GEL341 Reading 01

Question 1

Geomorphology

Answer 1

A discourse on Earth forms

The study of Earth’s physical land-surface features, its landforms (rivers, hills, etc.)

Sometimes includes marine sublandforms, and landforms of other terrestrial-type planets and satellites

Investigates landforms and the processes that fashion them

Form, process, and the interrelationships between them are central to understanding origin & development of landform

Question 1

Constitution

Answer 1

One of 3 facets of geomorphology’s form or morphology

Chemical and physical properties described by material property variables

e.g. density, infiltration, capacity, permeability, moisture content, porosity

(Form variable)

Question 1

Configuration

Answer 1

One of 3 facets of geomorphology’s form or morphology
(Form variable)

Size and form described by geometry variables

e.g. Length, height, depth, distance, area, volume, angle, shape

Question 2

Mass flow

Answer 2

One of 3 facets of geomorphology’s form or morphology
​(Form variable)

Rates of flow described by such mass-flow variables as discharge, precipitation rate, and evaporation rate

e.g. Velocity, discharge, mass flow rate, erosion rate

Question 3

Dynamic variables

Answer 3

In contrast to form variables, dynamic variables are associated with geomorphic processes

Chemical and mechanical properties representing the expenditure of energy and the doing of work

Includes power, energy flux, force, stress, momentum

e.g. Energy, work, power, force, stress, momentum

*Atmosphere, hydrosphere, biosphere, humans*

Question 4

Example: components of a beach in geomorphology

Answer 4

Constitution:
degree of sorting grains
mean diameter of grains
grain shape
moister content of beach

Configuration = measures of beach geometry:
slope angle
beach profile form
water depth

Mass-flow variables:
rate of erosiion
transport
deposition

Question 5

Differential erosion

Answer 5

Erosion that occurs at irregular or varying rates, caused by the differences in the resistance and hardness of surface materials

Softer, weaker rocks wear away rapidly
Harder, more resistant rocks remain to form ridges, hills, or mountains

Question 6

Exogenic processes

Answer 6

External processes (surface, above-surface processes)

e.g. climate, weather, lifeform (animal/plant) activities, evolution, glacial activity

Question 7

Endogenic processes

Answer 7

Internal processes (subsurface processes)

e.g. Earthquakes, volcanic activity, bedrock properties, geological structure, orogenies, uplift/subsidence, continental motion & geology

Question 8

Extraterrestrial processes

Answer 8

Processes/forces that come from outside the earth

e.g. Asteroid impacts

Question 9

Approaches used by geomorphologists in studying landforms (4)

Answer 9

1. Process-response (process-form), or functional, approach.
   This builds upon chemistry & physics, and utilizes a systems methodology.
2. Landform evolution approach.
   Stems from historical geological science (geohistory).
   Explores the important historical dimension of many landforms.
3. Approach stemming from geographical spatial science.
   Characterizes landforms and landform systems.
4. Environmentally sensitive approach.
   To landforms, systems of landforms, landscapes at regional to global scales.

Question 10

[Surface] process geomorphology

Answer 10

Geomorphology based on the process-response (process-form), or functional, approach.

Predominates the field of geomorphology.

*Focus is around the mechanics of geomorphic processes and process-response relationships (how geomorphic systems respond to disturbances).

Question 11

Historical geomorphology

Answer 11

Geomorphology based on the landform evolution approach (based on historical geological science).

*Second to [surface] profess geomorphology, but also predominates geomorphology

Question 12

Terracette

Answer 12

Type of landform

Ridge on a hillside formed when saturated soil particles expand, and then contract as they dry – causing them to slowly move downhill

Question 13

Peneplain

Answer 13

Low-relief land surface produced by erosion over a long period, undisturbed by crustal movement

Implies the representation of a near-final stage of fluvial erosion

Question 14

Monadnock

Answer 14

a.k.a. inselberg

Isolated hill of bedrock standing conspicuously above the general level of surrounding area

Leftover erosional remnants composed of more erosion-resistant rock

Question 15

Geographical cycle

Answer 15

By William Morris Davis

Assumed uplift occurs quickly, then gradual erosion during a period of tectonic stability wears down the topography

Question 16

Long-term geomorphology

Answer 16

Studies of landforms and landscapes older than the Quaternary, or even late Quaternary

Question 17

Denudation

Answer 17

The long-term sum of processes that cause the wearing away of the Earth’s surface by moving water, ice, wind, and waves, leading to a reduction in elevation and relief of landforms and landscapes

Question 18

Isostasy

Answer 18

The reestablishment of gravitational equilibrium in the lithosphere following, for example, the melting of an icesheet or the deposition of sediment

Question 19

Metastable state

Answer 19

A particular excited state of an atom/nucleus/other system that has a longer lifetime than the ordinary excited states and that generally has a shorter liftetime than the lowest, often stable, energy state (ground state).

Question 20

Sediment budget

Answer 20

The blaance between sediment added to and removed from the coastal system

Surplus v. deficit