Whidbey Land Slide
West Side Whidbey Island Landslide. Pic. from Seattle Times |
One thing that helps to hold the bluffs in place is the roots from the trees growing on the faces of the bluffs. Trees, however, block the view, so people cut down the trees. It takes ten or fifteen years, but eventually the roots rot away, and the bluff becomes even more unstable. The worst conditions for these slides to occur are after a hard freeze, where the ice crystals open up and loosen the soil, followed by a heavy rain that soaks in and turns everything into thick soupy mud. The water also adds a lot of weight to the soil, and away it goes. Although there was no heavy rain just before this slide, there had been a really unusually heavy freak snow storm that dropped almost a foot of snow in that exact area. It was also very warm to be snowing, around forty degrees, and the snow mostly melted quickly. That probably added the weight to the soil and encouraged the slide.