Geomorphology: Mechanics and Evolution of Landscapes (GES )

Transcription

1 Geomorphology: Mechanics and Evolution of Landscapes (GES ) Instructor: Itai Haviv, room 331, building 58, office hours: Tuesday 11:15-13:15 Teaching assistant: May-Tal Sadeh, Room 127, building 58, office hours: Wednesday 09:00-11:00 Your info inputs: -Degree, Year, Department -background in Math, Physics, Geomorphology -software experience (Excel, Matlab, ArcGIS)

2 Geomorphology: Mechanics and Evolution of Landscapes (GES ) Course focus Process geomorphology: more emphasis on Why and How? Less on Where and When? Hillslopes, alluvial rivers, sediment transport, bedrock channels, hydrology, glaciers. Assignments and grading Labs and problem sets 30% Field work reports 20% Critical review 10% Exam 40% ALL MANDATORY! Field trips: Sunday Sunday During the field trip weeks Labs will be held on Thursday from 17:00 to 19:00

3 Geomorphology: Mechanics and Evolution of Landscapes (GES ) Textbook: Geomorphology: The mechanics and chemistry of landscapes, Anderson and Anderson, Cambridge University Press, 2010 Course material s will be posted in Highlearn

4 Why study geomorphology? Grand challenges in earth surface processes USA National Research Council, 2010 Landscapes on the Edge: New Horizons for Research on Earth's Surface

5 Landscapes are the interface for lithosphere-atmosphere interactions

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8 Molnar, 2004

9 Interacting processes

10 Guiding principles Conservation (of mass, energy, momentum) Transport Rules (flow of water and ice, transport of sediment, etc) Event Size, Frequency and Duration (storms, floods, climate variations, etc)

11 An exiting era for GeomorphologyNew frontiers 1. New geochronologic methods 2. Highly improved computational efficiency 3. Wide spread availability of high resolutions datasets including satellite imagery and Digital Elevation Models (DEM s). The ability to measure and quantify geomorphic features on all scales. 4. Data on extra-terrestrial landscapes

12 LIDAR (Light Detection and Ranging)

13 An exiting era for GeomorphologyNew frontiers 1. New geochronologic methods 2. Highly improved computational efficiency 3. Wide spread availability of high resolutions datasets including satellite imagery and Digital Elevation Models (DEM s). The ability to measure and quantify geomorphic features on all scales. 4. Data on extra-terrestrial landscapes

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15 1 reconstruct Earth s past in increasing detail including aspects of its geochemistry, biotic processes, topography, and particle and solute fluxes.

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19 2 Perron et al., 2009, Nature

20 3 Hasbergen and Paola, Geology

21 Hasbergen and Paola, Geology

22 Lave and Avouac, 2001, JGR

23 Are long-term exhumation rates correlated with monsoon precipitation? Bookhagen and Burbank, 2006

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25 Egholm et al., 2009, Nature

26 Topography Key questions Horizontal strain Steady state topographic profiles Steady state erosion rate x8 rainfall Stolar, Roe and Willett, 2007 (JGR) Rainfall intensity 3. Are long-term exhumation rates correlated with monsoon precipitation? Hodges, 2006

27 Whipple (2009), Nature modified from Willett (1999), JGR

28 Tree throw Gophers burrowing Gabet et al., 2003

29 Roering (2008)

30 Early concepts and prominent figures Grove Karl Gilbert ( , USGS director): The geology of the Henry mountains. Equality of action and dynamic equilibrium, graded rivers Lake Bonneville, discovered crustal flexure due to isostatic rebound and calculated mantle viscosity The convexity of Hilltops 1914 The transportation of debris by running water. Created a flume, modeled transport. Balanced force and resistance. Gilbert, 1909

31 Early concepts and prominent figures William Morris Davis ( , Harvard Professor): 1899 The geographical cycle The erosion cycle: Mountains evolve to peneplains. Structure, Process and Time dictate landscape evolution. Historical approach. Used evolution to explain natural cycles of landscapes. Assumed rapid (instantaneous) uplift. Davis, 1899

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33 Early concepts and prominent figures Walther Penck ( , Austrian) Morphological Analysis of Landforms (in German) (English version)

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