Glaciers often have lakes in front of them, known as proglacial lakes. These are usually formed by water building up behind a dam of moraine and/or ice. Sometimes these dams collapse, leading to violent flooding. These events are known as Glacial Lake Outburst Floods (GLOFs for short).
The Cordillera Blanca in Peru has many glacial lakes which threaten to break their dams, either by the water levels rising or by ice falling into the lake and displacing a large wave. In Peru dozens of dams have been strengthened and have had overflow channels cut into them to try to manage the risk. However this did not prevent catastrophic flooding occuring in April 2010 when a glacier partly collapsed into a lake near Carhuaz:
Footage here: http://news.bbc.co.uk/1/hi/world/americas/8617101.stm
These phenomena are possible wherever there are mountain glaciers, although it is thought that those in warmer areas may be most at risk of melting. There is also a feeling that the rates of collapse could increase as the climate warms. See the link below for information about GLOFs in the Himalayas and the UN’s response to the problem:
Filed under: IB Core: Patterns in Environmental Quality & Sustainability, IB Extreme Environments, IB Geography | Tagged: Peru | Leave a comment »