GL06 - Glaciers as a System Flashcards
In what context are most flows of energy questions related to within a glacial system?
Most flows of energy questions are in the context of the creation of a landform.
Why are glacial systems considered open systems?
- Glacial systems are open systems because materials (snow, rock, debris) are input into the glaciated landscape system from neighbouring systems which are later lost from the system as outputs.
What do we need to remember about all parts of the glacial system?
We need to remember that all parts of the system refer to energy and matter (eg. Sediment - we’ll look at this again later in the topic).
What are some inputs into the glacial system?
Kinetic energy (wind), thermal energy (sun), potential energy (altitude), precipitation, avalanche, meltwater, debris.
What are some throughputs (stores and flows) in the glacial system?
Snow, ice, debris, meltwater, thermal energy, water vapour (evaporation and sublimation), icebergs, debris.
What are some outputs of the glacial system?
Thermal energy, meltwater, water vapour (evaporation and sublimation), icebergs, debris.
How does energy within the glacial system shape the landscape?
The energy within the glacial system enables it to shape the landscape through natural processes.
Where does the energy driving the glacial system ultimately originate from?
- The energy driving the glacial system ultimately originates in the global hydrological cycle from solar energy.
- Energy ultimately comes from the Sun, which evaporates water or sublimates ice that forms clouds.
What happens to the gravitational potential energy of glacier ice as it flows down a valley?
- Once the glacier becomes sufficiently large to flow down the valley, the gravitational potential energy is converted to kinetic energy.
- It is this kinetic energy in the movement of the glacier which erodes bedrock to shape the landscape.
How is meltwater linked to the energy within the glacial system?
- Solar energy then melts the glacier ice to produce meltwater which again converts gravitational potential energy into kinetic energy to transport material down the valley in streams to create new landforms.
What role does solar energy play in shaping glacial valleys?
- Solar energy also drives physical weathering processes which are important in shaping glacial valleys.
What does diurnal mean?
- Diurnal refers to something that occurs or happens over the course of a day or daily cycle. It can also refer to the regular occurrence of a phenomenon within a 24-hour period.
What process is caused by the diurnal cycles of heating and cooling within a glacial system?
The diurnal cycles of heating and cooling cause freeze-thaw weathering.
What do all erosional processes within a glacial system form from?
- All erosional processes form from the principles of energy ultimately coming from the Sun e.g. precipitation falling due to gravitational potential energy, and freeze-thaw weathering caused by diurnal cycles of heating and cooling.
