Term
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Definition
| The scientific study of landscapes and the processes that shape them |
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Term
| What are the goals of geomorphology? |
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Definition
1) Organize landscapes through classification
2) Associate landforms with previous and contemporary processes |
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Term
| What is historical geomorphology? |
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Definition
| The study of the Evolutionary development of landscapes under a wide variety of climatic and geologic controls |
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Term
| What is Process Geomorphology? |
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Definition
| Study of earth surface process mechanics and how process leads to the genesis of landforms |
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Term
| Define process in relation to geomorphology |
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Definition
| The action involved when a force induces a change, either physical or chemical, in the materials or forms at Earth's surface |
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Term
| What is Endogenic geomorphology? |
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Definition
| Processes associated with tectonics and volcanic regions, especially during the Quaternary period (last 1.8 m.y.) |
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Term
| Who proposed the idea of Uniformitarianism? What is it? |
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Definition
| James Hutton 'The present is the key to the past'. The simplest explanations for the earth's surface rest on the idea that physical processes (erosion, deposition, gravity, etc.) that are observed in contemporary settings have acted over longer geologic timescales. |
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Term
| Who made the idea of Catastrophism famous? What is it? |
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Definition
| Baron Georges Cuvier 'Important changes to the physical environment are a result of catastrophic events' |
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Term
| What formed the Channeled Scablands? |
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Definition
| Periodic outbursts of water impounded behind glacial ice dams; occurred over eastern washington; flood peaks estimated to be 1,000 feet deep with the velocity of a fire hose |
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Term
| Who is John Wesley Powell? |
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Definition
| First through the Grand Canyon; introduced concept of base level |
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Term
| Who is Grove Karl Gilbert? |
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Definition
| First to promote concept of 'Grade', in which an equilibrium is achieved between slope, volume of water flowing, flow velocity, and sediment load; rivers adjust as a balance between force and resistance. |
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Term
| Who is William Morris Davis? |
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Definition
| 'Cycle of Erosion' ('Geographical Cycle') Expounded on the idea of base level. Stages of landscape denudation to an ultimately low, gently undulating PENEPLANE |
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Term
| What are the 3 stages of William Davis' 'Geographical Cycle? |
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Definition
1) Youth: downward incision into the recently uplifted land surface
2) Maturity: river meanders into the valley walls, widening its valley
3) Old age: land between valleys is reduced to minor topography |
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Term
| Describe Davis' Closed System theory (5 parts) |
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Definition
1) Clearly defined boundaries
2) No import or export of energy or matter
3) Maximum entropy (energy unavailable to perform work)
4) Initial system conditions determine the ultimate equilibrium condition
5) All stages simply are a function of time |
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Term
| Describe Gilbert's Open System theory (3 parts) |
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Definition
1) Requires a supply and removal of energy and matter for maintenance and preservation
2) Can attain a steady state, not dependent on initial conditions (equilibrium); tend to a statistically average condition
3) Self-regulation in ways that are not necessarily time dependent |
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Term
| List 4 Principles of Contemporary Process Geomorphology |
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Definition
1) A balance, or equilibrium, exists between processes and landforms. The balance is maintained by the interaction between forces and resistance.
2) Changes to a force / resistance relationship can stress a system beyond stability; this occurs when a threshold is exceeded
3) Certain processes initiate other processes
4) Geomorphic analyses can be made for a variety of spatial scales and timescales (e.g., instantaneous processes to those occurring over thousands of years) |
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Term
| List 6 Controls on Geomorphic Systems |
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Definition
1) Gravity
2) Climate (variation through time)
3) Geology (Lithology and Structure)
4) Biology
5) Anthropogenic Land-Use
6) Anthropogenic Controls (Direct) |
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Term
| List (in decreasing size) the Geomorphic Scale |
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Definition
Watershed (10^3 - 10^4 m)
Floodplain (10^2 - 10^3 m)
Reach (10^1 - 10^2 m)
Habitat (1 - 10 m)
Microhabitat (<0.1 m) |
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Term
| List the 4 Principles of Process-Based Geomorphology |
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Definition
1) A balance, or Equilibrium, exists between processes and landforms. The balance is maintained by the interaction between forces and resistance/inputs and outputs
2) Changes to a force/resistance (input/output) relationship can stress a system beyond stability; this occurs when a THRESHOLD is exceeded
3) Certain processes initiate other processes
4) Geomorphic analyses can be made for a variety of spatial scales and timescales |
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Term
| Define Negative Feedback Mechanism |
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Definition
| A process (or set of processes) that restore average conditions of a system following a disturbance |
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Term
| Define Positive Feedback Mechanism |
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Definition
| A process that reinforces the tendency of a system to change its condition following a disturbance |
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Term
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Definition
| The level at which a disturbance pushes a system into a new equilibrium |
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Term
| Conditions remain the same for the span of days to months |
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Definition
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Term
| Conditions fluctuate around an average condition for a period of decades to thousands of years |
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Definition
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Term
| Average condition of the system is gradually changing for a period of hundreds of thousands to millions of years |
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Definition
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Term
| The ability of an open system to self-regulate (stabilize through negative feedback mechanisms |
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Definition
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Term
| Length of time between initial disturbance and the initial reaction of the fluvial system |
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Definition
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Term
| Length of time the system takes to make adjustments following a disturbance |
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Definition
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Term
| Length of time from the onset of a disturbance to the persistence of new equilibrium conditions (sum of reaction and relaxation times) |
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Definition
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Term
| Shows proportions of Earth surface elevations above and below present sea level |
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Definition
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Term
| Regional uplift or depression that does NOT disrupt original rock structures (e.g., no faulting or intense folding) |
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Definition
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Term
| Concept that at a Depth of Compensation beneath a defined elevation, the pressure of overlying rock will be equal, regardless of how high the rock column is above this level (e.g., mountains require a low-density basement rock) |
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Definition
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Term
| What is a Fault Scarp? How does it defer from a Fault-Line scarp? |
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Definition
| Direct offset of land surface by fault movement. A fault-line scarp only occurs in association with differential erosion along a fault line. |
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Term
| What are the Milankovitch Cycles? |
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Definition
Predictable variations in solar radiation
-Involved in climate change measurements with Oxygen - 18 |
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