| Parameter |
Probable Range
of Values (MKS Units) |
Confidence in Your Estimate (On a scale of 0-10) |
Probability of
Occurrence (% prob. in N yrs) |
|
Location Slope north of Tacoma Narrows bridge -- analogous to other steep bluffs along the Puget Sound? |
|
5 | Less than 100% in 50 years (recurrence interval of at least 50 years) |
| Geometry |
Length: 150 m
Width: 120 m Thickness: 8 m Volume: 1.5 x 105 m3 |
5 | Geometry of 1949 landslide well defined |
| Speed | 7.5 tp 15 m/s | 5 | 5 to 10 seconds for slide to occur divided by half length |
| Slope Angle | 35 degrees | 9 | |
| Aspect | Parallel to slope fall line | 9 |