Comment: 21:38 - 22:57 (01:19)
Source: Annenberg/CPB Resources - Earth Revealed - 16. Mass Wasting
Keywords: "Ann Meeker", "mass wasting", landslide, creep, slump, mitigation, building, construction, drilling, geologist, structure, soil, sampling, "grain size", moisture, color, slope, fill, engineering
Our transcription: The main concern at this point is the possibility of major landslide activity.
Creep and slump can be easily mitigated by grading the slope provided, of course, that they're discovered prior to building.
But there are no such guarantees with landslides, which tend to be much larger and more deeply rooted.
So, once they complete their mapping work, Meeker and her crew begin the process of drilling.
The geologist being lowered into the hole examines the structure of the soil.
This helps determine the history of the landslide activity in the area.
And as we drill the hole in that area, we will be sampling the material to determine how strong it is.
We will also be describing it in terms of its soil characteristics, such as grain size, moisture, color, a variety of types of characteristics, which will be useful to the engineers in the office when they determine whether or not the material will be suitable to stand in the slope, or to be reused as fill somewhere else on the site.
If it turns out that there are landslides present, a decision will have to be made as to whether or not mitigation is possible both from a geologic and a financial standpoint.
Geology School Keywords