Are there landslides in Washington state?
Landslides are common in Washington state, with many occurring annually in the Puget Sound area, especially along the Sound’s steep shoreline bluffs. Landslide areas are deemed geologically-hazardous, environmentally-critical areas under the state Growth Management Act.
Where was the landslide in Washington state?
On March 22, 2014, 43 people die when a portion of a hill suddenly collapses and buries a neighborhood in the small community of Oso, Washington, some 55 miles northeast of Seattle. It was one of the deadliest mudslides in U.S. history.
Why does Washington have so many landslides?
The Seattle area was glaciated during the last ice age. The arrangement of glacial deposits and other weak rocks, along with the effects of coastal erosion, define where most landslides occur. Seattle has warm dry summers and cool moist winters.
When there is an impending landslide evacuation should be done immediately?
What should I do if a landslide or mudslide is occurring or likely to occur? If you suspect imminent danger, evacuate immediately. Inform affected neighbors if you can, and contact your public works, fire or police department.
What are the most common kinds of landslides?
Landslides are part of a more general erosion or surficial pro- cess known as mass wasting, which is simply the downslope movement of earth or surface materials due to gravity. They are classified into four main types: fall and toppling, slides (rotational and translational), flows and creep.
Why are landslides more common to steep slopes?
A landslide occurs because the force of gravity becomes greater than either friction or the internal strength of the rock, soil, or sediment. Pushing the rock is easier if the surface slopes downhill or is slippery. The same is true for landslides—steeper slopes have less friction, making landslides more common.
What was unique about the 2014 Oso landslide?
The mud, soil and rock debris left from the mudslide covered an area 1,500 ft (460 m) long, 4,400 ft (1,300 m) wide and deposited debris 30 to 70 ft (9.1 to 21.3 m) deep. A national geologist stated the flow of the landslide was extreme because of the extraordinary run-out of mud and debris.
When you are caught in landslide you should?
What to Do if You Suspect Imminent Landslide Danger
- Contact your local fire, police, or public works department. Local officials are the best persons able to assess potential danger.
- Inform affected neighbors.
- Curl into a tight ball and protect your head if escape is not possible.