I was raised in the foothills of the Sierra Nevadas. Every summer as we drove up the windy mountain road to our favorite campsite, riding in the rear facing seat of the family station wagon, my sister and I had our noses glued to the back windshield (had seatbelts even been invented yet?) searching for that poor lost little Indian. Dad told us the story every year, how the young man had gone out hunting, followed his prey just a little too far, and not made it back home. The tribe was worried, and they asked everyone to help with the search for Falling Rock.
This week we’re learning about mass wasting, also known as landslides. Colorado is lousy with them and I had dozens to choose from. But instead of selecting an epic road destroying event such as the one that took out McClure Pass in 1994 (it’s fixed now; I’ve biked it three times), I chose a subtle and sneaky type of mass wasting to share.
It’s called Creep.
The process occurs when freezing or moisture lifts ground particles at right angles to the slope, and then thawing or drying allows the particles to fall back down at a slightly lower level. Each cycle moves the particles a teensy distance down the slope. Year after year as soil alternately expands and contracts, gravity causes it to creep downhill. It’s sneaky because creep occurs on both steep and gentle slopes.
It’s what accounts for tombstones tilting and for those trees that bow at the base. The trees correct themselves; the tombstones eventually fall over.
Creep isn’t terribly exciting… unless it’s happening underneath the home you own. In Colorado Springs, about 70 homeowners discovered they were victims of this cunning little disaster.
Here’s a 20 second ABC video highlighting the issue. Many of these homes were built in 1955, and 60 years of creep is finally catching up. Why were their homes built on high risk landslide areas? Because there’s a disconnect between the geological survey and the builders / buyers. Results get buried in paperwork. Buyers expect the realtors to disclose potential hazards, but the real estate agents don’t know about them. What can be done? Jon White, senior engineering geologist at the Colorado Geological Survey, recommend prospective buyers should “have the house inspected and get your property evaluated by a geologist. If you’re sitting on a landslide and don’t know it, there is a chance you can lose everything.”
Hungry for more pictures? Here’s an excellent Denver Post photojournal, with scenes of the insides of these houses.
I think there’s a lesson here. Creep adds up. C.S. Lewis said it better than I can: “Every time you make a choice you are turning the central part of you, the part of you that chooses, into something a little different from what it was before. And taking your life as a whole, with all your innumerable choices, all your life long you are slowly turning this central thing either into a heavenly creature or into a hellish creature.” (Mere Christianity).