1. Intro to Geomorphology (Geos 450/550) Lecture 1: Controls on large-scale topography, course intro histogram of Earth's topography isostatic model for difference in elevation between continents and oceans thermo-isostatic model for the topography of mid- ocean ridges overview of syllabus (4 out of 5 field trips required) field trip #1

2. An elevation map of the surface of Earth

4. Histogram/frequency distribution/PDF of elevations

5. Frequency distribution of elevation from ETOPO5 elevation (m) # pixels in ETOPO5

7. Histogram/frequency distribution/PDF of elevations

8. The mountains of the oceans: mid-ocean ridges

9. Melting beneath mid-ocean ridges The melt rises out of the mantle because it is buoyant (less dense than the mantle)

10. 1300°C Liquidus Wet Solidus Dry Solidus Geotherm for Old Ocean Plate Temperature- depth plot for mantle beneath oceanic plates

11. The mountains of the oceans: mid-ocean ridges

12. Heat flow in Earth’s crust is governed by the diffusion equation: k is W/(m °K) (~3), ρ is kg/m 3 (~ 3x10 3 ), c is J/(kg °K) (~10 3 ) Fourier’s Law conservation of energy

13. Shape of mid-ocean ridges (Turcotte and Schubert, 4-202): This model combines diffusive heat flow, temperature- dependent density, and isostasy.

14. Boiling it down to the essence: Faster spreading ridges are broader, e.g. EPR spreading = 6 cm/yr MAR spreading = 1.5 cm.yr Model predicts that EPR should be 4x broader.

15. Shape of mid-ocean ridges: comparison to data elevation (m) distance from ridge axis (km)

16. Shape of mid-ocean ridges: effects of spreading rate

17. time (min) wind speed at 1 cm (m/s) # of

19. Tectonics (uplift/subsidence) Structure and composition of rock materials Climate (water & temperature) geomorphology

20. Modern geomorphology combines: Field measurements (soil profile descriptions) Remote sensing (airborne and ground-based lidar, GPR, seismic refr. etc.) Geochemistry (cosmogenic dating, immobile element conc.) Numerical Modeling

21. Field trip #1: Tortolita Mountain piedmont Pelletier et al. (2005)

22. Progressive stages of calcite accumulation in soils Coatings on underside of gravel Fine-textured parent material Coarse-textured parent material