UNITED STATES

Landslide Puts Homes at Risk
More than a dozen people were evacuated and homes put at risk as a hillside on Whidbey Island, Washington, slid into the sea. One home was pushed more than 60 meters (200 feet) into Puget Sound, and the area remains without electricity or safe roads.

According to the Centers for Disease Control, landslides result in about 25-50 deaths in the U.S. every year. Landslides are a known risk on Whidbey Island, however, and there were no injures as a result of this landslide. Why were residents prepared, and how can students be prepared for landslides or other natural hazards or “extreme natural events”?

Discussion ideas:

• Read our encyclopedic entry on landslides. It describes three major causes of landslides: geology, morphology, and human activity. What of these do students think was the leading cause of the Whidbey Island landslide?
  • Geology. The article describes how Whidbey Island’s geological structure was created by the retreat of the Vashon glacier more than 15,000 years ago. As the glacier retreated, “glacial till” (what geologist Terry Swanson calls “the stuff that looks like ground-up concrete”) overlaid sand and clay. An accumulation of water “keeps infiltrating the sand and hits the impenetrable clay. The water has to go somewhere, and a slide is created,” the article describes.
• Read our activity “Extreme Natural Events.” Follow through with the discussion questions there:
  • Can students list other extreme natural events?
  • What are some differences and similarities shared by events on this list? What extreme natural events are closely related to landslides?
    • avalanches
    • rockfalls
    • mudslides
    • earthquakes
  • What extreme natural events are most likely to happen in your area?
  • Have students experienced any extreme natural events?
• Read our activity “Preparing for Extreme Natural Events.” Follow through with the discussion questions:
  • Have students experienced any extreme natural events?
  • How were they prepared?
  • How could they have been better prepared?
• Read the Fact Sheet on Landslide Safety prepared by the Centers for Disease Control. In it, bullet points answer the question “What areas are at risk?” Do students think Whidbey Island was an “area at risk” for landslides?
  • Yes! Whidbey Island’s physical and human geography match several bullet points:
    • Areas where landslides have occurred before.
    • Steep slopes.
    • Slopes that have been altered for construction of buildings and roads.
    • Areas where surface runoff is directed.
• Read through “How to Prepare and Be Safe During a Landslide.” This website lists warning signs for landslides. What warning signs did residents of Whidbey Island notice before the landslide?
  • Changes occur in your landscape and Fences, retaining walls, utility poles, or trees tilt or move. The morning of the landslide, one Whidbey Island resident noticed 20 large trees missing from his backyard. By afternoon, 75 feet of the backyard itself had dropped into Puget Sound.
  • A faint rumbling sound that increases in volume. The same resident describes hearing a noise “like an earthquake, it rattled the whole house” on the morning of the landslide.
• Adapting to circumstances after an extreme natural event can be as important as preparing for one. What steps do students think the displaced residents of Whidbey Island should take? The website linked above has a list of suggestions.
  • Listen to local news for updates and emergency information.
  • Stay away from the slide area.
  • Help other residents who may be injured, or large families who may need additional assistance.
  • Help pets who may be neglected.
  • Alert authorities about downed power lines or damaged roadways.
  • Contact your insurance agency to see if your home is covered. (Landslide insurance is usually an additional cost.)

To NGEP’s favorite Whidbey Island resident: We hope you’re OK, Catherine!

Note: We’re experimenting with a new feature here on the NG Education Blog. “Current Event Connection” posts will connect educators with news stories and relevant discussion ideas featuring content from the NG Education website.