GLG 362/598 Geomorphology


GLG 362/598 Geomorphology

First Lecture

Handouts: Introductory information and syllabus

Geological Sciences and Geography Geomorphology courses

GPH211 Landform Processes (3)

Geographic characteristics of landforms and earth-surface processes, emphasizing erosion, transportation, deposition, and implications for human management of the environment.

Prerequisite: GPH 111. General Studies: L1.
 

 

GLG 362 - Geomorphology (3)

Land forms and processes which create and modify them.

Laboratory and field study of physiographic features. 2

hours lecture, 3 hours lab, some field trips during lab,

possible weekend field trips. Prerequesite: GLG

101

 
 

GPH511 Fluvial Processes (3)

Geographic aspects of fluvial geomorphology, with emphasis on river channel change, fluvial erosion, and sedimentation in the present environment. Prerequisites: GLG 101 (or GPH 111), 362(or GPH 211).
 

 

Your professor?s geomorphic training

Always interested in the landscape

Whittier College, B.A. geology and spanish (under the tutelage of Dr. Dallas D. Rhodes-whose notes and ideas are the basis of many of the lectures in this class, including this one)

Stanford University, PhD. (under the supervision of Dr. David D. Pollard-a firm believer in the quantitative investigation of physical processes in earth sciences).PhD. was entitled Coupled tectonic deformation and geomorphic degradation along the San Andreas Fault system.

Just returned from a sabbatical

Subject of great interest

This is a subject of great interest to me, especially the combination of geomorphology and tectonics in the study of active tectonics.I will use examples from my research and experience to share with anecdotes with which I am familiar.

Active Tectonics and quantitative structural geology and geomorphology research group

http://activetectonics.la.asu.edu

RESEARCH PROJECTS

Central Asia

Active Tectonics in the Pamirs

Active Tectonics along the Altyn Tagh Fault
 

 

California

Carrizo Plain Tectonogeomorphology Project

Santa Cruz Mountains Research Project

Ongoing studies of the 1992 Landers, California earthquake fault scarps along the Emerson Fault

Earthquake geology along the Cholame segment of the SAF
 

 

Arizona

In Progress: The Geology and Geophysics from Flagstaff to Phoenix; A GIS Database

Arizona State University Earthquake Information

Geology and Remote Sensing of the White Tanks Mountains, Arizona

Proterozoic Geology of the Union Hills, North Phoenix, Central Arizona

Central Arizona Phoenix Long Term Ecological Research project: Quaternary geology and geomorphology

Multi-Spectral Remote Sensing of Brush Fire Scars in Arid Urban Regions: Analysis of Future Fire and Flooding Hazards

Environmental Geophysics and recharge studies

Monitoring and studying the Black Canyon City Landslide

 
Urban and Natural processes and Greater Phoenix 2100
 
Quaternary geology and mapping notes as well as Salt River Field trip guide

 
 

Miscellaneous

 IQN Potsdam University Geology, geomorphology, and paleoseismology of tectonically active regions short course

 
Kite Photography Pages
 
AGU/NSF Geoinformatics Interim Steering Committee
 
EUROPALEOS--field training course in paleoseismology topographic and photo pages
 
Diffusion erosion modeling
 
Center for Spatial and Temporal Analysis of Environmental Data and Models
 
 

Geomorphology:  The study of landforms and the processes that produce them

Processes cause landforms, but landforms effect process

Physics, chemistry, biology as it effects the earth?s surface.

TIME: places geomorphology in geology places geomorphology in geology and not physical geography.
 

 

Key issues:

Walther's Law:
Vertical succession of stratigraphy reflects horizontal variation of landscape elements. (Paleoanthroplogy application)

Interest in landscape change

Relaxation model: input causes change until input is exhausted

?Davisian?-William Morris Davis (early 20th Century American geomorphologist who was quite outspoken about his ideas)

Davis considered landscape change in anthropomorphic terms and tied it conceptually to biological evolution. But there was a difference with Darwin in that Davis considered that input demands change (importance of history), while for Darwin, it was that random inputs provide the possibility of change (changes in process)
 

 

Equilibrium model: landforms and landscapes are in balance with energy input and output. This idea may be attributed to Walther Penck:
 

 

Walther Penck, a German geomorphologist, wrote "The earth's surface... is a limiting surface between different forces working in opposition to one another. Both processes produce displacements of the rock material: the [tectonic] forces displace it by raising the earth's crust above their surroundings, or sinking them below... [and] the [degrading] forces displace it by transporting solid material along the earth's surface" [Penck, 1953] (noted by [Merritts and Vincent, 1989; Thorn, 1988]). Penck's suggestion may be expressed as
 
,
 

in which the elevation of the topographic surface, H, is a function of horizontal coordinates (x, y  and time, t. Note that H is not a spatial coordinate, but a dependent variable equivalent to the initial shape at t = 0, H0(x, y), plus the vertical component of tectonic displacement, v(x, y, t), plus the vertical component of geomorphic displacement, g(x, y, t, H). The vertical component of displacement refers to displacement in the direction opposite to the gravity vector and is measured relative to the geoid (a positive vertical component of displacement-that is not deposition-is "surface uplift," [England and Molnar, 1990]).
 

 

References for the above quote:

England, P. and P. Molnar, Surface uplift, uplift of rocks, and exhumation of rocks, Geology, 18, 1173-1177, 1990.

Merritts, D. and K. R. Vincent, Geomorphic response of coastal streams to low, intermediate, and high rates of uplift, Mendocino triple junction region, northern California, Geological Society of America Bulletin, 101, 1373-1388, 1989.

Penck, W., Morphological analysis of land forms, 429 p., MacMillan, London, United Kingdom, 1953.

Thorn, C. E., Introduction to theoretical geomorphology, 247 p., Unwin & Hyman, Boston, MA, 1988.
 

 

Characteristic form evolves and is maintained. Material and properties generally remain constant. it implies that if the in equilibrium, we can relate process and form.

Ultimately, this approach denies the importance of history. Form tells nothing about age.

 

But, are these two approaches mutually contradictory?

 ?Palimpsest problem?

Contemporary landscape bears the imprint of earlier processes (regimes) as well as present-day ones (?history matters?-S. Gould). remnant and modern forms (example is glaciated areas of high latitude where there are many remnant forms).

Makes a problem for mapping and describing the landscape.

Environmental geology

Humans and their environment (the landscape)

We need to understand what happens on the earth?s surface because we live here.

Enhance enjoyment (?when is a mountain not a mountain?)?

Classic vs. process geomorphology

Classic geomorphology (qualitative, taxonomic classification of the landscape-?stamp collecting?) versus quantitative, process-based approach.

Difficulty in applying a broad, physics based approach to landscape development. TIME and complexity.

 

Basics of process geomorphology

1) Assume balance between forms and process (equilibrium and quasi-equilibrium)

2) Balance created and maintained by the interaction between energy states (kinetic and potential); force and resistance.

3) Changes in force-resistance balance may push the landscape and processes too far: thresholds of change exist: fundamental change of process and thus form.

4) Processes are linked: processes are linked with multiple levels of feedback.

5) Geomorphic analysis occurs at different temporal scales.

 

August 27, 2002