Today's post features a big avalanche, called 'The West Salt Creek landslide'. In 2014, a massive mass of ground start sliding down until it stopped 4.5 km further. The enormous avalanche moved almost 30 million cubic meters of mud, ground and debris. On the way down it destroyed roads and irrigation ditches and killed three persons. The cause of this massive disaster was the reactivation of an old antic sliding surface which was triggered, causing the enormous avalanche. The debris flow did blocked the local river, creating a temporal lake for two years (sadly, this is not visible on the picture). The landslide acted as a dam until the lake had grown too much and breached through the dam. This caused a flood which only caused some minor damage at roads and houses downstream.
This landslide was probably not induced by humans but often are mass movements initialized by dumping material on unstable slope, bad drainage, deforestation, etc. You can find a big list of such disasters on wikipedia. A landslide in Shenzhen in China killed 78 people one year after this one. The landslide originated in a dumping site, right next to the expanding city. Still, I have chosen to show you this one as it is such a clear example and despite all the misery it brought up on to the locals, it's an impressive shot!
© Google Earth/USDA Farm Service Agency
source:
http://coloradogeologicalsurvey.org/geologic-hazards/landslides/west-salt-creek-landslide/
wikipedia.com as usual...