1. The Origin, Evolution and Metrics of Topography
(Philippines 2006; Stephen Evans)
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2. The Origin, Evolution and Metrics of Topography
Lectures:
Origins of Topography
Evolution of Topography
Metrics of Topography
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3. Two Fundamental Distinctions Between Hillslopes
Transport Limited Hillslopes Weathering Limited Hillslopes
Strength Limited Hillslopes
supply >> capacity
soil mantled landscape
capacity >> supply
bare, rocky landscape
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4. Landslides in the Earth System
11/8/2018
(Dave Montgomery, Washington, USA)

5. Impacts on Earth Systems
Lithosphere
Sculpt local topography
Trigger shallow crustal response
Flexure, Isostacy, Magma
Limit growth of volcanos
Limit bedrock river incision
Hydrosphere
Impact water and sediment fluxes
Can account for ~50% of the total global sediment flux
Trigger tsunamis or outburst floods
Biosphere
Impact rates of soil production
Alter hillslope and riparian habitats
Anthrosphere
Pose hazards to human life, property and infrastructure
Expose rock to weathering, alter atmospheric chemistry
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6. Widely Varying Scales of Impacts
Size of feature
26 orders of magnitude in volume!
Largest features are submarine
Density/Frequency
3-11 orders of magnitude
Higher density from precip events than earthquakes
Occurrence per triggering event
(Seismic, Precipitation, Snowmelt, etc.)
1 to 10’s of thousands
Duration of scar
Rapid vegetation regrowth or slow diffusion
1 to 10’s of thousands of years
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7. Landslides in all Environments
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8. Size-Frequency Distribution
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9. Geometric Scaling of Features
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10. Normalized Histograms
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11. Volume- Area Scaling
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12. If area affected is >50km2
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13. Mobilized volume >5km3
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14. Episodic, large magnitude sediment delivery events
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15. 11/8/2018
Kirchner et al, 2001