Whidbey Land Slide

West Side Whidbey Island Landslide. Pic. from Seattle Times

 Thanks to everyone for their concern. The landslide was perhaps fifteen miles from us, and we are in no danger whatever.Ever since the ice receded from the Puget Sound Basin, high bluffs have been sliding down onto the beaches. In fact, these bluffs are called "Feeder Bluffs" because they constantly feed new sand and gravel to the beaches. It's called "Beach Replenishment". From the top of those bluffs the view out over Puget Sound is outstanding. So, lots of folks build fancy houses near the edges of those bluffs. Eventually, though, the bluff slides, and houses get destroyed. Notice how close the houses are to the edge where it didn't slide.

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.