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How Do Landslides Occur



The earth's land moves at least a few centimetres a year. But there are times when it can move metres, even kilometres at a time. This is when there is a landslide, avalanches or mudslides. As the land slowly moves, by a few millimetres (mm) a day, it causes tension cracks in the earth and in the bedrock. As this tension increases and significant changes in moisture occur, from things like heavy rainfall or the fast melting of snow, the land begins to move more and more. Landslides can happen in different places and have different effects on people, buildings and animalsand the simple landscape.

Landslides that occur on the edge of a cliff will affect and endanger homes and lives. The debris which will be made up the sediments, possibly parts of or the whole home, will be deposited on the land below, which again, could endanger more lives, animal and other structures.Did You Know? Melting ice in the northrn hemisphere can cause ice dams that block rivers and force water to burst through shorelines. When the pressure of the water is too strong, sudden outburst floods surge downstream with blocks of ice 5 or 7 meters tall.


12 worst landslides in Modern History

1998 (Bangladesh, China): The two countries were hit with multiple major landslides due to heavy summer rains. Around 1,200 people were killed in Bangladesh and around 3,600 in China

October 30, 1998 (Nicaragua): Nearly 2,200 people were buried in a major landslip in  Casitas northwest of the Nicaraguan capital Managua in the wake of Cyclone Mitch

March 1998 (Pakistan): More than 1,500 people were killed in landslips and flooding in southwestern Pakistan

February 17, 2006 (Philippines): Some 133 bodies were recovered and 973 people left missing, presumed dead when a massive landslide obliterated the Philippine village of Guinsaugon

November 10, 2001 (Algeria): The Bab El-Oued quarter of Algiers was ravaged by flash floods and landslides, killing more than 700 people and leaving around 100 missing

July 20, 2000 (China): Heavy seasonal rains set off mudslides and landslips in the north of China, killing 625 people

June 5, 1996 (China): Two landslides left more than 200 people dead or missing in a gold mine in the Chinese province of Yunnan

December, 2004 (Philippines): Over 200 people killed after weeks of floods and mud slides in the eastern Philippines following a series of tropical storms

December 21, 2003 (Philippines): Punishing rains in the central and southern Philippines set off landslides that left at least 200 killed or missing

February 21, 2005 (Indonesia): A landslide in Indonesia killed more than 140 people near Bandung

July 17, 1997 (Tanzania): At least 100 people were buried alive when a gold mine sank in the Kanzera region of Tanzania

February 11, 2001 (Indonesia): At least 100 people were killed in floods and landslips after several days of rain on the Indonesian island of Java