Glaciated Landscapes Unit 1 Flashcards
What is a glacier?
A glacier is a moving dense body of ice that is constantly moving downhill under its own weight
What are the key components of the glacial system?
Inputs, outputs, stores, and transfers of energy and materials.
What does the glacial budget include?
The glacial budget describes how ice accumulates and melts on a glacier which ultimately determines whether a glacier advances or retreats
What are the two zones of a glacier?
- Zone of accumulation
- Zone of ablation
What happens if inputs to a glacier exceed outputs?
The glacier will grow (advance).
What happens if outputs exceed inputs in a glacier?
The glacier will shrink (retreat).
Fill in the blank: When snowflakes fall, they contain _______ and have a low density.
air
What is firn?
Compacted snow that has experienced one winter’s freezing and a summer’s melting.
What is the mass balance of a glacier?
The difference between inputs (accumulation) and outputs (ablation).
What are the three mechanisms identified by Milutin Milankovitch that affect Earth’s climate?
- Stretch (eccentricity) of orbit
- Axis Tilt (obliquity)
- Wobble (precession)
What is the significance of the Younger Dryas?
A rapid period of cooling towards the end of the last glacial period (Devensian) in the Northern Hemisphere.
True or False: The Earth’s current axial tilt is 23.5 degrees.
True
What factors determine the mass balance of a glacier?
- Inputs (accumulation)
- Outputs (ablation)
What are the conditions required for glacier formation?
Cold temperatures and sufficient snowfall.
What is the zone of equilibrium in a glacier?
The area where inputs equal outputs.
Fill in the blank: The long-term cyclical change between glacial and interglacial periods is mainly due to changes in the Earth’s _______.
orbit
What is meant by a positive feedback loop in the context of glaciers?
The decrease in temperature allows more glacial growth, which reflects more radiation and further reduces the temperature. This positive feedback loop allows glaciers to grow and grow, reducing the global temperatures. Glacier growth —> increased albedo —> decreased temperature —> more glacier growth