1. Mass Wasting and Slope Stability Jeff Clark Lawrence University

2. Course Details Physics of the Earth: Surficial Environments –Physical and chemical processes that shape Earth’s surface Focus on a few in depth Lecture and lab coupled Moving to integrate “field technology” Required 300 level course (prereqs) ~ 9 2/3 weeks (8-9 3-hr* labs) 6-10 students

3. Lab Context Third and fourth labs of term –depth Follows basic mapping and soils labs Lectures on mechanical weathering, slope stability, and mass wasting concurrent. All labs are group labs First “formal” lab write up

4. Goals of Lab Reinforce and build upon concepts/skills –Soils from previous labs and lectures –Mass wasting and slope stability –Strat columns New field and lab techniques –In situ strength estimates –Morphometric indices –Aerial rephotography –Sediment size analysis – fine fraction

5. Goals of Lab Scientific Habits of Mind –Sound observations to support inferences –Synthesis of multiple observations/data sets –Effective communication Written report with tables, figures, methods, results, discussion, etc. Other labs have oral or poster style communication forms

6. Lab Activities Create stratigraphic column –Measurements, sampling, and observations Measure slide morphometry –Use survey skills and identify slide features Map present shoreline and cliff –Relate to historic shoreline position

7. Top 5m of strat column Describe color, texture Measure strength Sample From GeoTest

8. In-situ measures of strength

9. Mophometric Index D/L Crozier, 1973; reprinted in Ritter, Kotchel and Miller, 2002

11. Mophometric Index D/L Crozier, 1973; reprinted in Ritter, Kotchel and Miller, 2002

12. Mapping and Rephotography

13. Second Week Determine rates of retreat – GIS Hydrometer analysis –Correlate with strength Moisture content? Revisit site? Compile report

14. Why does this lab “work” Multiple clear “textbook” possibilities for failure mechanism –Wave-cut toe, profoundly weak layer, pore water, historic changes in lake level Several Possible interpretations Requires synthesis of different types of observations/measurements

15. Problems Reports – students need guidance on structure and content –Use background reading article as model? Data sharing is problematic –Try electronic field forms/notebooks Students tend to wait until the second week to work on project –Build in credit bearing check points Too ambitious even for groups –May remove GPS mapping in future