Comment: 14:04 - 15:04 (01:00)
Source: Annenberg/CPB Resources - Earth Revealed - 16. Mass Wasting
Keywords: "Perry Ehlig", landslide, "Portuguese Bend", "Palos Verdes Peninsula", "mass wasting", "geologic hazard", "water table", well, movement, wave, erosion, base, gabion, shore
Our transcription: Perry Ehlig regularly monitors wells that have been installed to drain water from the slide area.
Thus far, lowering the level of the water table is an effort that seems to have paid off.
Measurements made along the edge of the slide indicate that the movement has slowed to a fraction of its former speed.
Ehlig hopes to completely stop the upper portion of the landslide within the next few years.
The lower edge, however, is a different and somewhat more complicated matter.
The problem here is that wave erosion undermines the base of the landslide, which weakens its upslope area further.
Without protection coastal erosion will continue to be a factor contributing to movement.
Rock filled cages called "gabions" have been tested along part of the shoreline successfully reducing the wave erosion and helping to stabilize the slide.
Geology School Keywords