone, Bangladesh 1876 Bay of Bengal 200,000
7. Chittagong, Bangladesh 1897 Bay of Bengal 175,000
8. Super Typhoon Nina, China 1975 (Aug 5) West Pacific 171,000
9. Cyclone 02B, Bangladesh 1991 (May 5) Bay of Bengal 138,866
10. Cyclone Nargis, Myanmar 2008 (May 3) Bay of Bengal 138,366
11. Swatlow, China 1922 (Jul 27) West Pacific 100,000
12. Great Bombay Cyclone, India 1882 Arabian Sea 100,000
source: www.wunderground.com
