Naked Science– Jul 19, 2017
Landslides are among the most deadly of nature’s awesome forces, the raw power of our planet at its most overwhelming. Throughout history they have taken a terrible toll in human life and property destruction. Science is doing what little it can to find out what causes landslides and to predict or prevent such disasters. But, ironically, it is often the actions of humans and our desire to live in areas of great scenic beauty that make the dangers and the effects of landslides even worse.
Naked Science follows the landslide detectives, such as geologist Randy Jibson, who investigates the cause of a 2005 landslide in the Californian town of La Conchita. He characterises the disaster as a “slide” type of land movement, a mass of mud and earth dragged downslope as a single cohesive mass by the overwhelming power of gravity.
Such events often move slowly; but at la Conchita the slide moved faster than a person could run, wiping out more than a dozen homes and killing ten residents. Jibson’s enquires eventually uncover a fault line in the hillside allowing water to flow through the hill and fatally weaken the slope.
A second investigation looks into the cause of Australia’s worst ever landslide in village of Threadbo, New South Wales. More than 2000 cubic metres of mud and rock smashed through three ski-lodges and buried 20 people. It was Australia’s worst-ever landslide. The film tells the story of ski-instructor Stuart Diver, the only survivor, who was found under the wreckage three days later lying alongside the dead body of his young wife. Naked Science reveals how the cause was finally traced to a leaking water pipe saturating the ground.
Scientists at research centres in Oregon in the USA and at Davos in Switzerland, show how they are developing lightweight netting protection to guard against the dangers of rock falls. But such systems would have been of little use at Yosemite Park in California where two massive rocks 350 times as heavy as the Statue of Liberty, crashed in freefall 3000 feet down a mountainside to kill and injure people at a nearby nature centre.
Finally Naked Science looks to the future, examining the scientific controversy over a landslide yet-to-happen in the Canary Islands off the coast of Africa. Some scientists believe that the entire mountain side of the volcanic island of La Palma could collapse into the sea in a future eruption. The landslide would send a massive tsunami across the Atlantic Ocean to wipe out East Coast America in a tsunami dwarfing even the horrors of the 2004 Asian tidal-wave disaster. Naked Science predicts that if and when this happens it could be the most deadly landslide ever witnessed by man.